🔖 release 0.7.3

.github/workflows/ci.yml

@@ -67,9 +67,15 @@ jobs:
           moon check --deny-warn
           moon test --deny-warn
           moon check --target native --deny-warn
+          moon check --target wasm --deny-warn
           moon check --target wasm-gc --deny-warn
           moon check --target js --deny-warn
 
+      - name: Test wasm path
+        shell: bash
+        run: |
+          moon test --target wasm --deny-warn
+
       - name: Run sync example
         shell: bash
         run: |
@@ -105,15 +111,17 @@ jobs:
         run: |
           moon update
 
-      - name: Check async package on wasm-gc and js
+      - name: Check async package on wasm, wasm-gc and js
         shell: bash
         run: |
+          moon check src-async --target wasm --deny-warn
           moon check src-async --target wasm-gc --deny-warn
           moon check src-async --target js --deny-warn
 
-      - name: Test async package on wasm-gc and js
+      - name: Test async package on wasm, wasm-gc and js
         shell: bash
         run: |
+          moon test src-async --target wasm --deny-warn
           moon test src-async --target wasm-gc --deny-warn
           moon test src-async --target js --deny-warn
 

.gitignore

@@ -26,5 +26,8 @@ docs/.vitepress/cache/
 docs/.vitepress/dist/
 docs/.vitepress/generated/
 
+# Benchmark package has no public API; moon info emits an empty snapshot.
+benchmarks/pkg.generated.mbti
+
 # vibecoding
 AGENTS/

Agent.md

@@ -0,0 +1,26 @@
+# Agent Notes
+
+## Version Releases
+
+Do not update package versions and installation snippets by hand. Run the
+repository release helper from the root instead:
+
+```powershell
+.\scripts\update-version.ps1 <x.x.x>
+```
+
+For a normal patch release, the script updates `moon.mod`, all current
+installation examples, creates the next `docs/changes/<release>(<version>).md`,
+and adds it to `docs/changes/index.md`. Review and replace any generated `TODO`
+entries in the release note before committing.
+
+For a major or minor package-version change, supply the public release number
+explicitly so it is not inferred:
+
+```powershell
+.\scripts\update-version.ps1 <x.x.x> -ReleaseVersion <x.x.x>
+```
+
+Use `-WhatIf` to preview the target files. Pass `-Change`, `-Verification`,
+and `-Note` to populate release-note sections directly. Validate the edited
+repository before committing with a `gitmoji + short desc` message.

README.md

@@ -17,7 +17,7 @@ BitLogger 的文档按使用路径组织：先完成一个可运行的日志输
 ```bash
 moon new log-demo
 cd log-demo
-moon add Nanaloveyuki/BitLogger@0.7.1
+moon add Nanaloveyuki/BitLogger@0.7.3
 ```
 
 ### 2. 写入第一条结构化日志
@@ -54,9 +54,8 @@ fn main {
 
 ## 支持情况
 
-- `BitLogger` 当前在 CI 中检查/验证的目标是 `native`、`js`、`wasm-gc`
-- `bitlogger_async` 当前在 CI 中检查 `native`、`js`、`wasm-gc`，测试覆盖 `native`、`js`、`wasm-gc`
-- `wasm` 目标在源码 `moon.pkg` 中保留声明，但当前未纳入 CI 验证口径
+- `BitLogger` 当前在 CI 中检查/验证的目标是 `native`、`wasm`、`js`、`wasm-gc`
+- `bitlogger_async` 当前在 CI 中检查和测试 `native`、`wasm`、`js`、`wasm-gc`
 - `llvm` 目前按实验性目标处理，当前环境未完成验证
 - 文件输出是 native 能力；跨端代码里建议先判断 `native_files_supported()`
 - `src-async` 可用，但示例 `examples/async_basic` 目前仍按 native 入口提供
@@ -69,6 +68,7 @@ fn main {
 - 配置驱动构建：`build_logger(...)`、`build_async_logger(...)`
 - 组合能力：queue、filter、patch、fanout、split、callback
 - 异步日志：独立 `src-async` package
+- Trace context：标准 `trace_id`、`span_id`、`trace_flags`、`trace_state` 字段绑定
 
 ## 文档
 

benchmarks/README.md

@@ -0,0 +1,11 @@
+# BitLogger Benchmarks
+
+Run the native baseline from the repository root:
+
+```powershell
+moon bench benchmarks --target native --release --deny-warn
+```
+
+The suite measures callback emission, trace-context field binding, synchronous queue enqueue-and-flush, and native file writes. It intentionally has no pass/fail threshold: compare results only on the same machine, toolchain, target, and power profile.
+
+Async throughput remains lifecycle-sensitive and is exercised by the native integration test rather than mixed into these synchronous microbenchmarks. Record its end-to-end measurements separately when profiling an application workload.

benchmarks/bitlogger_bench.mbt

@@ -0,0 +1,61 @@
+///|
+let benchmark_record : @log.Record = @log.Record::new(
+  @log.Level::Info,
+  "benchmark record",
+  target="bench",
+  fields=[@log.field("component", "bitlogger")],
+)
+
+///|
+test "bench callback logger emission" (it : @bench.T) {
+  let writes : Ref[Int] = Ref(0)
+  let logger = @log.Logger::new(@log.callback_sink(fn(_) { writes.val += 1 }))
+  it.bench(fn() {
+    logger.info("benchmark record", fields=[
+      @log.field("component", "bitlogger"),
+    ])
+    it.keep(writes.val)
+  })
+}
+
+///|
+test "bench trace context field binding" (it : @bench.T) {
+  let writes : Ref[Int] = Ref(0)
+  let context = @log.trace_context("trace-bench", "span-bench")
+  let logger = @log.Logger::new(@log.callback_sink(fn(_) { writes.val += 1 })).with_trace_context(
+    context,
+  )
+  it.bench(fn() {
+    logger.info("benchmark record", fields=[@log.field("event", "request")])
+    it.keep(writes.val)
+  })
+}
+
+///|
+test "bench queued logger enqueue and flush" (it : @bench.T) {
+  let writes : Ref[Int] = Ref(0)
+  let logger = @log.Logger::new(@log.callback_sink(fn(_) { writes.val += 1 })).with_queue(
+    max_pending=8,
+  )
+  it.bench(fn() {
+    logger.info("benchmark record")
+    it.keep(logger.sink.flush())
+  })
+}
+
+///|
+test "bench native file sink write" (it : @bench.T) {
+  let sink = @log.file_sink(
+    "logs/bitlogger-benchmark.log",
+    append=false,
+    auto_flush=false,
+    formatter=fn(rec) { rec.message },
+  )
+  if sink.is_available() {
+    it.bench(fn() {
+      sink.write(benchmark_record)
+      it.keep(sink.write_failures())
+    })
+    ignore(sink.close())
+  }
+}

benchmarks/moon.pkg

@@ -0,0 +1,4 @@
+import {
+  "Nanaloveyuki/BitLogger/src" @log,
+  "moonbitlang/core/bench",
+}

docs/.vitepress/config.mts

@@ -121,6 +121,7 @@ function buildExtendSidebar(): DefaultTheme.SidebarItem[] {
     { text: 'Sink Composition', link: '/extend/composition' },
     { text: 'Text Formatting', link: '/extend/formatting' },
     { text: 'Target Boundaries', link: '/extend/targets' },
+    { text: 'Trace Context', link: '/extend/observability' },
   ]
 }
 
@@ -141,6 +142,7 @@ function buildChineseExtendSidebar(): DefaultTheme.SidebarItem[] {
     { text: 'Sink 组合', link: '/zh/extend/composition' },
     { text: '文本格式与样式', link: '/zh/extend/formatting' },
     { text: '目标平台边界', link: '/zh/extend/targets' },
+    { text: 'Trace Context', link: '/zh/extend/observability' },
   ]
 }
 

docs/README-en.md

@@ -18,7 +18,7 @@ The documentation is organized around complete usage flows. Start with an execut
 ```bash
 moon new log-demo
 cd log-demo
-moon add Nanaloveyuki/BitLogger@0.7.1
+moon add Nanaloveyuki/BitLogger@0.7.3
 ```
 
 ### 2. Import And Log
@@ -44,7 +44,7 @@ Continue with the [Examples guide](./examples/index.md): console fields, file ro
 
 ## Support Status
 
-- Current local verification covers `native`, `js`, `wasm`, and `wasm-gc` for the main `src` package and `src-async`
+- CI checks and tests `native`, `wasm`, `js`, and `wasm-gc` for the main `src` package and `src-async`
 - `llvm` is still treated as experimental in the current release context and was not locally re-verified in the current environment
 - The source packages still declare `wasm` support alongside `native`, `llvm`, `js`, and `wasm-gc`; see [`target-verification.md`](./api/target-verification.md) for the current release-facing verification boundary
 - File output is a native capability; check `native_files_supported()` in cross-target code
@@ -58,6 +58,7 @@ Continue with the [Examples guide](./examples/index.md): console fields, file ro
 - Config-based builders: `build_logger(...)` and `build_async_logger(...)`
 - Composition helpers: queue, filter, patch, fanout, split, callback
 - Separate async package under `src-async`
+- Trace-context binding through standard `trace_id`, `span_id`, `trace_flags`, and `trace_state` fields
 
 ## Documentation
 

docs/api/async-logger-build-config-to-json.md

@@ -13,14 +13,14 @@ key-word:
 
 ## Async-logger-build-config-to-json
 
-Convert `AsyncLoggerBuildConfig` into a `JsonValue`. This helper exports both the base synchronous logger config and the async runtime config as one structured payload.
+Convert `AsyncLoggerBuildConfig` into a `Json`. This helper exports both the base synchronous logger config and the async runtime config as one structured payload.
 
 ### Interface
 
 ```moonbit
 pub fn async_logger_build_config_to_json(
   config : AsyncLoggerBuildConfig,
-) -> @json_parser.JsonValue {}
+) -> Json {}
 ```
 
 #### input
@@ -29,7 +29,7 @@ pub fn async_logger_build_config_to_json(
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the full async build config.
+- `Json` - Structured JSON representation of the full async build config.
 
 ### Explanation
 

docs/api/async-logger-config-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Async-logger-config-to-json
 
-Convert a typed `AsyncLoggerConfig` into a `JsonValue`. This helper exports async queue capacity, overflow policy, batch sizing, linger timing, and flush behavior in a structured form.
+Convert a typed `AsyncLoggerConfig` into a `Json`. This helper exports async queue capacity, overflow policy, batch sizing, linger timing, and flush behavior in a structured form.
 
 ### Interface
 
 ```moonbit
-pub fn async_logger_config_to_json(config : AsyncLoggerConfig) -> @json_parser.JsonValue {}
+pub fn async_logger_config_to_json(config : AsyncLoggerConfig) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn async_logger_config_to_json(config : AsyncLoggerConfig) -> @json_parser.J
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the async config.
+- `Json` - Structured JSON representation of the async config.
 
 ### Explanation
 

docs/api/async-logger-state-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Async-logger-state-to-json
 
-Convert `AsyncLoggerState` into a `JsonValue`. This helper is the structured export path for async logger runtime snapshots or manually constructed state values when callers want machine-readable diagnostics instead of a plain string.
+Convert `AsyncLoggerState` into a `Json`. This helper is the structured export path for async logger runtime snapshots or manually constructed state values when callers want machine-readable diagnostics instead of a plain string.
 
 ### Interface
 
 ```moonbit
-pub fn async_logger_state_to_json(state : AsyncLoggerState) -> @json_parser.JsonValue {}
+pub fn async_logger_state_to_json(state : AsyncLoggerState) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn async_logger_state_to_json(state : AsyncLoggerState) -> @json_parser.Json
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the async logger snapshot.
+- `Json` - Structured JSON representation of the async logger snapshot.
 
 ### Explanation
 
@@ -62,7 +62,7 @@ In this example, callers receive a structured value that can be composed into la
 When another serializer or pipeline expects a JSON value:
 ```moonbit
 let payload = async_logger_state_to_json(logger.state())
-println(@json_parser.stringify(payload))
+println(payload.stringify())
 ```
 
 In this example, the helper stays useful even outside the built-in stringify wrapper.

docs/api/async-logger-with-trace-context.md

@@ -0,0 +1,21 @@
+---
+name: async-logger-with-trace-context
+group: api
+category: async
+update-time: 20260719
+description: Bind TraceContext fields before records enter an AsyncLogger queue.
+key-word:
+    - async
+    - trace
+    - context
+---
+
+## Async-logger-with-trace-context
+
+```moonbit
+let contextual = logger.with_trace_context(
+  @bitlogger.trace_context("trace-1", "span-1"),
+)
+```
+
+The helper stores the mapped fields on the returned async logger and preserves its queue, lifecycle, target, and threshold state. Context is added before records are enqueued.

docs/api/async-runtime-state-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Async-runtime-state-to-json
 
-Convert `AsyncRuntimeState` into a `JsonValue`. This helper exports the async runtime mode and background worker capability in a structured form.
+Convert `AsyncRuntimeState` into a `Json`. This helper exports the async runtime mode and background worker capability in a structured form.
 
 ### Interface
 
 ```moonbit
-pub fn async_runtime_state_to_json(state : AsyncRuntimeState) -> @json_parser.JsonValue {}
+pub fn async_runtime_state_to_json(state : AsyncRuntimeState) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn async_runtime_state_to_json(state : AsyncRuntimeState) -> @json_parser.Js
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the runtime state.
+- `Json` - Structured JSON representation of the runtime state.
 
 ### Explanation
 

docs/api/file-rotation-config-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## File-rotation-config-to-json
 
-Convert `FileRotation` into a `JsonValue`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
+Convert `FileRotation` into a `Json`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
 
 ### Interface
 
 ```moonbit
-pub fn file_rotation_config_to_json(config : FileRotation) -> @json_parser.JsonValue {}
+pub fn file_rotation_config_to_json(config : FileRotation) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn file_rotation_config_to_json(config : FileRotation) -> @json_parser.JsonV
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the rotation policy.
+- `Json` - Structured JSON representation of the rotation policy.
 
 ### Explanation
 
@@ -82,7 +82,7 @@ e.g.:
 
 ### Notes
 
-1. Use this helper when downstream code expects `JsonValue` rather than a typed `FileRotation` value.
+1. Use this helper when downstream code expects `Json` rather than a typed `FileRotation` value.
 
 2. Pair it with `file_rotation(...)` when building rotation policy in code before export.
 

docs/api/file-sink-policy-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## File-sink-policy-to-json
 
-Convert `FileSinkPolicy` into a `JsonValue`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
+Convert `FileSinkPolicy` into a `Json`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
 
 ### Interface
 
 ```moonbit
-pub fn file_sink_policy_to_json(policy : FileSinkPolicy) -> @json_parser.JsonValue {}
+pub fn file_sink_policy_to_json(policy : FileSinkPolicy) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn file_sink_policy_to_json(policy : FileSinkPolicy) -> @json_parser.JsonVal
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the file policy.
+- `Json` - Structured JSON representation of the file policy.
 
 ### Explanation
 
@@ -73,7 +73,7 @@ e.g.:
 
 ### Notes
 
-1. Use this helper when downstream code expects `JsonValue` rather than text.
+1. Use this helper when downstream code expects `Json` rather than text.
 
 2. It pairs naturally with `FileSink::policy()`, `RuntimeSink::file_policy()`, and related default-policy accessors.
 

docs/api/file-sink-state-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## File-sink-state-to-json
 
-Convert `FileSinkState` into a `JsonValue`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
+Convert `FileSinkState` into a `Json`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
 
 ### Interface
 
 ```moonbit
-pub fn file_sink_state_to_json(state : FileSinkState) -> @json_parser.JsonValue {}
+pub fn file_sink_state_to_json(state : FileSinkState) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn file_sink_state_to_json(state : FileSinkState) -> @json_parser.JsonValue
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the file sink state.
+- `Json` - Structured JSON representation of the file sink state.
 
 ### Explanation
 
@@ -72,7 +72,7 @@ e.g.:
 
 ### Notes
 
-1. Use this helper when diagnostics consumers expect `JsonValue`.
+1. Use this helper when diagnostics consumers expect `Json`.
 
 2. It pairs naturally with `FileSink::state()`, `RuntimeSink::file_state()`, and `ConfiguredLogger::file_state()`.
 

docs/api/index.md

@@ -31,6 +31,7 @@ BitLogger API navigation.
 - [logger-with-timestamp.md](./logger-with-timestamp.md)
 - [logger-with-context-fields.md](./logger-with-context-fields.md)
 - [logger-bind.md](./logger-bind.md)
+- [logger-with-trace-context.md](./logger-with-trace-context.md)
 - [logger-with-filter.md](./logger-with-filter.md)
 - [logger-with-patch.md](./logger-with-patch.md)
 - [logger-with-queue.md](./logger-with-queue.md)
@@ -99,6 +100,10 @@ BitLogger API navigation.
 - [fields.md](./fields.md)
 - [text-formatter-config-type.md](./text-formatter-config-type.md)
 
+## Observability
+
+- [trace-context.md](./trace-context.md)
+
 ## Record and level
 
 - [record.md](./record.md)
@@ -266,6 +271,7 @@ BitLogger API navigation.
 - [async-logger-with-min-level.md](./async-logger-with-min-level.md)
 - [async-logger-with-timestamp.md](./async-logger-with-timestamp.md)
 - [async-logger-with-context-fields.md](./async-logger-with-context-fields.md)
+- [async-logger-with-trace-context.md](./async-logger-with-trace-context.md)
 - [async-logger-with-filter.md](./async-logger-with-filter.md)
 - [async-logger-with-patch.md](./async-logger-with-patch.md)
 
@@ -322,6 +328,7 @@ BitLogger API navigation.
 - [library-logger-child.md](./library-logger-child.md)
 - [library-logger-with-context-fields.md](./library-logger-with-context-fields.md)
 - [library-logger-bind.md](./library-logger-bind.md)
+- [library-logger-with-trace-context.md](./library-logger-with-trace-context.md)
 - [library-logger-is-enabled.md](./library-logger-is-enabled.md)
 - [library-logger-log.md](./library-logger-log.md)
 - [library-logger-info.md](./library-logger-info.md)
@@ -341,6 +348,7 @@ BitLogger API navigation.
 - [library-async-logger-child.md](./library-async-logger-child.md)
 - [library-async-logger-with-context-fields.md](./library-async-logger-with-context-fields.md)
 - [library-async-logger-bind.md](./library-async-logger-bind.md)
+- [library-async-logger-with-trace-context.md](./library-async-logger-with-trace-context.md)
 - [library-async-logger-is-enabled.md](./library-async-logger-is-enabled.md)
 - [library-async-logger-log.md](./library-async-logger-log.md)
 - [library-async-logger-info.md](./library-async-logger-info.md)

docs/api/library-async-logger-with-trace-context.md

@@ -0,0 +1,15 @@
+---
+name: library-async-logger-with-trace-context
+group: api
+category: facade
+update-time: 20260719
+description: Bind TraceContext fields through the restricted LibraryAsyncLogger facade.
+key-word:
+    - library
+    - async
+    - trace
+---
+
+## Library-async-logger-with-trace-context
+
+`LibraryAsyncLogger::with_trace_context(...)` returns a derived library facade with `trace_id`, `span_id`, `trace_flags`, and optional `trace_state` attached to each later record. It does not start a worker or change lifecycle state.

docs/api/library-logger-with-trace-context.md

@@ -0,0 +1,20 @@
+---
+name: library-logger-with-trace-context
+group: api
+category: facade
+update-time: 20260719
+description: Bind TraceContext fields through the restricted LibraryLogger facade.
+key-word:
+    - library
+    - trace
+    - context
+---
+
+## Library-logger-with-trace-context
+
+```moonbit
+let logger = LibraryLogger::new(console_sink())
+  .with_trace_context(trace_context("trace-1", "span-1"))
+```
+
+The derived facade preserves its library-facing API while wrapping the sink with context fields. Use `to_logger()` only when broader composition is required.

docs/api/logger-config-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Logger-config-to-json
 
-Convert a typed `LoggerConfig` into a `JsonValue`. This helper is the structured export path when config should be persisted, inspected, or embedded into larger JSON payloads.
+Convert a typed `LoggerConfig` into a `Json`. This helper is the structured export path when config should be persisted, inspected, or embedded into larger JSON payloads.
 
 ### Interface
 
 ```moonbit
-pub fn logger_config_to_json(config : LoggerConfig) -> @json_parser.JsonValue {}
+pub fn logger_config_to_json(config : LoggerConfig) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn logger_config_to_json(config : LoggerConfig) -> @json_parser.JsonValue {}
 
 #### output
 
-- `JsonValue` - JSON representation of the logger config.
+- `Json` - JSON representation of the logger config.
 
 ### Explanation
 
@@ -73,5 +73,5 @@ e.g.:
 
 1. Use this helper when you need a reusable JSON value rather than a final JSON string.
 
-2. Use `stringify_logger_config(...)` when the next consumer expects JSON text instead of `JsonValue`.
+2. Use `stringify_logger_config(...)` when the next consumer expects JSON text instead of `Json`.
 

docs/api/logger-with-trace-context.md

@@ -0,0 +1,22 @@
+---
+name: logger-with-trace-context
+group: api
+category: logger
+update-time: 20260719
+description: Bind a TraceContext to every record from a synchronous Logger.
+key-word:
+    - logger
+    - trace
+    - context
+---
+
+## Logger-with-trace-context
+
+```moonbit
+pub fn[S] Logger::with_trace_context(
+  self : Logger[S],
+  context : TraceContext,
+) -> Logger[ContextSink[S]]
+```
+
+Returns a derived logger that prepends the context fields to every record. The original logger is unchanged. This is equivalent to `with_context_fields(context.as_fields())`, while making trace intent explicit.

docs/api/queue-config-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Queue-config-to-json
 
-Convert a typed `QueueConfig` into a `JsonValue`. This helper is the structured export path for synchronous queue wrapper configuration when callers want machine-readable config output.
+Convert a typed `QueueConfig` into a `Json`. This helper is the structured export path for synchronous queue wrapper configuration when callers want machine-readable config output.
 
 ### Interface
 
 ```moonbit
-pub fn queue_config_to_json(queue : QueueConfig) -> @json_parser.JsonValue {}
+pub fn queue_config_to_json(queue : QueueConfig) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn queue_config_to_json(queue : QueueConfig) -> @json_parser.JsonValue {}
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the queue config.
+- `Json` - Structured JSON representation of the queue config.
 
 ### Explanation
 
@@ -74,5 +74,5 @@ e.g.:
 
 1. Use this helper when you need a reusable JSON value rather than a final JSON string.
 
-2. Use `stringify_queue_config(...)` when the next consumer expects text instead of `JsonValue`.
+2. Use `stringify_queue_config(...)` when the next consumer expects text instead of `Json`.
 

docs/api/runtime-file-state-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Runtime-file-state-to-json
 
-Convert `RuntimeFileState` into a `JsonValue`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
+Convert `RuntimeFileState` into a `Json`. On the root `src` facade, this helper forwards to the concrete serializer owned by `src/file_model`.
 
 ### Interface
 
 ```moonbit
-pub fn runtime_file_state_to_json(state : RuntimeFileState) -> @json_parser.JsonValue {}
+pub fn runtime_file_state_to_json(state : RuntimeFileState) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn runtime_file_state_to_json(state : RuntimeFileState) -> @json_parser.Json
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the runtime file state.
+- `Json` - Structured JSON representation of the runtime file state.
 
 ### Explanation
 

docs/api/sink-config-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Sink-config-to-json
 
-Convert `SinkConfig` into a `JsonValue`. This helper is used directly for sink export and indirectly when exporting `LoggerConfig`.
+Convert `SinkConfig` into a `Json`. This helper is used directly for sink export and indirectly when exporting `LoggerConfig`.
 
 ### Interface
 
 ```moonbit
-pub fn sink_config_to_json(config : SinkConfig) -> @json_parser.JsonValue {}
+pub fn sink_config_to_json(config : SinkConfig) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn sink_config_to_json(config : SinkConfig) -> @json_parser.JsonValue {}
 
 #### output
 
-- `JsonValue` - JSON representation of the sink configuration.
+- `Json` - JSON representation of the sink configuration.
 
 ### Explanation
 

docs/api/stringify-async-logger-build-config.md

@@ -40,7 +40,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` returns compact JSON.
 - `pretty=true` returns indented JSON for human inspection.
 - This helper is built on top of `async_logger_build_config_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured async build-config export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured async build-config export helper.
 - The output keeps `logger` and `async_config` as separate sections, matching supported parser input.
 - The serialized `logger` section preserves the full `LoggerConfig` shape, even though `build_async_text_logger(...)` later consumes only the selected text-oriented subset of that logger config.
 - That includes preserving whatever `logger.sink.kind` text is present in the config, even though the later text-specific builder path still ignores that sink-kind branch and constructs `FormattedConsoleSink` from `logger.sink.text_formatter`.
@@ -80,7 +80,7 @@ In this example, compact JSON is returned without extra formatting.
 ### Error Case
 
 e.g.:
-- If callers need a `JsonValue` for further composition, they should use `async_logger_build_config_to_json(...)` instead.
+- If callers need a `Json` for further composition, they should use `async_logger_build_config_to_json(...)` instead.
 
 - If only one layer of config is required, this helper may be broader than necessary.
 
@@ -96,7 +96,7 @@ e.g.:
 
 4. In particular, serialized `logger.sink.kind` text is descriptive config data, not a guarantee that the text-specific builder path will branch on that sink kind later.
 
-5. Use `async_logger_build_config_to_json(...)` when the next consumer still needs a `JsonValue` for composition before final stringification.
+5. Use `async_logger_build_config_to_json(...)` when the next consumer still needs a `Json` for composition before final stringification.
 
 6. After parsing, the same text can also feed the application or library facade builders; string export preserves one shared build-config shape, not a direct-builder-only route.
 

docs/api/stringify-async-logger-config.md

@@ -37,7 +37,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` returns compact JSON suitable for transport and snapshots.
 - `pretty=true` returns indented JSON for humans.
 - This helper is built on top of `async_logger_config_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured async-config export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured async-config export helper.
 - The exported text follows the supported async config schema rather than internal queue implementation details.
 - Canonical policy labels such as `DropNewest` and `Never` are emitted even though the parser also accepts aliases like `DropLatest` and `None`.
 
@@ -68,7 +68,7 @@ In this example, compact JSON is returned without extra formatting.
 ### Error Case
 
 e.g.:
-- If callers need a `JsonValue` for composition, they should use `async_logger_config_to_json(...)` instead.
+- If callers need a `Json` for composition, they should use `async_logger_config_to_json(...)` instead.
 
 - If invalid constructor inputs were normalized earlier, the resulting text contains the normalized config values.
 
@@ -78,5 +78,5 @@ e.g.:
 
 2. If negative `max_pending` semantics matter, remember that the serialized text preserves the config value while runtime queue creation later clamps the queue limit to `0`.
 
-3. Use `async_logger_config_to_json(...)` when the next consumer still needs a `JsonValue` for composition before final stringification.
+3. Use `async_logger_config_to_json(...)` when the next consumer still needs a `Json` for composition before final stringification.
 

docs/api/stringify-async-logger-state.md

@@ -40,7 +40,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` returns compact JSON.
 - `pretty=true` returns indented JSON suitable for human diagnostics.
 - This helper is built on top of `async_logger_state_to_json(...)`.
-- Internally it stringifies the same JSON snapshot shape returned by the public export helper, using `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`.
+- Internally it stringifies the same JSON snapshot shape returned by the public export helper, using `value.stringify(...)` or `value.stringify(indent=2)`.
 - The compact form matches snapshots such as `{"runtime":{"mode":"native_worker","background_worker":true},"phase":"ready","pending_count":0,...}`.
 - String output is convenient for logs, CLI output, and startup diagnostics.
 - The serializer does not care whether the input came from a live logger read or a synthetic `AsyncLoggerState::new(...)` call.
@@ -83,7 +83,7 @@ e.g.:
 
 2. The compact output shape is already locked by the async runtime snapshot tests, so it is suitable for stable diagnostics and assertions.
 
-3. Use `async_logger_state_to_json(...)` when the next consumer still needs a `JsonValue` for composition before final stringification.
+3. Use `async_logger_state_to_json(...)` when the next consumer still needs a `Json` for composition before final stringification.
 
 4. Pair it with `AsyncLogger::state()` for current logger diagnostics, or with `AsyncLoggerState::new(...)` when exporting a manual snapshot built by tests or adapters.
 

docs/api/stringify-async-runtime-state.md

@@ -40,7 +40,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` returns compact JSON.
 - `pretty=true` returns indented JSON for human diagnostics.
 - This helper is built on top of `async_runtime_state_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured runtime-state export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured runtime-state export helper.
 - The compact form matches the tested snapshot shape such as `{"mode":"native_worker","background_worker":true}`.
 - It is well-suited for startup banners, support reports, and target capability logs.
 
@@ -79,5 +79,5 @@ e.g.:
 
 2. This helper is the direct text form of the same two-field runtime snapshot exported by `async_runtime_state_to_json(...)`.
 
-3. Use `async_runtime_state_to_json(...)` when the next consumer still needs a `JsonValue` for composition before final stringification.
+3. Use `async_runtime_state_to_json(...)` when the next consumer still needs a `Json` for composition before final stringification.
 

docs/api/stringify-file-sink-policy.md

@@ -66,7 +66,7 @@ In this example, compact JSON is produced without extra formatting logic.
 ### Error Case
 
 e.g.:
-- If callers need a `JsonValue` for composition rather than text, `file_sink_policy_to_json(...)` is the better API.
+- If callers need a `Json` for composition rather than text, `file_sink_policy_to_json(...)` is the better API.
 
 - If rotation is disabled, the output still includes `rotation` as `null`.
 

docs/api/stringify-logger-config.md

@@ -37,7 +37,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` produces compact JSON.
 - `pretty=true` produces indented human-readable JSON.
 - This helper builds on top of `logger_config_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured logger-config export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured logger-config export helper.
 - Output is stable and suited for roundtrip config workflows.
 
 ### How to Use
@@ -71,7 +71,7 @@ e.g.:
 
 ### Notes
 
-1. Use this helper when the next consumer expects JSON text instead of `JsonValue`.
+1. Use this helper when the next consumer expects JSON text instead of `Json`.
 
 2. Use `logger_config_to_json(...)` when you still need to embed the config inside a larger JSON object before final stringification.
 

docs/api/stringify-queue-config.md

@@ -37,7 +37,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` returns compact JSON suitable for logs and snapshots.
 - `pretty=true` returns indented JSON for human inspection.
 - This helper is built on top of `queue_config_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured export helper.
 - The resulting text follows the same queue schema accepted by config parsing flows.
 
 ### How to Use
@@ -67,13 +67,13 @@ In this example, compact JSON is returned without extra formatting.
 ### Error Case
 
 e.g.:
-- If callers need a `JsonValue` for further composition, this API is the wrong layer and `queue_config_to_json(...)` should be used instead.
+- If callers need a `Json` for further composition, this API is the wrong layer and `queue_config_to_json(...)` should be used instead.
 
 - If queue policy is too aggressive for workload burst size, serialization still succeeds because this helper only exports config.
 
 ### Notes
 
-1. Use this helper when the next consumer expects JSON text instead of `JsonValue`.
+1. Use this helper when the next consumer expects JSON text instead of `Json`.
 
 2. Use `queue_config_to_json(...)` when you still need to embed the queue config inside a larger JSON object before final stringification.
 

docs/api/stringify-runtime-file-state.md

@@ -69,7 +69,7 @@ In this example, compact JSON is returned without extra formatting logic.
 ### Error Case
 
 e.g.:
-- If callers need a `JsonValue` rather than text, `runtime_file_state_to_json(...)` is the better API.
+- If callers need a `Json` rather than text, `runtime_file_state_to_json(...)` is the better API.
 
 - If queue wrapping is not relevant, `stringify_file_sink_state(...)` may be the simpler API.
 

docs/api/stringify-sink-config.md

@@ -37,7 +37,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` gives compact JSON.
 - `pretty=true` gives indented output.
 - This helper builds on top of `sink_config_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured sink export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured sink export helper.
 - It is useful when examples or generated docs want to show only sink-specific config.
 
 ### How to Use
@@ -71,7 +71,7 @@ e.g.:
 
 ### Notes
 
-1. Use this helper when the next consumer expects JSON text instead of `JsonValue`.
+1. Use this helper when the next consumer expects JSON text instead of `Json`.
 
 2. Use `sink_config_to_json(...)` when you still need to embed the sink config inside a larger JSON object before final stringification.
 

docs/api/stringify-text-formatter-config.md

@@ -40,7 +40,7 @@ Detailed rules explaining key parameters and behaviors
 - `pretty=false` returns compact JSON.
 - `pretty=true` returns indented JSON for humans.
 - This helper is built on top of `text_formatter_config_to_json(...)`.
-- Internally it serializes the `JsonValue` result with `@json_parser.stringify(...)` or `@json_parser.stringify_pretty(value, 2)`, so the text form stays aligned with the structured formatter export helper.
+- Internally it serializes the `Json` result with `value.stringify(...)` or `value.stringify(indent=2)`, so the text form stays aligned with the structured formatter export helper.
 - The output preserves the supported formatter config schema instead of any runtime-only formatter instance details.
 
 ### How to Use
@@ -76,7 +76,7 @@ e.g.:
 
 ### Notes
 
-1. Use this helper when the next consumer expects JSON text instead of `JsonValue`.
+1. Use this helper when the next consumer expects JSON text instead of `Json`.
 
 2. Use `text_formatter_config_to_json(...)` when you still need to embed formatter config inside a larger JSON object before final stringification.
 

docs/api/text-formatter-config-to-json.md

@@ -13,12 +13,12 @@ key-word:
 
 ## Text-formatter-config-to-json
 
-Convert a typed `TextFormatterConfig` into a `JsonValue`. This helper exports formatter toggles, separators, color settings, markup behavior, and optional style tags in a machine-readable form.
+Convert a typed `TextFormatterConfig` into a `Json`. This helper exports formatter toggles, separators, color settings, markup behavior, and optional style tags in a machine-readable form.
 
 ### Interface
 
 ```moonbit
-pub fn text_formatter_config_to_json(config : TextFormatterConfig) -> @json_parser.JsonValue {}
+pub fn text_formatter_config_to_json(config : TextFormatterConfig) -> Json {}
 ```
 
 #### input
@@ -27,7 +27,7 @@ pub fn text_formatter_config_to_json(config : TextFormatterConfig) -> @json_pars
 
 #### output
 
-- `JsonValue` - Structured JSON representation of the formatter config.
+- `Json` - Structured JSON representation of the formatter config.
 
 ### Explanation
 

docs/api/trace-context.md

@@ -0,0 +1,25 @@
+---
+name: trace-context
+group: api
+category: observability
+update-time: 20260719
+description: Represent and bind distributed trace metadata using stable structured-log fields.
+key-word:
+    - trace
+    - context
+    - observability
+---
+
+## Trace-context
+
+`TraceContext` carries the standard log fields used to correlate records with distributed traces: `trace_id`, `span_id`, `trace_flags`, and optional `trace_state`.
+
+```moonbit
+let context = trace_context(
+  "4bf92f3577b34da6a3ce929d0e0e4736",
+  "00f067aa0ba902b7",
+  trace_state="vendor=value",
+)
+```
+
+Use `context.as_fields()` when integrating with a custom carrier, or pass the value to a logger's `with_trace_context(...)` helper. BitLogger does not parse HTTP headers or export OTLP data; an application-owned tracing library remains responsible for propagation and sampling.

docs/changes/1.1.2(0.7.2).md

@@ -0,0 +1,21 @@
+## BitLogger Update Changes
+
+version 1.1.2(0.7.2)
+
+### JSON
+
+- refactor: replace `maria/json_parser` with the official `moonbitlang/core/json` implementation
+- refactor: preserve existing serialized JSON field shapes while JSON conversion APIs now return the built-in `Json` type
+
+### Docs
+
+- docs: update installation snippets to `Nanaloveyuki/BitLogger@0.7.2`
+- docs: add this 1.1.2(0.7.2) release entry to the change index
+
+### Verification
+
+- verify: pass formatting, warning-denied checks, and default, native, JavaScript, WebAssembly, and Wasm-GC test targets
+
+### Notes
+
+- LLVM was not tested because the local MoonBit toolchain is missing the experimental LLVM core bundle required by that target

docs/changes/1.1.3(0.7.3).md

@@ -0,0 +1,19 @@
+## BitLogger Update Changes
+
+version 1.1.3(0.7.3)
+
+### Changes
+
+- Add wasm CI checks and tests for the sync and async packages.
+- Add TraceContext binding for sync and async logger facades.
+- Add native async file lifecycle integration coverage and reproducible benchmarks.
+
+### Verification
+
+- Pass moon fmt --check, warning-denied checks, and tests across native, wasm, wasm-gc, and js.
+- Build the VitePress documentation site and run the native benchmark suite.
+
+### Notes
+
+- LLVM remains experimental and was not verified locally.
+- TraceContext maps structured fields only; HTTP propagation and OTLP export remain application-owned.

docs/changes/index.md

@@ -2,6 +2,8 @@
 
 Versioned BitLogger change summaries.
 
+- [1.1.3](./1.1.3(0.7.3).md)
+- [1.1.2](./1.1.2(0.7.2).md)
 - [1.1.1](./1.1.1(0.7.1).md)
 - [1.1.0](./1.1.0(0.7.0).md)
 - [1.0.1](./1.0.1(0.6.1).md)

docs/examples/console.md

@@ -5,7 +5,7 @@ Use this flow for command-line tools and services that need a human-readable sta
 ## Install And Import
 
 ```bash
-moon add Nanaloveyuki/BitLogger@0.7.1
+moon add Nanaloveyuki/BitLogger@0.7.3
 ```
 
 ```moonbit

docs/extend/index.md

@@ -10,5 +10,6 @@ Start from an [Example flow](../examples/index.md), then add one extension at a
 | Send records to multiple destinations or route by level | [Sink composition](./composition.md) | More explicit construction than presets. |
 | Control terminal appearance | [Text formatting](./formatting.md) | Formatting affects presentation, not record structure. |
 | Share code across native and web targets | [Target boundaries](./targets.md) | File and async runtime behavior differ by backend. |
+| Correlate logs with distributed requests | [Trace context](./observability.md) | Propagation and export stay application-owned. |
 
 For exact function signatures, follow each page's links into the [API reference](../api/index.md).

docs/extend/observability.md

@@ -0,0 +1,18 @@
+# Trace Context
+
+BitLogger keeps trace interoperability in its structured record model rather than owning HTTP propagation or a telemetry transport. Use the tracing library already selected by the application to extract a request context, then bind its identifiers to the logger.
+
+```moonbit
+let request_logger = logger.with_trace_context(
+  @log.trace_context(
+    trace_id,
+    span_id,
+    trace_flags="01",
+    trace_state=trace_state,
+  ),
+)
+```
+
+Every record from `request_logger` receives `trace_id`, `span_id`, `trace_flags`, and, when supplied, `trace_state`. The base logger is unchanged, so a child request cannot leak identifiers into unrelated work.
+
+Use `context.as_fields()` for a custom logger facade. BitLogger intentionally does not parse `traceparent` headers, create spans, make sampling decisions, or export OTLP data; those concerns remain with the application tracing implementation.

docs/zh/examples/console.md

@@ -7,7 +7,7 @@
 ```bash
 moon new log-demo
 cd log-demo
-moon add Nanaloveyuki/BitLogger@0.7.1
+moon add Nanaloveyuki/BitLogger@0.7.3
 ```
 
 在应用的 `moon.pkg` 中加入：

docs/zh/extend/index.md

@@ -10,5 +10,6 @@
 | 同时发送到多个位置或按 level 路由 | [Sink 组合](./composition.md) | 比 preset 更需要显式构造。 |
 | 调整终端可读性 | [文本格式](./formatting.md) | 格式只改变呈现，不改变记录结构。 |
 | 在 native 与 web 目标之间共享代码 | [目标平台边界](./targets.md) | 文件与异步运行时行为因后端而异。 |
+| 将日志关联到分布式请求 | [Trace context](./observability.md) | 传播与导出仍由应用负责。 |
 
 需要精确函数签名时，沿页面链接进入[英文 API 参考](../../api/index.md)。

docs/zh/extend/observability.md

@@ -0,0 +1,13 @@
+# Trace Context
+
+BitLogger 通过结构化字段承载 trace 上下文，不负责 HTTP 传播或遥测传输。应用应继续使用已选定的 tracing 库提取请求上下文，再把标识绑定到 logger。
+
+```moonbit
+let request_logger = logger.with_trace_context(
+  @log.trace_context(trace_id, span_id, trace_flags="01"),
+)
+```
+
+派生 logger 的每条记录都会带有 `trace_id`、`span_id`、`trace_flags`，以及传入时的 `trace_state`。原 logger 不会被修改，避免请求上下文泄漏到无关任务。
+
+`context.as_fields()` 可用于自定义 facade。`traceparent` 解析、span 创建、采样与 OTLP 导出仍由应用选用的 tracing 实现负责。

moon.mod

@@ -1,9 +1,8 @@
 name = "Nanaloveyuki/BitLogger"
 
-version = "0.7.1"
+version = "0.7.3"
 
 import {
-  "maria/json_parser@0.1.1",
   "moonbitlang/async@0.20.2",
 }
 

scripts/update-version.ps1

@@ -0,0 +1,184 @@
+<#
+.SYNOPSIS
+Updates BitLogger's package version, installation snippets, and release-note entry.
+
+.DESCRIPTION
+For patch releases, the public release version is inferred from the latest
+changes entry. For example, after 1.1.2(0.7.2), running:
+
+  .\scripts\update-version.ps1 0.7.3
+
+creates 1.1.3(0.7.3). A major or minor package-version change requires an
+explicit -ReleaseVersion so the public release sequence is never guessed.
+
+The generated release note uses supplied -Change, -Verification, and -Note
+entries. Without them it contains TODO markers that must be completed before
+the release is committed.
+#>
+[CmdletBinding(SupportsShouldProcess)]
+param(
+  [Parameter(Mandatory, Position = 0)]
+  [ValidatePattern('^\d+\.\d+\.\d+$')]
+  [string]$Version,
+
+  [ValidatePattern('^\d+\.\d+\.\d+$')]
+  [string]$ReleaseVersion,
+
+  [string[]]$Change,
+  [string[]]$Verification,
+  [string[]]$Note
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+function Read-TextFile([string]$Path) {
+  [System.IO.File]::ReadAllText($Path)
+}
+
+function Write-TextFile([string]$Path, [string]$Content) {
+  $encoding = New-Object System.Text.UTF8Encoding($false)
+  [System.IO.File]::WriteAllText($Path, $Content, $encoding)
+}
+
+function Replace-ExactlyOnce(
+  [string]$Content,
+  [string]$Pattern,
+  [string]$Replacement,
+  [string]$Path
+) {
+  $matches = [regex]::Matches($Content, $Pattern)
+  if ($matches.Count -ne 1) {
+    throw "Expected exactly one match for '$Pattern' in $Path, found $($matches.Count)."
+  }
+  [regex]::Replace($Content, $Pattern, $Replacement, 1)
+}
+
+function Format-BulletList([string[]]$Items, [string]$Fallback) {
+  $entries = if ($null -eq $Items -or $Items.Count -eq 0) {
+    @($Fallback)
+  } else {
+    $Items
+  }
+  ($entries | ForEach-Object { "- $_" }) -join [Environment]::NewLine
+}
+
+$repoRoot = Split-Path -Parent $PSScriptRoot
+$moonModPath = Join-Path $repoRoot 'moon.mod'
+$changesIndexPath = Join-Path $repoRoot 'docs/changes/index.md'
+
+foreach ($path in @($moonModPath, $changesIndexPath)) {
+  if (-not (Test-Path -LiteralPath $path)) {
+    throw "Required repository file is missing: $path"
+  }
+}
+
+$moonMod = Read-TextFile $moonModPath
+$currentVersionMatch = [regex]::Match($moonMod, '(?m)^version\s*=\s*"(?<version>\d+\.\d+\.\d+)"\s*$')
+if (-not $currentVersionMatch.Success) {
+  throw "Could not read the package version from $moonModPath."
+}
+$currentVersion = [version]$currentVersionMatch.Groups['version'].Value
+$targetVersion = [version]$Version
+if ($targetVersion -le $currentVersion) {
+  throw "Target version $Version must be greater than the current version $currentVersion."
+}
+
+$changesIndex = Read-TextFile $changesIndexPath
+$latestReleaseMatch = [regex]::Match(
+  $changesIndex,
+  '(?m)^- \[(?<release>\d+\.\d+\.\d+)\]\(\./(?<file>\d+\.\d+\.\d+\(\d+\.\d+\.\d+\)\.md)\)\s*$'
+)
+if (-not $latestReleaseMatch.Success) {
+  throw "Could not read the latest release entry from $changesIndexPath."
+}
+
+$latestReleaseVersion = [version]$latestReleaseMatch.Groups['release'].Value
+$latestPackageVersionMatch = [regex]::Match(
+  $latestReleaseMatch.Groups['file'].Value,
+  '\((?<version>\d+\.\d+\.\d+)\)\.md$'
+)
+if (-not $latestPackageVersionMatch.Success -or $latestPackageVersionMatch.Groups['version'].Value -ne $currentVersion.ToString()) {
+  throw 'The latest changes entry must describe the current moon.mod package version before starting a new release.'
+}
+if ([string]::IsNullOrWhiteSpace($ReleaseVersion)) {
+  if ($targetVersion.Major -ne $currentVersion.Major -or $targetVersion.Minor -ne $currentVersion.Minor) {
+    throw 'A major or minor package-version change requires -ReleaseVersion, for example: -ReleaseVersion 1.2.0.'
+  }
+  $ReleaseVersion = "$($latestReleaseVersion.Major).$($latestReleaseVersion.Minor).$($targetVersion.Build)"
+}
+
+$releaseFileName = "$ReleaseVersion($Version).md"
+$releasePath = Join-Path $repoRoot "docs/changes/$releaseFileName"
+if (Test-Path -LiteralPath $releasePath) {
+  throw "Release note already exists: $releasePath"
+}
+if ($changesIndex.Contains("./$releaseFileName")) {
+  throw "Release index already contains: $releaseFileName"
+}
+
+$updatedMoonMod = Replace-ExactlyOnce `
+  $moonMod `
+  '(?m)^version\s*=\s*"\d+\.\d+\.\d+"\s*$' `
+  "version = `"$Version`"" `
+  $moonModPath
+
+$installFiles = @(
+  'README.md',
+  'docs/README-en.md',
+  'docs/examples/console.md',
+  'docs/zh/examples/console.md'
+)
+$updatedFiles = @{}
+foreach ($relativePath in $installFiles) {
+  $path = Join-Path $repoRoot $relativePath
+  if (-not (Test-Path -LiteralPath $path)) {
+    throw "Required installation example is missing: $path"
+  }
+  $content = Read-TextFile $path
+  $updatedFiles[$path] = Replace-ExactlyOnce `
+    $content `
+    'Nanaloveyuki/BitLogger@\d+\.\d+\.\d+' `
+    "Nanaloveyuki/BitLogger@$Version" `
+    $path
+}
+
+$updatedChangesIndex = $changesIndex.Replace(
+  $latestReleaseMatch.Value,
+  "- [$ReleaseVersion](./$releaseFileName)$([Environment]::NewLine)$($latestReleaseMatch.Value)"
+)
+
+$releaseNote = @"
+## BitLogger Update Changes
+
+version $ReleaseVersion($Version)
+
+### Changes
+
+$(Format-BulletList $Change 'TODO: summarize the user-visible changes in this release.')
+
+### Verification
+
+$(Format-BulletList $Verification 'TODO: record the commands and targets verified for this release.')
+
+### Notes
+
+$(Format-BulletList $Note 'TODO: record release limitations or compatibility notes when applicable.')
+"@
+
+$writeTargets = @($moonModPath, $changesIndexPath, $releasePath) + $updatedFiles.Keys
+if ($PSCmdlet.ShouldProcess(($writeTargets -join ', '), "update to $Version")) {
+  Write-TextFile $moonModPath $updatedMoonMod
+  foreach ($path in $updatedFiles.Keys) {
+    Write-TextFile $path $updatedFiles[$path]
+  }
+  Write-TextFile $changesIndexPath $updatedChangesIndex
+  Write-TextFile $releasePath $releaseNote
+}
+
+if ($WhatIfPreference) {
+  Write-Output "Previewed release $ReleaseVersion($Version)."
+} else {
+  Write-Output "Prepared release $ReleaseVersion($Version)."
+}
+Write-Output "Release notes: $releasePath"

src-async/BitLoggerAsync_test.mbt

@@ -455,6 +455,30 @@ async test "async logger with_context_fields prepends shared fields without muta
   inspect(written_fields.val[2].value, content="test")
 }
 
+///|
+test "async facades bind trace context through standard fields" {
+  let context = @bitlogger.trace_context("trace-async", "span-async")
+  let base = async_logger(
+    @bitlogger.callback_sink(fn(_) {  }),
+    config=AsyncLoggerConfig::new(max_pending=4),
+    min_level=@bitlogger.Level::Info,
+  )
+  let derived = base.with_trace_context(context)
+  inspect(base.context_fields.length(), content="0")
+  inspect(derived.context_fields.length(), content="3")
+  inspect(derived.context_fields[0].key, content="trace_id")
+  inspect(derived.context_fields[0].value, content="trace-async")
+  inspect(derived.context_fields[1].key, content="span_id")
+  inspect(derived.context_fields[2].value, content="01")
+
+  let library = LibraryAsyncLogger::new(@bitlogger.callback_sink(fn(_) {  })).with_trace_context(
+    context,
+  )
+  let full = library.to_async_logger()
+  inspect(full.context_fields.length(), content="3")
+  inspect(full.context_fields[1].value, content="span-async")
+}
+
 ///|
 async test "async logger child composes target and preserves other state" {
   let written_target : Ref[String] = Ref("")
@@ -831,29 +855,29 @@ test "async json helpers export stable structured shapes" {
       flush=AsyncFlushPolicy::Batch,
     ),
   )
-  let config_obj = config_json.as_object().unwrap()
+  let config_obj = config_json.expect_json_object()
   inspect(
-    @json_parser.stringify(config_json),
+    config_json.stringify(),
     content="{\"max_pending\":8,\"max_batch\":3,\"linger_ms\":25,\"overflow\":\"DropOldest\",\"flush\":\"Batch\"}",
   )
   inspect(
-    config_obj.get("max_pending").unwrap().as_number().unwrap().to_int(),
+    config_obj.get("max_pending").unwrap().expect_json_number().to_int(),
     content="8",
   )
   inspect(
-    config_obj.get("max_batch").unwrap().as_number().unwrap().to_int(),
+    config_obj.get("max_batch").unwrap().expect_json_number().to_int(),
     content="3",
   )
   inspect(
-    config_obj.get("linger_ms").unwrap().as_number().unwrap().to_int(),
+    config_obj.get("linger_ms").unwrap().expect_json_number().to_int(),
     content="25",
   )
   inspect(
-    config_obj.get("overflow").unwrap().as_string().unwrap(),
+    config_obj.get("overflow").unwrap().expect_json_string(),
     content="DropOldest",
   )
   inspect(
-    config_obj.get("flush").unwrap().as_string().unwrap(),
+    config_obj.get("flush").unwrap().expect_json_string(),
     content="Batch",
   )
 
@@ -874,85 +898,84 @@ test "async json helpers export stable structured shapes" {
       ),
     ),
   )
-  let build_obj = build_json.as_object().unwrap()
-  let logger_obj = build_obj.get("logger").unwrap().as_object().unwrap()
-  let sink_obj = logger_obj.get("sink").unwrap().as_object().unwrap()
+  let build_obj = build_json.expect_json_object()
+  let logger_obj = build_obj.get("logger").unwrap().expect_json_object()
+  let sink_obj = logger_obj.get("sink").unwrap().expect_json_object()
   let formatter_obj = sink_obj
     .get("text_formatter")
     .unwrap()
-    .as_object()
-    .unwrap()
-  let async_obj = build_obj.get("async_config").unwrap().as_object().unwrap()
+    .expect_json_object()
+  let async_obj = build_obj.get("async_config").unwrap().expect_json_object()
 
   inspect(
-    logger_obj.get("min_level").unwrap().as_string().unwrap(),
+    logger_obj.get("min_level").unwrap().expect_json_string(),
     content="WARN",
   )
   inspect(
-    logger_obj.get("target").unwrap().as_string().unwrap(),
+    logger_obj.get("target").unwrap().expect_json_string(),
     content="async.roundtrip",
   )
   inspect(
-    logger_obj.get("timestamp").unwrap().as_bool().unwrap(),
+    logger_obj.get("timestamp").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(logger_obj.get("queue") is None, content="true")
   inspect(
-    sink_obj.get("kind").unwrap().as_string().unwrap(),
+    sink_obj.get("kind").unwrap().expect_json_string(),
     content="text_console",
   )
-  inspect(sink_obj.get("path").unwrap().as_string().unwrap(), content="")
-  inspect(sink_obj.get("append").unwrap().as_bool().unwrap(), content="true")
+  inspect(sink_obj.get("path").unwrap().expect_json_string(), content="")
+  inspect(sink_obj.get("append").unwrap().expect_json_bool(), content="true")
   inspect(
-    sink_obj.get("auto_flush").unwrap().as_bool().unwrap(),
+    sink_obj.get("auto_flush").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_timestamp").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_timestamp").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("separator").unwrap().expect_json_string(),
     content=" ",
   )
   inspect(
-    formatter_obj.get("field_separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("field_separator").unwrap().expect_json_string(),
     content=" ",
   )
   inspect(
-    formatter_obj.get("template").unwrap().as_string().unwrap(),
+    formatter_obj.get("template").unwrap().expect_json_string(),
     content="",
   )
   inspect(
-    formatter_obj.get("color_mode").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_mode").unwrap().expect_json_string(),
     content="never",
   )
   inspect(
-    formatter_obj.get("color_support").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_support").unwrap().expect_json_string(),
     content="truecolor",
   )
   inspect(
-    formatter_obj.get("style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("style_markup").unwrap().expect_json_string(),
     content="full",
   )
   inspect(
-    async_obj.get("max_pending").unwrap().as_number().unwrap().to_int(),
+    async_obj.get("max_pending").unwrap().expect_json_number().to_int(),
     content="2",
   )
   inspect(
-    async_obj.get("max_batch").unwrap().as_number().unwrap().to_int(),
+    async_obj.get("max_batch").unwrap().expect_json_number().to_int(),
     content="5",
   )
   inspect(
-    async_obj.get("linger_ms").unwrap().as_number().unwrap().to_int(),
+    async_obj.get("linger_ms").unwrap().expect_json_number().to_int(),
     content="40",
   )
   inspect(
-    async_obj.get("overflow").unwrap().as_string().unwrap(),
+    async_obj.get("overflow").unwrap().expect_json_string(),
     content="DropNewest",
   )
   inspect(
-    async_obj.get("flush").unwrap().as_string().unwrap(),
+    async_obj.get("flush").unwrap().expect_json_string(),
     content="Shutdown",
   )
 }
@@ -961,103 +984,102 @@ test "async json helpers export stable structured shapes" {
 test "async build config json export materializes parsed omitted defaults" {
   let parsed = parse_async_logger_build_config_text("{}")
   let build_json = async_logger_build_config_to_json(parsed)
-  let build_obj = build_json.as_object().unwrap()
-  let logger_obj = build_obj.get("logger").unwrap().as_object().unwrap()
-  let sink_obj = logger_obj.get("sink").unwrap().as_object().unwrap()
+  let build_obj = build_json.expect_json_object()
+  let logger_obj = build_obj.get("logger").unwrap().expect_json_object()
+  let sink_obj = logger_obj.get("sink").unwrap().expect_json_object()
   let formatter_obj = sink_obj
     .get("text_formatter")
     .unwrap()
-    .as_object()
-    .unwrap()
-  let async_obj = build_obj.get("async_config").unwrap().as_object().unwrap()
+    .expect_json_object()
+  let async_obj = build_obj.get("async_config").unwrap().expect_json_object()
 
   inspect(
-    @json_parser.stringify(build_json),
+    build_json.stringify(),
     content="{\"logger\":{\"min_level\":\"INFO\",\"target\":\"\",\"timestamp\":false,\"sink\":{\"kind\":\"console\",\"path\":\"\",\"append\":true,\"auto_flush\":true,\"text_formatter\":{\"show_timestamp\":true,\"show_level\":true,\"show_target\":true,\"show_fields\":true,\"separator\":\" \",\"field_separator\":\" \",\"template\":\"\",\"color_mode\":\"never\",\"color_support\":\"truecolor\",\"style_markup\":\"full\",\"target_style_markup\":\"disabled\",\"fields_style_markup\":\"disabled\"}}},\"async_config\":{\"max_pending\":0,\"max_batch\":1,\"linger_ms\":0,\"overflow\":\"Blocking\",\"flush\":\"Never\"}}",
   )
   inspect(
-    logger_obj.get("min_level").unwrap().as_string().unwrap(),
+    logger_obj.get("min_level").unwrap().expect_json_string(),
     content="INFO",
   )
-  inspect(logger_obj.get("target").unwrap().as_string().unwrap(), content="")
+  inspect(logger_obj.get("target").unwrap().expect_json_string(), content="")
   inspect(
-    logger_obj.get("timestamp").unwrap().as_bool().unwrap(),
+    logger_obj.get("timestamp").unwrap().expect_json_bool(),
     content="false",
   )
   inspect(logger_obj.get("queue") is None, content="true")
-  inspect(sink_obj.get("kind").unwrap().as_string().unwrap(), content="console")
-  inspect(sink_obj.get("path").unwrap().as_string().unwrap(), content="")
-  inspect(sink_obj.get("append").unwrap().as_bool().unwrap(), content="true")
+  inspect(sink_obj.get("kind").unwrap().expect_json_string(), content="console")
+  inspect(sink_obj.get("path").unwrap().expect_json_string(), content="")
+  inspect(sink_obj.get("append").unwrap().expect_json_bool(), content="true")
   inspect(
-    sink_obj.get("auto_flush").unwrap().as_bool().unwrap(),
+    sink_obj.get("auto_flush").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_timestamp").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_timestamp").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_level").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_level").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_target").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_target").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_fields").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_fields").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("separator").unwrap().expect_json_string(),
     content=" ",
   )
   inspect(
-    formatter_obj.get("field_separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("field_separator").unwrap().expect_json_string(),
     content=" ",
   )
   inspect(
-    formatter_obj.get("template").unwrap().as_string().unwrap(),
+    formatter_obj.get("template").unwrap().expect_json_string(),
     content="",
   )
   inspect(
-    formatter_obj.get("color_mode").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_mode").unwrap().expect_json_string(),
     content="never",
   )
   inspect(
-    formatter_obj.get("color_support").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_support").unwrap().expect_json_string(),
     content="truecolor",
   )
   inspect(
-    formatter_obj.get("style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("style_markup").unwrap().expect_json_string(),
     content="full",
   )
   inspect(
-    formatter_obj.get("target_style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("target_style_markup").unwrap().expect_json_string(),
     content="disabled",
   )
   inspect(
-    formatter_obj.get("fields_style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("fields_style_markup").unwrap().expect_json_string(),
     content="disabled",
   )
   inspect(formatter_obj.get("style_tags") is None, content="true")
   inspect(
-    async_obj.get("max_pending").unwrap().as_number().unwrap().to_int(),
+    async_obj.get("max_pending").unwrap().expect_json_number().to_int(),
     content="0",
   )
   inspect(
-    async_obj.get("max_batch").unwrap().as_number().unwrap().to_int(),
+    async_obj.get("max_batch").unwrap().expect_json_number().to_int(),
     content="1",
   )
   inspect(
-    async_obj.get("linger_ms").unwrap().as_number().unwrap().to_int(),
+    async_obj.get("linger_ms").unwrap().expect_json_number().to_int(),
     content="0",
   )
   inspect(
-    async_obj.get("overflow").unwrap().as_string().unwrap(),
+    async_obj.get("overflow").unwrap().expect_json_string(),
     content="Blocking",
   )
-  inspect(async_obj.get("flush").unwrap().as_string().unwrap(), content="Never")
+  inspect(async_obj.get("flush").unwrap().expect_json_string(), content="Never")
 }
 
 ///|
@@ -1068,7 +1090,7 @@ test "async config parsers reject malformed input" {
   })() catch {
     err => err.to_string()
   }
-  inspect(invalid_json_error.contains("UnexpectedToken"), content="true")
+  inspect(invalid_json_error != "no error", content="true")
 
   let wrong_type_error = (fn() -> String raise {
     ignore(parse_async_logger_config_text("{\"max_pending\":\"many\"}"))
@@ -1144,7 +1166,7 @@ test "async runtime capability helpers stay consistent" {
   )
   inspect(state.background_worker == worker_supported, content="true")
   inspect(
-    @json_parser.stringify(async_runtime_state_to_json(state)),
+    async_runtime_state_to_json(state).stringify(),
     content=if worker_supported {
       "{\"mode\":\"native_worker\",\"background_worker\":true}"
     } else {
@@ -1225,7 +1247,7 @@ test "async logger state snapshot reflects current counters and runtime" {
     content="Shutdown",
   )
   inspect(
-    @json_parser.stringify(async_logger_state_to_json(state)),
+    async_logger_state_to_json(state).stringify(),
     content=if async_runtime_supports_background_worker() {
       "{\"runtime\":{\"mode\":\"native_worker\",\"background_worker\":true},\"phase\":\"ready\",\"pending_count\":0,\"dropped_count\":0,\"is_closed\":false,\"is_running\":false,\"has_failed\":false,\"backlog_retained\":false,\"can_rerun\":true,\"terminal\":false,\"last_error\":\"\",\"flush_policy\":\"Shutdown\"}"
     } else {

src-async/async_logger_shared.mbt

@@ -48,9 +48,7 @@ pub fn async_runtime_state() -> AsyncRuntimeState {
 }
 
 ///|
-pub fn async_runtime_state_to_json(
-  state : AsyncRuntimeState,
-) -> @json_parser.JsonValue {
+pub fn async_runtime_state_to_json(state : AsyncRuntimeState) -> Json {
   @utils.async_runtime_state_to_json(state)
 }
 
@@ -63,9 +61,7 @@ pub fn stringify_async_runtime_state(
 }
 
 ///|
-pub fn async_logger_state_to_json(
-  state : AsyncLoggerState,
-) -> @json_parser.JsonValue {
+pub fn async_logger_state_to_json(state : AsyncLoggerState) -> Json {
   @utils.async_logger_state_to_json(state)
 }
 
@@ -88,9 +84,7 @@ pub fn parse_async_logger_config_text(
 }
 
 ///|
-pub fn async_logger_config_to_json(
-  config : AsyncLoggerConfig,
-) -> @json_parser.JsonValue {
+pub fn async_logger_config_to_json(config : AsyncLoggerConfig) -> Json {
   @utils.async_logger_config_to_json(config)
 }
 
@@ -115,7 +109,7 @@ pub fn parse_async_logger_build_config_text(
 ///|
 pub fn async_logger_build_config_to_json(
   config : AsyncLoggerBuildConfig,
-) -> @json_parser.JsonValue {
+) -> Json {
   @utils.async_logger_build_config_to_json(config)
 }
 
@@ -280,6 +274,14 @@ pub fn[S] AsyncLogger::with_context_fields(
   { ..self, context_fields: fields }
 }
 
+///|
+pub fn[S] AsyncLogger::with_trace_context(
+  self : AsyncLogger[S],
+  context : @bitlogger.TraceContext,
+) -> AsyncLogger[S] {
+  self.with_context_fields(context.as_fields())
+}
+
 ///|
 pub fn[S] AsyncLogger::with_filter(
   self : AsyncLogger[S],

src-async/async_native_file_integration_test.mbt

@@ -0,0 +1,90 @@
+///|
+async test "native async file lifecycle flushes rotates and restarts" {
+  if !@bitlogger.native_files_supported() {
+    inspect(@bitlogger.native_files_supported(), content="false")
+  } else {
+    let path = "logs/bitlogger-async-native-e2e.log"
+    let first_flushes : Ref[Int] = Ref(0)
+    let first_sink = @bitlogger.file_sink(
+      path,
+      append=false,
+      auto_flush=false,
+      rotation=Some(@bitlogger.file_rotation(8, max_backups=1)),
+      formatter=fn(rec) { rec.message },
+    )
+    let first = async_logger(
+      first_sink,
+      config=AsyncLoggerConfig::new(
+        max_pending=4,
+        overflow=AsyncOverflowPolicy::Blocking,
+        max_batch=4,
+        linger_ms=0,
+        flush=AsyncFlushPolicy::Batch,
+      ),
+      min_level=@bitlogger.Level::Info,
+      target="async.file.e2e",
+      flush=fn(sink) {
+        first_flushes.val += 1
+        ignore(sink.flush())
+      },
+    )
+
+    @async.with_task_group(group => {
+      group.spawn_bg(() => first.run())
+      first.info("first-record")
+      first.shutdown()
+    })
+
+    inspect(first.is_closed(), content="true")
+    inspect(first.has_failed(), content="false")
+    inspect(first.pending_count(), content="0")
+    inspect(first_flushes.val > 0, content="true")
+    inspect(first_sink.path(), content="logs/bitlogger-async-native-e2e.log")
+    inspect(first_sink.rotation_enabled(), content="true")
+    inspect(first_sink.rotation_failures(), content="0")
+    inspect(first_sink.write_failures(), content="0")
+    inspect(first_sink.flush_failures(), content="0")
+    inspect(first_sink.close(), content="true")
+
+    let restart_flushes : Ref[Int] = Ref(0)
+    let restarted_sink = @bitlogger.file_sink(
+      path,
+      append=true,
+      auto_flush=false,
+      rotation=Some(@bitlogger.file_rotation(8, max_backups=1)),
+      formatter=fn(rec) { rec.message },
+    )
+    let restarted = async_logger(
+      restarted_sink,
+      config=AsyncLoggerConfig::new(
+        max_pending=4,
+        overflow=AsyncOverflowPolicy::Blocking,
+        max_batch=4,
+        linger_ms=0,
+        flush=AsyncFlushPolicy::Shutdown,
+      ),
+      min_level=@bitlogger.Level::Info,
+      target="async.file.e2e",
+      flush=fn(sink) {
+        restart_flushes.val += 1
+        ignore(sink.flush())
+      },
+    )
+
+    @async.with_task_group(group => {
+      group.spawn_bg(() => restarted.run())
+      restarted.info("second-record")
+      restarted.shutdown()
+    })
+
+    inspect(restarted.is_closed(), content="true")
+    inspect(restarted.has_failed(), content="false")
+    inspect(restarted.pending_count(), content="0")
+    inspect(restart_flushes.val, content="1")
+    inspect(restarted_sink.rotation_enabled(), content="true")
+    inspect(restarted_sink.rotation_failures(), content="0")
+    inspect(restarted_sink.write_failures(), content="0")
+    inspect(restarted_sink.flush_failures(), content="0")
+    inspect(restarted_sink.close(), content="true")
+  }
+}

src-async/json_test_helpers_test.mbt

@@ -0,0 +1,32 @@
+///|
+fn Json::expect_json_object(self : Json) -> Map[String, Json] {
+  match self {
+    Json::Object(value) => value
+    _ => abort("Expected JSON object")
+  }
+}
+
+///|
+fn Json::expect_json_number(self : Json) -> Double {
+  match self {
+    Json::Number(value, ..) => value
+    _ => abort("Expected JSON number")
+  }
+}
+
+///|
+fn Json::expect_json_string(self : Json) -> String {
+  match self {
+    Json::String(value) => value
+    _ => abort("Expected JSON string")
+  }
+}
+
+///|
+fn Json::expect_json_bool(self : Json) -> Bool {
+  match self {
+    Json::True => true
+    Json::False => false
+    _ => abort("Expected JSON bool")
+  }
+}

src-async/library_async_logger.mbt

@@ -93,6 +93,14 @@ pub fn[S] LibraryAsyncLogger::bind(
   self.with_context_fields(fields)
 }
 
+///|
+pub fn[S] LibraryAsyncLogger::with_trace_context(
+  self : LibraryAsyncLogger[S],
+  context : @bitlogger.TraceContext,
+) -> LibraryAsyncLogger[S] {
+  library_async_logger(self.inner.with_trace_context(context))
+}
+
 ///|
 pub fn[S] LibraryAsyncLogger::is_enabled(
   self : LibraryAsyncLogger[S],

src-async/moon.pkg

@@ -1,7 +1,7 @@
 import {
   "Nanaloveyuki/BitLogger/src" @bitlogger,
   "Nanaloveyuki/BitLogger/src-async/utils",
-  "maria/json_parser",
+  "moonbitlang/core/json",
   "moonbitlang/async",
   "moonbitlang/async/aqueue",
   "moonbitlang/core/env",

src-async/pkg.generated.mbti

@@ -6,7 +6,6 @@ import {
   "Nanaloveyuki/BitLogger/src/core",
   "Nanaloveyuki/BitLogger/src/runtime",
   "Nanaloveyuki/BitLogger/src/sink_graph",
-  "maria/json_parser",
   "moonbitlang/async/aqueue",
   "moonbitlang/core/ref",
 }
@@ -14,11 +13,11 @@ import {
 // Values
 pub fn[S] async_logger(S, config? : @utils.AsyncLoggerConfig, min_level? : @core.Level, target? : String, flush? : (S) -> Unit raise) -> AsyncLogger[S]
 
-pub fn async_logger_build_config_to_json(@utils.AsyncLoggerBuildConfig) -> @json_parser.JsonValue
+pub fn async_logger_build_config_to_json(@utils.AsyncLoggerBuildConfig) -> Json
 
-pub fn async_logger_config_to_json(@utils.AsyncLoggerConfig) -> @json_parser.JsonValue
+pub fn async_logger_config_to_json(@utils.AsyncLoggerConfig) -> Json
 
-pub fn async_logger_state_to_json(@utils.AsyncLoggerState) -> @json_parser.JsonValue
+pub fn async_logger_state_to_json(@utils.AsyncLoggerState) -> Json
 
 pub fn async_runtime_mode() -> @utils.AsyncRuntimeMode
 
@@ -26,7 +25,7 @@ pub fn async_runtime_mode_label(@utils.AsyncRuntimeMode) -> String
 
 pub fn async_runtime_state() -> @utils.AsyncRuntimeState
 
-pub fn async_runtime_state_to_json(@utils.AsyncRuntimeState) -> @json_parser.JsonValue
+pub fn async_runtime_state_to_json(@utils.AsyncRuntimeState) -> Json
 
 pub fn async_runtime_supports_background_worker() -> Bool
 
@@ -115,6 +114,7 @@ pub fn[S] AsyncLogger::with_min_level(Self[S], @core.Level) -> Self[S]
 pub fn[S] AsyncLogger::with_patch(Self[S], (@core.Record) -> @core.Record) -> Self[S]
 pub fn[S] AsyncLogger::with_target(Self[S], String) -> Self[S]
 pub fn[S] AsyncLogger::with_timestamp(Self[S], enabled? : Bool) -> Self[S]
+pub fn[S] AsyncLogger::with_trace_context(Self[S], @core.TraceContext) -> Self[S]
 
 pub struct LibraryAsyncLogger[S] {
   inner : AsyncLogger[S]
@@ -132,6 +132,7 @@ pub fn[S] LibraryAsyncLogger::to_async_logger(Self[S]) -> AsyncLogger[S]
 pub async fn[S] LibraryAsyncLogger::warn(Self[S], String, fields? : Array[@core.Field]) -> Unit
 pub fn[S] LibraryAsyncLogger::with_context_fields(Self[S], Array[@core.Field]) -> Self[S]
 pub fn[S] LibraryAsyncLogger::with_target(Self[S], String) -> Self[S]
+pub fn[S] LibraryAsyncLogger::with_trace_context(Self[S], @core.TraceContext) -> Self[S]
 
 // Type aliases
 pub type ApplicationAsyncLogger = AsyncLogger[@runtime.RuntimeSink]

src-async/utils/async_models.mbt

@@ -154,12 +154,10 @@ pub fn AsyncLoggerState::new(
 }
 
 ///|
-pub fn async_runtime_state_to_json(
-  state : AsyncRuntimeState,
-) -> @json_parser.JsonValue {
-  @json_parser.JsonValue::Object({
-    "mode": @json_parser.JsonValue::String(async_runtime_mode_label(state.mode)),
-    "background_worker": @json_parser.JsonValue::Bool(state.background_worker),
+pub fn async_runtime_state_to_json(state : AsyncRuntimeState) -> Json {
+  Json::object({
+    "mode": Json::string(async_runtime_mode_label(state.mode)),
+    "background_worker": Json::boolean(state.background_worker),
   })
 }
 
@@ -170,9 +168,9 @@ pub fn stringify_async_runtime_state(
 ) -> String {
   let value = async_runtime_state_to_json(state)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
@@ -186,37 +184,25 @@ fn async_flush_policy_label(policy : AsyncFlushPolicy) -> String {
 }
 
 ///|
-fn async_logger_state_to_json_value(
-  state : AsyncLoggerState,
-) -> @json_parser.JsonValue {
-  @json_parser.JsonValue::Object({
+fn async_logger_state_to_json_value(state : AsyncLoggerState) -> Json {
+  Json::object({
     "runtime": async_runtime_state_to_json(state.runtime),
-    "phase": @json_parser.JsonValue::String(
-      async_lifecycle_phase_label(state.phase),
-    ),
-    "pending_count": @json_parser.JsonValue::Number(
-      state.pending_count.to_double(),
-    ),
-    "dropped_count": @json_parser.JsonValue::Number(
-      state.dropped_count.to_double(),
-    ),
-    "is_closed": @json_parser.JsonValue::Bool(state.is_closed),
-    "is_running": @json_parser.JsonValue::Bool(state.is_running),
-    "has_failed": @json_parser.JsonValue::Bool(state.has_failed),
-    "backlog_retained": @json_parser.JsonValue::Bool(state.backlog_retained),
-    "can_rerun": @json_parser.JsonValue::Bool(state.can_rerun),
-    "terminal": @json_parser.JsonValue::Bool(state.terminal),
-    "last_error": @json_parser.JsonValue::String(state.last_error),
-    "flush_policy": @json_parser.JsonValue::String(
-      async_flush_policy_label(state.flush_policy),
-    ),
+    "phase": Json::string(async_lifecycle_phase_label(state.phase)),
+    "pending_count": Json::number(state.pending_count.to_double()),
+    "dropped_count": Json::number(state.dropped_count.to_double()),
+    "is_closed": Json::boolean(state.is_closed),
+    "is_running": Json::boolean(state.is_running),
+    "has_failed": Json::boolean(state.has_failed),
+    "backlog_retained": Json::boolean(state.backlog_retained),
+    "can_rerun": Json::boolean(state.can_rerun),
+    "terminal": Json::boolean(state.terminal),
+    "last_error": Json::string(state.last_error),
+    "flush_policy": Json::string(async_flush_policy_label(state.flush_policy)),
   })
 }
 
 ///|
-pub fn async_logger_state_to_json(
-  state : AsyncLoggerState,
-) -> @json_parser.JsonValue {
+pub fn async_logger_state_to_json(state : AsyncLoggerState) -> Json {
   async_logger_state_to_json_value(state)
 }
 
@@ -227,9 +213,9 @@ pub fn stringify_async_logger_state(
 ) -> String {
   let value = async_logger_state_to_json_value(state)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
@@ -293,53 +279,38 @@ fn parse_async_flush(name : String) -> AsyncFlushPolicy raise {
 pub fn parse_async_logger_config_text(
   input : String,
 ) -> AsyncLoggerConfig raise {
-  let root = @json_parser.parse(input)
-  let obj = match root.as_object() {
-    Some(obj) => obj
-    None => raise Failure::Failure("Expected object for async logger config")
+  let root = @json.parse(input)
+  let obj = match root {
+    Json::Object(obj) => obj
+    _ => raise Failure::Failure("Expected object for async logger config")
   }
   let max_pending = match obj.get("max_pending") {
-    Some(value) =>
-      match value.as_number() {
-        Some(number) => number.to_int()
-        None =>
-          raise Failure::Failure("Expected number at async_config.max_pending")
-      }
+    Some(Json::Number(number, ..)) => number.to_int()
+    Some(_) =>
+      raise Failure::Failure("Expected number at async_config.max_pending")
     None => 0
   }
   let overflow = match obj.get("overflow") {
-    Some(value) =>
-      match value.as_string() {
-        Some(text) => parse_async_overflow(text)
-        None =>
-          raise Failure::Failure("Expected string at async_config.overflow")
-      }
+    Some(Json::String(text)) => parse_async_overflow(text)
+    Some(_) =>
+      raise Failure::Failure("Expected string at async_config.overflow")
     None => AsyncOverflowPolicy::Blocking
   }
   let max_batch = match obj.get("max_batch") {
-    Some(value) =>
-      match value.as_number() {
-        Some(number) => number.to_int()
-        None =>
-          raise Failure::Failure("Expected number at async_config.max_batch")
-      }
+    Some(Json::Number(number, ..)) => number.to_int()
+    Some(_) =>
+      raise Failure::Failure("Expected number at async_config.max_batch")
     None => 1
   }
   let linger_ms = match obj.get("linger_ms") {
-    Some(value) =>
-      match value.as_number() {
-        Some(number) => number.to_int()
-        None =>
-          raise Failure::Failure("Expected number at async_config.linger_ms")
-      }
+    Some(Json::Number(number, ..)) => number.to_int()
+    Some(_) =>
+      raise Failure::Failure("Expected number at async_config.linger_ms")
     None => 0
   }
   let flush = match obj.get("flush") {
-    Some(value) =>
-      match value.as_string() {
-        Some(text) => parse_async_flush(text)
-        None => raise Failure::Failure("Expected string at async_config.flush")
-      }
+    Some(Json::String(text)) => parse_async_flush(text)
+    Some(_) => raise Failure::Failure("Expected string at async_config.flush")
     None => AsyncFlushPolicy::Never
   }
   AsyncLoggerConfig::new(
@@ -352,23 +323,19 @@ pub fn parse_async_logger_config_text(
 }
 
 ///|
-pub fn async_logger_config_to_json(
-  config : AsyncLoggerConfig,
-) -> @json_parser.JsonValue {
-  @json_parser.JsonValue::Object({
-    "max_pending": @json_parser.JsonValue::Number(
-      config.max_pending.to_double(),
-    ),
-    "max_batch": @json_parser.JsonValue::Number(config.max_batch.to_double()),
-    "linger_ms": @json_parser.JsonValue::Number(config.linger_ms.to_double()),
-    "overflow": @json_parser.JsonValue::String(
+pub fn async_logger_config_to_json(config : AsyncLoggerConfig) -> Json {
+  Json::object({
+    "max_pending": Json::number(config.max_pending.to_double()),
+    "max_batch": Json::number(config.max_batch.to_double()),
+    "linger_ms": Json::number(config.linger_ms.to_double()),
+    "overflow": Json::string(
       match config.overflow {
         AsyncOverflowPolicy::Blocking => "Blocking"
         AsyncOverflowPolicy::DropOldest => "DropOldest"
         AsyncOverflowPolicy::DropNewest => "DropNewest"
       },
     ),
-    "flush": @json_parser.JsonValue::String(
+    "flush": Json::string(
       match config.flush {
         AsyncFlushPolicy::Never => "Never"
         AsyncFlushPolicy::Batch => "Batch"
@@ -385,9 +352,9 @@ pub fn stringify_async_logger_config(
 ) -> String {
   let value = async_logger_config_to_json(config)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
@@ -409,21 +376,20 @@ pub fn AsyncLoggerBuildConfig::new(
 pub fn parse_async_logger_build_config_text(
   input : String,
 ) -> AsyncLoggerBuildConfig raise {
-  let root = @json_parser.parse(input)
-  let obj = match root.as_object() {
-    Some(obj) => obj
-    None =>
+  let root = @json.parse(input)
+  let obj = match root {
+    Json::Object(obj) => obj
+    _ =>
       raise Failure::Failure(
         "Expected object at async logger build config root",
       )
   }
   let logger = match obj.get("logger") {
-    Some(value) =>
-      @bitlogger.parse_logger_config_text(@json_parser.stringify(value))
+    Some(value) => @bitlogger.parse_logger_config_text(value.stringify())
     None => @bitlogger.default_logger_config()
   }
   let async_config = match obj.get("async_config") {
-    Some(value) => parse_async_logger_config_text(@json_parser.stringify(value))
+    Some(value) => parse_async_logger_config_text(value.stringify())
     None => AsyncLoggerConfig::new()
   }
   AsyncLoggerBuildConfig::new(logger~, async_config~)
@@ -432,8 +398,8 @@ pub fn parse_async_logger_build_config_text(
 ///|
 pub fn async_logger_build_config_to_json(
   config : AsyncLoggerBuildConfig,
-) -> @json_parser.JsonValue {
-  @json_parser.JsonValue::Object({
+) -> Json {
+  Json::object({
     "logger": @bitlogger.logger_config_to_json(config.logger),
     "async_config": async_logger_config_to_json(config.async_config),
   })
@@ -446,8 +412,8 @@ pub fn stringify_async_logger_build_config(
 ) -> String {
   let value = async_logger_build_config_to_json(config)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }

src-async/utils/moon.pkg

@@ -1,4 +1,4 @@
 import {
   "Nanaloveyuki/BitLogger/src" @bitlogger,
-  "maria/json_parser",
+  "moonbitlang/core/json",
 }

src-async/utils/pkg.generated.mbti

@@ -3,19 +3,18 @@ package "Nanaloveyuki/BitLogger/src-async/utils"
 
 import {
   "Nanaloveyuki/BitLogger/src/config_model",
-  "maria/json_parser",
 }
 
 // Values
-pub fn async_logger_build_config_to_json(AsyncLoggerBuildConfig) -> @json_parser.JsonValue
+pub fn async_logger_build_config_to_json(AsyncLoggerBuildConfig) -> Json
 
-pub fn async_logger_config_to_json(AsyncLoggerConfig) -> @json_parser.JsonValue
+pub fn async_logger_config_to_json(AsyncLoggerConfig) -> Json
 
-pub fn async_logger_state_to_json(AsyncLoggerState) -> @json_parser.JsonValue
+pub fn async_logger_state_to_json(AsyncLoggerState) -> Json
 
 pub fn async_runtime_mode_label(AsyncRuntimeMode) -> String
 
-pub fn async_runtime_state_to_json(AsyncRuntimeState) -> @json_parser.JsonValue
+pub fn async_runtime_state_to_json(AsyncRuntimeState) -> Json
 
 pub fn compatibility_async_runtime_mode() -> AsyncRuntimeMode
 

src/config.mbt

@@ -39,7 +39,7 @@ pub fn parse_logger_config_text(
 }
 
 ///|
-pub fn queue_config_to_json(queue : QueueConfig) -> @json_parser.JsonValue {
+pub fn queue_config_to_json(queue : QueueConfig) -> Json {
   @config_model.queue_config_to_json(queue)
 }
 
@@ -52,9 +52,7 @@ pub fn stringify_queue_config(
 }
 
 ///|
-pub fn text_formatter_config_to_json(
-  config : TextFormatterConfig,
-) -> @json_parser.JsonValue {
+pub fn text_formatter_config_to_json(config : TextFormatterConfig) -> Json {
   @config_model.text_formatter_config_to_json(config)
 }
 
@@ -67,14 +65,12 @@ pub fn stringify_text_formatter_config(
 }
 
 ///|
-pub fn file_rotation_config_to_json(
-  config : FileRotation,
-) -> @json_parser.JsonValue {
+pub fn file_rotation_config_to_json(config : FileRotation) -> Json {
   @file_model.file_rotation_config_to_json(config)
 }
 
 ///|
-pub fn sink_config_to_json(config : SinkConfig) -> @json_parser.JsonValue {
+pub fn sink_config_to_json(config : SinkConfig) -> Json {
   @config_model.sink_config_to_json(config)
 }
 
@@ -87,7 +83,7 @@ pub fn stringify_sink_config(
 }
 
 ///|
-pub fn logger_config_to_json(config : LoggerConfig) -> @json_parser.JsonValue {
+pub fn logger_config_to_json(config : LoggerConfig) -> Json {
   @config_model.logger_config_to_json(config)
 }
 

src/config_model/config.mbt

@@ -170,102 +170,84 @@ pub fn default_logger_config() -> LoggerConfig {
 
 ///|
 fn expect_object(
-  value : @json_parser.JsonValue,
+  value : Json,
   context : String,
-) -> Map[String, @json_parser.JsonValue] raise ConfigError {
-  match value.as_object() {
-    Some(obj) => obj
-    None => raise ConfigError::InvalidConfig("Expected object at " + context)
+) -> Map[String, Json] raise ConfigError {
+  match value {
+    Json::Object(obj) => obj
+    _ => raise ConfigError::InvalidConfig("Expected object at " + context)
   }
 }
 
 ///|
 fn get_string(
-  obj : Map[String, @json_parser.JsonValue],
+  obj : Map[String, Json],
   key : String,
   default? : String = "",
 ) -> String raise ConfigError {
   match obj.get(key) {
     None => default
-    Some(value) =>
-      match value.as_string() {
-        Some(text) => text
-        None =>
-          raise ConfigError::InvalidConfig("Expected string at key " + key)
-      }
+    Some(Json::String(text)) => text
+    Some(_) => raise ConfigError::InvalidConfig("Expected string at key " + key)
   }
 }
 
 ///|
 fn get_optional_string(
-  obj : Map[String, @json_parser.JsonValue],
+  obj : Map[String, Json],
   key : String,
 ) -> String? raise ConfigError {
   match obj.get(key) {
     None => None
-    Some(value) =>
-      match value.as_string() {
-        Some(text) => Some(text)
-        None =>
-          raise ConfigError::InvalidConfig("Expected string at key " + key)
-      }
+    Some(Json::String(text)) => Some(text)
+    Some(_) => raise ConfigError::InvalidConfig("Expected string at key " + key)
   }
 }
 
 ///|
 fn get_bool(
-  obj : Map[String, @json_parser.JsonValue],
+  obj : Map[String, Json],
   key : String,
   default~ : Bool,
 ) -> Bool raise ConfigError {
   match obj.get(key) {
     None => default
-    Some(value) =>
-      match value.as_bool() {
-        Some(flag) => flag
-        None => raise ConfigError::InvalidConfig("Expected bool at key " + key)
-      }
+    Some(Json::True) => true
+    Some(Json::False) => false
+    Some(_) => raise ConfigError::InvalidConfig("Expected bool at key " + key)
   }
 }
 
 ///|
 fn get_int(
-  obj : Map[String, @json_parser.JsonValue],
+  obj : Map[String, Json],
   key : String,
   default~ : Int,
 ) -> Int raise ConfigError {
   match obj.get(key) {
     None => default
-    Some(value) =>
-      match value.as_number() {
-        Some(number) => number.to_int()
-        None =>
-          raise ConfigError::InvalidConfig("Expected number at key " + key)
-      }
+    Some(Json::Number(number, ..)) => number.to_int()
+    Some(_) => raise ConfigError::InvalidConfig("Expected number at key " + key)
   }
 }
 
 ///|
 fn get_optional_int64_string(
-  obj : Map[String, @json_parser.JsonValue],
+  obj : Map[String, Json],
   key : String,
 ) -> Int64? raise ConfigError {
   match obj.get(key) {
     None => None
-    Some(value) =>
-      match value.as_string() {
-        Some(text) =>
-          Some(
-            @string.parse_int64(text) catch {
-              _ =>
-                raise ConfigError::InvalidConfig(
-                  "Expected int64 string at key " + key,
-                )
-            },
-          )
-        None =>
-          raise ConfigError::InvalidConfig("Expected string at key " + key)
-      }
+    Some(Json::String(text)) =>
+      Some(
+        @string.parse_int64(text) catch {
+          _ =>
+            raise ConfigError::InvalidConfig(
+              "Expected int64 string at key " + key,
+            )
+        },
+      )
+    Some(_) => raise ConfigError::InvalidConfig("Expected string at key " + key)
   }
 }
 
@@ -355,7 +337,7 @@ fn sink_kind_label(kind : SinkKind) -> String {
 
 ///|
 fn parse_text_formatter_config(
-  value : @json_parser.JsonValue,
+  value : Json,
 ) -> TextFormatterConfig raise ConfigError {
   let obj = expect_object(value, "text_formatter")
   TextFormatterConfig::new(
@@ -388,7 +370,7 @@ fn parse_text_formatter_config(
 
 ///|
 fn parse_text_style_config(
-  value : @json_parser.JsonValue,
+  value : Json,
   context : String,
 ) -> @formatting.TextStyle raise ConfigError {
   let obj = expect_object(value, context)
@@ -404,7 +386,7 @@ fn parse_text_style_config(
 
 ///|
 fn parse_style_tags_config(
-  value : @json_parser.JsonValue,
+  value : Json,
 ) -> Map[String, @formatting.TextStyle] raise ConfigError {
   let obj = expect_object(value, "text_formatter.style_tags")
   let style_tags : Map[String, @formatting.TextStyle] = Map([])
@@ -418,9 +400,7 @@ fn parse_style_tags_config(
 }
 
 ///|
-fn parse_queue_config(
-  value : @json_parser.JsonValue,
-) -> QueueConfig raise ConfigError {
+fn parse_queue_config(value : Json) -> QueueConfig raise ConfigError {
   let obj = expect_object(value, "queue")
   QueueConfig::new(
     get_int(obj, "max_pending", default=0),
@@ -430,7 +410,7 @@ fn parse_queue_config(
 
 ///|
 fn parse_file_rotation_config(
-  value : @json_parser.JsonValue,
+  value : Json,
 ) -> @file_model.FileRotation raise ConfigError {
   let obj = expect_object(value, "sink.rotation")
   let max_backups = get_int(obj, "max_backups", default=1)
@@ -446,9 +426,7 @@ fn parse_file_rotation_config(
 }
 
 ///|
-fn parse_sink_config(
-  value : @json_parser.JsonValue,
-) -> SinkConfig raise ConfigError {
+fn parse_sink_config(value : Json) -> SinkConfig raise ConfigError {
   let obj = expect_object(value, "sink")
   let kind = parse_sink_kind(get_string(obj, "kind", default="console"))
   let formatter = match obj.get("text_formatter") {
@@ -480,7 +458,7 @@ fn parse_sink_config(
 pub fn parse_logger_config_text(
   input : String,
 ) -> LoggerConfig raise ConfigError {
-  let root = @json_parser.parse(input) catch {
+  let root = @json.parse(input) catch {
     e => raise ConfigError::InvalidConfig("Invalid JSON: " + e.to_string())
   }
   let obj = expect_object(root, "root")
@@ -500,10 +478,10 @@ pub fn parse_logger_config_text(
 }
 
 ///|
-pub fn queue_config_to_json(queue : QueueConfig) -> @json_parser.JsonValue {
-  @json_parser.JsonValue::Object({
-    "max_pending": @json_parser.JsonValue::Number(queue.max_pending.to_double()),
-    "overflow": @json_parser.JsonValue::String(
+pub fn queue_config_to_json(queue : QueueConfig) -> Json {
+  Json::object({
+    "max_pending": Json::number(queue.max_pending.to_double()),
+    "overflow": Json::string(
       match queue.overflow {
         @queue_model.QueueOverflowPolicy::DropNewest => "DropNewest"
         @queue_model.QueueOverflowPolicy::DropOldest => "DropOldest"
@@ -519,76 +497,70 @@ pub fn stringify_queue_config(
 ) -> String {
   let value = queue_config_to_json(queue)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
 ///|
-pub fn text_formatter_config_to_json(
-  config : TextFormatterConfig,
-) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "show_timestamp": @json_parser.JsonValue::Bool(config.show_timestamp),
-    "show_level": @json_parser.JsonValue::Bool(config.show_level),
-    "show_target": @json_parser.JsonValue::Bool(config.show_target),
-    "show_fields": @json_parser.JsonValue::Bool(config.show_fields),
-    "separator": @json_parser.JsonValue::String(config.separator),
-    "field_separator": @json_parser.JsonValue::String(config.field_separator),
-    "template": @json_parser.JsonValue::String(config.template),
-    "color_mode": @json_parser.JsonValue::String(
-      @formatting.color_mode_label(config.color_mode),
-    ),
-    "color_support": @json_parser.JsonValue::String(
+pub fn text_formatter_config_to_json(config : TextFormatterConfig) -> Json {
+  let obj : Map[String, Json] = {
+    "show_timestamp": Json::boolean(config.show_timestamp),
+    "show_level": Json::boolean(config.show_level),
+    "show_target": Json::boolean(config.show_target),
+    "show_fields": Json::boolean(config.show_fields),
+    "separator": Json::string(config.separator),
+    "field_separator": Json::string(config.field_separator),
+    "template": Json::string(config.template),
+    "color_mode": Json::string(@formatting.color_mode_label(config.color_mode)),
+    "color_support": Json::string(
       @formatting.color_support_label(config.color_support),
     ),
-    "style_markup": @json_parser.JsonValue::String(
+    "style_markup": Json::string(
       @formatting.style_markup_mode_label(config.style_markup),
     ),
-    "target_style_markup": @json_parser.JsonValue::String(
+    "target_style_markup": Json::string(
       @formatting.style_markup_mode_label(config.target_style_markup),
     ),
-    "fields_style_markup": @json_parser.JsonValue::String(
+    "fields_style_markup": Json::string(
       @formatting.style_markup_mode_label(config.fields_style_markup),
     ),
   }
   if config.style_tags.length() != 0 {
     obj["style_tags"] = style_tags_config_to_json(config.style_tags)
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
-fn text_style_config_to_json(
-  style : @formatting.TextStyle,
-) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "bold": @json_parser.JsonValue::Bool(style.bold),
-    "dim": @json_parser.JsonValue::Bool(style.dim),
-    "italic": @json_parser.JsonValue::Bool(style.italic),
-    "underline": @json_parser.JsonValue::Bool(style.underline),
+fn text_style_config_to_json(style : @formatting.TextStyle) -> Json {
+  let obj : Map[String, Json] = {
+    "bold": Json::boolean(style.bold),
+    "dim": Json::boolean(style.dim),
+    "italic": Json::boolean(style.italic),
+    "underline": Json::boolean(style.underline),
   }
   match style.fg {
-    Some(value) => obj["fg"] = @json_parser.JsonValue::String(value)
+    Some(value) => obj["fg"] = Json::string(value)
     None => ()
   }
   match style.bg {
-    Some(value) => obj["bg"] = @json_parser.JsonValue::String(value)
+    Some(value) => obj["bg"] = Json::string(value)
     None => ()
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
 fn style_tags_config_to_json(
   style_tags : Map[String, @formatting.TextStyle],
-) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = Map([])
+) -> Json {
+  let obj : Map[String, Json] = Map([])
   for name, style in style_tags {
     obj[name] = text_style_config_to_json(style)
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
@@ -598,19 +570,19 @@ pub fn stringify_text_formatter_config(
 ) -> String {
   let value = text_formatter_config_to_json(config)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
 ///|
-pub fn sink_config_to_json(config : SinkConfig) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "kind": @json_parser.JsonValue::String(sink_kind_label(config.kind)),
-    "path": @json_parser.JsonValue::String(config.path),
-    "append": @json_parser.JsonValue::Bool(config.append),
-    "auto_flush": @json_parser.JsonValue::Bool(config.auto_flush),
+pub fn sink_config_to_json(config : SinkConfig) -> Json {
+  let obj : Map[String, Json] = {
+    "kind": Json::string(sink_kind_label(config.kind)),
+    "path": Json::string(config.path),
+    "append": Json::boolean(config.append),
+    "auto_flush": Json::boolean(config.auto_flush),
     "text_formatter": text_formatter_config_to_json(config.text_formatter),
   }
   match config.rotation {
@@ -618,7 +590,7 @@ pub fn sink_config_to_json(config : SinkConfig) -> @json_parser.JsonValue {
     Some(rotation) =>
       obj["rotation"] = @file_model.file_rotation_config_to_json(rotation)
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
@@ -628,25 +600,25 @@ pub fn stringify_sink_config(
 ) -> String {
   let value = sink_config_to_json(config)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
 ///|
-pub fn logger_config_to_json(config : LoggerConfig) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "min_level": @json_parser.JsonValue::String(config.min_level.label()),
-    "target": @json_parser.JsonValue::String(config.target),
-    "timestamp": @json_parser.JsonValue::Bool(config.timestamp),
+pub fn logger_config_to_json(config : LoggerConfig) -> Json {
+  let obj : Map[String, Json] = {
+    "min_level": Json::string(config.min_level.label()),
+    "target": Json::string(config.target),
+    "timestamp": Json::boolean(config.timestamp),
     "sink": sink_config_to_json(config.sink),
   }
   match config.queue {
     None => ()
     Some(queue) => obj["queue"] = queue_config_to_json(queue)
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
@@ -656,8 +628,8 @@ pub fn stringify_logger_config(
 ) -> String {
   let value = logger_config_to_json(config)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }

src/config_model/moon.pkg

@@ -3,6 +3,6 @@ import {
   "Nanaloveyuki/BitLogger/src/file_model",
   "Nanaloveyuki/BitLogger/src/formatting",
   "Nanaloveyuki/BitLogger/src/queue_model",
-  "maria/json_parser",
+  "moonbitlang/core/json",
   "moonbitlang/core/string",
 }

src/config_model/pkg.generated.mbti

@@ -6,7 +6,6 @@ import {
   "Nanaloveyuki/BitLogger/src/file_model",
   "Nanaloveyuki/BitLogger/src/formatting",
   "Nanaloveyuki/BitLogger/src/queue_model",
-  "maria/json_parser",
 }
 
 // Values
@@ -16,13 +15,13 @@ pub fn default_sink_config() -> SinkConfig
 
 pub fn default_text_formatter_config() -> TextFormatterConfig
 
-pub fn logger_config_to_json(LoggerConfig) -> @json_parser.JsonValue
+pub fn logger_config_to_json(LoggerConfig) -> Json
 
 pub fn parse_logger_config_text(String) -> LoggerConfig raise ConfigError
 
-pub fn queue_config_to_json(QueueConfig) -> @json_parser.JsonValue
+pub fn queue_config_to_json(QueueConfig) -> Json
 
-pub fn sink_config_to_json(SinkConfig) -> @json_parser.JsonValue
+pub fn sink_config_to_json(SinkConfig) -> Json
 
 pub fn stringify_logger_config(LoggerConfig, pretty? : Bool) -> String
 
@@ -32,7 +31,7 @@ pub fn stringify_sink_config(SinkConfig, pretty? : Bool) -> String
 
 pub fn stringify_text_formatter_config(TextFormatterConfig, pretty? : Bool) -> String
 
-pub fn text_formatter_config_to_json(TextFormatterConfig) -> @json_parser.JsonValue
+pub fn text_formatter_config_to_json(TextFormatterConfig) -> Json
 
 // Errors
 pub(all) suberror ConfigError {

src/core/pkg.generated.mbti

@@ -39,6 +39,15 @@ pub fn Record::with_fields(Self, Array[Field]) -> Self
 pub fn Record::with_message(Self, String) -> Self
 pub fn Record::with_target(Self, String) -> Self
 
+pub struct TraceContext {
+  trace_id : String
+  span_id : String
+  trace_flags : String
+  trace_state : String?
+}
+pub fn TraceContext::as_fields(Self) -> Array[Field]
+pub fn TraceContext::new(String, String, trace_flags? : String, trace_state? : String) -> Self
+
 // Type aliases
 
 // Traits

src/core/trace_context.mbt

@@ -0,0 +1,31 @@
+///|
+pub struct TraceContext {
+  trace_id : String
+  span_id : String
+  trace_flags : String
+  trace_state : String?
+}
+
+///|
+pub fn TraceContext::new(
+  trace_id : String,
+  span_id : String,
+  trace_flags? : String = "01",
+  trace_state? : String,
+) -> TraceContext {
+  { trace_id, span_id, trace_flags, trace_state }
+}
+
+///|
+pub fn TraceContext::as_fields(self : TraceContext) -> Array[Field] {
+  let fields = [
+    field("trace_id", self.trace_id),
+    field("span_id", self.span_id),
+    field("trace_flags", self.trace_flags),
+  ]
+  match self.trace_state {
+    Some(value) => fields.push(field("trace_state", value))
+    None => ()
+  }
+  fields
+}

src/file_model/file_json.mbt

@@ -1,34 +1,27 @@
 ///|
-pub fn file_rotation_config_to_json(
-  config : FileRotation,
-) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "max_bytes": @json_parser.JsonValue::Number(config.max_bytes.to_double()),
-    "max_backups": @json_parser.JsonValue::Number(
-      config.max_backups.to_double(),
-    ),
+pub fn file_rotation_config_to_json(config : FileRotation) -> Json {
+  let obj : Map[String, Json] = {
+    "max_bytes": Json::number(config.max_bytes.to_double()),
+    "max_backups": Json::number(config.max_backups.to_double()),
   }
   match config.native_wide_max_bytes {
-    Some(value) =>
-      obj["max_bytes_i64"] = @json_parser.JsonValue::String(value.to_string())
+    Some(value) => obj["max_bytes_i64"] = Json::string(value.to_string())
     None => ()
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
-pub fn file_sink_policy_to_json(
-  policy : FileSinkPolicy,
-) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "append": @json_parser.JsonValue::Bool(policy.append),
-    "auto_flush": @json_parser.JsonValue::Bool(policy.auto_flush),
+pub fn file_sink_policy_to_json(policy : FileSinkPolicy) -> Json {
+  let obj : Map[String, Json] = {
+    "append": Json::boolean(policy.append),
+    "auto_flush": Json::boolean(policy.auto_flush),
   }
   match policy.rotation {
-    None => obj["rotation"] = @json_parser.JsonValue::Null
+    None => obj["rotation"] = Json::null()
     Some(rotation) => obj["rotation"] = file_rotation_config_to_json(rotation)
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
@@ -38,37 +31,29 @@ pub fn stringify_file_sink_policy(
 ) -> String {
   let value = file_sink_policy_to_json(policy)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }
 
 ///|
-pub fn file_sink_state_to_json(state : FileSinkState) -> @json_parser.JsonValue {
-  let obj : Map[String, @json_parser.JsonValue] = {
-    "path": @json_parser.JsonValue::String(state.path),
-    "available": @json_parser.JsonValue::Bool(state.available),
-    "append": @json_parser.JsonValue::Bool(state.append),
-    "auto_flush": @json_parser.JsonValue::Bool(state.auto_flush),
-    "open_failures": @json_parser.JsonValue::Number(
-      state.open_failures.to_double(),
-    ),
-    "write_failures": @json_parser.JsonValue::Number(
-      state.write_failures.to_double(),
-    ),
-    "flush_failures": @json_parser.JsonValue::Number(
-      state.flush_failures.to_double(),
-    ),
-    "rotation_failures": @json_parser.JsonValue::Number(
-      state.rotation_failures.to_double(),
-    ),
+pub fn file_sink_state_to_json(state : FileSinkState) -> Json {
+  let obj : Map[String, Json] = {
+    "path": Json::string(state.path),
+    "available": Json::boolean(state.available),
+    "append": Json::boolean(state.append),
+    "auto_flush": Json::boolean(state.auto_flush),
+    "open_failures": Json::number(state.open_failures.to_double()),
+    "write_failures": Json::number(state.write_failures.to_double()),
+    "flush_failures": Json::number(state.flush_failures.to_double()),
+    "rotation_failures": Json::number(state.rotation_failures.to_double()),
   }
   match state.rotation {
-    None => obj["rotation"] = @json_parser.JsonValue::Null
+    None => obj["rotation"] = Json::null()
     Some(rotation) => obj["rotation"] = file_rotation_config_to_json(rotation)
   }
-  @json_parser.JsonValue::Object(obj)
+  Json::object(obj)
 }
 
 ///|
@@ -78,8 +63,8 @@ pub fn stringify_file_sink_state(
 ) -> String {
   let value = file_sink_state_to_json(state)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }

src/file_model/moon.pkg

@@ -1,3 +1,3 @@
 import {
-  "maria/json_parser",
+  "moonbitlang/core/json",
 }

src/file_model/pkg.generated.mbti

@@ -1,22 +1,18 @@
 // Generated using `moon info`, DON'T EDIT IT
 package "Nanaloveyuki/BitLogger/src/file_model"
 
-import {
-  "maria/json_parser",
-}
-
 // Values
 pub fn file_rotation(Int, max_backups? : Int) -> FileRotation
 
-pub fn file_rotation_config_to_json(FileRotation) -> @json_parser.JsonValue
+pub fn file_rotation_config_to_json(FileRotation) -> Json
 
 pub fn file_rotation_i64(Int64, max_backups? : Int) -> FileRotation
 
-pub fn file_sink_policy_to_json(FileSinkPolicy) -> @json_parser.JsonValue
+pub fn file_sink_policy_to_json(FileSinkPolicy) -> Json
 
-pub fn file_sink_state_to_json(FileSinkState) -> @json_parser.JsonValue
+pub fn file_sink_state_to_json(FileSinkState) -> Json
 
-pub fn runtime_file_state_to_json(RuntimeFileState) -> @json_parser.JsonValue
+pub fn runtime_file_state_to_json(RuntimeFileState) -> Json
 
 pub fn stringify_file_sink_policy(FileSinkPolicy, pretty? : Bool) -> String
 

src/file_model/runtime_file_state.mbt

@@ -17,18 +17,12 @@ pub fn RuntimeFileState::new(
 }
 
 ///|
-pub fn runtime_file_state_to_json(
-  state : RuntimeFileState,
-) -> @json_parser.JsonValue {
-  @json_parser.JsonValue::Object({
+pub fn runtime_file_state_to_json(state : RuntimeFileState) -> Json {
+  Json::object({
     "file": file_sink_state_to_json(state.file),
-    "queued": @json_parser.JsonValue::Bool(state.queued),
-    "pending_count": @json_parser.JsonValue::Number(
-      state.pending_count.to_double(),
-    ),
-    "dropped_count": @json_parser.JsonValue::Number(
-      state.dropped_count.to_double(),
-    ),
+    "queued": Json::boolean(state.queued),
+    "pending_count": Json::number(state.pending_count.to_double()),
+    "dropped_count": Json::number(state.dropped_count.to_double()),
   })
 }
 
@@ -39,8 +33,8 @@ pub fn stringify_runtime_file_state(
 ) -> String {
   let value = runtime_file_state_to_json(state)
   if pretty {
-    @json_parser.stringify_pretty(value, 2)
+    value.stringify(indent=2)
   } else {
-    @json_parser.stringify(value)
+    value.stringify()
   }
 }

src/json_test_helpers_test.mbt

@@ -0,0 +1,32 @@
+///|
+fn Json::expect_json_object(self : Json) -> Map[String, Json] {
+  match self {
+    Json::Object(value) => value
+    _ => abort("Expected JSON object")
+  }
+}
+
+///|
+fn Json::expect_json_number(self : Json) -> Double {
+  match self {
+    Json::Number(value, ..) => value
+    _ => abort("Expected JSON number")
+  }
+}
+
+///|
+fn Json::expect_json_string(self : Json) -> String {
+  match self {
+    Json::String(value) => value
+    _ => abort("Expected JSON string")
+  }
+}
+
+///|
+fn Json::expect_json_bool(self : Json) -> Bool {
+  match self {
+    Json::True => true
+    Json::False => false
+    _ => abort("Expected JSON bool")
+  }
+}

src/library_logger.mbt

@@ -80,6 +80,14 @@ pub fn[S] LibraryLogger::bind(
   self.with_context_fields(fields)
 }
 
+///|
+pub fn[S] LibraryLogger::with_trace_context(
+  self : LibraryLogger[S],
+  context : TraceContext,
+) -> LibraryLogger[ContextSink[S]] {
+  library_logger(self.inner.with_trace_context(context))
+}
+
 ///|
 pub fn[S] LibraryLogger::is_enabled(
   self : LibraryLogger[S],

src/logger.mbt

@@ -57,6 +57,14 @@ pub fn[S] Logger::bind(
   self.with_context_fields(fields)
 }
 
+///|
+pub fn[S] Logger::with_trace_context(
+  self : Logger[S],
+  context : TraceContext,
+) -> Logger[ContextSink[S]] {
+  self.with_context_fields(context.as_fields())
+}
+
 ///|
 pub fn[S] Logger::with_filter(
   self : Logger[S],

src/logger_config_json_helpers_test.mbt

@@ -43,11 +43,7 @@ test "config subtype json helpers stringify stable shapes" {
     content="{\"kind\":\"file\",\"path\":\"logs/demo.log\",\"append\":false,\"auto_flush\":false,\"text_formatter\":{\"show_timestamp\":false,\"show_level\":true,\"show_target\":true,\"show_fields\":true,\"separator\":\" \",\"field_separator\":\" \",\"template\":\"\",\"color_mode\":\"auto\",\"color_support\":\"truecolor\",\"style_markup\":\"full\",\"target_style_markup\":\"disabled\",\"fields_style_markup\":\"disabled\"},\"rotation\":{\"max_bytes\":128,\"max_backups\":2}}",
   )
   inspect(
-    @json_parser.stringify(
-      file_rotation_config_to_json(
-        file_rotation_i64(4294967296L, max_backups=2),
-      ),
-    ),
+    file_rotation_config_to_json(file_rotation_i64(4294967296L, max_backups=2)).stringify(),
     content="{\"max_bytes\":2147483647,\"max_backups\":2,\"max_bytes_i64\":\"4294967296\"}",
   )
 }
@@ -57,17 +53,17 @@ test "config json helpers export stable structured shapes" {
   let queue_json = queue_config_to_json(
     QueueConfig::new(8, overflow=QueueOverflowPolicy::DropOldest),
   )
-  let queue_obj = queue_json.as_object().unwrap()
+  let queue_obj = queue_json.expect_json_object()
   inspect(
-    @json_parser.stringify(queue_json),
+    queue_json.stringify(),
     content="{\"max_pending\":8,\"overflow\":\"DropOldest\"}",
   )
   inspect(
-    queue_obj.get("max_pending").unwrap().as_number().unwrap().to_int(),
+    queue_obj.get("max_pending").unwrap().expect_json_number().to_int(),
     content="8",
   )
   inspect(
-    queue_obj.get("overflow").unwrap().as_string().unwrap(),
+    queue_obj.get("overflow").unwrap().expect_json_string(),
     content="DropOldest",
   )
 
@@ -88,55 +84,54 @@ test "config json helpers export stable structured shapes" {
       style_tags={ "accent": text_style(fg=Some("#4cc9f0"), bold=true) },
     ),
   )
-  let formatter_obj = formatter_json.as_object().unwrap()
+  let formatter_obj = formatter_json.expect_json_object()
   let style_tags_obj = formatter_obj
     .get("style_tags")
     .unwrap()
-    .as_object()
-    .unwrap()
-  let accent_obj = style_tags_obj.get("accent").unwrap().as_object().unwrap()
+    .expect_json_object()
+  let accent_obj = style_tags_obj.get("accent").unwrap().expect_json_object()
   inspect(
-    formatter_obj.get("show_timestamp").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_timestamp").unwrap().expect_json_bool(),
     content="false",
   )
   inspect(
-    formatter_obj.get("show_target").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_target").unwrap().expect_json_bool(),
     content="false",
   )
   inspect(
-    formatter_obj.get("separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("separator").unwrap().expect_json_string(),
     content=" | ",
   )
   inspect(
-    formatter_obj.get("field_separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("field_separator").unwrap().expect_json_string(),
     content=",",
   )
   inspect(
-    formatter_obj.get("template").unwrap().as_string().unwrap(),
+    formatter_obj.get("template").unwrap().expect_json_string(),
     content="[{level}] {message} :: {fields}",
   )
   inspect(
-    formatter_obj.get("color_mode").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_mode").unwrap().expect_json_string(),
     content="always",
   )
   inspect(
-    formatter_obj.get("color_support").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_support").unwrap().expect_json_string(),
     content="basic",
   )
   inspect(
-    formatter_obj.get("style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("style_markup").unwrap().expect_json_string(),
     content="builtin",
   )
   inspect(
-    formatter_obj.get("target_style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("target_style_markup").unwrap().expect_json_string(),
     content="builtin",
   )
   inspect(
-    formatter_obj.get("fields_style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("fields_style_markup").unwrap().expect_json_string(),
     content="disabled",
   )
-  inspect(accent_obj.get("bold").unwrap().as_bool().unwrap(), content="true")
-  inspect(accent_obj.get("fg").unwrap().as_string().unwrap(), content="#4cc9f0")
+  inspect(accent_obj.get("bold").unwrap().expect_json_bool(), content="true")
+  inspect(accent_obj.get("fg").unwrap().expect_json_string(), content="#4cc9f0")
 
   let sink_json = sink_config_to_json(
     SinkConfig::new(
@@ -151,37 +146,36 @@ test "config json helpers export stable structured shapes" {
       ),
     ),
   )
-  let sink_obj = sink_json.as_object().unwrap()
+  let sink_obj = sink_json.expect_json_object()
   let sink_formatter_obj = sink_obj
     .get("text_formatter")
     .unwrap()
-    .as_object()
-    .unwrap()
-  let rotation_obj = sink_obj.get("rotation").unwrap().as_object().unwrap()
-  inspect(sink_obj.get("kind").unwrap().as_string().unwrap(), content="file")
+    .expect_json_object()
+  let rotation_obj = sink_obj.get("rotation").unwrap().expect_json_object()
+  inspect(sink_obj.get("kind").unwrap().expect_json_string(), content="file")
   inspect(
-    sink_obj.get("path").unwrap().as_string().unwrap(),
+    sink_obj.get("path").unwrap().expect_json_string(),
     content="logs/demo.log",
   )
-  inspect(sink_obj.get("append").unwrap().as_bool().unwrap(), content="false")
+  inspect(sink_obj.get("append").unwrap().expect_json_bool(), content="false")
   inspect(
-    sink_obj.get("auto_flush").unwrap().as_bool().unwrap(),
+    sink_obj.get("auto_flush").unwrap().expect_json_bool(),
     content="false",
   )
   inspect(
-    sink_formatter_obj.get("show_timestamp").unwrap().as_bool().unwrap(),
+    sink_formatter_obj.get("show_timestamp").unwrap().expect_json_bool(),
     content="false",
   )
   inspect(
-    sink_formatter_obj.get("color_mode").unwrap().as_string().unwrap(),
+    sink_formatter_obj.get("color_mode").unwrap().expect_json_string(),
     content="auto",
   )
   inspect(
-    rotation_obj.get("max_bytes").unwrap().as_number().unwrap().to_int(),
+    rotation_obj.get("max_bytes").unwrap().expect_json_number().to_int(),
     content="128",
   )
   inspect(
-    rotation_obj.get("max_backups").unwrap().as_number().unwrap().to_int(),
+    rotation_obj.get("max_backups").unwrap().expect_json_number().to_int(),
     content="2",
   )
   inspect(rotation_obj.get("max_bytes_i64") is None, content="true")
@@ -189,17 +183,17 @@ test "config json helpers export stable structured shapes" {
   let wide_rotation_json = file_rotation_config_to_json(
     file_rotation_i64(4294967296L, max_backups=3),
   )
-  let wide_rotation_obj = wide_rotation_json.as_object().unwrap()
+  let wide_rotation_obj = wide_rotation_json.expect_json_object()
   inspect(
-    wide_rotation_obj.get("max_bytes").unwrap().as_number().unwrap().to_int(),
+    wide_rotation_obj.get("max_bytes").unwrap().expect_json_number().to_int(),
     content="2147483647",
   )
   inspect(
-    wide_rotation_obj.get("max_backups").unwrap().as_number().unwrap().to_int(),
+    wide_rotation_obj.get("max_backups").unwrap().expect_json_number().to_int(),
     content="3",
   )
   inspect(
-    wide_rotation_obj.get("max_bytes_i64").unwrap().as_string().unwrap(),
+    wide_rotation_obj.get("max_bytes_i64").unwrap().expect_json_string(),
     content="4294967296",
   )
 
@@ -212,28 +206,28 @@ test "config json helpers export stable structured shapes" {
       queue=Some(QueueConfig::new(8, overflow=QueueOverflowPolicy::DropNewest)),
     ),
   )
-  let logger_obj = logger_json.as_object().unwrap()
-  let logger_sink_obj = logger_obj.get("sink").unwrap().as_object().unwrap()
-  let logger_queue_obj = logger_obj.get("queue").unwrap().as_object().unwrap()
+  let logger_obj = logger_json.expect_json_object()
+  let logger_sink_obj = logger_obj.get("sink").unwrap().expect_json_object()
+  let logger_queue_obj = logger_obj.get("queue").unwrap().expect_json_object()
   inspect(
-    logger_obj.get("min_level").unwrap().as_string().unwrap(),
+    logger_obj.get("min_level").unwrap().expect_json_string(),
     content="WARN",
   )
-  inspect(logger_obj.get("target").unwrap().as_string().unwrap(), content="api")
+  inspect(logger_obj.get("target").unwrap().expect_json_string(), content="api")
   inspect(
-    logger_obj.get("timestamp").unwrap().as_bool().unwrap(),
+    logger_obj.get("timestamp").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    logger_sink_obj.get("kind").unwrap().as_string().unwrap(),
+    logger_sink_obj.get("kind").unwrap().expect_json_string(),
     content="text_console",
   )
   inspect(
-    logger_queue_obj.get("max_pending").unwrap().as_number().unwrap().to_int(),
+    logger_queue_obj.get("max_pending").unwrap().expect_json_number().to_int(),
     content="8",
   )
   inspect(
-    logger_queue_obj.get("overflow").unwrap().as_string().unwrap(),
+    logger_queue_obj.get("overflow").unwrap().expect_json_string(),
     content="DropNewest",
   )
 }
@@ -242,81 +236,80 @@ test "config json helpers export stable structured shapes" {
 test "logger config json export materializes parsed omitted defaults" {
   let parsed = parse_logger_config_text("{}")
   let logger_json = logger_config_to_json(parsed)
-  let logger_obj = logger_json.as_object().unwrap()
-  let sink_obj = logger_obj.get("sink").unwrap().as_object().unwrap()
+  let logger_obj = logger_json.expect_json_object()
+  let sink_obj = logger_obj.get("sink").unwrap().expect_json_object()
   let formatter_obj = sink_obj
     .get("text_formatter")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
 
   inspect(
-    @json_parser.stringify(logger_json),
+    logger_json.stringify(),
     content="{\"min_level\":\"INFO\",\"target\":\"\",\"timestamp\":false,\"sink\":{\"kind\":\"console\",\"path\":\"\",\"append\":true,\"auto_flush\":true,\"text_formatter\":{\"show_timestamp\":true,\"show_level\":true,\"show_target\":true,\"show_fields\":true,\"separator\":\" \",\"field_separator\":\" \",\"template\":\"\",\"color_mode\":\"never\",\"color_support\":\"truecolor\",\"style_markup\":\"full\",\"target_style_markup\":\"disabled\",\"fields_style_markup\":\"disabled\"}}}",
   )
   inspect(
-    logger_obj.get("min_level").unwrap().as_string().unwrap(),
+    logger_obj.get("min_level").unwrap().expect_json_string(),
     content="INFO",
   )
-  inspect(logger_obj.get("target").unwrap().as_string().unwrap(), content="")
+  inspect(logger_obj.get("target").unwrap().expect_json_string(), content="")
   inspect(
-    logger_obj.get("timestamp").unwrap().as_bool().unwrap(),
+    logger_obj.get("timestamp").unwrap().expect_json_bool(),
     content="false",
   )
   inspect(logger_obj.get("queue") is None, content="true")
-  inspect(sink_obj.get("kind").unwrap().as_string().unwrap(), content="console")
-  inspect(sink_obj.get("path").unwrap().as_string().unwrap(), content="")
-  inspect(sink_obj.get("append").unwrap().as_bool().unwrap(), content="true")
+  inspect(sink_obj.get("kind").unwrap().expect_json_string(), content="console")
+  inspect(sink_obj.get("path").unwrap().expect_json_string(), content="")
+  inspect(sink_obj.get("append").unwrap().expect_json_bool(), content="true")
   inspect(
-    sink_obj.get("auto_flush").unwrap().as_bool().unwrap(),
+    sink_obj.get("auto_flush").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_timestamp").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_timestamp").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_level").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_level").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_target").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_target").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("show_fields").unwrap().as_bool().unwrap(),
+    formatter_obj.get("show_fields").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    formatter_obj.get("separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("separator").unwrap().expect_json_string(),
     content=" ",
   )
   inspect(
-    formatter_obj.get("field_separator").unwrap().as_string().unwrap(),
+    formatter_obj.get("field_separator").unwrap().expect_json_string(),
     content=" ",
   )
   inspect(
-    formatter_obj.get("template").unwrap().as_string().unwrap(),
+    formatter_obj.get("template").unwrap().expect_json_string(),
     content="",
   )
   inspect(
-    formatter_obj.get("color_mode").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_mode").unwrap().expect_json_string(),
     content="never",
   )
   inspect(
-    formatter_obj.get("color_support").unwrap().as_string().unwrap(),
+    formatter_obj.get("color_support").unwrap().expect_json_string(),
     content="truecolor",
   )
   inspect(
-    formatter_obj.get("style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("style_markup").unwrap().expect_json_string(),
     content="full",
   )
   inspect(
-    formatter_obj.get("target_style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("target_style_markup").unwrap().expect_json_string(),
     content="disabled",
   )
   inspect(
-    formatter_obj.get("fields_style_markup").unwrap().as_string().unwrap(),
+    formatter_obj.get("fields_style_markup").unwrap().expect_json_string(),
     content="disabled",
   )
   inspect(formatter_obj.get("style_tags") is None, content="true")

src/moon.pkg

@@ -9,7 +9,6 @@ import {
   "Nanaloveyuki/BitLogger/src/queue_model",
   "Nanaloveyuki/BitLogger/src/runtime",
   "Nanaloveyuki/BitLogger/src/sink_graph",
-  "maria/json_parser",
   "moonbitlang/core/array",
   "moonbitlang/core/builtin",
   "moonbitlang/core/env",

src/pkg.generated.mbti

@@ -10,7 +10,6 @@ import {
   "Nanaloveyuki/BitLogger/src/queue_model",
   "Nanaloveyuki/BitLogger/src/runtime",
   "Nanaloveyuki/BitLogger/src/sink_graph",
-  "maria/json_parser",
 }
 
 // Values
@@ -70,15 +69,15 @@ pub fn file(String, min_level? : @core.Level, target? : String, timestamp? : Boo
 
 pub fn file_rotation(Int, max_backups? : Int) -> @file_model.FileRotation
 
-pub fn file_rotation_config_to_json(@file_model.FileRotation) -> @json_parser.JsonValue
+pub fn file_rotation_config_to_json(@file_model.FileRotation) -> Json
 
 pub fn file_rotation_i64(Int64, max_backups? : Int) -> @file_model.FileRotation
 
 pub fn file_sink(String, append? : Bool, auto_flush? : Bool, rotation? : @file_model.FileRotation?, formatter? : (@core.Record) -> String) -> @file_runtime.FileSink
 
-pub fn file_sink_policy_to_json(@file_model.FileSinkPolicy) -> @json_parser.JsonValue
+pub fn file_sink_policy_to_json(@file_model.FileSinkPolicy) -> Json
 
-pub fn file_sink_state_to_json(@file_model.FileSinkState) -> @json_parser.JsonValue
+pub fn file_sink_state_to_json(@file_model.FileSinkState) -> Json
 
 pub fn[S] filter_sink(S, (@core.Record) -> Bool) -> @sink_graph.FilterSink[S]
 
@@ -106,7 +105,7 @@ pub fn level_at_least(@core.Level) -> (@core.Record) -> Bool
 
 pub fn log(@core.Level, String, fields? : Array[@core.Field]) -> Unit
 
-pub fn logger_config_to_json(@config_model.LoggerConfig) -> @json_parser.JsonValue
+pub fn logger_config_to_json(@config_model.LoggerConfig) -> Json
 
 pub fn message_contains(String) -> (@core.Record) -> Bool
 
@@ -126,7 +125,7 @@ pub fn[S] patch_sink(S, (@core.Record) -> @core.Record) -> @sink_graph.PatchSink
 
 pub fn prefix_message(String) -> (@core.Record) -> @core.Record
 
-pub fn queue_config_to_json(@config_model.QueueConfig) -> @json_parser.JsonValue
+pub fn queue_config_to_json(@config_model.QueueConfig) -> Json
 
 pub fn[S] queued_sink(S, max_pending? : Int, overflow? : @queue_model.QueueOverflowPolicy) -> @sink_graph.QueuedSink[S]
 
@@ -136,7 +135,7 @@ pub fn redact_fields(Array[String], placeholder? : String) -> (@core.Record) ->
 
 pub fn reset_global_style_tag_registry() -> Unit
 
-pub fn runtime_file_state_to_json(@file_model.RuntimeFileState) -> @json_parser.JsonValue
+pub fn runtime_file_state_to_json(@file_model.RuntimeFileState) -> Json
 
 pub fn set_default_min_level(@core.Level) -> Unit
 
@@ -146,7 +145,7 @@ pub fn set_global_style_tag_registry(@formatting.StyleTagRegistry) -> Unit
 
 pub fn set_target(String) -> (@core.Record) -> @core.Record
 
-pub fn sink_config_to_json(@config_model.SinkConfig) -> @json_parser.JsonValue
+pub fn sink_config_to_json(@config_model.SinkConfig) -> Json
 
 pub fn[A, B] split_by_level(A, B, min_level? : @core.Level) -> @sink_graph.SplitSink[A, B]
 
@@ -182,12 +181,14 @@ pub fn text_console_sink(@formatting.TextFormatter) -> @sink_graph.FormattedCons
 
 pub fn text_formatter(show_timestamp? : Bool, show_level? : Bool, show_target? : Bool, show_fields? : Bool, separator? : String, field_separator? : String, template? : String, color_mode? : @formatting.ColorMode, color_support? : @formatting.ColorSupport, style_markup? : @formatting.StyleMarkupMode, target_style_markup? : @formatting.StyleMarkupMode, fields_style_markup? : @formatting.StyleMarkupMode, style_tags? : @formatting.StyleTagRegistry?) -> @formatting.TextFormatter
 
-pub fn text_formatter_config_to_json(@config_model.TextFormatterConfig) -> @json_parser.JsonValue
+pub fn text_formatter_config_to_json(@config_model.TextFormatterConfig) -> Json
 
 pub fn text_style(fg? : String?, bg? : String?, bold? : Bool, dim? : Bool, italic? : Bool, underline? : Bool) -> @formatting.TextStyle
 
 pub fn trace(String, fields? : Array[@core.Field]) -> Unit
 
+pub fn trace_context(String, String, trace_flags? : String, trace_state? : String) -> @core.TraceContext
+
 pub fn warn(String, fields? : Array[@core.Field]) -> Unit
 
 pub fn with_file_rotation(@config_model.LoggerConfig, Int, max_backups? : Int) -> @config_model.LoggerConfig
@@ -213,6 +214,7 @@ pub fn[S] LibraryLogger::to_logger(Self[S]) -> Logger[S]
 pub fn[S : @sink_graph.Sink] LibraryLogger::warn(Self[S], String, fields? : Array[@core.Field]) -> Unit
 pub fn[S] LibraryLogger::with_context_fields(Self[S], Array[@core.Field]) -> Self[@sink_graph.ContextSink[S]]
 pub fn[S] LibraryLogger::with_target(Self[S], String) -> Self[S]
+pub fn[S] LibraryLogger::with_trace_context(Self[S], @core.TraceContext) -> Self[@sink_graph.ContextSink[S]]
 
 pub struct Logger[S] {
   min_level : @core.Level
@@ -277,6 +279,7 @@ pub fn[S] Logger::with_patch(Self[S], (@core.Record) -> @core.Record) -> Self[@s
 pub fn[S] Logger::with_queue(Self[S], max_pending? : Int, overflow? : @queue_model.QueueOverflowPolicy) -> Self[@sink_graph.QueuedSink[S]]
 pub fn[S] Logger::with_target(Self[S], String) -> Self[S]
 pub fn[S] Logger::with_timestamp(Self[S], enabled? : Bool) -> Self[S]
+pub fn[S] Logger::with_trace_context(Self[S], @core.TraceContext) -> Self[@sink_graph.ContextSink[S]]
 
 // Type aliases
 pub type ApplicationLogger = Logger[@runtime.RuntimeSink]
@@ -359,6 +362,8 @@ pub using @config_model {type TextFormatterConfig}
 
 pub using @formatting {type TextStyle}
 
+pub using @core {type TraceContext}
+
 pub using @sink_graph {trait Sink}
 
 // Traits

src/record.mbt

@@ -1,6 +1,9 @@
 ///|
 pub type Field = @core.Field
 
+///|
+pub type TraceContext = @core.TraceContext
+
 ///|
 pub fn field(key : String, value : String) -> Field {
   @core.field(key, value)
@@ -11,6 +14,25 @@ pub fn fields(entries : Array[(String, String)]) -> Array[Field] {
   @core.fields(entries)
 }
 
+///|
+pub fn trace_context(
+  trace_id : String,
+  span_id : String,
+  trace_flags? : String = "01",
+  trace_state? : String,
+) -> TraceContext {
+  match trace_state {
+    Some(value) =>
+      @core.TraceContext::new(
+        trace_id,
+        span_id,
+        trace_flags~,
+        trace_state=value,
+      )
+    None => @core.TraceContext::new(trace_id, span_id, trace_flags~)
+  }
+}
+
 ///|
 pub type Record = @core.Record
 

src/runtime/moon.pkg

@@ -4,5 +4,5 @@ import {
   "Nanaloveyuki/BitLogger/src/file_model",
   "Nanaloveyuki/BitLogger/src/formatting",
   "Nanaloveyuki/BitLogger/src/sink_graph",
-  "maria/json_parser",
+  "moonbitlang/core/json",
 }

src/runtime/pkg.generated.mbti

@@ -7,7 +7,6 @@ import {
   "Nanaloveyuki/BitLogger/src/file_model",
   "Nanaloveyuki/BitLogger/src/file_runtime",
   "Nanaloveyuki/BitLogger/src/sink_graph",
-  "maria/json_parser",
 }
 
 // Values
@@ -15,7 +14,7 @@ pub fn apply_queue_config(RuntimeSink, @config_model.QueueConfig) -> RuntimeSink
 
 pub fn build_runtime_sink(@config_model.SinkConfig) -> RuntimeSink
 
-pub fn runtime_file_state_to_json(@file_model.RuntimeFileState) -> @json_parser.JsonValue
+pub fn runtime_file_state_to_json(@file_model.RuntimeFileState) -> Json
 
 pub fn stringify_runtime_file_state(@file_model.RuntimeFileState, pretty? : Bool) -> String
 

src/runtime/runtime_logger.mbt

@@ -55,9 +55,7 @@ pub struct RuntimeSinkProgress {
 }
 
 ///|
-pub fn runtime_file_state_to_json(
-  state : RuntimeFileState,
-) -> @json_parser.JsonValue {
+pub fn runtime_file_state_to_json(state : RuntimeFileState) -> Json {
   @file_model.runtime_file_state_to_json(state)
 }
 

src/runtime_file_json_test.mbt

@@ -3,17 +3,17 @@ test "file state json helpers stringify stable snapshots" {
   let rotation_json = file_rotation_config_to_json(
     file_rotation(64, max_backups=2),
   )
-  let rotation_obj = rotation_json.as_object().unwrap()
+  let rotation_obj = rotation_json.expect_json_object()
   inspect(
-    @json_parser.stringify(rotation_json),
+    rotation_json.stringify(),
     content="{\"max_bytes\":64,\"max_backups\":2}",
   )
   inspect(
-    rotation_obj.get("max_bytes").unwrap().as_number().unwrap().to_int(),
+    rotation_obj.get("max_bytes").unwrap().expect_json_number().to_int(),
     content="64",
   )
   inspect(
-    rotation_obj.get("max_backups").unwrap().as_number().unwrap().to_int(),
+    rotation_obj.get("max_backups").unwrap().expect_json_number().to_int(),
     content="2",
   )
   inspect(rotation_obj.get("max_bytes_i64") is None, content="true")
@@ -21,9 +21,9 @@ test "file state json helpers stringify stable snapshots" {
   let wide_rotation_json = file_rotation_config_to_json(
     file_rotation_i64(4294967296L, max_backups=2),
   )
-  let wide_rotation_obj = wide_rotation_json.as_object().unwrap()
+  let wide_rotation_obj = wide_rotation_json.expect_json_object()
   inspect(
-    wide_rotation_obj.get("max_bytes_i64").unwrap().as_string().unwrap(),
+    wide_rotation_obj.get("max_bytes_i64").unwrap().expect_json_string(),
     content="4294967296",
   )
 
@@ -40,51 +40,50 @@ test "file state json helpers stringify stable snapshots" {
       rotation_failures=4,
     ),
   )
-  let plain_obj = plain.as_object().unwrap()
+  let plain_obj = plain.expect_json_object()
   let plain_rotation_obj = plain_obj
     .get("rotation")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
   inspect(
-    @json_parser.stringify(plain),
+    plain.stringify(),
     content="{\"path\":\"logs/demo.log\",\"available\":true,\"append\":false,\"auto_flush\":true,\"open_failures\":1,\"write_failures\":2,\"flush_failures\":3,\"rotation_failures\":4,\"rotation\":{\"max_bytes\":64,\"max_backups\":2}}",
   )
   inspect(
-    plain_obj.get("path").unwrap().as_string().unwrap(),
+    plain_obj.get("path").unwrap().expect_json_string(),
     content="logs/demo.log",
   )
   inspect(
-    plain_obj.get("available").unwrap().as_bool().unwrap(),
+    plain_obj.get("available").unwrap().expect_json_bool(),
     content="true",
   )
-  inspect(plain_obj.get("append").unwrap().as_bool().unwrap(), content="false")
+  inspect(plain_obj.get("append").unwrap().expect_json_bool(), content="false")
   inspect(
-    plain_obj.get("auto_flush").unwrap().as_bool().unwrap(),
+    plain_obj.get("auto_flush").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    plain_obj.get("open_failures").unwrap().as_number().unwrap().to_int(),
+    plain_obj.get("open_failures").unwrap().expect_json_number().to_int(),
     content="1",
   )
   inspect(
-    plain_obj.get("write_failures").unwrap().as_number().unwrap().to_int(),
+    plain_obj.get("write_failures").unwrap().expect_json_number().to_int(),
     content="2",
   )
   inspect(
-    plain_obj.get("flush_failures").unwrap().as_number().unwrap().to_int(),
+    plain_obj.get("flush_failures").unwrap().expect_json_number().to_int(),
     content="3",
   )
   inspect(
-    plain_obj.get("rotation_failures").unwrap().as_number().unwrap().to_int(),
+    plain_obj.get("rotation_failures").unwrap().expect_json_number().to_int(),
     content="4",
   )
   inspect(
-    plain_rotation_obj.get("max_bytes").unwrap().as_number().unwrap().to_int(),
+    plain_rotation_obj.get("max_bytes").unwrap().expect_json_number().to_int(),
     content="64",
   )
   inspect(
-    plain_rotation_obj.get("max_backups").unwrap().as_number().unwrap().to_int(),
+    plain_rotation_obj.get("max_backups").unwrap().expect_json_number().to_int(),
     content="2",
   )
 
@@ -101,18 +100,16 @@ test "file state json helpers stringify stable snapshots" {
       rotation_failures=0,
     ),
   )
-  let wide_obj = wide.as_object().unwrap()
+  let wide_obj = wide.expect_json_object()
   let wide_state_rotation_obj = wide_obj
     .get("rotation")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
   inspect(
     wide_state_rotation_obj
     .get("max_bytes")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="2147483647",
   )
@@ -120,13 +117,12 @@ test "file state json helpers stringify stable snapshots" {
     wide_state_rotation_obj
     .get("max_backups")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="3",
   )
   inspect(
-    wide_state_rotation_obj.get("max_bytes_i64").unwrap().as_string().unwrap(),
+    wide_state_rotation_obj.get("max_bytes_i64").unwrap().expect_json_string(),
     content="4294967296",
   )
   inspect(
@@ -167,27 +163,27 @@ test "runtime file state json helpers stringify queue snapshots" {
       dropped_count=5,
     ),
   )
-  let runtime_obj = runtime_json.as_object().unwrap()
-  let runtime_file_obj = runtime_obj.get("file").unwrap().as_object().unwrap()
-  inspect(runtime_obj.get("queued").unwrap().as_bool().unwrap(), content="true")
+  let runtime_obj = runtime_json.expect_json_object()
+  let runtime_file_obj = runtime_obj.get("file").unwrap().expect_json_object()
+  inspect(runtime_obj.get("queued").unwrap().expect_json_bool(), content="true")
   inspect(
-    runtime_obj.get("pending_count").unwrap().as_number().unwrap().to_int(),
+    runtime_obj.get("pending_count").unwrap().expect_json_number().to_int(),
     content="7",
   )
   inspect(
-    runtime_obj.get("dropped_count").unwrap().as_number().unwrap().to_int(),
+    runtime_obj.get("dropped_count").unwrap().expect_json_number().to_int(),
     content="5",
   )
   inspect(
-    runtime_file_obj.get("path").unwrap().as_string().unwrap(),
+    runtime_file_obj.get("path").unwrap().expect_json_string(),
     content="logs/queue.log",
   )
   inspect(
-    runtime_file_obj.get("available").unwrap().as_bool().unwrap(),
+    runtime_file_obj.get("available").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    runtime_file_obj.get("rotation").unwrap() is @json_parser.JsonValue::Null,
+    runtime_file_obj.get("rotation").unwrap() is Json::Null,
     content="true",
   )
 
@@ -232,23 +228,20 @@ test "runtime file state json helpers stringify queue snapshots" {
       dropped_count=0,
     ),
   )
-  let wide_runtime_obj = wide_runtime_json.as_object().unwrap()
+  let wide_runtime_obj = wide_runtime_json.expect_json_object()
   let wide_runtime_file_obj = wide_runtime_obj
     .get("file")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
   let wide_runtime_rotation_obj = wide_runtime_file_obj
     .get("rotation")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
   inspect(
     wide_runtime_rotation_obj
     .get("max_bytes")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="2147483647",
   )
@@ -256,13 +249,12 @@ test "runtime file state json helpers stringify queue snapshots" {
     wide_runtime_rotation_obj
     .get("max_backups")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="2",
   )
   inspect(
-    wide_runtime_rotation_obj.get("max_bytes_i64").unwrap().as_string().unwrap(),
+    wide_runtime_rotation_obj.get("max_bytes_i64").unwrap().expect_json_string(),
     content="4294967296",
   )
 }
@@ -276,31 +268,29 @@ test "file sink policy json helpers stringify stable policies" {
       rotation=Some(file_rotation(96, max_backups=3)),
     ),
   )
-  let policy_obj = policy_json.as_object().unwrap()
+  let policy_obj = policy_json.expect_json_object()
   let policy_rotation_obj = policy_obj
     .get("rotation")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
   inspect(
-    @json_parser.stringify(policy_json),
+    policy_json.stringify(),
     content="{\"append\":false,\"auto_flush\":true,\"rotation\":{\"max_bytes\":96,\"max_backups\":3}}",
   )
-  inspect(policy_obj.get("append").unwrap().as_bool().unwrap(), content="false")
+  inspect(policy_obj.get("append").unwrap().expect_json_bool(), content="false")
   inspect(
-    policy_obj.get("auto_flush").unwrap().as_bool().unwrap(),
+    policy_obj.get("auto_flush").unwrap().expect_json_bool(),
     content="true",
   )
   inspect(
-    policy_rotation_obj.get("max_bytes").unwrap().as_number().unwrap().to_int(),
+    policy_rotation_obj.get("max_bytes").unwrap().expect_json_number().to_int(),
     content="96",
   )
   inspect(
     policy_rotation_obj
     .get("max_backups")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="3",
   )
@@ -312,18 +302,16 @@ test "file sink policy json helpers stringify stable policies" {
       rotation=Some(file_rotation_i64(4294967296L, max_backups=4)),
     ),
   )
-  let wide_policy_obj = wide_policy_json.as_object().unwrap()
+  let wide_policy_obj = wide_policy_json.expect_json_object()
   let wide_policy_rotation_obj = wide_policy_obj
     .get("rotation")
     .unwrap()
-    .as_object()
-    .unwrap()
+    .expect_json_object()
   inspect(
     wide_policy_rotation_obj
     .get("max_bytes")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="2147483647",
   )
@@ -331,13 +319,12 @@ test "file sink policy json helpers stringify stable policies" {
     wide_policy_rotation_obj
     .get("max_backups")
     .unwrap()
-    .as_number()
-    .unwrap()
+    .expect_json_number()
     .to_int(),
     content="4",
   )
   inspect(
-    wide_policy_rotation_obj.get("max_bytes_i64").unwrap().as_string().unwrap(),
+    wide_policy_rotation_obj.get("max_bytes_i64").unwrap().expect_json_string(),
     content="4294967296",
   )
   inspect(

src/runtime_logger.mbt

@@ -8,9 +8,7 @@ pub type RuntimeFileState = @file_model.RuntimeFileState
 pub type RuntimeSinkProgress = @runtime.RuntimeSinkProgress
 
 ///|
-pub fn runtime_file_state_to_json(
-  state : RuntimeFileState,
-) -> @json_parser.JsonValue {
+pub fn runtime_file_state_to_json(state : RuntimeFileState) -> Json {
   @file_model.runtime_file_state_to_json(state)
 }
 

src/sinks_file.mbt

@@ -29,9 +29,7 @@ pub fn native_files_supported() -> Bool {
 }
 
 ///|
-pub fn file_sink_policy_to_json(
-  policy : FileSinkPolicy,
-) -> @json_parser.JsonValue {
+pub fn file_sink_policy_to_json(policy : FileSinkPolicy) -> Json {
   @file_model.file_sink_policy_to_json(policy)
 }
 
@@ -44,7 +42,7 @@ pub fn stringify_file_sink_policy(
 }
 
 ///|
-pub fn file_sink_state_to_json(state : FileSinkState) -> @json_parser.JsonValue {
+pub fn file_sink_state_to_json(state : FileSinkState) -> Json {
   @file_model.file_sink_state_to_json(state)
 }
 

src/trace_context_test.mbt

@@ -0,0 +1,40 @@
+///|
+test "trace context maps W3C fields in a stable order" {
+  let context = trace_context(
+    "4bf92f3577b34da6a3ce929d0e0e4736",
+    "00f067aa0ba902b7",
+    trace_state="vendor=value",
+  )
+  let fields = context.as_fields()
+  inspect(fields.length(), content="4")
+  inspect(fields[0].key, content="trace_id")
+  inspect(fields[0].value, content="4bf92f3577b34da6a3ce929d0e0e4736")
+  inspect(fields[1].key, content="span_id")
+  inspect(fields[1].value, content="00f067aa0ba902b7")
+  inspect(fields[2].key, content="trace_flags")
+  inspect(fields[2].value, content="01")
+  inspect(fields[3].key, content="trace_state")
+  inspect(fields[3].value, content="vendor=value")
+}
+
+///|
+test "sync facades bind trace context without mutating their base logger" {
+  let captured : Ref[Array[Field]] = Ref([])
+  let base = Logger::new(callback_sink(fn(rec) { captured.val = rec.fields }))
+  let context = trace_context("trace-1", "span-1", trace_flags="00")
+  let derived = base.with_trace_context(context)
+  base.info("base")
+  inspect(captured.val.length(), content="0")
+  derived.info("derived", fields=[field("event", "request")])
+  inspect(captured.val.length(), content="4")
+  inspect(captured.val[0].key, content="trace_id")
+  inspect(captured.val[2].value, content="00")
+  inspect(captured.val[3].key, content="event")
+
+  let library = LibraryLogger::new(
+    callback_sink(fn(rec) { captured.val = rec.fields }),
+  ).with_trace_context(context)
+  library.info("library")
+  inspect(captured.val.length(), content="3")
+  inspect(captured.val[1].value, content="span-1")
+}