Clean up the code a bit

Cargo.lock

@@ -470,8 +470,7 @@ dependencies = [
 [[package]]
 name = "async-openai"
 version = "0.28.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14d76e2f5af19477d6254415acc95ba97c6cc6f3b1e3cb4676b7f0fab8194298"
+source = "git+https://github.com/meilisearch/async-openai?branch=optional-type-function#603f1d17bb4530c45fb9a6e93294ab715a7af869"
 dependencies = [
  "async-openai-macros",
  "backoff",
@@ -496,8 +495,7 @@ dependencies = [
 [[package]]
 name = "async-openai-macros"
 version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0289cba6d5143bfe8251d57b4a8cac036adf158525a76533a7082ba65ec76398"
+source = "git+https://github.com/meilisearch/async-openai?branch=optional-type-function#603f1d17bb4530c45fb9a6e93294ab715a7af869"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3784,6 +3782,7 @@ dependencies = [
  "brotli 6.0.0",
  "bstr",
  "build-info",
+ "bumpalo",
  "byte-unit",
  "bytes",
  "cargo_toml",

crates/dump/src/lib.rs

@@ -305,6 +305,7 @@ pub(crate) mod test {
             localized_attributes: Setting::NotSet,
             facet_search: Setting::NotSet,
             prefix_search: Setting::NotSet,
+            chat: Setting::NotSet,
             _kind: std::marker::PhantomData,
         };
         settings.check()

crates/dump/src/reader/compat/v5_to_v6.rs

@@ -398,6 +398,7 @@ impl<T> From<v5::Settings<T>> for v6::Settings<v6::Unchecked> {
             search_cutoff_ms: v6::Setting::NotSet,
             facet_search: v6::Setting::NotSet,
             prefix_search: v6::Setting::NotSet,
+            chat: v6::Setting::NotSet,
             _kind: std::marker::PhantomData,
         }
     }

crates/index-scheduler/src/insta_snapshot.rs

@@ -34,6 +34,7 @@ pub fn snapshot_index_scheduler(scheduler: &IndexScheduler) -> String {
         planned_failures: _,
         run_loop_iteration: _,
         embedders: _,
+        chat_settings: _,
     } = scheduler;
 
     let rtxn = env.read_txn().unwrap();

crates/index-scheduler/src/lib.rs

@@ -212,7 +212,7 @@ impl IndexScheduler {
             #[cfg(test)]
             run_loop_iteration: self.run_loop_iteration.clone(),
             features: self.features.clone(),
-            chat_settings: self.chat_settings.clone(),
+            chat_settings: self.chat_settings,
         }
     }
 
@@ -870,12 +870,12 @@ impl IndexScheduler {
 
     pub fn chat_settings(&self) -> Result<Option<serde_json::Value>> {
         let rtxn = self.env.read_txn().map_err(Error::HeedTransaction)?;
-        self.chat_settings.get(&rtxn, &"main").map_err(Into::into)
+        self.chat_settings.get(&rtxn, "main").map_err(Into::into)
     }
 
     pub fn put_chat_settings(&self, settings: &serde_json::Value) -> Result<()> {
         let mut wtxn = self.env.write_txn().map_err(Error::HeedTransaction)?;
-        self.chat_settings.put(&mut wtxn, &"main", &settings)?;
+        self.chat_settings.put(&mut wtxn, "main", settings)?;
         wtxn.commit().map_err(Error::HeedTransaction)?;
         Ok(())
     }

crates/meilisearch-auth/src/lib.rs

@@ -165,6 +165,7 @@ impl AuthController {
     }
 }
 
+#[derive(Debug)]
 pub struct AuthFilter {
     search_rules: Option<SearchRules>,
     key_authorized_indexes: SearchRules,
@@ -351,6 +352,7 @@ pub struct IndexSearchRules {
 fn generate_default_keys(store: &HeedAuthStore) -> Result<()> {
     store.put_api_key(Key::default_admin())?;
     store.put_api_key(Key::default_search())?;
+    store.put_api_key(Key::default_chat())?;
 
     Ok(())
 }

crates/meilisearch-types/src/deserr/mod.rs

@@ -4,9 +4,12 @@ use std::marker::PhantomData;
 use std::ops::ControlFlow;
 
 use deserr::errors::{JsonError, QueryParamError};
-use deserr::{take_cf_content, DeserializeError, IntoValue, MergeWithError, ValuePointerRef};
+use deserr::{
+    take_cf_content, DeserializeError, Deserr, IntoValue, MergeWithError, ValuePointerRef,
+};
+use milli::update::ChatSettings;
 
-use crate::error::deserr_codes::*;
+use crate::error::deserr_codes::{self, *};
 use crate::error::{
     Code, DeserrParseBoolError, DeserrParseIntError, ErrorCode, InvalidTaskDateError,
     ParseOffsetDateTimeError,
@@ -33,6 +36,7 @@ pub struct DeserrError<Format, C: Default + ErrorCode> {
     pub code: Code,
     _phantom: PhantomData<(Format, C)>,
 }
+
 impl<Format, C: Default + ErrorCode> DeserrError<Format, C> {
     pub fn new(msg: String, code: Code) -> Self {
         Self { msg, code, _phantom: PhantomData }
@@ -117,6 +121,16 @@ impl<C: Default + ErrorCode> DeserializeError for DeserrQueryParamError<C> {
     }
 }
 
+impl Deserr<DeserrError<DeserrJson, deserr_codes::InvalidSettingsIndexChat>> for ChatSettings {
+    fn deserialize_from_value<V: IntoValue>(
+        value: deserr::Value<V>,
+        location: ValuePointerRef,
+    ) -> Result<Self, DeserrError<DeserrJson, deserr_codes::InvalidSettingsIndexChat>> {
+        Deserr::<JsonError>::deserialize_from_value(value, location)
+            .map_err(|e| DeserrError::new(e.to_string(), InvalidSettingsIndexChat.error_code()))
+    }
+}
+
 pub fn immutable_field_error(field: &str, accepted: &[&str], code: Code) -> DeserrJsonError {
     let msg = format!(
         "Immutable field `{field}`: expected one of {}",

crates/meilisearch-types/src/error.rs

@@ -387,7 +387,8 @@ VectorEmbeddingError                  , InvalidRequest       , BAD_REQUEST ;
 NotFoundSimilarId                     , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentEditionContext         , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentEditionFunctionFilter  , InvalidRequest       , BAD_REQUEST ;
-EditDocumentsByFunctionError          , InvalidRequest       , BAD_REQUEST
+EditDocumentsByFunctionError          , InvalidRequest       , BAD_REQUEST ;
+InvalidSettingsIndexChat              , InvalidRequest       , BAD_REQUEST
 }
 
 impl ErrorCode for JoinError {

crates/meilisearch-types/src/keys.rs

@@ -158,6 +158,21 @@ impl Key {
             updated_at: now,
         }
     }
+
+    pub fn default_chat() -> Self {
+        let now = OffsetDateTime::now_utc();
+        let uid = Uuid::new_v4();
+        Self {
+            name: Some("Default Chat API Key".to_string()),
+            description: Some("Use it to chat and search from the frontend".to_string()),
+            uid,
+            actions: vec![Action::Chat, Action::Search],
+            indexes: vec![IndexUidPattern::all()],
+            expires_at: None,
+            created_at: now,
+            updated_at: now,
+        }
+    }
 }
 
 fn parse_expiration_date(
@@ -310,7 +325,10 @@ pub enum Action {
     NetworkUpdate,
     #[serde(rename = "chat.get")]
     #[deserr(rename = "chat.get")]
-    ChatGet,
+    Chat,
+    #[serde(rename = "chatSettings.*")]
+    #[deserr(rename = "chatSettings.*")]
+    ChatSettingsAll,
     #[serde(rename = "chatSettings.get")]
     #[deserr(rename = "chatSettings.get")]
     ChatSettingsGet,
@@ -342,6 +360,9 @@ impl Action {
             SETTINGS_ALL => Some(Self::SettingsAll),
             SETTINGS_GET => Some(Self::SettingsGet),
             SETTINGS_UPDATE => Some(Self::SettingsUpdate),
+            CHAT_SETTINGS_ALL => Some(Self::ChatSettingsAll),
+            CHAT_SETTINGS_GET => Some(Self::ChatSettingsGet),
+            CHAT_SETTINGS_UPDATE => Some(Self::ChatSettingsUpdate),
             STATS_ALL => Some(Self::StatsAll),
             STATS_GET => Some(Self::StatsGet),
             METRICS_ALL => Some(Self::MetricsAll),
@@ -358,7 +379,7 @@ impl Action {
             EXPERIMENTAL_FEATURES_UPDATE => Some(Self::ExperimentalFeaturesUpdate),
             NETWORK_GET => Some(Self::NetworkGet),
             NETWORK_UPDATE => Some(Self::NetworkUpdate),
-            CHAT_GET => Some(Self::ChatGet),
+            CHAT => Some(Self::Chat),
             _otherwise => None,
         }
     }
@@ -408,7 +429,8 @@ pub mod actions {
     pub const NETWORK_GET: u8 = NetworkGet.repr();
     pub const NETWORK_UPDATE: u8 = NetworkUpdate.repr();
 
-    pub const CHAT_GET: u8 = ChatGet.repr();
+    pub const CHAT: u8 = Chat.repr();
+    pub const CHAT_SETTINGS_ALL: u8 = ChatSettingsAll.repr();
     pub const CHAT_SETTINGS_GET: u8 = ChatSettingsGet.repr();
     pub const CHAT_SETTINGS_UPDATE: u8 = ChatSettingsUpdate.repr();
 }

crates/meilisearch-types/src/settings.rs

@@ -11,6 +11,7 @@ use fst::IntoStreamer;
 use milli::disabled_typos_terms::DisabledTyposTerms;
 use milli::index::{IndexEmbeddingConfig, PrefixSearch};
 use milli::proximity::ProximityPrecision;
+pub use milli::update::ChatSettings;
 use milli::update::Setting;
 use milli::{Criterion, CriterionError, FilterableAttributesRule, Index, DEFAULT_VALUES_PER_FACET};
 use serde::{Deserialize, Serialize, Serializer};
@@ -185,7 +186,7 @@ impl<E: DeserializeError> Deserr<E> for SettingEmbeddingSettings {
 /// Holds all the settings for an index. `T` can either be `Checked` if they represents settings
 /// whose validity is guaranteed, or `Unchecked` if they need to be validated. In the later case, a
 /// call to `check` will return a `Settings<Checked>` from a `Settings<Unchecked>`.
-#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Eq, Deserr, ToSchema)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Deserr, ToSchema)]
 #[serde(
     deny_unknown_fields,
     rename_all = "camelCase",
@@ -199,72 +200,86 @@ pub struct Settings<T> {
     #[deserr(default, error = DeserrJsonError<InvalidSettingsDisplayedAttributes>)]
     #[schema(value_type = Option<Vec<String>>, example = json!(["id", "title", "description", "url"]))]
     pub displayed_attributes: WildcardSetting,
+
     /// Fields in which to search for matching query words sorted by order of importance.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsSearchableAttributes>)]
     #[schema(value_type = Option<Vec<String>>, example = json!(["title", "description"]))]
     pub searchable_attributes: WildcardSetting,
+
     /// Attributes to use for faceting and filtering. See [Filtering and Faceted Search](https://www.meilisearch.com/docs/learn/filtering_and_sorting/search_with_facet_filters).
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsFilterableAttributes>)]
     #[schema(value_type = Option<Vec<FilterableAttributesRule>>, example = json!(["release_date", "genre"]))]
     pub filterable_attributes: Setting<Vec<FilterableAttributesRule>>,
+
     /// Attributes to use when sorting search results.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsSortableAttributes>)]
     #[schema(value_type = Option<Vec<String>>, example = json!(["release_date"]))]
     pub sortable_attributes: Setting<BTreeSet<String>>,
+
     /// List of ranking rules sorted by order of importance. The order is customizable.
     /// [A list of ordered built-in ranking rules](https://www.meilisearch.com/docs/learn/relevancy/relevancy).
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsRankingRules>)]
     #[schema(value_type = Option<Vec<String>>, example = json!([RankingRuleView::Words, RankingRuleView::Typo, RankingRuleView::Proximity, RankingRuleView::Attribute, RankingRuleView::Exactness]))]
     pub ranking_rules: Setting<Vec<RankingRuleView>>,
+
     /// List of words ignored when present in search queries.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsStopWords>)]
     #[schema(value_type = Option<Vec<String>>, example = json!(["the", "a", "them", "their"]))]
     pub stop_words: Setting<BTreeSet<String>>,
+
     /// List of characters not delimiting where one term begins and ends.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsNonSeparatorTokens>)]
     #[schema(value_type = Option<Vec<String>>, example = json!([" ", "\n"]))]
     pub non_separator_tokens: Setting<BTreeSet<String>>,
+
     /// List of characters delimiting where one term begins and ends.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsSeparatorTokens>)]
     #[schema(value_type = Option<Vec<String>>, example = json!(["S"]))]
     pub separator_tokens: Setting<BTreeSet<String>>,
+
     /// List of strings Meilisearch should parse as a single term.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsDictionary>)]
     #[schema(value_type = Option<Vec<String>>, example = json!(["iPhone pro"]))]
     pub dictionary: Setting<BTreeSet<String>>,
+
     /// List of associated words treated similarly. A word associated to an array of word as synonyms.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsSynonyms>)]
     #[schema(value_type = Option<BTreeMap<String, Vec<String>>>, example = json!({ "he": ["she", "they", "them"], "phone": ["iPhone", "android"]}))]
     pub synonyms: Setting<BTreeMap<String, Vec<String>>>,
+
     /// Search returns documents with distinct (different) values of the given field.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsDistinctAttribute>)]
     #[schema(value_type = Option<String>, example = json!("sku"))]
     pub distinct_attribute: Setting<String>,
+
     /// Precision level when calculating the proximity ranking rule.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsProximityPrecision>)]
     #[schema(value_type = Option<String>, example = json!(ProximityPrecisionView::ByAttribute))]
     pub proximity_precision: Setting<ProximityPrecisionView>,
+
     /// Customize typo tolerance feature.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsTypoTolerance>)]
     #[schema(value_type = Option<TypoSettings>, example = json!({ "enabled": true, "disableOnAttributes": ["title"]}))]
     pub typo_tolerance: Setting<TypoSettings>,
+
     /// Faceting settings.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsFaceting>)]
     #[schema(value_type = Option<FacetingSettings>, example = json!({ "maxValuesPerFacet": 10, "sortFacetValuesBy": { "genre": FacetValuesSort::Count }}))]
     pub faceting: Setting<FacetingSettings>,
+
     /// Pagination settings.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsPagination>)]
@@ -276,24 +291,34 @@ pub struct Settings<T> {
     #[deserr(default, error = DeserrJsonError<InvalidSettingsEmbedders>)]
     #[schema(value_type = Option<BTreeMap<String, SettingEmbeddingSettings>>)]
     pub embedders: Setting<BTreeMap<String, SettingEmbeddingSettings>>,
+
     /// Maximum duration of a search query.
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsSearchCutoffMs>)]
     #[schema(value_type = Option<u64>, example = json!(50))]
     pub search_cutoff_ms: Setting<u64>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsLocalizedAttributes>)]
     #[schema(value_type = Option<Vec<LocalizedAttributesRuleView>>, example = json!(50))]
     pub localized_attributes: Setting<Vec<LocalizedAttributesRuleView>>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsFacetSearch>)]
     #[schema(value_type = Option<bool>, example = json!(true))]
     pub facet_search: Setting<bool>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default, error = DeserrJsonError<InvalidSettingsPrefixSearch>)]
     #[schema(value_type = Option<PrefixSearchSettings>, example = json!("Hemlo"))]
     pub prefix_search: Setting<PrefixSearchSettings>,
 
+    /// Customize the chat prompting.
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default, error = DeserrJsonError<InvalidSettingsIndexChat>)]
+    #[schema(value_type = Option<ChatSettings>)]
+    pub chat: Setting<ChatSettings>,
+
     #[serde(skip)]
     #[deserr(skip)]
     pub _kind: PhantomData<T>,
@@ -359,6 +384,7 @@ impl Settings<Checked> {
             localized_attributes: Setting::Reset,
             facet_search: Setting::Reset,
             prefix_search: Setting::Reset,
+            chat: Setting::Reset,
             _kind: PhantomData,
         }
     }
@@ -385,6 +411,7 @@ impl Settings<Checked> {
             localized_attributes: localized_attributes_rules,
             facet_search,
             prefix_search,
+            chat,
             _kind,
         } = self;
 
@@ -409,6 +436,7 @@ impl Settings<Checked> {
             localized_attributes: localized_attributes_rules,
             facet_search,
             prefix_search,
+            chat,
             _kind: PhantomData,
         }
     }
@@ -459,6 +487,7 @@ impl Settings<Unchecked> {
             localized_attributes: self.localized_attributes,
             facet_search: self.facet_search,
             prefix_search: self.prefix_search,
+            chat: self.chat,
             _kind: PhantomData,
         }
     }
@@ -533,8 +562,9 @@ impl Settings<Unchecked> {
                     Setting::Set(this)
                 }
             },
-            prefix_search: other.prefix_search.or(self.prefix_search),
             facet_search: other.facet_search.or(self.facet_search),
+            prefix_search: other.prefix_search.or(self.prefix_search),
+            chat: other.chat.clone().or(self.chat.clone()),
             _kind: PhantomData,
         }
     }
@@ -573,6 +603,7 @@ pub fn apply_settings_to_builder(
         localized_attributes: localized_attributes_rules,
         facet_search,
         prefix_search,
+        chat,
         _kind,
     } = settings;
 
@@ -783,6 +814,12 @@ pub fn apply_settings_to_builder(
         Setting::Reset => builder.reset_facet_search(),
         Setting::NotSet => (),
     }
+
+    match chat {
+        Setting::Set(chat) => builder.set_chat(chat.clone()),
+        Setting::Reset => builder.reset_chat(),
+        Setting::NotSet => (),
+    }
 }
 
 pub enum SecretPolicy {
@@ -880,14 +917,11 @@ pub fn settings(
         })
         .collect();
     let embedders = Setting::Set(embedders);
-
     let search_cutoff_ms = index.search_cutoff(rtxn)?;
-
     let localized_attributes_rules = index.localized_attributes_rules(rtxn)?;
-
     let prefix_search = index.prefix_search(rtxn)?.map(PrefixSearchSettings::from);
-
     let facet_search = index.facet_search(rtxn)?;
+    let chat = index.chat_config(rtxn).map(ChatSettings::from)?;
 
     let mut settings = Settings {
         displayed_attributes: match displayed_attributes {
@@ -925,8 +959,9 @@ pub fn settings(
             Some(rules) => Setting::Set(rules.into_iter().map(|r| r.into()).collect()),
             None => Setting::Reset,
         },
-        prefix_search: Setting::Set(prefix_search.unwrap_or_default()),
         facet_search: Setting::Set(facet_search),
+        prefix_search: Setting::Set(prefix_search.unwrap_or_default()),
+        chat: Setting::Set(chat),
         _kind: PhantomData,
     };
 
@@ -1154,6 +1189,7 @@ pub(crate) mod test {
             search_cutoff_ms: Setting::NotSet,
             facet_search: Setting::NotSet,
             prefix_search: Setting::NotSet,
+            chat: Setting::NotSet,
             _kind: PhantomData::<Unchecked>,
         };
 
@@ -1185,6 +1221,8 @@ pub(crate) mod test {
             search_cutoff_ms: Setting::NotSet,
             facet_search: Setting::NotSet,
             prefix_search: Setting::NotSet,
+            chat: Setting::NotSet,
+
             _kind: PhantomData::<Unchecked>,
         };
 

crates/meilisearch-types/src/task_view.rs

@@ -8,7 +8,7 @@ use crate::error::ResponseError;
 use crate::settings::{Settings, Unchecked};
 use crate::tasks::{serialize_duration, Details, IndexSwap, Kind, Status, Task, TaskId};
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, ToSchema)]
+#[derive(Debug, Clone, PartialEq, Serialize, ToSchema)]
 #[serde(rename_all = "camelCase")]
 #[schema(rename_all = "camelCase")]
 pub struct TaskView {
@@ -67,7 +67,7 @@ impl TaskView {
     }
 }
 
-#[derive(Default, Debug, PartialEq, Eq, Clone, Serialize, Deserialize, ToSchema)]
+#[derive(Default, Debug, PartialEq, Clone, Serialize, Deserialize, ToSchema)]
 #[serde(rename_all = "camelCase")]
 #[schema(rename_all = "camelCase")]
 pub struct DetailsView {

crates/meilisearch-types/src/tasks.rs

@@ -597,7 +597,7 @@ impl fmt::Display for ParseTaskKindError {
 }
 impl std::error::Error for ParseTaskKindError {}
 
-#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize)]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize)]
 pub enum Details {
     DocumentAdditionOrUpdate {
         received_documents: u64,

crates/meilisearch/Cargo.toml

@@ -32,6 +32,7 @@ async-trait = "0.1.85"
 bstr = "1.11.3"
 byte-unit = { version = "5.1.6", features = ["serde"] }
 bytes = "1.9.0"
+bumpalo = "3.16.0"
 clap = { version = "4.5.24", features = ["derive", "env"] }
 crossbeam-channel = "0.5.15"
 deserr = { version = "0.6.3", features = ["actix-web"] }
@@ -112,7 +113,7 @@ utoipa = { version = "5.3.1", features = [
     "openapi_extensions",
 ] }
 utoipa-scalar = { version = "0.3.0", optional = true, features = ["actix-web"] }
-async-openai = "0.28.1"
+async-openai = { git = "https://github.com/meilisearch/async-openai", branch = "optional-type-function" }
 actix-web-lab = { version = "0.24.1", default-features = false }
 
 [dev-dependencies]

crates/meilisearch/src/extractors/authentication/mod.rs

@@ -4,6 +4,7 @@ use std::marker::PhantomData;
 use std::ops::Deref;
 use std::pin::Pin;
 
+use actix_web::http::header::AUTHORIZATION;
 use actix_web::web::Data;
 use actix_web::FromRequest;
 pub use error::AuthenticationError;
@@ -94,36 +95,44 @@ impl<P: Policy + 'static, D: 'static + Clone> FromRequest for GuardedData<P, D>
         _payload: &mut actix_web::dev::Payload,
     ) -> Self::Future {
         match req.app_data::<Data<AuthController>>().cloned() {
-            Some(auth) => match req
-                .headers()
-                .get("Authorization")
-                .map(|type_token| type_token.to_str().unwrap_or_default().splitn(2, ' '))
-            {
-                Some(mut type_token) => match type_token.next() {
-                    Some("Bearer") => {
-                        // TODO: find a less hardcoded way?
-                        let index = req.match_info().get("index_uid");
-                        match type_token.next() {
-                            Some(token) => Box::pin(Self::auth_bearer(
-                                auth,
-                                token.to_string(),
-                                index.map(String::from),
-                                req.app_data::<D>().cloned(),
-                            )),
-                            None => Box::pin(err(AuthenticationError::InvalidToken.into())),
-                        }
-                    }
-                    _otherwise => {
-                        Box::pin(err(AuthenticationError::MissingAuthorizationHeader.into()))
-                    }
-                },
-                None => Box::pin(Self::auth_token(auth, req.app_data::<D>().cloned())),
+            Some(auth) => match extract_token_from_request(req) {
+                Ok(Some(token)) => {
+                    // TODO: find a less hardcoded way?
+                    let index = req.match_info().get("index_uid");
+                    Box::pin(Self::auth_bearer(
+                        auth,
+                        token.to_string(),
+                        index.map(String::from),
+                        req.app_data::<D>().cloned(),
+                    ))
+                }
+                Ok(None) => Box::pin(Self::auth_token(auth, req.app_data::<D>().cloned())),
+                Err(e) => Box::pin(err(e.into())),
             },
             None => Box::pin(err(AuthenticationError::IrretrievableState.into())),
         }
     }
 }
 
+pub fn extract_token_from_request(
+    req: &actix_web::HttpRequest,
+) -> Result<Option<&str>, AuthenticationError> {
+    match req
+        .headers()
+        .get(AUTHORIZATION)
+        .map(|type_token| type_token.to_str().unwrap_or_default().splitn(2, ' '))
+    {
+        Some(mut type_token) => match type_token.next() {
+            Some("Bearer") => match type_token.next() {
+                Some(token) => Ok(Some(token)),
+                None => Err(AuthenticationError::InvalidToken),
+            },
+            _otherwise => Err(AuthenticationError::MissingAuthorizationHeader),
+        },
+        None => Ok(None),
+    }
+}
+
 pub trait Policy {
     fn authenticate(
         auth: Data<AuthController>,
@@ -299,8 +308,8 @@ pub mod policies {
             auth: &AuthController,
             token: &str,
         ) -> Result<TenantTokenOutcome, AuthError> {
-            // Only search action can be accessed by a tenant token.
-            if A != actions::SEARCH {
+            // Only search and chat actions can be accessed by a tenant token.
+            if A != actions::SEARCH && A != actions::CHAT {
                 return Ok(TenantTokenOutcome::NotATenantToken);
             }
 

crates/meilisearch/src/routes/indexes/settings.rs

@@ -6,7 +6,7 @@ use meilisearch_types::deserr::DeserrJsonError;
 use meilisearch_types::error::ResponseError;
 use meilisearch_types::index_uid::IndexUid;
 use meilisearch_types::settings::{
-    settings, SecretPolicy, SettingEmbeddingSettings, Settings, Unchecked,
+    settings, ChatSettings, SecretPolicy, SettingEmbeddingSettings, Settings, Unchecked,
 };
 use meilisearch_types::tasks::KindWithContent;
 use tracing::debug;
@@ -508,6 +508,17 @@ make_setting_routes!(
         camelcase_attr: "prefixSearch",
         analytics: PrefixSearchAnalytics
     },
+    {
+        route: "/chat",
+        update_verb: put,
+        value_type: ChatSettings,
+        err_type: meilisearch_types::deserr::DeserrJsonError<
+            meilisearch_types::error::deserr_codes::InvalidSettingsIndexChat,
+        >,
+        attr: chat,
+        camelcase_attr: "chat",
+        analytics: ChatAnalytics
+    },
 );
 
 #[utoipa::path(
@@ -597,6 +608,7 @@ pub async fn update_all(
             ),
             facet_search: FacetSearchAnalytics::new(new_settings.facet_search.as_ref().set()),
             prefix_search: PrefixSearchAnalytics::new(new_settings.prefix_search.as_ref().set()),
+            chat: ChatAnalytics::new(new_settings.chat.as_ref().set()),
         },
         &req,
     );

crates/meilisearch/src/routes/indexes/settings_analytics.rs

@@ -10,8 +10,8 @@ use meilisearch_types::locales::{Locale, LocalizedAttributesRuleView};
 use meilisearch_types::milli::update::Setting;
 use meilisearch_types::milli::FilterableAttributesRule;
 use meilisearch_types::settings::{
-    FacetingSettings, PaginationSettings, PrefixSearchSettings, ProximityPrecisionView,
-    RankingRuleView, SettingEmbeddingSettings, TypoSettings,
+    ChatSettings, FacetingSettings, PaginationSettings, PrefixSearchSettings,
+    ProximityPrecisionView, RankingRuleView, SettingEmbeddingSettings, TypoSettings,
 };
 use serde::Serialize;
 
@@ -39,6 +39,7 @@ pub struct SettingsAnalytics {
     pub non_separator_tokens: NonSeparatorTokensAnalytics,
     pub facet_search: FacetSearchAnalytics,
     pub prefix_search: PrefixSearchAnalytics,
+    pub chat: ChatAnalytics,
 }
 
 impl Aggregate for SettingsAnalytics {
@@ -198,6 +199,7 @@ impl Aggregate for SettingsAnalytics {
                 set: new.prefix_search.set | self.prefix_search.set,
                 value: new.prefix_search.value.or(self.prefix_search.value),
             },
+            chat: ChatAnalytics { set: new.chat.set | self.chat.set },
         })
     }
 
@@ -674,3 +676,18 @@ impl PrefixSearchAnalytics {
         SettingsAnalytics { prefix_search: self, ..Default::default() }
     }
 }
+
+#[derive(Serialize, Default)]
+pub struct ChatAnalytics {
+    pub set: bool,
+}
+
+impl ChatAnalytics {
+    pub fn new(settings: Option<&ChatSettings>) -> Self {
+        Self { set: settings.is_some() }
+    }
+
+    pub fn into_settings(self) -> SettingsAnalytics {
+        SettingsAnalytics { chat: self, ..Default::default() }
+    }
+}

crates/meilisearch/src/routes/settings/chat.rs

@@ -1,10 +1,9 @@
-use std::collections::BTreeMap;
-
 use actix_web::web::{self, Data};
 use actix_web::HttpResponse;
 use index_scheduler::IndexScheduler;
 use meilisearch_types::error::ResponseError;
 use meilisearch_types::keys::actions;
+use meilisearch_types::milli::update::Setting;
 use serde::{Deserialize, Serialize};
 
 use crate::extractors::authentication::policies::ActionPolicy;
@@ -25,10 +24,11 @@ async fn get_settings(
         Data<IndexScheduler>,
     >,
 ) -> Result<HttpResponse, ResponseError> {
-    let settings = match index_scheduler.chat_settings()? {
+    let mut settings = match index_scheduler.chat_settings()? {
         Some(value) => serde_json::from_value(value).unwrap(),
-        None => ChatSettings::default(),
+        None => GlobalChatSettings::default(),
     };
+    settings.hide_secrets();
     Ok(HttpResponse::Ok().json(settings))
 }
 
@@ -37,38 +37,96 @@ async fn patch_settings(
         ActionPolicy<{ actions::CHAT_SETTINGS_UPDATE }>,
         Data<IndexScheduler>,
     >,
-    web::Json(chat_settings): web::Json<ChatSettings>,
+    web::Json(new): web::Json<GlobalChatSettings>,
 ) -> Result<HttpResponse, ResponseError> {
-    let chat_settings = serde_json::to_value(chat_settings).unwrap();
-    index_scheduler.put_chat_settings(&chat_settings)?;
+    let old = match index_scheduler.chat_settings()? {
+        Some(value) => serde_json::from_value(value).unwrap(),
+        None => GlobalChatSettings::default(),
+    };
+
+    let settings = GlobalChatSettings {
+        source: new.source.or(old.source),
+        base_api: new.base_api.clone().or(old.base_api),
+        api_key: new.api_key.clone().or(old.api_key),
+        prompts: match (new.prompts, old.prompts) {
+            (Setting::NotSet, set) | (set, Setting::NotSet) => set,
+            (Setting::Set(_) | Setting::Reset, Setting::Reset) => Setting::Reset,
+            (Setting::Reset, Setting::Set(set)) => Setting::Set(set),
+            // If both are set we must merge the prompts settings
+            (Setting::Set(new), Setting::Set(old)) => Setting::Set(ChatPrompts {
+                system: new.system.or(old.system),
+                search_description: new.search_description.or(old.search_description),
+                search_q_param: new.search_q_param.or(old.search_q_param),
+                search_index_uid_param: new.search_index_uid_param.or(old.search_index_uid_param),
+                pre_query: new.pre_query.or(old.pre_query),
+            }),
+        },
+    };
+
+    let value = serde_json::to_value(settings).unwrap();
+    index_scheduler.put_chat_settings(&value)?;
     Ok(HttpResponse::Ok().finish())
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields, rename_all = "camelCase")]
-pub struct ChatSettings {
-    pub source: String,
-    pub endpoint: Option<String>,
-    pub api_key: Option<String>,
-    pub prompts: ChatPrompts,
-    pub indexes: BTreeMap<String, ChatIndexSettings>,
+pub enum ChatSource {
+    OpenAi,
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(deny_unknown_fields, rename_all = "camelCase")]
+pub struct GlobalChatSettings {
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub source: Setting<ChatSource>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub base_api: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub api_key: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub prompts: Setting<ChatPrompts>,
+}
+
+impl GlobalChatSettings {
+    pub fn hide_secrets(&mut self) {
+        match &mut self.api_key {
+            Setting::Set(key) => Self::hide_secret(key),
+            Setting::Reset => (),
+            Setting::NotSet => (),
+        }
+    }
+
+    fn hide_secret(secret: &mut String) {
+        match secret.len() {
+            x if x < 10 => {
+                secret.replace_range(.., "XXX...");
+            }
+            x if x < 20 => {
+                secret.replace_range(2.., "XXXX...");
+            }
+            x if x < 30 => {
+                secret.replace_range(3.., "XXXXX...");
+            }
+            _x => {
+                secret.replace_range(5.., "XXXXXX...");
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(deny_unknown_fields, rename_all = "camelCase")]
 pub struct ChatPrompts {
-    pub system: String,
-    pub search_description: String,
-    pub search_q_param: String,
-    pub search_index_uid_param: String,
-    pub pre_query: String,
-}
-
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(deny_unknown_fields, rename_all = "camelCase")]
-pub struct ChatIndexSettings {
-    pub description: String,
-    pub document_template: String,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub system: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub search_description: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub search_q_param: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub search_index_uid_param: Setting<String>,
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    pub pre_query: Setting<String>,
 }
 
 const DEFAULT_SYSTEM_MESSAGE: &str = "You are a highly capable research assistant with access to powerful search tools. IMPORTANT INSTRUCTIONS:\
@@ -91,21 +149,29 @@ const DEFAULT_SEARCH_IN_INDEX_INDEX_PARAMETER_TOOL_DESCRIPTION: &str =
 "The name of the index to search within. An index is a collection of documents organized for search. \
 Selecting the right index ensures the most relevant results for the user query";
 
-impl Default for ChatSettings {
+impl Default for GlobalChatSettings {
     fn default() -> Self {
-        ChatSettings {
-            source: "openai".to_string(),
-            endpoint: None,
-            api_key: None,
-            prompts: ChatPrompts {
-                system: DEFAULT_SYSTEM_MESSAGE.to_string(),
-                search_description: DEFAULT_SEARCH_IN_INDEX_TOOL_DESCRIPTION.to_string(),
-                search_q_param: DEFAULT_SEARCH_IN_INDEX_Q_PARAMETER_TOOL_DESCRIPTION.to_string(),
-                search_index_uid_param: DEFAULT_SEARCH_IN_INDEX_INDEX_PARAMETER_TOOL_DESCRIPTION
-                    .to_string(),
-                pre_query: "".to_string(),
-            },
-            indexes: BTreeMap::new(),
+        GlobalChatSettings {
+            source: Setting::NotSet,
+            base_api: Setting::NotSet,
+            api_key: Setting::NotSet,
+            prompts: Setting::Set(ChatPrompts::default()),
+        }
+    }
+}
+
+impl Default for ChatPrompts {
+    fn default() -> Self {
+        ChatPrompts {
+            system: Setting::Set(DEFAULT_SYSTEM_MESSAGE.to_string()),
+            search_description: Setting::Set(DEFAULT_SEARCH_IN_INDEX_TOOL_DESCRIPTION.to_string()),
+            search_q_param: Setting::Set(
+                DEFAULT_SEARCH_IN_INDEX_Q_PARAMETER_TOOL_DESCRIPTION.to_string(),
+            ),
+            search_index_uid_param: Setting::Set(
+                DEFAULT_SEARCH_IN_INDEX_INDEX_PARAMETER_TOOL_DESCRIPTION.to_string(),
+            ),
+            pre_query: Setting::Set(Default::default()),
         }
     }
 }

crates/meilisearch/src/search/mod.rs

@@ -122,6 +122,7 @@ pub struct SearchQuery {
 #[derive(Debug, Clone, Copy, PartialEq, Deserr, ToSchema, Serialize)]
 #[deserr(try_from(f64) = TryFrom::try_from -> InvalidSearchRankingScoreThreshold)]
 pub struct RankingScoreThreshold(f64);
+
 impl std::convert::TryFrom<f64> for RankingScoreThreshold {
     type Error = InvalidSearchRankingScoreThreshold;
 
@@ -279,8 +280,8 @@ impl fmt::Debug for SearchQuery {
 #[deserr(error = DeserrJsonError<InvalidSearchHybridQuery>, rename_all = camelCase, deny_unknown_fields)]
 #[serde(rename_all = "camelCase")]
 pub struct HybridQuery {
-    #[deserr(default, error = DeserrJsonError<InvalidSearchSemanticRatio>, default)]
-    #[schema(value_type = f32, default)]
+    #[deserr(default, error = DeserrJsonError<InvalidSearchSemanticRatio>)]
+    #[schema(default, value_type = f32)]
     #[serde(default)]
     pub semantic_ratio: SemanticRatio,
     #[deserr(error = DeserrJsonError<InvalidSearchEmbedder>)]
@@ -882,7 +883,7 @@ pub fn add_search_rules(filter: &mut Option<Value>, rules: IndexSearchRules) {
     }
 }
 
-fn prepare_search<'t>(
+pub fn prepare_search<'t>(
     index: &'t Index,
     rtxn: &'t RoTxn,
     query: &'t SearchQuery,

crates/meilisearch/tests/auth/api_keys.rs

@@ -820,6 +820,22 @@ async fn list_api_keys() {
           "createdAt": "[ignored]",
           "updatedAt": "[ignored]"
         },
+        {
+          "name": "Default Chat API Key",
+          "description": "Use it to chat and search from the frontend",
+          "key": "[ignored]",
+          "uid": "[ignored]",
+          "actions": [
+            "search",
+            "chat.get"
+          ],
+          "indexes": [
+            "*"
+          ],
+          "expiresAt": null,
+          "createdAt": "[ignored]",
+          "updatedAt": "[ignored]"
+        },
         {
           "name": "Default Search API Key",
           "description": "Use it to search from the frontend",

crates/milli/src/external_documents_ids.rs

@@ -32,13 +32,13 @@ impl ExternalDocumentsIds {
         &self,
         rtxn: &RoTxn<'_>,
         external_id: A,
-    ) -> heed::Result<Option<u32>> {
+    ) -> heed::Result<Option<DocumentId>> {
         self.0.get(rtxn, external_id.as_ref())
     }
 
     /// An helper function to debug this type, returns an `HashMap` of both,
     /// soft and hard fst maps, combined.
-    pub fn to_hash_map(&self, rtxn: &RoTxn<'_>) -> heed::Result<HashMap<String, u32>> {
+    pub fn to_hash_map(&self, rtxn: &RoTxn<'_>) -> heed::Result<HashMap<String, DocumentId>> {
         let mut map = HashMap::default();
         for result in self.0.iter(rtxn)? {
             let (external, internal) = result?;

crates/milli/src/fields_ids_map.rs

@@ -7,6 +7,7 @@ use crate::FieldId;
 mod global;
 pub mod metadata;
 pub use global::GlobalFieldsIdsMap;
+pub use metadata::{FieldIdMapWithMetadata, MetadataBuilder};
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct FieldsIdsMap {

crates/milli/src/index.rs

@@ -23,6 +23,7 @@ use crate::heed_codec::facet::{
 use crate::heed_codec::version::VersionCodec;
 use crate::heed_codec::{BEU16StrCodec, FstSetCodec, StrBEU16Codec, StrRefCodec};
 use crate::order_by_map::OrderByMap;
+use crate::prompt::PromptData;
 use crate::proximity::ProximityPrecision;
 use crate::vector::{ArroyStats, ArroyWrapper, Embedding, EmbeddingConfig};
 use crate::{
@@ -79,6 +80,7 @@ pub mod main_key {
     pub const PREFIX_SEARCH: &str = "prefix_search";
     pub const DOCUMENTS_STATS: &str = "documents_stats";
     pub const DISABLED_TYPOS_TERMS: &str = "disabled_typos_terms";
+    pub const CHAT: &str = "chat";
 }
 
 pub mod db_name {
@@ -1691,6 +1693,25 @@ impl Index {
         self.main.remap_key_type::<Str>().delete(txn, main_key::FACET_SEARCH)
     }
 
+    pub fn chat_config(&self, txn: &RoTxn<'_>) -> heed::Result<ChatConfig> {
+        self.main
+            .remap_types::<Str, SerdeJson<_>>()
+            .get(txn, main_key::CHAT)
+            .map(|o| o.unwrap_or_default())
+    }
+
+    pub(crate) fn put_chat_config(
+        &self,
+        txn: &mut RwTxn<'_>,
+        val: &ChatConfig,
+    ) -> heed::Result<()> {
+        self.main.remap_types::<Str, SerdeJson<_>>().put(txn, main_key::CHAT, &val)
+    }
+
+    pub(crate) fn delete_chat_config(&self, txn: &mut RwTxn<'_>) -> heed::Result<bool> {
+        self.main.remap_key_type::<Str>().delete(txn, main_key::CHAT)
+    }
+
     pub fn localized_attributes_rules(
         &self,
         rtxn: &RoTxn<'_>,
@@ -1917,13 +1938,59 @@ pub struct IndexEmbeddingConfig {
     pub user_provided: RoaringBitmap,
 }
 
+#[derive(Debug, Default, Deserialize, Serialize)]
+pub struct ChatConfig {
+    pub description: String,
+    /// Contains the document template and max template length.
+    pub prompt: PromptData,
+    pub search_parameters: SearchParameters,
+}
+
+#[derive(Debug, Default, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SearchParameters {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub hybrid: Option<HybridQuery>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub limit: Option<usize>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub sort: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub distinct: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub matching_strategy: Option<MatchingStrategy>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub attributes_to_search_on: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub ranking_score_threshold: Option<f64>,
+}
+
+#[derive(Debug, Default, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct HybridQuery {
+    pub semantic_ratio: f32,
+    pub embedder: String,
+}
+
 #[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
 pub struct PrefixSettings {
     pub prefix_count_threshold: usize,
     pub max_prefix_length: usize,
     pub compute_prefixes: PrefixSearch,
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum MatchingStrategy {
+    /// Remove query words from last to first
+    Last,
+    /// All query words are mandatory
+    All,
+    /// Remove query words from the most frequent to the least
+    Frequency,
+}
+
 #[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Default)]
 #[serde(rename_all = "camelCase")]
 pub enum PrefixSearch {

crates/milli/src/lib.rs

@@ -52,18 +52,19 @@ pub use search::new::{
 };
 use serde_json::Value;
 pub use thread_pool_no_abort::{PanicCatched, ThreadPoolNoAbort, ThreadPoolNoAbortBuilder};
-pub use {charabia as tokenizer, heed, rhai};
+pub use {arroy, charabia as tokenizer, heed, rhai};
 
 pub use self::asc_desc::{AscDesc, AscDescError, Member, SortError};
-pub use self::attribute_patterns::AttributePatterns;
-pub use self::attribute_patterns::PatternMatch;
+pub use self::attribute_patterns::{AttributePatterns, PatternMatch};
 pub use self::criterion::{default_criteria, Criterion, CriterionError};
 pub use self::error::{
     Error, FieldIdMapMissingEntry, InternalError, SerializationError, UserError,
 };
 pub use self::external_documents_ids::ExternalDocumentsIds;
 pub use self::fieldids_weights_map::FieldidsWeightsMap;
-pub use self::fields_ids_map::{FieldsIdsMap, GlobalFieldsIdsMap};
+pub use self::fields_ids_map::{
+    FieldIdMapWithMetadata, FieldsIdsMap, GlobalFieldsIdsMap, MetadataBuilder,
+};
 pub use self::filterable_attributes_rules::{
     FilterFeatures, FilterableAttributesFeatures, FilterableAttributesPatterns,
     FilterableAttributesRule,
@@ -84,8 +85,6 @@ pub use self::search::{
 };
 pub use self::update::ChannelCongestion;
 
-pub use arroy;
-
 pub type Result<T> = std::result::Result<T, error::Error>;
 
 pub type Attribute = u32;

crates/milli/src/prompt/mod.rs

@@ -105,10 +105,10 @@ impl Prompt {
             max_bytes,
         };
 
-        // render template with special object that's OK with `doc.*` and `fields.*`
-        this.template
-            .render(&template_checker::TemplateChecker)
-            .map_err(NewPromptError::invalid_fields_in_template)?;
+        // // render template with special object that's OK with `doc.*` and `fields.*`
+        // this.template
+        //     .render(&template_checker::TemplateChecker)
+        //     .map_err(NewPromptError::invalid_fields_in_template)?;
 
         Ok(this)
     }

crates/milli/src/update/chat.rs

@@ -0,0 +1,259 @@
+use std::error::Error;
+use std::fmt;
+
+use deserr::errors::JsonError;
+use deserr::Deserr;
+use serde::{Deserialize, Serialize};
+use utoipa::ToSchema;
+
+use crate::index::{self, ChatConfig, SearchParameters};
+use crate::prompt::{default_max_bytes, PromptData};
+use crate::update::Setting;
+use crate::TermsMatchingStrategy;
+
+#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Deserr, ToSchema)]
+#[serde(deny_unknown_fields, rename_all = "camelCase")]
+#[deserr(error = JsonError, deny_unknown_fields, rename_all = camelCase)]
+pub struct ChatSettings {
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<String>)]
+    pub description: Setting<String>,
+
+    /// A liquid template used to render documents to a text that can be embedded.
+    ///
+    /// Meillisearch interpolates the template for each document and sends the resulting text to the embedder.
+    /// The embedder then generates document vectors based on this text.
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<String>)]
+    pub document_template: Setting<String>,
+
+    /// Rendered texts are truncated to this size. Defaults to 400.
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<usize>)]
+    pub document_template_max_bytes: Setting<usize>,
+
+    /// The search parameters to use for the LLM.
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<ChatSearchParams>)]
+    pub search_parameters: Setting<ChatSearchParams>,
+}
+
+impl From<ChatConfig> for ChatSettings {
+    fn from(config: ChatConfig) -> Self {
+        let ChatConfig {
+            description,
+            prompt: PromptData { template, max_bytes },
+            search_parameters,
+        } = config;
+        ChatSettings {
+            description: Setting::Set(description),
+            document_template: Setting::Set(template),
+            document_template_max_bytes: Setting::Set(
+                max_bytes.unwrap_or(default_max_bytes()).get(),
+            ),
+            search_parameters: Setting::Set({
+                let SearchParameters {
+                    hybrid,
+                    limit,
+                    sort,
+                    distinct,
+                    matching_strategy,
+                    attributes_to_search_on,
+                    ranking_score_threshold,
+                } = search_parameters;
+
+                let hybrid = hybrid.map(|index::HybridQuery { semantic_ratio, embedder }| {
+                    HybridQuery { semantic_ratio: SemanticRatio(semantic_ratio), embedder }
+                });
+
+                let matching_strategy = matching_strategy.map(|ms| match ms {
+                    index::MatchingStrategy::Last => MatchingStrategy::Last,
+                    index::MatchingStrategy::All => MatchingStrategy::All,
+                    index::MatchingStrategy::Frequency => MatchingStrategy::Frequency,
+                });
+
+                let ranking_score_threshold = ranking_score_threshold.map(RankingScoreThreshold);
+
+                ChatSearchParams {
+                    hybrid: Setting::some_or_not_set(hybrid),
+                    limit: Setting::some_or_not_set(limit),
+                    sort: Setting::some_or_not_set(sort),
+                    distinct: Setting::some_or_not_set(distinct),
+                    matching_strategy: Setting::some_or_not_set(matching_strategy),
+                    attributes_to_search_on: Setting::some_or_not_set(attributes_to_search_on),
+                    ranking_score_threshold: Setting::some_or_not_set(ranking_score_threshold),
+                }
+            }),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Deserr, ToSchema)]
+#[serde(deny_unknown_fields, rename_all = "camelCase")]
+#[deserr(error = JsonError, deny_unknown_fields, rename_all = camelCase)]
+pub struct ChatSearchParams {
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<HybridQuery>)]
+    pub hybrid: Setting<HybridQuery>,
+
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default = Setting::Set(20))]
+    #[schema(value_type = Option<usize>)]
+    pub limit: Setting<usize>,
+
+    // #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    // #[deserr(default)]
+    // pub attributes_to_retrieve: Option<BTreeSet<String>>,
+
+    // #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    // #[deserr(default)]
+    // pub filter: Option<Value>,
+    //
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<Vec<String>>)]
+    pub sort: Setting<Vec<String>>,
+
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<String>)]
+    pub distinct: Setting<String>,
+
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<MatchingStrategy>)]
+    pub matching_strategy: Setting<MatchingStrategy>,
+
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<Vec<String>>)]
+    pub attributes_to_search_on: Setting<Vec<String>>,
+
+    #[serde(default, skip_serializing_if = "Setting::is_not_set")]
+    #[deserr(default)]
+    #[schema(value_type = Option<RankingScoreThreshold>)]
+    pub ranking_score_threshold: Setting<RankingScoreThreshold>,
+}
+
+#[derive(Debug, Clone, Default, Deserr, ToSchema, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+#[deserr(error = JsonError, rename_all = camelCase, deny_unknown_fields)]
+pub struct HybridQuery {
+    #[deserr(default)]
+    #[serde(default)]
+    #[schema(default, value_type = f32)]
+    pub semantic_ratio: SemanticRatio,
+    #[schema(value_type = String)]
+    pub embedder: String,
+}
+
+#[derive(Debug, Clone, Copy, Deserr, ToSchema, PartialEq, Serialize, Deserialize)]
+#[deserr(try_from(f32) = TryFrom::try_from -> InvalidSearchSemanticRatio)]
+pub struct SemanticRatio(f32);
+
+impl Default for SemanticRatio {
+    fn default() -> Self {
+        SemanticRatio(0.5)
+    }
+}
+
+impl std::convert::TryFrom<f32> for SemanticRatio {
+    type Error = InvalidSearchSemanticRatio;
+
+    fn try_from(f: f32) -> Result<Self, Self::Error> {
+        // the suggested "fix" is: `!(0.0..=1.0).contains(&f)`` which is allegedly less readable
+        #[allow(clippy::manual_range_contains)]
+        if f > 1.0 || f < 0.0 {
+            Err(InvalidSearchSemanticRatio)
+        } else {
+            Ok(SemanticRatio(f))
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct InvalidSearchSemanticRatio;
+
+impl Error for InvalidSearchSemanticRatio {}
+
+impl fmt::Display for InvalidSearchSemanticRatio {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "the value of `semanticRatio` is invalid, expected a float between `0.0` and `1.0`."
+        )
+    }
+}
+
+impl std::ops::Deref for SemanticRatio {
+    type Target = f32;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Deserr, ToSchema, Serialize, Deserialize)]
+#[deserr(rename_all = camelCase)]
+#[serde(rename_all = "camelCase")]
+pub enum MatchingStrategy {
+    /// Remove query words from last to first
+    Last,
+    /// All query words are mandatory
+    All,
+    /// Remove query words from the most frequent to the least
+    Frequency,
+}
+
+impl Default for MatchingStrategy {
+    fn default() -> Self {
+        Self::Last
+    }
+}
+
+impl From<MatchingStrategy> for TermsMatchingStrategy {
+    fn from(other: MatchingStrategy) -> Self {
+        match other {
+            MatchingStrategy::Last => Self::Last,
+            MatchingStrategy::All => Self::All,
+            MatchingStrategy::Frequency => Self::Frequency,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Deserr, ToSchema, Serialize, Deserialize)]
+#[deserr(try_from(f64) = TryFrom::try_from -> InvalidSearchRankingScoreThreshold)]
+pub struct RankingScoreThreshold(pub f64);
+
+impl std::convert::TryFrom<f64> for RankingScoreThreshold {
+    type Error = InvalidSearchRankingScoreThreshold;
+
+    fn try_from(f: f64) -> Result<Self, Self::Error> {
+        // the suggested "fix" is: `!(0.0..=1.0).contains(&f)`` which is allegedly less readable
+        #[allow(clippy::manual_range_contains)]
+        if f > 1.0 || f < 0.0 {
+            Err(InvalidSearchRankingScoreThreshold)
+        } else {
+            Ok(RankingScoreThreshold(f))
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct InvalidSearchRankingScoreThreshold;
+
+impl Error for InvalidSearchRankingScoreThreshold {}
+
+impl fmt::Display for InvalidSearchRankingScoreThreshold {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "the value of `rankingScoreThreshold` is invalid, expected a float between `0.0` and `1.0`."
+        )
+    }
+}

crates/milli/src/update/mod.rs

@@ -1,4 +1,5 @@
 pub use self::available_ids::AvailableIds;
+pub use self::chat::ChatSettings;
 pub use self::clear_documents::ClearDocuments;
 pub use self::concurrent_available_ids::ConcurrentAvailableIds;
 pub use self::facet::bulk::FacetsUpdateBulk;
@@ -13,6 +14,7 @@ pub use self::words_prefix_integer_docids::WordPrefixIntegerDocids;
 pub use self::words_prefixes_fst::WordsPrefixesFst;
 
 mod available_ids;
+mod chat;
 mod clear_documents;
 mod concurrent_available_ids;
 pub(crate) mod del_add;

crates/milli/src/update/settings.rs

@@ -11,9 +11,10 @@ use roaring::RoaringBitmap;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use time::OffsetDateTime;
 
+use super::chat::{ChatSearchParams, RankingScoreThreshold};
 use super::del_add::{DelAdd, DelAddOperation};
 use super::index_documents::{IndexDocumentsConfig, Transform};
-use super::IndexerConfig;
+use super::{ChatSettings, IndexerConfig};
 use crate::attribute_patterns::PatternMatch;
 use crate::constants::RESERVED_GEO_FIELD_NAME;
 use crate::criterion::Criterion;
@@ -22,11 +23,11 @@ use crate::error::UserError;
 use crate::fields_ids_map::metadata::{FieldIdMapWithMetadata, MetadataBuilder};
 use crate::filterable_attributes_rules::match_faceted_field;
 use crate::index::{
-    IndexEmbeddingConfig, PrefixSearch, DEFAULT_MIN_WORD_LEN_ONE_TYPO,
-    DEFAULT_MIN_WORD_LEN_TWO_TYPOS,
+    ChatConfig, IndexEmbeddingConfig, MatchingStrategy, PrefixSearch,
+    DEFAULT_MIN_WORD_LEN_ONE_TYPO, DEFAULT_MIN_WORD_LEN_TWO_TYPOS,
 };
 use crate::order_by_map::OrderByMap;
-use crate::prompt::default_max_bytes;
+use crate::prompt::{default_max_bytes, PromptData};
 use crate::proximity::ProximityPrecision;
 use crate::update::index_documents::IndexDocumentsMethod;
 use crate::update::{IndexDocuments, UpdateIndexingStep};
@@ -123,6 +124,15 @@ impl<T> Setting<T> {
         *self = new;
         true
     }
+
+    #[track_caller]
+    pub fn unwrap(self) -> T {
+        match self {
+            Setting::Set(value) => value,
+            Setting::Reset => panic!("Setting::Reset unwrapped"),
+            Setting::NotSet => panic!("Setting::NotSet unwrapped"),
+        }
+    }
 }
 
 impl<T: Serialize> Serialize for Setting<T> {
@@ -185,6 +195,7 @@ pub struct Settings<'a, 't, 'i> {
     localized_attributes_rules: Setting<Vec<LocalizedAttributesRule>>,
     prefix_search: Setting<PrefixSearch>,
     facet_search: Setting<bool>,
+    chat: Setting<ChatSettings>,
 }
 
 impl<'a, 't, 'i> Settings<'a, 't, 'i> {
@@ -223,6 +234,7 @@ impl<'a, 't, 'i> Settings<'a, 't, 'i> {
             localized_attributes_rules: Setting::NotSet,
             prefix_search: Setting::NotSet,
             facet_search: Setting::NotSet,
+            chat: Setting::NotSet,
             indexer_config,
         }
     }
@@ -453,6 +465,14 @@ impl<'a, 't, 'i> Settings<'a, 't, 'i> {
         self.facet_search = Setting::Reset;
     }
 
+    pub fn set_chat(&mut self, value: ChatSettings) {
+        self.chat = Setting::Set(value);
+    }
+
+    pub fn reset_chat(&mut self) {
+        self.chat = Setting::Reset;
+    }
+
     #[tracing::instrument(
         level = "trace"
         skip(self, progress_callback, should_abort, settings_diff),
@@ -1239,6 +1259,126 @@ impl<'a, 't, 'i> Settings<'a, 't, 'i> {
         Ok(())
     }
 
+    fn update_chat_config(&mut self) -> heed::Result<bool> {
+        match &mut self.chat {
+            Setting::Set(ChatSettings {
+                description: new_description,
+                document_template: new_document_template,
+                document_template_max_bytes: new_document_template_max_bytes,
+                search_parameters: new_search_parameters,
+            }) => {
+                let mut old = self.index.chat_config(self.wtxn)?;
+                let ChatConfig {
+                    ref mut description,
+                    prompt: PromptData { ref mut template, ref mut max_bytes },
+                    ref mut search_parameters,
+                } = old;
+
+                match new_description {
+                    Setting::Set(d) => *description = d.clone(),
+                    Setting::Reset => *description = Default::default(),
+                    Setting::NotSet => (),
+                }
+
+                match new_document_template {
+                    Setting::Set(dt) => *template = dt.clone(),
+                    Setting::Reset => *template = Default::default(),
+                    Setting::NotSet => (),
+                }
+
+                match new_document_template_max_bytes {
+                    Setting::Set(m) => *max_bytes = NonZeroUsize::new(*m),
+                    Setting::Reset => *max_bytes = Some(default_max_bytes()),
+                    Setting::NotSet => (),
+                }
+
+                match new_search_parameters {
+                    Setting::Set(sp) => {
+                        let ChatSearchParams {
+                            hybrid,
+                            limit,
+                            sort,
+                            distinct,
+                            matching_strategy,
+                            attributes_to_search_on,
+                            ranking_score_threshold,
+                        } = sp;
+
+                        match hybrid {
+                            Setting::Set(hybrid) => {
+                                search_parameters.hybrid = Some(crate::index::HybridQuery {
+                                    semantic_ratio: *hybrid.semantic_ratio,
+                                    embedder: hybrid.embedder.clone(),
+                                })
+                            }
+                            Setting::Reset => search_parameters.hybrid = None,
+                            Setting::NotSet => (),
+                        }
+
+                        match limit {
+                            Setting::Set(limit) => search_parameters.limit = Some(*limit),
+                            Setting::Reset => search_parameters.limit = None,
+                            Setting::NotSet => (),
+                        }
+
+                        match sort {
+                            Setting::Set(sort) => search_parameters.sort = Some(sort.clone()),
+                            Setting::Reset => search_parameters.sort = None,
+                            Setting::NotSet => (),
+                        }
+
+                        match distinct {
+                            Setting::Set(distinct) => {
+                                search_parameters.distinct = Some(distinct.clone())
+                            }
+                            Setting::Reset => search_parameters.distinct = None,
+                            Setting::NotSet => (),
+                        }
+
+                        match matching_strategy {
+                            Setting::Set(matching_strategy) => {
+                                let strategy = match matching_strategy {
+                                    super::chat::MatchingStrategy::Last => MatchingStrategy::Last,
+                                    super::chat::MatchingStrategy::All => MatchingStrategy::All,
+                                    super::chat::MatchingStrategy::Frequency => {
+                                        MatchingStrategy::Frequency
+                                    }
+                                };
+                                search_parameters.matching_strategy = Some(strategy)
+                            }
+                            Setting::Reset => search_parameters.matching_strategy = None,
+                            Setting::NotSet => (),
+                        }
+
+                        match attributes_to_search_on {
+                            Setting::Set(attributes_to_search_on) => {
+                                search_parameters.attributes_to_search_on =
+                                    Some(attributes_to_search_on.clone())
+                            }
+                            Setting::Reset => search_parameters.attributes_to_search_on = None,
+                            Setting::NotSet => (),
+                        }
+
+                        match ranking_score_threshold {
+                            Setting::Set(RankingScoreThreshold(score)) => {
+                                search_parameters.ranking_score_threshold = Some(*score)
+                            }
+                            Setting::Reset => search_parameters.ranking_score_threshold = None,
+                            Setting::NotSet => (),
+                        }
+                    }
+                    Setting::Reset => *search_parameters = Default::default(),
+                    Setting::NotSet => (),
+                }
+
+                self.index.put_chat_config(self.wtxn, &old)?;
+                Ok(true)
+            }
+            Setting::Reset => self.index.delete_chat_config(self.wtxn),
+            Setting::NotSet => Ok(false),
+        }
+    }
+
     pub fn execute<FP, FA>(mut self, progress_callback: FP, should_abort: FA) -> Result<()>
     where
         FP: Fn(UpdateIndexingStep) + Sync,
@@ -1276,6 +1416,7 @@ impl<'a, 't, 'i> Settings<'a, 't, 'i> {
         self.update_facet_search()?;
         self.update_localized_attributes_rules()?;
         self.update_disabled_typos_terms()?;
+        self.update_chat_config()?;
 
         let embedding_config_updates = self.update_embedding_configs()?;
 

crates/milli/src/update/test_settings.rs

@@ -897,6 +897,7 @@ fn test_correct_settings_init() {
                 prefix_search,
                 facet_search,
                 disable_on_numbers,
+                chat,
             } = settings;
             assert!(matches!(searchable_fields, Setting::NotSet));
             assert!(matches!(displayed_fields, Setting::NotSet));

crates/milli/src/vector/settings.rs

@@ -33,6 +33,7 @@ pub struct EmbeddingSettings {
     ///
     /// - Defaults to `openAi`
     pub source: Setting<EmbedderSource>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<String>)]
@@ -55,6 +56,7 @@ pub struct EmbeddingSettings {
     /// - For source `openAi`, defaults to `text-embedding-3-small`
     /// - For source `huggingFace`, defaults to `BAAI/bge-base-en-v1.5`
     pub model: Setting<String>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<String>)]
@@ -75,6 +77,7 @@ pub struct EmbeddingSettings {
     /// - When `model` is set to default, defaults to `617ca489d9e86b49b8167676d8220688b99db36e`
     /// - Otherwise, defaults to `null`
     pub revision: Setting<String>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<OverridePooling>)]
@@ -96,6 +99,7 @@ pub struct EmbeddingSettings {
     ///
     /// - Embedders created before this parameter was available default to `forceMean` to preserve the existing behavior.
     pub pooling: Setting<OverridePooling>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<String>)]
@@ -118,6 +122,7 @@ pub struct EmbeddingSettings {
     ///
     /// - This setting is partially hidden when returned by the settings
     pub api_key: Setting<String>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<String>)]
@@ -141,6 +146,7 @@ pub struct EmbeddingSettings {
     /// - For source `openAi`, the dimensions is the maximum allowed by the model.
     /// - For sources `ollama` and `rest`, the dimensions are inferred by embedding a sample text.
     pub dimensions: Setting<usize>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<bool>)]
@@ -167,6 +173,7 @@ pub struct EmbeddingSettings {
     /// first enabling it. If you are unsure of whether the performance-relevancy tradeoff is right for you,
     /// we recommend to use this parameter on a test index first.
     pub binary_quantized: Setting<bool>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<bool>)]
@@ -183,6 +190,7 @@ pub struct EmbeddingSettings {
     ///
     /// - 🏗️ When modified, embeddings are regenerated for documents whose rendering through the template produces a different text.
     pub document_template: Setting<String>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<usize>)]
@@ -201,6 +209,7 @@ pub struct EmbeddingSettings {
     ///
     /// - Defaults to 400
     pub document_template_max_bytes: Setting<usize>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<String>)]
@@ -219,6 +228,7 @@ pub struct EmbeddingSettings {
     /// - 🌱 When modified for source `openAi`, embeddings are never regenerated
     /// - 🏗️ When modified for sources `ollama` and `rest`, embeddings are always regenerated
     pub url: Setting<String>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<serde_json::Value>)]
@@ -236,6 +246,7 @@ pub struct EmbeddingSettings {
     ///
     /// - 🏗️ Changing the value of this parameter always regenerates embeddings
     pub request: Setting<serde_json::Value>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<serde_json::Value>)]
@@ -253,6 +264,7 @@ pub struct EmbeddingSettings {
     ///
     /// - 🏗️ Changing the value of this parameter always regenerates embeddings
     pub response: Setting<serde_json::Value>,
+
     #[serde(default, skip_serializing_if = "Setting::is_not_set")]
     #[deserr(default)]
     #[schema(value_type = Option<BTreeMap<String, String>>)]