Add typed table extensions (MCP + presets) for downstream consumers

beacon-api/src/axum/admin/extensions.rs

@@ -0,0 +1,63 @@
+//! Admin endpoints for managing a table's downstream extensions.
+
+use std::sync::Arc;
+
+use ::axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    Json,
+};
+use beacon_core::api::TableExtensions;
+use beacon_core::runtime::Runtime;
+
+use super::bad_request;
+
+/// Replaces the named table's extensions document (MCP descriptor, query
+/// presets). The document is validated against the table schema; an empty body
+/// (`{}`) clears all extensions.
+#[tracing::instrument(level = "info", skip(state, extensions))]
+#[utoipa::path(
+    tag = "admin",
+    put,
+    path = "/api/admin/table-extensions/{table_name}",
+    params(("table_name" = String, Path, description = "Registered table name")),
+    request_body = TableExtensions,
+    responses(
+        (status = 200, description = "Extensions updated"),
+        (status = 400, description = "Invalid request, validation failed, or table not found")
+    ),
+    security(("basic-auth" = []))
+)]
+pub(crate) async fn set_table_extensions(
+    State(state): State<Arc<Runtime>>,
+    Path(table_name): Path<String>,
+    Json(extensions): Json<TableExtensions>,
+) -> Result<(), (StatusCode, String)> {
+    state
+        .set_table_extensions(table_name, extensions)
+        .await
+        .map_err(bad_request)
+}
+
+/// Removes all extensions from the named table.
+#[tracing::instrument(level = "info", skip(state))]
+#[utoipa::path(
+    tag = "admin",
+    delete,
+    path = "/api/admin/table-extensions/{table_name}",
+    params(("table_name" = String, Path, description = "Registered table name")),
+    responses(
+        (status = 200, description = "Extensions removed"),
+        (status = 400, description = "Table not found or removal failed")
+    ),
+    security(("basic-auth" = []))
+)]
+pub(crate) async fn delete_table_extensions(
+    State(state): State<Arc<Runtime>>,
+    Path(table_name): Path<String>,
+) -> Result<(), (StatusCode, String)> {
+    state
+        .delete_table_extensions(table_name)
+        .await
+        .map_err(bad_request)
+}

beacon-api/src/axum/admin/mod.rs

@@ -14,6 +14,7 @@ use crate::axum::auth::basic_auth;
 
 mod check;
 mod crawlers;
+mod extensions;
 mod external_tables;
 
 /// OpenAPI document marker for the admin surface.
@@ -37,6 +38,10 @@ pub(crate) fn setup_admin_router() -> (Router<Arc<Runtime>>, utoipa::openapi::Op
         ))
         .routes(routes!(crawlers::run_crawler))
         .routes(routes!(external_tables::create_external_table))
+        .routes(routes!(
+            extensions::set_table_extensions,
+            extensions::delete_table_extensions
+        ))
         .layer(::axum::middleware::from_fn(basic_auth))
         .split_for_parts();
 

beacon-api/src/axum/client/mod.rs

@@ -41,6 +41,7 @@ pub(crate) fn setup_client_router() -> (Router<Arc<Runtime>>, utoipa::openapi::O
         .routes(routes!(tables::list_tables_with_schema))
         .routes(routes!(tables::default_table))
         .routes(routes!(tables::list_table_schema))
+        .routes(routes!(tables::list_table_extensions))
         .routes(routes!(tables::list_table_config))
         .routes(routes!(tables::default_table_schema))
         .routes(routes!(functions::list_functions))

beacon-api/src/axum/client/tables.rs

@@ -7,7 +7,7 @@ use ::axum::{
     http::StatusCode,
     Json,
 };
-use beacon_core::api::{SchemaFieldView, SchemaView, TableConfigView};
+use beacon_core::api::{SchemaFieldView, SchemaView, TableConfigView, TableExtensions};
 use beacon_core::runtime::Runtime;
 use utoipa::{IntoParams, ToSchema};
 
@@ -152,6 +152,48 @@ pub(crate) async fn list_table_config(
     }
 }
 
+/// Query parameters for [`list_table_extensions`].
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize, ToSchema, IntoParams)]
+pub struct ListTableExtensionsQuery {
+    /// Name of the registered table whose extensions to return.
+    pub table_name: String,
+}
+
+/// Returns the downstream extensions (MCP descriptor, query presets) attached to
+/// the named table, or 404 if the table is not registered. A table with no
+/// extensions returns an empty object.
+#[tracing::instrument(level = "info", skip(state))]
+#[utoipa::path(
+    tag = "tables",
+    get,
+    path = "/api/table-extensions",
+    params(ListTableExtensionsQuery),
+    responses(
+        (status = 200, description = "The table's extensions", body = TableExtensions),
+        (status = 404, description = "Table not found"),
+    ),
+    security(
+        (),
+        ("basic-auth" = []),
+        ("bearer" = [])
+    )
+)]
+pub(crate) async fn list_table_extensions(
+    State(state): State<Arc<Runtime>>,
+    Query(query): Query<ListTableExtensionsQuery>,
+) -> Result<Json<TableExtensions>, (StatusCode, String)> {
+    match state.get_table_extensions(query.table_name.clone()).await {
+        Ok(extensions) => Ok(Json(extensions)),
+        Err(error) => {
+            tracing::error!(?error, "error listing table extensions");
+            Err((
+                StatusCode::NOT_FOUND,
+                format!("Table {} not found", query.table_name),
+            ))
+        }
+    }
+}
+
 /// Returns the Arrow schema of the runtime's default table.
 #[tracing::instrument(level = "info", skip(state))]
 #[utoipa::path(

beacon-core/src/api.rs

@@ -12,6 +12,11 @@ use crate::metrics::ConsolidatedMetrics;
 use serde_json::{Map, Value};
 use utoipa::ToSchema;
 
+/// Re-exported typed table-extension contracts (see [`crate::extensions`]).
+pub use crate::extensions::{
+    McpExtension, Preset, PresetExtension, PresetFilter, TableExtensions,
+};
+
 /// A single parameter of a registered function.
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize, ToSchema)]
 pub struct FunctionParameterInfo {