MCP Server Couchbase vs Legion MCP

get_scopes_in_bucket

Get the names of all scopes in the given bucket.

get_cluster_health_and_services

Get cluster health status and list of all running services. This tool provides health monitoring by: - Getting health status of all running services with latency information (via ping) - Listing all services running on the cluster with their endpoints - Showing connection status and node information for each service If bucket_name is provided, it actively pings services from the perspective of the bucket. Otherwise, it uses cluster-level ping to get the health status of the cluster. Returns: - Cluster health status with service-level connection details and latency measurements

get_document_by_id

Get a document by its ID from the specified scope and collection. If the document is not found, it will raise an exception.

lookup_subdocument

Look up parts of a document without fetching the whole thing, using Couchbase sub-document operations. Use this instead of get_document_by_id when you only need a few fields, a presence check, or the size of an array/object inside a document — AND you already know the exact field path(s) to look up (e.g. from a prior get_document_by_id call on this same document, from the user explicitly naming the field, or from a known/confirmed schema for this collection). IMPORTANT: Do NOT guess field paths. If you don't already know the document's exact field names/structure, call get_document_by_id first (or instead) — a guessed path that doesn't exist returns a per-path error here rather than the real data, and reporting "not found" for a wrong guess is worse than just fetching the whole document and reading the right field. Provide one or more of the following. Each is a list of sub-document paths using Couchbase's dot/bracket path syntax (e.g. "address.city", "tags[0]", "tags[-1]" for the last array element): - get_paths: fetch the VALUE at each path. - exists_paths: check whether each path exists, without fetching its value (cheaper than get_paths — no payload transfer — when you only need a yes/no answer). - count_paths: get the number of elements in the array or object at each path (fails per-path if the path isn't an array/object). At least one of get_paths, exists_paths, or count_paths must be provided. As a rule of thumb, keep the combined number of paths across all three to 16 or fewer — Couchbase limits subdocument operations per call, though the exact limit is server-side and may change. If the server rejects the call (too many paths, or another constraint like path length or nesting depth), the whole call fails with {"error": "..."}. A path that doesn't exist (or otherwise fails, e.g. count on a non-array/object) does NOT fail the whole call — it is reported individually as {"error": ...} in the returned dict so the other requested paths can still be resolved. Returns a dict with a key for each category that was requested (only requested categories are included): { "get": {"<path>": {"value": <value>} | {"error": "..."}}, "exists": {"<path>": {"value": true | false} | {"error": "..."}}, "count": {"<path>": {"value": <count>} | {"error": "..."}}, } On a connection/lookup failure, or an invalid request (no paths / too many paths), returns {"error": "<message>"} instead.

get_schema_for_collection

Get the schema for a collection in the specified scope. Returns a dictionary with the collection name and the schema returned by running INFER query on the Couchbase collection.

run_sql_plus_plus_query

Run a SQL++ query on a scope and return the results as a list of JSON objects. The query will be run on the specified scope in the specified bucket. The query should use collection names directly without bucket/scope prefixes, as the scope context is automatically set. Use ``named_parameters`` to bind values to ``$name`` placeholders in the query instead of concatenating user input into the statement. This prevents SQL++ injection Example: query = "SELECT * FROM users WHERE age > 18" # Incorrect: "SELECT * FROM bucket.scope.users WHERE age > 18" For creating a new index, prefer the create_index tool over a raw CREATE INDEX statement here — it defers the build by default and tells you the recommended next step. Use list_indexes to check whether an index is online before relying on it in a query plan.

explain_sql_plus_plus_query

Generate and evaluate an EXPLAIN plan for a SQL++ query. It provides information about the execution plan for the query. The EXPLAIN statement is run in the specified scope in the specified bucket. It returns query metadata along with an extracted plan and plan evaluation.