Self-Hosted Supabase MCP Server

Overview

This project provides a Model Context Protocol (MCP) server designed specifically for interacting with self-hosted Supabase instances. It bridges the gap between MCP clients (like IDE extensions) and your local or privately hosted Supabase projects, enabling database introspection, management, and interaction directly from your development environment.

This server was built from scratch, drawing lessons from adapting the official Supabase cloud MCP server, to provide a minimal, focused implementation tailored for the self-hosted use case.

Purpose

The primary goal of this server is to enable developers using self-hosted Supabase installations to leverage MCP-based tools for tasks such as:

• Querying database schemas and data.
• Managing database migrations.
• Inspecting database statistics and connections.
• Managing authentication users.
• Interacting with Supabase Storage.
• Generating type definitions.

It avoids the complexities of the official cloud server related to multi-project management and cloud-specific APIs, offering a streamlined experience for single-project, self-hosted environments.

Features (Implemented Tools)

Tools are categorized by privilege level: - Regular tools are accessible by any authenticated Supabase JWT (authenticated or service_role role). - Privileged tools require a service_role JWT (HTTP mode) or direct database/service-key access (stdio mode).

Schema & Migrations

Tool	Description	Privilege
list_tables	Lists tables in the database schemas	Regular
list_extensions	Lists installed PostgreSQL extensions	Regular
list_available_extensions	Lists all available (installable) extensions	Regular
list_migrations	Lists applied migrations from supabase_migrations.schema_migrations	Regular
apply_migration	Applies a SQL migration and records it in supabase_migrations.schema_migrations	Privileged
list_table_columns	Lists columns for a specific table	Regular
list_indexes	Lists indexes for a specific table	Regular
list_constraints	Lists constraints for a specific table	Regular
list_foreign_keys	Lists foreign keys for a specific table	Regular
list_triggers	Lists triggers for a specific table	Regular
list_database_functions	Lists user-defined database functions	Regular
get_function_definition	Gets the source definition of a function	Regular
get_trigger_definition	Gets the source definition of a trigger	Regular

Database Operations & Stats

Tool	Description	Privilege
execute_sql	Executes an arbitrary SQL query	Privileged
explain_query	Runs EXPLAIN ANALYZE on a query	Privileged
get_database_connections	Shows active connections (pg_stat_activity)	Regular
get_database_stats	Retrieves database statistics (pg_stat_*)	Regular
get_index_stats	Shows index usage statistics	Regular
get_vector_index_stats	Shows pgvector index statistics	Regular

Security & RLS

Tool	Description	Privilege
list_rls_policies	Lists Row-Level Security policies for a table	Regular
get_rls_status	Shows RLS enabled/disabled status for tables	Regular
get_advisors	Retrieves security and performance advisory notices	Regular

Project Configuration

Tool	Description	Privilege
get_project_url	Returns the configured Supabase URL	Regular
verify_jwt_secret	Checks if the JWT secret is configured	Regular

Development & Extension Tools

Tool	Description	Privilege
generate_typescript_types	Generates TypeScript types from the database schema	Regular
rebuild_hooks	Restarts the pg_net worker (if used)	Privileged
get_logs	Retrieves recent log entries (analytics stack or CSV fallback)	Regular

Auth User Management

Tool	Description	Privilege
list_auth_users	Lists users from auth.users	Regular
get_auth_user	Retrieves details for a specific user	Regular
create_auth_user	Creates a new user in auth.users (password bcrypt-hashed via pgcrypto)	Privileged
update_auth_user	Updates user details (password bcrypt-hashed if changed)	Privileged
delete_auth_user	Deletes a user from auth.users	Privileged

Storage

Tool	Description	Privilege
list_storage_buckets	Lists all storage buckets	Regular
list_storage_objects	Lists objects within a specific bucket	Regular
get_storage_config	Retrieves storage bucket configuration	Regular
update_storage_config	Updates storage bucket settings	Privileged

Realtime Inspection

Tool	Description	Privilege
list_realtime_publications	Lists PostgreSQL publications (e.g. supabase_realtime)	Regular

Extension-Specific Tools

Tool	Description	Privilege
list_cron_jobs	Lists scheduled jobs (requires pg_cron extension)	Regular
get_cron_job_history	Shows recent execution history for a cron job	Regular
list_vector_indexes	Lists pgvector indexes (requires pgvector extension)	Regular

Edge Functions

Tool	Description	Privilege
list_edge_functions	Lists deployed Edge Functions	Regular
get_edge_function_details	Gets details and metadata for an Edge Function	Regular
list_edge_function_logs	Retrieves recent logs for an Edge Function	Regular

---

About supabase_migrations.schema_migrations

The list_migrations and apply_migration tools rely on the supabase_migrations.schema_migrations table. This table is created and managed by the Supabase CLI — it is not part of the MCP server itself.

How the table is created:

The table is automatically created when you initialise or run migrations using the Supabase CLI:

supabase db push        # pushes local migrations to a remote database
supabase migration up   # applies pending local migration files

If you have never run the Supabase CLI against your database, the table will not exist and list_migrations will return an error. You can create it manually with:

CREATE SCHEMA IF NOT EXISTS supabase_migrations;
CREATE TABLE IF NOT EXISTS supabase_migrations.schema_migrations (
    version text NOT NULL PRIMARY KEY,
    name    text NOT NULL DEFAULT '',
    inserted_at timestamptz NOT NULL DEFAULT now()
);

Schema difference vs. official Supabase:

The Supabase cloud platform tracks additional columns (e.g. statements, dirty). This MCP server uses the minimal schema (version + name + inserted_at) that is compatible with the Supabase CLI's local-development workflow. If your existing table has extra columns they are simply ignored.

Setup and Installation

Installing via Smithery

To install Self-Hosted Supabase MCP Server for Claude Desktop automatically via Smithery:

npx -y @smithery/cli install @HenkDz/selfhosted-supabase-mcp --client claude

Prerequisites

• Bun v1.1 or later (replaces Node.js/npm — used for runtime and builds)
• Access to your self-hosted Supabase instance (URL, keys, and optionally a direct PostgreSQL connection string).

Steps

1. Clone the repository: bash git clone <repository-url> cd selfhosted-supabase-mcp
2. Install dependencies: bash bun install
3. Build the project: bash bun run build This compiles the TypeScript source to JavaScript in the dist directory.

Configuration

The server requires configuration details for your Supabase instance. These can be provided via command-line arguments or environment variables. CLI arguments take precedence.

Required:

• --url <url> or SUPABASE_URL=<url>: The main HTTP URL of your Supabase project (e.g., http://localhost:8000).
• --anon-key <key> or SUPABASE_ANON_KEY=<key>: Your Supabase project's anonymous key.

Optional (but Recommended/Required for certain tools):

• --service-key <key> or SUPABASE_SERVICE_ROLE_KEY=<key>: Your Supabase project's service role key. Required for privileged tools and for auto-creating the execute_sql helper function on startup.
• --db-url <url> or DATABASE_URL=<url>: The direct PostgreSQL connection string for your Supabase database (e.g., postgresql://postgres:password@localhost:5432/postgres). Required for tools needing direct database access (apply_migration, Auth tools, Storage tools, pg_catalog queries).
• --jwt-secret <secret> or SUPABASE_AUTH_JWT_SECRET=<secret>: Your Supabase project's JWT secret. Required when using --transport http and needed by the verify_jwt_secret tool.
• --tools-config <path>: Path to a JSON file specifying which tools to enable (whitelist). If omitted, all tools are enabled. Format: {"enabledTools": ["tool_name_1", "tool_name_2"]}.

HTTP transport options (when using --transport http):

• --port <number>: HTTP server port (default: 3000).
• --host <string>: HTTP server host (default: 127.0.0.1).
• --cors-origins <origins>: Comma-separated list of allowed CORS origins. Defaults to localhost only.
• --rate-limit-window <ms>: Rate limit window in milliseconds (default: 60000).
• --rate-limit-max <count>: Max requests per rate limit window (default: 100).
• --request-timeout <ms>: Request timeout in milliseconds (default: 30000).

Important Notes:

• execute_sql Helper Function: Many tools rely on a public.execute_sql function within your Supabase database for SQL execution via RPC. The server attempts to check for this function on startup. If it's missing and a service-key and db-url are provided, it will attempt to create the function automatically. If creation fails or keys aren't provided, tools relying solely on RPC may fail.
• Direct Database Access: Tools interacting directly with privileged schemas (auth, storage) or system catalogs (pg_catalog) generally require DATABASE_URL to be configured.
• Coolify / reverse-proxy deployments:
  • The DATABASE_URL must use the internal hostname reachable from wherever the MCP server process runs, not the public-facing domain.
  • An ECONNRESET error during startup means the DATABASE_URL cannot be reached from the server's network context.
  • The server will still start successfully and all tools that don't require a direct DB connection will continue to work normally.

Security

HTTP transport (recommended for remote access)

When running with --transport http, the server enforces: - JWT authentication on all /mcp endpoints using your SUPABASE_AUTH_JWT_SECRET. - Privilege-based access control (RBAC) — the role claim in the JWT determines which tools are accessible: - service_role: Full access (all tools including privileged ones). - authenticated: Regular tools only. - anon: No tool access. - Rate limiting — configurable request rate limit per IP address. - CORS — configurable allow-list of origins (defaults to localhost only). - Security headers — X-Content-Type-Options, X-Frame-Options, Strict-Transport-Security, etc. - Request timeouts — configurable timeout to prevent resource exhaustion.

Stdio transport (local development)

Stdio mode has no authentication — all tools (including privileged ones) are accessible. It is intended for trusted local clients only (e.g., an IDE extension running on your local machine). A warning is printed on startup when this mode is used.

Password handling for auth user tools

create_auth_user and update_auth_user accept a plain-text password from the MCP client, then immediately hash it with bcrypt (via PostgreSQL's pgcrypto extension: crypt($password, gen_salt('bf'))) before storing it in auth.users. The plain-text password is never stored. Passwords are passed as query parameters (not string-interpolated into SQL), preventing SQL injection.

Note: The password travels over the MCP transport in plain text between the MCP client and server. This is inherent to the MCP protocol interface and unavoidable at this layer. Use the HTTP transport with TLS termination (e.g., behind Kong/nginx) for network protection.

SQL execution security

All database operations in the MCP server use parameterized queries ($1, $2, ...) to prevent SQL injection. The execute_sql tool is an intentional exception — it executes arbitrary SQL by design (it is the tool's purpose). This tool is restricted to service_role privilege level to limit exposure.

Usage

Stdio mode (local MCP clients)

Run the server using Bun, providing the necessary configuration:

```bash

Using CLI arguments (stdio mode — default)

bun run dist/index.js --url http://localhost:8000 --anon-key \