@supabase/mcp-server-postgrest

Automatically discovers PostgREST-exposed database tables, views, and functions by querying the OpenAPI schema endpoint, then registers them as MCP tools with typed parameters derived from the schema. Uses the MCP tool registry pattern to expose database operations as callable functions with JSON Schema validation, enabling LLM agents to understand available database operations without manual configuration.

Translates MCP tool invocations into HTTP requests to PostgREST endpoints, handling parameter binding, query string construction, and response parsing. Supports filtering, sorting, pagination, and RPC function calls by mapping tool arguments to PostgREST query parameters and request bodies, with automatic JSON response deserialization and error handling.

Manages PostgREST authentication by injecting API keys or JWT tokens into HTTP request headers for each tool invocation. Supports both Supabase API key authentication and custom JWT tokens, with configurable header names and token refresh logic to maintain valid credentials across multiple database operations.

Implements the MCP server protocol by managing tool registration, request routing, and response serialization. Handles MCP message parsing, tool discovery requests, tool call invocations, and error responses according to the MCP specification, with proper async/await patterns for non-blocking database operations.

Catches PostgREST HTTP errors (4xx, 5xx responses) and normalizes them into MCP-compatible error responses with descriptive messages. Handles common database errors (constraint violations, authentication failures, not found) and translates them into human-readable error messages that LLM clients can understand and act upon.