Nominatim MCP Server

Geocoding, reverse geocoding, and spatial queries via OpenStreetMap Nominatim and Overpass. That is what the nominatim mcp server brings to an AI assistant: the same capability, reachable through the Model Context Protocol rather than a separate app or dashboard.

The short version

• Declarative tool definitions — single file per tool, framework handles registration and validation
• Unified error handling across all tools
• Pluggable auth (none, jwt, oauth)
• Swappable storage backends: in-memory, filesystem, Supabase, Cloudflare KV/R2/D1
• Structured logging with optional OpenTelemetry tracing
• Runs locally (stdio/HTTP) or on Cloudflare Workers from the same codebase

The tools it exposes

The server publishes 8 tools. What each one is for:

• openstreetmap_search_places — Convert a place name or address to geographic coordinates and structured place data
• openstreetmap_reverse_geocode — Convert latitude/longitude coordinates to the nearest address or place name
• openstreetmap_lookup_objects — Fetch address details for one or more known OSM objects by their IDs
• openstreetmap_query_nearby — Find OSM features within a radius around a geographic point
• openstreetmap_query_bbox — Find OSM features within a rectangular bounding box
• openstreetmap_query_raw — Execute a raw Overpass QL query for advanced spatial operations
• Prerequisites — The Prerequisites tool exposed by this server
• Installation — The Installation tool exposed by this server

What it needs from you

Configuration is passed through the environment: MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL, OSM_NOMINATIM_BASE_URL, OSM_OVERPASS_BASE_URL, MCP_HTTP_ENDPOINT_PATH, MCP_PUBLIC_URL. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

• Bun v1.3.0 or higher (or Node.js ≥24.0.0). - No API key required — Nominatim and Overpass are public APIs. For heavy use, consider pointing OSM_NOMINATIM_BASE_URL and OSM_OVERPASS_BASE_URL at self-hosted or mirror instances.

Getting it running

Because this one is hosted, setup is mostly authentication — you point your client at the endpoint and approve access. Nothing runs on your machine, so there is no runtime to keep patched.

How it compares

Among the cloud and infrastructure options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Nominatim's toolset — openstreetmap_search_places, openstreetmap_reverse_geocode, openstreetmap_lookup_objects and 5 more — is a fair guide to whether it matches your workflow. It is maintained by cyanheads; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against Nominatim's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Things to watch

• Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
• Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
• Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.