The PostalDataPI MCP Server enables AI agents to look up, validate, and search postal codes across 240+ countries with rich geographic metadata.
Look up postal codes (lookup_postal_code): Retrieve city, state/region, and abbreviation for any postal code — including US ZIP codes, UK postcodes, German PLZ, Japanese postal codes, and more.
Validate postal codes (validate_postal_code): Check whether a given postal code exists in a specified country, useful for verifying addresses in forms or order processing.
Search by city (search_by_city): Find all postal codes associated with a specific city; for US cities, a state name or abbreviation can be provided to narrow results.
Get full metadata (get_postal_code_metadata): Retrieve comprehensive details including coordinates (latitude/longitude), timezone, administrative hierarchy (state/province, county, municipality), elevation, and place name.
MCP (Model Context Protocol) server for PostalDataPI — lets AI agents look up, validate, and search postal codes across 240+ countries and territories with rich metadata: timezone, administrative regions, elevation, and coordinates.
Tool | Description |
| Get city, state/region, and abbreviation for a postal code (US ZIP, UK postcode, German PLZ, etc.) |
| Check if a postal code exists in a country |
| Find all postal codes for a city |
| Full metadata: coordinates, admin hierarchy, timezone, elevation, and more |
Related MCP server: Postio
Sign up at postaldatapi.com/register — 1,000 free queries, no credit card required.
pip install postaldatapi-mcpclaude mcp add --transport stdio postaldatapi -- \
env POSTALDATAPI_KEY=your_api_key_here postaldatapi-mcpAdd to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):
{
"mcpServers": {
"postaldatapi": {
"command": "postaldatapi-mcp",
"env": {
"POSTALDATAPI_KEY": "your_api_key_here"
}
}
}
}Once configured, ask Claude naturally:
"What city is ZIP code 90210?"
"Look up UK postcode SW1A"
"Is 10115 a valid German postal code?"
"What are the postal codes for Beverly Hills, CA?"
"Get the coordinates for postal code 100-0001 in Japan"
Claude will automatically use the PostalDataPI tools to answer.
240+ countries and territories including US, UK, Canada, Germany, France, Japan, Australia, Brazil, India, and many more. See the full list at postaldatapi.com/countries.
Beyond basic lookups, the get_postal_code_metadata tool returns up to 18 fields per postal code including:
Coordinates (latitude, longitude)
Timezone (e.g., America/Mexico_City, Europe/Berlin)
Administrative hierarchy (state/province, county, municipality)
Elevation (meters above sea level)
Place name and country information
Example response for Mexico City 06000:
{
"postalCode": "06000",
"country": "MX",
"placeName": "Centro",
"latitude": 19.4364,
"longitude": -99.1553,
"timezone": "America/Mexico_City",
"adminLevel1": "Ciudad de México",
"adminLevel2": "Cuauhtémoc",
"elevation": 2239
}Get full metadata for a postal code including coordinates.
Returns latitude, longitude, county/municipality, and all available country-specific fields. Use this when someone needs geographic coordinates, timezone, or detailed location data for a postal code.
Args: postal_code: The postal code to look up country: ISO 3166-1 alpha-2 country code. Defaults to "US".
Returns: Full metadata including coordinates, region, and country-specific fields.
Inputs: postal_code (required), country. Returns: result
Look up a postal code and get city, state, and region information.
Works for ZIP codes (US), postcodes (UK), PLZ (Germany), and postal codes in 70+ countries. Use this when someone asks about a postal code, wants to know what city a ZIP code belongs to, or needs address information.
Args: postal_code: The postal code to look up (e.g., "90210", "SW1A", "10115", "100-0001") country: ISO 3166-1 alpha-2 country code (e.g., "US", "GB", "DE", "JP"). Defaults to "US".
Returns: City, state/region, and abbreviation for the postal code.
Inputs: postal_code (required), country. Returns: result
Find all postal codes for a given city.
Use this when someone has a city name and needs the postal codes that serve it. For US cities, provide the state name or 2-letter abbreviation.
Args: city: City name (e.g., "Beverly Hills", "Berlin", "Tokyo") state: State or region name/abbreviation. Required for US cities (e.g., "CA" or "California"). country: ISO 3166-1 alpha-2 country code. Defaults to "US".
Returns: List of postal codes for the city.
Inputs: city (required), state, country. Returns: result
Check whether a postal code exists in a given country.
Use this when someone wants to verify if a postal code is valid before processing an order, form, or address.
Args: postal_code: The postal code to validate country: ISO 3166-1 alpha-2 country code. Defaults to "US".
Returns: Whether the postal code is valid or invalid.
Inputs: postal_code (required), country. Returns: result
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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Scored across 4 tools
The tools have distinct primary purposes: get_postal_code_metadata for detailed geographic data, lookup_postal_code for basic address information, search_by_city for reverse lookup, and validate_postal_code for validation. However, get_postal_code_metadata and lookup_postal_code could be confused as both retrieve postal code information, though their descriptions clarify different use cases.
All tool names follow a consistent snake_case pattern with clear verb_noun structure: get_postal_code_metadata, lookup_postal_code, search_by_city, validate_postal_code. The naming is predictable and readable throughout the set.
With 4 tools, this is well-scoped for a postal code data server. Each tool serves a distinct function in the domain, and the count is appropriate for covering core operations without being overwhelming or insufficient.
The toolset covers key postal code operations: lookup, validation, reverse search, and metadata retrieval. A minor gap exists in lacking explicit update or delete operations, but these are not typically needed for a read-only data service, and agents can work effectively with the provided tools.
Postal lookups for 120 countries with cited sources; deep US tier: demographics, climate, area codes
Hosted libpostal: messy free-text postal addresses → structured fields. No 2-4GB self-host.
Free, keyless postal/ZIP code lookup: place name(s), state/region, and coordinates.
Postal code lookup with place names and coordinates for 60+ countries. Via Zippopotam.us.
