Tools (4)

lookup_postal_code
search_by_place
list_supported_countries
report_feedback

lookup_postal_code

Look up location details for a postal/ZIP code — city, state, country, and coordinates.

Supports 70+ countries including US, UK, Norway, Germany, France, Japan, and more.

Parameter	Type	Required	Description
`country_code`	`string`	required	ISO 3166-1 alpha-2 country code (e.g. 'US', 'NO', 'DE').
`postal_code`	`string`	required	Postal or ZIP code to look up (e.g. '90210', '0150').

JSON-RPC Request

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "id": 1,
  "params": {
    "name": "lookup_postal_code",
    "arguments": {
      "country_code": "NO",
      "postal_code": "example"
    }
  }
}

search_by_place

Find postal codes for a city within a country and state.

Useful for reverse lookup — find postal codes when you know the place name.

Parameter	Type	Required	Description
`country_code`	`string`	required	ISO 3166-1 alpha-2 country code (e.g. 'US', 'DE').
`state`	`string`	required	State or province name (e.g. 'California', 'Bayern').
`city`	`string`	required	City or place name (e.g. 'Los Angeles', 'München').

JSON-RPC Request

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "id": 1,
  "params": {
    "name": "search_by_place",
    "arguments": {
      "country_code": "NO",
      "state": "example",
      "city": "example"
    }
  }
}

list_supported_countries

List all countries supported for postal code lookup.

Returns ISO country codes and names for all 70+ supported countries.

JSON-RPC Request

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "id": 1,
  "params": {
    "name": "list_supported_countries",
    "arguments": {}
  }
}

report_feedback

Report a bug, feature request, or general feedback for this data source.

Use this when something doesn't work as expected, when you'd like
a new feature, or when you have suggestions for improvement.

Args:
feedback: Describe the issue or suggestion.
feedback_type: One of 'bug', 'feature_request', or 'general'.

Parameter	Type	Required	Description
`feedback`	`string`	required
`feedback_type`	`string`	optional	(default: "general")

JSON-RPC Request

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "id": 1,
  "params": {
    "name": "report_feedback",
    "arguments": {
      "feedback": "example"
    }
  }
}

Quick Start

Shell

curl -X POST "https://context.gnist.ai/mcp/postal-codes/" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "Gnist-API-Key: YOUR_API_KEY" \
  -d '{"jsonrpc": "2.0", "method": "tools/call", "id": 1, "params": {"name": "lookup_postal_code", "arguments": {"country_code": "example", "postal_code": "example"}}}'

Python

import httpx

resp = httpx.post(
    "https://context.gnist.ai/mcp/postal-codes/",
    headers={"Gnist-API-Key": "YOUR_API_KEY", "Content-Type": "application/json"},
    json={
  "jsonrpc": "2.0",
  "method": "tools/call",
  "id": 1,
  "params": {
    "name": "lookup_postal_code",
    "arguments": {
      "country_code": "example",
      "postal_code": "example"
    }
  }
},
)
print(resp.json())