Japan Address from Postal Code (HeartRails Geo)

heartrailsgeo/postal-lookup

Look up the Japanese towns that share a seven-digit postal code: prefecture, city or ward and town, each with its kana reading, and the longitude and latitude of the town area. Names are in Japanese. A postal code that does not exist is refused as a validation error.

activeper callv1

Price

$0.0026 per call

You pay the price shown. If a call turns out to cost more than its quote, you pay the actual price, capped at twice the quote. No monthly minimum. Top-ups start at $5.

Data source

HeartRails Geo API

Postal code, address and coordinate data from HeartRails Geo API (geoapi.heartrails.com), built from Japan Post postal codes and the Ministry of Land, Infrastructure, Transport and Tourism location reference information. Required credit: 出典：「位置参照情報ダウンロードサービス」（国土交通省）を加工して作成. Served by Eden Engine; not an official HeartRails product.

Use it

Five steps: search, inspect, learn, run, settle. No per-tool setup; your agent reaches this tool through the meta-tools it already has.

Connect once and your AI can find and run this tool, and any other it needs.

Install it Create an account

agent

// 1. search: find the tool
omnial_search({ query: "what you need" })

// 2. inspect: price and input schema
omnial_inspect({ tool: "heartrailsgeo/postal-lookup" })

// 3. learn: read the usage guide at runtime
omnial_learn({ tool: "heartrailsgeo/postal-lookup" })

// 4. run: price the exact call first, then run it
omnial_execute({ tool: "heartrailsgeo/postal-lookup", input: { /* see input_schema */ }, dry_run: true })
omnial_execute({ tool: "heartrailsgeo/postal-lookup", input: { /* ... */ } })

// 5. settle: the call is charged when it finishes, nothing to do

Not connected yet? Point your MCP client at https://mcp.eden-engine.com/mcp, then copy a config for your client.

Pricing

Every charge this tool can incur.

Charge	Price
Per call	$0.0026

Updated: Oct 21, 2026

Input and output schemas

Input schema

input_schema.json

{
  "type": "object",
  "required": [
    "postal"
  ],
  "properties": {
    "postal": {
      "type": "string",
      "pattern": "^[0-9]{7}$",
      "description": "A seven-digit Japanese postal code, digits only, no hyphen, for example 1000001."
    }
  },
  "additionalProperties": false
}

Output schema

output_schema.json

{
  "type": "object",
  "required": [
    "response"
  ],
  "properties": {
    "response": {
      "type": "object",
      "required": [
        "location"
      ],
      "properties": {
        "location": {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "x": {
                "type": [
                  "string",
                  "number"
                ],
                "description": "Longitude, WGS84 degrees."
              },
              "y": {
                "type": [
                  "string",
                  "number"
                ],
                "description": "Latitude, WGS84 degrees."
              },
              "city": {
                "type": "string",
                "description": "City or ward, in Japanese."
              },
              "town": {
                "type": "string",
                "description": "Town area (chome or oaza), in Japanese."
              },
              "postal": {
                "type": "string",
                "description": "Seven-digit postal code, no hyphen."
              },
              "distance": {
                "type": "number",
                "description": "Metres from the given point; only on a coordinate search."
              },
              "city_kana": {
                "type": "string"
              },
              "town_kana": {
                "type": "string"
              },
              "prefecture": {
                "type": "string",
                "description": "Prefecture, in Japanese."
              }
            },
            "additionalProperties": true
          },
          "description": "The town areas that share the postal code; usually one, sometimes several."
        }
      },
      "additionalProperties": true
    }
  },
  "additionalProperties": true
}