> ## Documentation Index
> Fetch the complete documentation index at: https://docs.checkthatfield.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Usage

> Calls made with this key this month, against its quota. Not counted itself.



## OpenAPI

````yaml /api-reference/openapi.json get /usage
openapi: 3.1.0
info:
  title: Check That Field API
  description: >-
    How likely England's fields are to be built on for housing, and the housing
    planning applications around them. Send your key as `Authorization: Bearer
    ctf_sk_live_…`. Errors are `{"error": {"code", "message"}}`.
  version: 1.0.0
servers:
  - url: https://api.checkthatfield.com/v1
    description: Production
security:
  - HTTPBearer: []
paths:
  /usage:
    get:
      summary: Usage
      description: >-
        Calls made with this key this month, against its quota. Not counted
        itself.
      operationId: usage_usage_get
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/UsageOut'
        '401':
          description: No key, or one we don't know.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
        '403':
          description: The key has been revoked.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
        '404':
          description: No such field, postcode or place.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
        '409':
          description: A place name matches several places; `error.choices` lists them.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
        '422':
          description: >-
            The question can't be answered as asked, or the place is outside
            England.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
        '429':
          description: The month's calls are used up, or too many calls a minute.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
        '503':
          description: The search took too long. Try a smaller radius or a postcode.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorOut'
      security:
        - HTTPBearer: []
components:
  schemas:
    UsageOut:
      properties:
        month:
          type: string
          title: Month
          description: The calendar month counted, YYYY-MM (UTC).
        calls:
          type: integer
          title: Calls
          description: Calls answered this month.
        quota:
          type: integer
          title: Quota
          description: Calls allowed a month.
        remaining:
          type: integer
          title: Remaining
          description: Calls left this month.
        resets_at:
          type: string
          format: date-time
          title: Resets At
          description: When the count starts again (UTC).
      type: object
      required:
        - month
        - calls
        - quota
        - remaining
        - resets_at
      title: UsageOut
    ErrorOut:
      properties:
        error:
          $ref: '#/components/schemas/ErrorBody'
      type: object
      required:
        - error
      title: ErrorOut
    ErrorBody:
      properties:
        code:
          type: string
          title: Code
          description: >-
            invalid_key, key_revoked, not_found, ambiguous, outside_england,
            bad_request, quota_exceeded, rate_limited, too_slow, …
        message:
          type: string
          title: Message
          description: What went wrong, in plain words.
      type: object
      required:
        - code
        - message
      title: ErrorBody
  securitySchemes:
    HTTPBearer:
      type: http
      description: Your secret key, ctf_sk_live_…
      scheme: bearer

````

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