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

# List geo metros

> List geo metro code-name pairs for buyer-side targeting resolution and display. Send only numeric string codes in campaign constraints.geo_metros; request fields=geo_metro_names on campaign reads when display labels are needed.



## OpenAPI

````yaml /v2/buyer-api-v2.yaml get /targeting/geo-metros
openapi: 3.0.0
info:
  title: Scope3 Buyer API
  version: 2.0.0
  description: |-
    REST API for advertisers to manage advertisers, campaigns, and reporting.

    ## Authentication

    All endpoints require a Bearer token in the Authorization header:
    ```
    Authorization: Bearer your-api-key
    ```

    ## Base URL

    `https://api.interchange.io/api/v2/buyer`

    ## For AI Agents

    AI agents can use the MCP endpoint at `/mcp/v2/buyer` with three tools:
    - `initialize`: Start an MCP session
    - `api_call`: Make REST API calls
    - `ask_about_capability`: Learn about API features
servers:
  - url: https://api.interchange.io/api/v2/buyer
    description: Production server
security: []
tags:
  - name: Account
    description: Account management, service tokens, and preferences
  - name: Advertisers
    description: Manage advertisers
  - name: Product Discovery
    description: Discover and select products
  - name: Campaigns
    description: Manage advertising campaigns
  - name: Creatives
    description: Build, manage, and sync campaign creatives via AdCP Creative Protocol
  - name: Reporting
    description: Access performance metrics
  - name: Event Sources
    description: >-
      Manage event source configurations and log conversion/marketing events for
      attribution
  - name: Property Lists
    description: Validate property lists against AAO registry
  - name: Sales Agents
    description: View and connect sales agents
  - name: Measurement
    description: Measurement sources, records, context, and freshness
  - name: Syndication
    description: Syndicate resources to ADCP agents
  - name: Tasks
    description: Track async operation status
  - name: Planning Briefs
    description: >-
      Share prospective briefs with publishers and collect their
      fit/quote/clarify/decline/book responses (gated by the
      demand-supply-signals flag).
  - name: Buyer Billing
    description: >-
      Consolidated invoicing for buyers — invoices and pending invoice items
      issued by Scope3 across the buyer customer.
  - name: MCP
    description: Model Context Protocol endpoints for AI agents
paths:
  /targeting/geo-metros:
    get:
      tags:
        - Campaigns
      summary: List geo metros
      description: >-
        List geo metro code-name pairs for buyer-side targeting resolution and
        display. Send only numeric string codes in campaign
        constraints.geo_metros; request fields=geo_metro_names on campaign reads
        when display labels are needed.
      operationId: listGeoMetros
      parameters:
        - in: query
          name: system
          schema:
            description: >-
              Targeting system to look up. Defaults to nielsen_dma; currently
              only nielsen_dma is supported.
            example: nielsen_dma
            default: nielsen_dma
            allOf:
              - $ref: '#/components/schemas/TargetingDimensionSystem'
          description: >-
            Targeting system to look up. Defaults to nielsen_dma; currently only
            nielsen_dma is supported.
      responses:
        '200':
          description: List geo metros
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GeoMetrosResponse'
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
      security:
        - bearerAuth: []
components:
  schemas:
    TargetingDimensionSystem:
      description: Supported targeting dimension system
      example: nielsen_dma
      type: string
      enum:
        - nielsen_dma
    GeoMetrosResponse:
      description: >-
        Geo metro codes and English display labels for buyer-side display and
        input resolution.
      type: object
      properties:
        system:
          description: Targeting system these entries belong to
          example: nielsen_dma
          allOf:
            - $ref: '#/components/schemas/TargetingDimensionSystem'
        locale:
          description: >-
            Locale for the display labels. Currently only English labels are
            supported.
          example: en-US
          type: string
          enum:
            - en-US
        entries:
          description: Known code-name pairs for this system
          type: array
          items:
            $ref: '#/components/schemas/TargetingDimensionEntry'
      required:
        - system
        - locale
        - entries
      additionalProperties: false
    ErrorResponse:
      description: Standard error response
      type: object
      properties:
        data:
          type: string
          nullable: true
          enum:
            - null
        error:
          $ref: '#/components/schemas/ApiError'
      required:
        - data
        - error
      additionalProperties: false
    TargetingDimensionEntry:
      type: object
      properties:
        code:
          description: String code for this targeting value
          example: '532'
          type: string
        name:
          description: Human-readable display label
          example: Albany-Schenectady-Troy
          type: string
      required:
        - code
        - name
      additionalProperties: false
    ApiError:
      description: Structured error object
      type: object
      properties:
        code:
          description: Machine-readable error code
          type: string
        message:
          description: Human-readable error message
          type: string
        field:
          description: Field path associated with the error
          type: string
        details:
          description: Additional error context
          type: object
          additionalProperties: {}
      required:
        - code
        - message
      additionalProperties: false
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: API key or access token

````