> ## 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. # Update test cohort > Update an existing test cohort. ## OpenAPI ````yaml /v2/buyer-api-v2.yaml put /advertisers/{advertiserId}/test-cohorts/{cohortId} 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: Signup description: Request reviewed access to Interchange - name: Account description: Account management, service tokens, and preferences - name: Asks description: >- What you are waiting on Scope3 for — support, product, and supply asks in one list - 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: 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: /advertisers/{advertiserId}/test-cohorts/{cohortId}: put: tags: - Measurement summary: Update test cohort description: Update an existing test cohort. operationId: updateTestCohort parameters: - in: path name: cohortId schema: description: Unique identifier for the test cohort example: cohort_abc123 type: string minLength: 1 required: true description: Unique identifier for the test cohort requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/UpdateTestCohortInput' responses: '200': description: Update test cohort content: application/json: schema: $ref: '#/components/schemas/TestCohortResponse' '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: UpdateTestCohortInput: description: Request body for updating a test cohort (all fields optional) type: object properties: name: description: Updated name of the test cohort example: West Coast Treatment Group - Updated type: string minLength: 1 maxLength: 255 description: description: Updated description of the test cohort type: string maxLength: 1000 cohortType: description: Updated type classification for the cohort type: string minLength: 1 role: description: Updated role of the cohort in the test type: string enum: - TREATMENT - CONTROL - OBSERVATION definition: description: Updated cohort targeting definition allOf: - $ref: '#/components/schemas/CohortDefinition' estimatedSize: description: Updated estimated number of users in this cohort type: integer minimum: 0 maximum: 9007199254740991 TestCohortResponse: description: Response containing a single test cohort type: object properties: cohort: $ref: '#/components/schemas/TestCohortOutput' required: - cohort 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 CohortDefinition: description: >- Flexible definition for cohort targeting criteria. Type is required, additional fields vary by type. type: object properties: type: description: >- Type of cohort definition (e.g., "zip_code", "user_segment", "geo_region", "custom") example: zip_code type: string minLength: 1 required: - type additionalProperties: {} TestCohortOutput: description: Test cohort resource representation type: object properties: id: description: Unique identifier for the test cohort example: cohort_abc123 type: string advertiserId: description: Advertiser ID that owns this cohort example: '12345' type: string name: description: Name of the test cohort example: West Coast Treatment Group type: string description: description: Description of the test cohort type: string cohortType: description: Type classification for the cohort example: geographic type: string role: description: Role of the cohort in the test type: string enum: - TREATMENT - CONTROL - OBSERVATION definition: description: Cohort targeting definition allOf: - $ref: '#/components/schemas/CohortDefinition' estimatedSize: description: Estimated number of users in this cohort example: 50000 type: integer minimum: 0 maximum: 9007199254740991 isActive: description: Whether the cohort is currently active type: boolean createdAt: description: When the cohort was created (ISO 8601) example: '2025-01-15T10:30:00Z' type: string format: date-time pattern: >- ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z))$ updatedAt: description: When the cohort was last updated (ISO 8601) example: '2025-01-20T14:45:00Z' type: string format: date-time pattern: >- ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z))$ required: - id - advertiserId - name - cohortType - role - definition - isActive - createdAt - updatedAt 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 ````