> ## Documentation Index > Fetch the complete documentation index at: https://docs.coval.ai/llms.txt > Use this file to discover all available pages before exploring further. # Retrieve a named simulation attribute > Returns an exact, case-sensitive top-level attribute from the simulation's current active test case. Names are literal keys, including dots, rather than paths. URL-encode names when necessary. Requires simulations:read permission. The simulation, run, test case and test set must be accessible in the authenticated organization and workspace. A resolved workspace is required. Select one with X-Coval-Workspace-Id when the organization has no default workspace. Legacy unassigned rows are accessible only through the default workspace. Monitoring conversations and deleted runs are excluded. This endpoint can be used while a simulation is running or after it finishes. JSON values return directly without an envelope. Null is a successful JSON value, while an absent attribute returns 404. Changes to the test case are visible on subsequent requests. This endpoint does not capture a snapshot or persist tool-call events. An object with type: image_ref is reserved for image references and must contain attachment: , matching exactly one media attachment on the test case. Image responses contain raw PNG/JPEG bytes, with a maximum size of 4 MiB. Ordinary objects without that marker return unchanged. This deliberately returns content instead of an AIP-131 resource envelope: customer tool handlers consume the fixture directly, including image bytes. Both JSON and image response content are limited to 4 MiB. ## OpenAPI ````yaml /api-reference/v1/simulations-v1.yaml get /simulations/{simulation_id}/attributes/{attribute_name} openapi: 3.0.3 info: title: Coval Simulated Conversations API version: 1.0.0 description: | Launch and manage voice simulations for AI agent testing. contact: name: Coval API Support email: support@coval.dev url: https://docs.coval.ai license: name: Proprietary url: https://coval.dev/terms servers: - url: https://api.coval.dev/v1 description: Production API security: - ApiKeyAuth: [] tags: - name: Simulated Conversations description: Launch and manage individual simulation executions - name: Metric Outputs description: Retrieve metric computation results for simulations paths: /simulations/{simulation_id}/attributes/{attribute_name}: get: tags: - Simulated Conversations summary: Retrieve a named simulation attribute description: > Returns an exact, case-sensitive top-level attribute from the simulation's current active test case. Names are literal keys, including dots, rather than paths. URL-encode names when necessary. Requires simulations:read permission. The simulation, run, test case and test set must be accessible in the authenticated organization and workspace. A resolved workspace is required. Select one with X-Coval-Workspace-Id when the organization has no default workspace. Legacy unassigned rows are accessible only through the default workspace. Monitoring conversations and deleted runs are excluded. This endpoint can be used while a simulation is running or after it finishes. JSON values return directly without an envelope. Null is a successful JSON value, while an absent attribute returns 404. Changes to the test case are visible on subsequent requests. This endpoint does not capture a snapshot or persist tool-call events. An object with type: image_ref is reserved for image references and must contain attachment: , matching exactly one media attachment on the test case. Image responses contain raw PNG/JPEG bytes, with a maximum size of 4 MiB. Ordinary objects without that marker return unchanged. This deliberately returns content instead of an AIP-131 resource envelope: customer tool handlers consume the fixture directly, including image bytes. Both JSON and image response content are limited to 4 MiB. operationId: getSimulationAttribute parameters: - name: simulation_id in: path required: true schema: type: string maxLength: 512 - name: attribute_name in: path required: true schema: type: string maxLength: 512 responses: '200': description: >- The attribute value or referenced image. Responses use Cache-Control no-store. content: application/json: schema: description: Any native JSON value. Null is a present attribute value. anyOf: - type: object nullable: true additionalProperties: true - type: array items: {} - type: string - type: number - type: boolean examples: string: value: pro object: value: enabled: true count: 3 image/png: schema: type: string format: binary image/jpeg: schema: type: string format: binary '400': description: >- Missing or invalid path parameters, or invalid image-reference metadata. '401': description: Missing or invalid API key. '403': description: >- The API key lacks simulations:read permission or no workspace was resolved. '404': description: >- The simulation, test case, attribute or referenced image is unavailable. '413': description: The JSON value or referenced image exceeds 4 MiB. '500': description: An unexpected retrieval or storage error occurred. '503': description: Organization database routing is temporarily unavailable. '504': description: The attribute retrieval exceeded its request time budget. components: securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key description: | API key for authentication. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.