> ## Documentation Index > Fetch the complete documentation index at: https://docs.retellai.com/llms.txt > Use this file to discover all available pages before exploring further. # Update Test Case Definition > Update a test case definition ## OpenAPI ````yaml openapi-final put /update-test-case-definition/{test_case_definition_id} openapi: 3.0.3 info: title: Retell SDK version: 3.0.0 contact: name: Retell Support url: https://www.retellai.com/ email: support@retellai.com license: name: Apache 2.0 url: https://www.apache.org/licenses/LICENSE-2.0.html servers: - url: https://api.retellai.com description: The production server. security: - api_key: [] paths: /update-test-case-definition/{test_case_definition_id}: put: description: Update a test case definition operationId: updateTestCaseDefinition parameters: - in: path name: test_case_definition_id schema: type: string required: true description: ID of the test case definition to update requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/TestCaseDefinitionInput' responses: '200': description: Test case definition updated successfully content: application/json: schema: $ref: '#/components/schemas/TestCaseDefinition' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/InternalServerError' x-codeSamples: - lang: JavaScript source: >- import Retell from 'retell-sdk'; const client = new Retell({ apiKey: process.env['RETELL_API_KEY'], // This is the default and can be omitted }); const testCaseDefinitionResponse = await client.tests.updateTestCaseDefinition( 'test_case_definition_id', ); console.log(testCaseDefinitionResponse.test_case_definition_id); - lang: Python source: >- import os from retell import Retell client = Retell( api_key=os.environ.get("RETELL_API_KEY"), # This is the default and can be omitted ) test_case_definition_response = client.tests.update_test_case_definition( test_case_definition_id="test_case_definition_id", ) print(test_case_definition_response.test_case_definition_id) components: schemas: TestCaseDefinitionInput: type: object properties: name: type: string description: Name of the test case definition response_engine: $ref: '#/components/schemas/RetellResponseEngine' description: >- Response engine to use for the test case. Custom LLM is not supported. user_prompt: type: string description: User prompt to simulate in the test case metrics: type: array items: type: string description: Array of metric names to evaluate dynamic_variables: type: object additionalProperties: type: string description: Dynamic variables to inject into the response engine tool_mocks: type: array items: $ref: '#/components/schemas/ToolMock' description: Mock tool calls for testing llm_model: $ref: '#/components/schemas/LLMModel' description: LLM model to use for simulation TestCaseDefinition: allOf: - $ref: '#/components/schemas/TestCaseDefinitionInput' - type: object required: - name - response_engine - metrics - user_prompt - dynamic_variables - tool_mocks - llm_model - test_case_definition_id - type - creation_timestamp - user_modified_timestamp properties: test_case_definition_id: type: string description: Unique identifier for the test case definition type: type: string enum: - simulation description: Type of test case definition creation_timestamp: type: integer description: >- Timestamp when the test case definition was created (milliseconds since epoch) user_modified_timestamp: type: integer description: >- Timestamp when the test case definition was last modified (milliseconds since epoch) RetellResponseEngine: oneOf: - $ref: '#/components/schemas/ResponseEngineRetellLm' - $ref: '#/components/schemas/ResponseEngineConversationFlow' description: Response engine for test cases. Custom LLM is not supported. ToolMock: type: object required: - tool_name - input_match_rule - output properties: tool_name: type: string description: Name of the tool to mock input_match_rule: $ref: '#/components/schemas/ToolMockInputMatchRule' description: Rule for matching tool calls output: type: string maxLength: 15000 description: >- The output of the tool call that will be fed into the LLM. Should be a JSON string. result: type: boolean nullable: true description: >- For tool calls like transfer_call that require a boolean result. Optional for most tools. LLMModel: type: string enum: - gpt-4.1 - gpt-4.1-mini - gpt-4.1-nano - gpt-5 - gpt-5-mini - gpt-5-nano - gpt-5.1 - gpt-5.2 - gpt-5.4 - gpt-5.4-mini - gpt-5.4-nano - gpt-5.5 - claude-4.5-sonnet - claude-4.6-sonnet - claude-4.5-haiku - gemini-2.5-flash-lite - gemini-3.0-flash - gemini-3.1-flash-lite description: Available LLM models for agents. ResponseEngineRetellLm: type: object required: - type - llm_id properties: type: type: string enum: - retell-llm description: type of the Response Engine. llm_id: type: string description: id of the Retell LLM Response Engine. version: type: number example: 0 description: Version of the Retell LLM Response Engine. nullable: true ResponseEngineConversationFlow: type: object required: - type - conversation_flow_id properties: type: type: string enum: - conversation-flow description: type of the Response Engine. conversation_flow_id: type: string description: ID of the Conversation Flow Response Engine. version: type: number example: 0 description: Version of the Conversation Flow Response Engine. nullable: true ToolMockInputMatchRule: oneOf: - type: object required: - type properties: type: type: string enum: - any description: Match any input of the tool - type: object required: - type - args properties: type: type: string enum: - partial_match description: Match only calls with specific arguments args: type: object description: Arguments to match. Only provided fields will be checked responses: BadRequest: description: Bad Request content: application/json: schema: type: object properties: status: type: string enum: - error message: type: string example: Invalid request format, please check API reference. Unauthorized: description: Unauthorized content: application/json: schema: type: object properties: status: type: string enum: - error message: type: string example: API key is missing or invalid. NotFound: description: Not Found content: application/json: schema: type: object properties: status: type: string enum: - error message: type: string example: The requested resource was not found. TooManyRequests: description: Too Many Requests content: application/json: schema: type: object properties: status: type: string enum: - error message: type: string example: Account rate limited, please throttle your requests. InternalServerError: description: Internal Server Error content: application/json: schema: type: object properties: status: type: string enum: - error message: type: string example: An unexpected server error occurred. securitySchemes: api_key: type: http scheme: bearer bearerFormat: string description: >- Authentication header containing API key (find it in dashboard). The format is "Bearer YOUR_API_KEY" ````