> ## Documentation Index > Fetch the complete documentation index at: https://docs.tracks.alpic.ai/llms.txt > Use this file to discover all available pages before exploring further. # Send a follow-up prompt > Asks the agent to continue where its last prompt stopped. Accepted only while the run is `idle`; the run is `working` again until the agent stops. ## OpenAPI ````yaml https://tracks.alpic.ai/api/openapi.json post /runs/{id}/prompts openapi: 3.1.0 info: title: Tracks API version: 0.0.1 description: >- Run coding agents such as Claude Code in isolated sandboxes with an API key of your organization. Create a run with a prompt, then follow its output and what it costs, or launch an experiment to compare agents on your scenarios. servers: - url: https://tracks.alpic.ai/api security: [] tags: - name: Runs description: Start coding agents and follow their work. - name: Files description: Upload files to place in a run's sandbox. - name: Connections description: >- Let agents use MCP servers as one of their users, without their credentials entering the sandbox. - name: Experiments description: >- Define scenarios to give several agents in several variants, judged on what they did. - name: Executions description: Launch experiments and read their results. - name: Library description: What your experiments can give their agents. - name: System paths: /runs/{id}/prompts: post: tags: - Runs summary: Send a follow-up prompt description: >- Asks the agent to continue where its last prompt stopped. Accepted only while the run is `idle`; the run is `working` again until the agent stops. operationId: runs.sendPrompt parameters: - name: id in: path schema: $ref: '#/components/schemas/RunId' required: true requestBody: content: application/json: schema: $ref: '#/components/schemas/SendPromptInput' required: true responses: '202': description: One instruction to the agent and the work it did in response. content: application/json: schema: anyOf: - $ref: '#/components/schemas/UnfinishedPrompt' - $ref: '#/components/schemas/FinishedPrompt' description: One instruction to the agent and the work it did in response. '400': description: >- The request is invalid: a value is missing, has the wrong type or is out of range. Fix it before sending the request again. content: application/json: schema: $ref: '#/components/schemas/InvalidRequestEncoded' '401': description: >- The API key is missing, malformed or revoked, or its organization is closed. content: application/json: schema: $ref: '#/components/schemas/ApiKeyRefusedEncoded' '404': description: No run with this id exists in your organization. content: application/json: schema: $ref: '#/components/schemas/RunNotFoundEncoded' '409': description: >- The run accepts no prompt now: it is one-shot, has ended, or is still working on a prompt. content: application/json: schema: $ref: '#/components/schemas/RunNotIdleEncoded' '422': description: >- The agent cannot use this model. The message lists the models it can use. content: application/json: schema: $ref: '#/components/schemas/ModelNotOfferedEncoded' '503': description: >- The model provider could not be reached to check the model. Retry later. content: application/json: schema: $ref: '#/components/schemas/ModelProviderUnavailableEncoded' security: - bearer: [] components: schemas: RunId: type: string description: Unique identifier of the run. SendPromptInput: type: object properties: text: type: string minLength: 1 description: What you ask the agent to do next. model: type: string minLength: 1 description: Model for this prompt only. Defaults to the run's model. required: - text additionalProperties: false UnfinishedPrompt: type: object properties: run_id: $ref: '#/components/schemas/RunId' index: type: integer minimum: 1 maximum: 9007199254740991 description: Position of the prompt in its run, starting at 1. text: type: string description: What you asked the agent to do. model: type: string description: Model for this prompt, when not the run's. submitted_at: type: string status: type: string enum: - working - failed - canceled description: >- `working` while the agent works on it. `failed` or `canceled` when the run ended before the prompt finished. required: - run_id - index - text - submitted_at - status additionalProperties: false description: A prompt the agent has not finished. FinishedPrompt: type: object properties: run_id: $ref: '#/components/schemas/RunId' index: type: integer minimum: 1 maximum: 9007199254740991 description: Position of the prompt in its run, starting at 1. text: type: string description: What you asked the agent to do. model: type: string description: Model for this prompt, when not the run's. submitted_at: type: string status: type: string enum: - finished description: The agent stopped, whatever its exit code. finished_at: type: string exit_code: type: integer minimum: -9007199254740991 maximum: 9007199254740991 description: Exit code of the agent. required: - run_id - index - text - submitted_at - status - finished_at - exit_code additionalProperties: false description: A prompt the agent has finished. InvalidRequestEncoded: type: object properties: _tag: type: string enum: - InvalidRequest message: type: string description: Every problem found, in one sentence. location: type: string enum: - path - query - header - body description: The part of the request that is wrong. issues: type: array items: $ref: '#/components/schemas/RequestIssue' description: Each problem found, with where it is. required: - _tag - message - location - issues additionalProperties: false ApiKeyRefusedEncoded: type: object properties: _tag: type: string enum: - ApiKeyRefused message: type: string required: - _tag - message additionalProperties: false RunNotFoundEncoded: type: object properties: _tag: type: string enum: - RunNotFound message: type: string required: - _tag - message additionalProperties: false RunNotIdleEncoded: type: object properties: _tag: type: string enum: - RunNotIdle message: type: string required: - _tag - message additionalProperties: false ModelNotOfferedEncoded: type: object properties: _tag: type: string enum: - ModelNotOffered message: type: string required: - _tag - message additionalProperties: false ModelProviderUnavailableEncoded: type: object properties: _tag: type: string enum: - ModelProviderUnavailable message: type: string required: - _tag - message additionalProperties: false RequestIssue: type: object properties: path: type: array items: anyOf: - type: string - type: number - type: string enum: - Infinity - '-Infinity' - NaN description: >- Keys leading to the wrong value inside that part of the request, such as `["agent", "model"]`. Empty when the problem concerns that part as a whole. message: type: string description: What is wrong with the value. required: - path - message additionalProperties: false description: One problem found in the request. securitySchemes: bearer: description: >- An API key of your organization, starting with `trk_`, sent as `Authorization: Bearer `. type: http scheme: bearer ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.