> ## Documentation Index > Fetch the complete documentation index at: https://abstract-pbc.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Retrieve a chat completion > Returns an LLM completion your account created. A completion from a retired model reads back from its kept answer. ## OpenAPI ````yaml /api-reference/openapi.yaml get /v1/chat/completions/{completion_id} openapi: 3.1.0 info: title: Abstract API version: 1.0.0 summary: Robot action models and LLMs behind one API key. description: > `POST /v1/chat/completions` serves the LLM models. `GET /v1/chat/completions/{completion_id}` reads an LLM completion your account created. `POST /v1/get_action` and `POST /v1/end_session` serve the robot action models in Dream Labs' request shape. `GET /v1/models` lists the LLM model ids. contact: name: Abstract url: https://abstract.inc servers: - url: https://api.abstract.inc security: - bearerAuth: [] tags: - name: Chat completions - name: Robot actions description: End-effector and model-specific native joint action contracts. - name: Catalog - name: CLI credentials paths: /v1/chat/completions/{completion_id}: get: tags: - Chat completions summary: Retrieve a chat completion description: >- Returns an LLM completion your account created. A completion from a retired model reads back from its kept answer. operationId: retrieveChatCompletion parameters: - $ref: '#/components/parameters/AbstractVersion' - name: completion_id in: path required: true description: The `id` from the POST answer. schema: type: string pattern: ^[A-Za-z0-9_-]{1,200}$ responses: '200': description: The finished chat completion. headers: Request-Id: $ref: '#/components/headers/RequestId' Abstract-Version: $ref: '#/components/headers/AbstractVersion' content: application/json: schema: $ref: '#/components/schemas/ChatCompletion' example: id: resp_abc123 object: chat.completion created: 1790000000 model: glm-5.3 choices: - index: 0 message: role: assistant content: >- RFC 8628 defines the OAuth 2.0 device authorization grant. finish_reason: stop usage: prompt_tokens: 14 prompt_tokens_details: cached_tokens: 0 completion_tokens: 96 total_tokens: 110 '401': $ref: '#/components/responses/Unauthorized' '404': description: >- `not_found`: no completion with this id belongs to your account, or a retired model's answer was never kept. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: '`invalid_id`: the id breaks its format.' content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '502': description: >- `upstream_failed` (the model did not complete the request) or `invalid_upstream_response`. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '503': $ref: '#/components/responses/Unavailable' components: parameters: AbstractVersion: name: Abstract-Version in: header required: false description: >- The API version your client was written for. `2026-10-27` is the only version. Without this header the request is answered under the newest version; a version the API does not answer is refused with `400 unsupported_api_version` before anything runs. schema: type: string enum: - '2026-10-27' headers: RequestId: description: >- `req_` and 32 hex characters, new for each HTTP attempt, a retry included. An error repeats it as `error.request_id`. Quote it when you report a problem. schema: type: string pattern: ^req_[0-9a-f]{32}$ AbstractVersion: description: >- The API version this answer was made under: the `Abstract-Version` the request sent, or the newest version when it sent none. schema: type: string schemas: ChatCompletion: type: object required: - id - object - created - model - choices - usage properties: id: type: string object: type: string const: chat.completion created: type: integer description: Unix seconds. model: type: string choices: type: array items: type: object properties: index: type: integer message: type: object properties: role: type: string const: assistant content: type: - string - 'null' description: The LLM answer. reasoning_content: type: string description: LLM models. The model's reasoning, when it reports it. refusal: type: string description: LLM models. The model's refusal, when it refuses. finish_reason: type: string enum: - stop - length - content_filter - error usage: $ref: '#/components/schemas/ChunkUsage' ErrorResponse: type: object required: - error properties: error: type: object required: - message - type - code - retryable - retry_after_s - request_id properties: message: type: string description: For people. It can change. type: type: string param: type: - string - 'null' description: The request field at fault, when one is. code: type: string description: Branch on this. See [Errors and limits](/errors). retryable: type: boolean description: >- Whether this same request may be sent again. When the route gives no answer of its own, `true` for 408, 429 and 503. retry_after_s: type: - number - 'null' description: The `Retry-After` header in seconds, or `null`. request_id: type: string pattern: ^req_[0-9a-f]{32}$ description: >- This answer's `Request-Id` header. Quote it when you report a problem. ChunkUsage: type: object required: - prompt_tokens - completion_tokens - total_tokens properties: prompt_tokens: type: integer description: >- Prompt tokens, cached ones included. For a robot model, the model's prompt tokens for the chunk. prompt_tokens_details: type: object properties: cached_tokens: type: integer description: >- The part of `prompt_tokens` served from cache. For a robot model, reused from earlier chunks of the episode. completion_tokens: type: integer description: >- Output tokens. For a robot model, the action rows the model computed, before any `action_horizon` cut. total_tokens: type: integer responses: Unauthorized: description: '`missing_api_key` or `invalid_api_key`.' content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: Invalid API key. type: invalid_request_error code: invalid_api_key Unavailable: description: >- A dependency is down, for example `auth_unavailable`, `billing_unavailable`, `metering_unavailable` or `engine_unavailable`. Retry with backoff. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' securitySchemes: bearerAuth: type: http scheme: bearer description: >- Your Abstract API key. Get it with `abstract login`, pass it as `$(abstract token)`. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.