> ## Documentation Index
> Fetch the complete documentation index at: https://docs.together.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Get checkpoint

> Returns metadata for a checkpoint: type, base model, LoRA rank, step, and owning session.



## OpenAPI

````yaml openapi.yaml GET /rl/checkpoints/{id}
openapi: 3.1.0
info:
  title: Together APIs
  description: The Together REST API. See https://docs.together.ai for more details.
  version: 2.0.0
  termsOfService: https://www.together.ai/terms-of-service
  contact:
    name: Together Support
    url: https://www.together.ai/contact
  license:
    name: MIT
    url: https://github.com/togethercomputer/openapi/blob/main/LICENSE
servers:
  - url: https://api.together.ai/v1
    description: Default environment for APIs
  - url: https://api-inference.together.ai/v2
    description: Optimized environment for inference
security:
  - bearerAuth: []
paths:
  /rl/checkpoints/{id}:
    get:
      tags:
        - RL
      summary: Get checkpoint
      description: >-
        Returns metadata for a checkpoint: type, base model, LoRA rank, step,
        and owning session.
      operationId: getCheckpoint
      parameters:
        - name: id
          in: path
          required: true
          schema:
            description: ID of the checkpoint
            type: string
      responses:
        '200':
          description: Checkpoint metadata
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/RL.Checkpoint'
        default:
          description: An unexpected error response.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorData'
components:
  schemas:
    RL.Checkpoint:
      type: object
      description: Metadata for a saved checkpoint
      required:
        - id
        - session_id
        - base_model
        - type
        - step
        - created_at
      properties:
        id:
          type: string
          example: 123e4567-e89b-12d3-a456-426614174000
          description: Unique identifier for the checkpoint
        session_id:
          type: string
          example: 123e4567-e89b-12d3-a456-426614174000
          description: Training session that produced the checkpoint
        base_model:
          type: string
          example: Qwen/Qwen3.5-4B
          description: Base model the checkpoint was trained from
        type:
          $ref: '#/components/schemas/RL.CheckpointType'
          example: CHECKPOINT_TYPE_TRAINING
          description: >-
            Kind of checkpoint. CHECKPOINT_TYPE_TRAINING is the full training
            state (weights and optimizer state), for resuming a training session
            with its optimizer state; CHECKPOINT_TYPE_INFERENCE is a model ready
            for serving or download, also added to your models.
        step:
          oneOf:
            - type: string
            - type: integer
          example: '42'
          description: Training step at time of save
        lora_rank:
          type: integer
          example: 32
          description: >-
            LoRA rank of the session that produced this checkpoint. Absent for
            full-weight sessions and for checkpoints saved before this field was
            recorded.
        created_at:
          type: string
          format: date-time
          example: '2026-01-02T00:00:00Z'
          description: Timestamp when the checkpoint was created
        inference_registration:
          $ref: '#/components/schemas/RL.InferenceCheckpointRegistration'
          description: >-
            Model registry artifacts to deploy or download this inference
            checkpoint from. Absent for training checkpoints and when the
            checkpoint was not uploaded to the registry.
        training_registration:
          $ref: '#/components/schemas/RL.ModelRegistryArtifact'
          description: >-
            Model registry artifact holding this training checkpoint's training
            state, used to resume training rather than to deploy. Absent for
            inference checkpoints and when the checkpoint was not uploaded to
            the registry.
    ErrorData:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              nullable: false
            type:
              type: string
              nullable: false
            param:
              type: string
              nullable: true
              default: null
            code:
              type: string
              nullable: true
              default: null
          required:
            - type
            - message
    RL.CheckpointType:
      type: string
      description: Whether a checkpoint is saved for training resume or inference download.
      enum:
        - CHECKPOINT_TYPE_TRAINING
        - CHECKPOINT_TYPE_INFERENCE
    RL.InferenceCheckpointRegistration:
      type: object
      description: >-
        Where an inference checkpoint's weights are stored in the Together model
        registry. At least one of `model` and `adapter` is set.
      properties:
        model:
          $ref: '#/components/schemas/RL.ModelRegistryArtifact'
          description: >-
            Full model weights. Set for full-weight training, and for LoRA
            training on custom base weights, where the merged model is deployed
            instead of the adapter.
        adapter:
          $ref: '#/components/schemas/RL.ModelRegistryArtifact'
          description: >-
            LoRA adapter weights, deployed on top of the base model. Set for
            LoRA training on the base model's own weights.
    RL.ModelRegistryArtifact:
      type: object
      description: A specific revision of a model in the Together model registry
      required:
        - id
        - revision_id
      properties:
        id:
          type: string
          example: ml_abc123
          description: >-
            ID of the model in the Together model registry, as used by the
            models API
        revision_id:
          type: string
          example: rv_def456
          description: Revision of the model that holds this checkpoint
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      x-bearer-format: bearer
      x-default: default

````

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