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

# List a session's checkpoints



## OpenAPI

````yaml /api-reference/openapi.json get /v1/sessions/{session_id}/checkpoints
openapi: 3.1.0
info:
  title: Veri API
  description: >-
    REST API for the Veri RL post-training platform. All requests require a
    Bearer API key (`vk_` prefix).
  license:
    name: ''
  version: 0.1.0
servers:
  - url: https://api.veri.studio
    description: Production
security: []
tags:
  - name: Training jobs
    description: Create, monitor, and manage training jobs.
  - name: Datasets
    description: Upload and connect training datasets.
  - name: Deployments
    description: Serve trained models and run inference.
  - name: Volumes
    description: Persistent file storage mounted into jobs.
  - name: Models
    description: Custom model registry deployments serve from.
  - name: Regions
    description: Discover available launch regions.
  - name: GPU
    description: Live GPU availability by provider and region.
  - name: Code artifacts
    description: Upload custom training script bundles.
  - name: Billing
    description: Credit balance and transaction history.
  - name: API keys
    description: Create and revoke API keys.
  - name: Account
    description: The authenticated caller's identity.
  - name: Settings
    description: Account-level integrations (Weights & Biases).
  - name: Metrics
    description: Prometheus metrics export for your own observability stack.
  - name: Evaluators
    description: 'Evaluators: versioned scoring rules (LLM judge, code, human).'
  - name: Experiments
    description: >-
      Experiments: offline runs of a pinned dataset snapshot through a target,
      scored by pinned evaluators.
  - name: Annotation queues
    description: >-
      Human review: queue traces, threads and experiment items, reserve one at a
      time, score them and feed corrections back into datasets.
  - name: Monitors
    description: >-
      Monitors: evaluators scoring a sampled share of a deployment's live
      traffic.
  - name: Observability
    description: Agent conversations, agents and their traffic.
  - name: Public runs
    description: Unauthenticated reads of runs their owners published to Explore.
paths:
  /v1/sessions/{session_id}/checkpoints:
    get:
      tags:
        - Sessions
      summary: List a session's checkpoints
      operationId: list_checkpoints
      parameters:
        - name: session_id
          in: path
          description: Session ID
          required: true
          schema:
            type: string
      responses:
        '200':
          description: Live (unexpired) checkpoints, newest first
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PaginatedList_CheckpointResponse'
        '404':
          description: Not found in this workspace
      security:
        - bearerAuth: []
components:
  schemas:
    PaginatedList_CheckpointResponse:
      type: object
      required:
        - object
        - data
        - has_more
      properties:
        object:
          type: string
        data:
          type: array
          items:
            type: object
            description: >-
              Note the absence of `s3_prefix`: storage layout is not part of the
              API. The

              custom-models design already ruled against exposing bucket paths,
              and keeping

              them internal is what let C1 add a new prefix without an API
              change.
            required:
              - object
              - id
              - job_id
              - step
              - kind
              - payload
              - size_bytes
              - file_count
              - status
              - pinned
              - created_at
            properties:
              object:
                type: string
              id:
                type: string
              job_id:
                type: string
              step:
                type: integer
                format: int32
                description: Trainer global_step. Also addressable as `<job_id>@<step>`.
              kind:
                type: string
              payload:
                type: string
                description: >-
                  "resumable" (includes optimizer state) or "weights" (servable
                  only).
              size_bytes:
                type: integer
                format: int64
              file_count:
                type: integer
                format: int32
              status:
                type: string
              pinned:
                type: boolean
              metrics:
                description: >-
                  Loss/reward at this step, so picking the best step is a list
                  call.
              created_at:
                type: string
                format: date-time
              expires_at:
                type:
                  - string
                  - 'null'
                format: date-time
        has_more:
          type: boolean
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API key
      description: API key with the `vk_` prefix. Create one from the dashboard.

````

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