List training checkpoints

GET

https://api.fastino.ai

training

jobs

{job_id}

checkpoints

curl https://api.fastino.ai/v1/training/jobs/YOUR_TRAINING_JOB_ID/checkpoints \
  -H "X-API-Key: $FASTINO_API_KEY"

{
  "success": true,
  "checkpoints": [
    {
      "id": "CHECKPOINT_ID",
      "job_id": "YOUR_TRAINING_JOB_ID",
      "epoch": 5,
      "step": 500,
      "training_loss": 0.12,
      "validation_loss": 0.18,
      "is_deployable": true,
      "is_best": true,
      "is_final": true,
      "created_at": "2026-09-22T20:30:00Z",
      "updated_at": "2026-09-22T20:30:00Z"
    }
  ],
  "count": 1
}

GET /v1/training/jobs/{job_id}/checkpoints Returns checkpoints visible for a training job.

Request

string

required

Your Fastino API key.

string

required

Config-job UUID, or the interactive job_id returned by POST /v1/training/jobs/create-model.

curl https://api.fastino.ai/v1/training/jobs/YOUR_TRAINING_JOB_ID/checkpoints \
  -H "X-API-Key: $FASTINO_API_KEY"

Response

boolean

Whether the request succeeded.

object[]

Saved checkpoints. The item shape depends on the job type.

integer

Number of checkpoints returned.

Config job

Config checkpoints include id, job_id, epoch, step, loss, metric, deployment, and timestamp fields. Their id values are not accepted by the interactive checkpoint-download endpoint.

{
  "success": true,
  "checkpoints": [
    {
      "id": "CHECKPOINT_ID",
      "job_id": "YOUR_TRAINING_JOB_ID",
      "epoch": 5,
      "step": 500,
      "training_loss": 0.12,
      "validation_loss": 0.18,
      "is_deployable": true,
      "is_best": true,
      "is_final": true,
      "created_at": "2026-09-22T20:30:00Z",
      "updated_at": "2026-09-22T20:30:00Z"
    }
  ],
  "count": 1
}

Interactive job

Interactive jobs also return run_id. Their checkpoints are live checkpoints, ordered newest first. Use checkpoint_id, such as sampler_weights/checkpoint-1, with the interactive checkpoint-download endpoint. Do not pass the config checkpoint id or tinker_path.

{
  "success": true,
  "run_id": "session-1:train:0",
  "checkpoints": [
    {
      "checkpoint_id": "sampler_weights/checkpoint-1",
      "checkpoint_type": "sampler",
      "time": "2026-09-22T20:30:00Z",
      "tinker_path": "tinker://session-1:train:0/sampler_weights/checkpoint-1",
      "size_bytes": 12345,
      "public": false,
      "user_metadata": null,
      "expires_at": null
    }
  ],
  "count": 1
}

An unknown or inaccessible job returns 404.

curl https://api.fastino.ai/v1/training/jobs/YOUR_TRAINING_JOB_ID/checkpoints \
  -H "X-API-Key: $FASTINO_API_KEY"

{
  "success": true,
  "checkpoints": [
    {
      "id": "CHECKPOINT_ID",
      "job_id": "YOUR_TRAINING_JOB_ID",
      "epoch": 5,
      "step": 500,
      "training_loss": 0.12,
      "validation_loss": 0.18,
      "is_deployable": true,
      "is_best": true,
      "is_final": true,
      "created_at": "2026-09-22T20:30:00Z",
      "updated_at": "2026-09-22T20:30:00Z"
    }
  ],
  "count": 1
}

Inference

Training

Request

Response

Config job

Interactive job

​Request

​Response

​Config job

​Interactive job

Request

Response

Config job

Interactive job