Training API Contract

Simple Summary

Scooling Lab exposes a small local training contract that only runs a synthetic fake-worker job. It does not train a model, install Unsloth, use private data, call external workers, or create model files.

Routes

• POST /training/jobs: createTrainingJob.
• GET /training/jobs/{job_id}: getTrainingJob.
• POST /training/jobs/{job_id}/cancel: cancelTrainingJob.
• GET /training/jobs/{job_id}/artifacts: listArtifacts.
• GET /training/jobs/{job_id}/provenance: getProvenance.
• DELETE /training/jobs/{job_id}/artifacts/{artifact_id}: deleteArtifact.

createTrainingJob Request

Allowed fields:

• idempotencyKey: safe identifier.
• datasetId: must be fixture:synthetic-tiny-v1.
• modelId: must be fixture-tiny-llm.
• requestedBy: non-secret caller label.
• retentionPolicy: optional bounded policyClass and ttlSeconds.
• trainingParameters: bounded epochs, learningRate, and dryRun: true.

Rejected at schema validation:

• Unknown fields.
• Worker URLs.
• Callback or webhook URLs.
• File paths or model paths.
• Shell strings or command fields.
• Unapproved model ids.
• Non-fixture dataset ids.

State Machine

Cancellation is accepted only from queued or running. Replaying the same state is idempotent. Every other transition returns INVALID_TRANSITION.

Provenance Records

Completed fixture jobs emit exactly one provenance record:

• jobId.
• datasetHash.
• artifactHash.
• baseModelId.
• trainingConfigHash.
• createdAt.
• schemaVersion.

The schema accepts only hashes, compact ids, and UTC timestamps. Unknown fields, path-like values, URL-like values, whitespace-bearing free text, prompts, document text, local paths, and token-shaped payloads are rejected by scooling_lab.provenance.validate_provenance_record. CI runs python -m scooling_lab.provenance --self-check.

listArtifacts includes provenanceRecordId, retentionPolicy, and expiresAt for each visible artifact. Deleted or expired artifacts are excluded.

Retention And Deletion

Retention policy classes are ephemeral, standard, and extended. Each class has bounded TTLs, and callers may only choose a TTL inside the class range. Expiry is evaluated on artifact, job, and provenance reads, and can also be evaluated explicitly through the sweep function.

deleteArtifact is idempotent. The cascade removes the artifact placeholder, artifact metadata, and provenance record. The job id remains as a deleted tombstone with no request, dataset, model, training parameter, artifact hash, dataset hash, or provenance fields. Deletion verification checks that the deleted artifact's hashes are absent from every public and persisted store serialization.

Safe Error Codes

• VALIDATION_ERROR.
• MALFORMED_JSON.
• NOT_FOUND.
• INVALID_TRANSITION.
• QUEUE_LIMIT_EXCEEDED.
• METHOD_NOT_ALLOWED.
• CONFLICT.
• INTERNAL_ERROR.

Errors return a stable code and public message only. They do not echo payloads, local paths, stack traces, worker addresses, or request bodies.

Fixture Queue And Quota Policy

The fake-worker queue defaults to five queued or running jobs. Duplicate create requests with the same validated request shape return the same deterministic job id. New jobs beyond the queue limit return QUEUE_LIMIT_EXCEEDED.

Audit Event Names

The T2 fake contract reserves these audit event names for later durable audit wiring:

• training.job.create.accepted.
• training.job.create.rejected.
• training.job.state.transitioned.
• training.job.cancel.accepted.
• training.job.cancel.rejected.
• training.artifact.placeholder.registered.
• training.artifact.provenance.recorded.
• training.artifact.deleted.
• training.artifact.retention.swept.
• training.bom.audit.passed.
• training.bom.audit.failed.