7 Node.js checks for image generation

The dev.to article introduces a Go contract and a checklist that guarantees exactly-once image generation for candidate scorecards in a Node.js hiring platform [Dev.to]. The guide ships a imagejob package written in Go that defines a Job struct, an Asset envelope, and a GenerateWithPolicy orchestrator [Dev.to]. This contract enforces a SHA-256-based idempotency key, validates required fields, and records each attempt through an Audit interface. The article also publishes a seven-step checklist that must run before any provider call:

1. Confirm rubric JSON passes schema and domain validation.
2. Verify the prompt derives from the immutable scoring run.
3. Resolve the logical model via a versioned catalog.
4. Bind the idempotency key to the semantic request.
5. Record the chosen route and policy version.
6. Permit fallback only for failure classes listed in policy.
7. Validate the returned media type, content digest, size, and provenance. Each step is tied to a concrete code path; for example, the GenerateWithPolicy function aborts on missing Asset fields and only retries when the error matches ErrTemporarilyUnavailable [Dev.to]. The checklist ensures idempotent audit trails, provider-agnostic fallback, and compliance boundaries. The SHA-256 hash guarantees that duplicate network calls cannot produce divergent assets [Dev.to]. An OpenAI-compatible contract does not guarantee that two providers accept the same model name or moderation policy, so the catalog-driven routing forces teams to map logical model classes to concrete provider-model pairs [OpenAI Docs]. The guide stresses that the hash is not an encryption mechanism and that candidate data must never appear in logs or telemetry, aligning with GDPR-style retention rules [pgvector].