Authentication and scopes
Send Authorization: Bearer on API requests. The hosted execution MCP instead uses X-Dreamtune-API-Key. Neither key is a Clerk dashboard session. A session label or end-user ID annotates an execution; it cannot select another tenant. Use models:read/models:run, tools:read/tools:run and compute:read/compute:run as selected in your key. Missing access fails explicitly.Creation and replay
Billable creation requires Idempotency-Key with 16–128 characters using ASCII letters, numbers, underscores or hyphens. Persist it before submission. Identical replay recovers the same operation. Changed input or attribution with the same key conflicts. A fresh key means a new operation and possible charge. A timeout leaves the execution outcome uncertain. Do not automatically repeat paid execution with another key. Read the saved operation, then reconcile its status. There is no automatic provider, model or credential substitution.HTTP versus execution state
Do not treat an HTTP 200 containing state failed as successful generation.
See errors for recovery by symptom.