Sume TTS source errors: which are safe to retry (status table)

Sume's script-source API for text-to-speech returns a small, fixed set of tts_ error codes. The question for client code is simple: retry, fix the request, or re-read state first. Every code below is raised before a provider call is dispatched, so a failed request creates no job and is not billed. Branch on code, not on the message wording.

Sume bills Sume TTS at $0.0475 per 1,000 characters, rounded up to the cent per job, and only for jobs that run.

Code by code

Idempotency

Generate calls take an idempotency-key header. Keep the same key when you retry the same request after a 503, so one logical line becomes one job. Change the key when you change the request, since the key names the request, not the attempt.

A small handler

Only the 503 is retried blindly. The 409 triggers a re-read.

RETRY_BLIND = {"tts_source_store_unavailable"}
REREAD = {"tts_source_revision_mismatch"}

def action(status, code):
    if code in RETRY_BLIND or status == 503:
        return "retry-with-backoff"
    if code in REREAD:
        return "reread-manifest"
    return "fix-request"

print(action(409, "tts_source_revision_mismatch"))
print(action(503, "tts_source_store_unavailable"))
print(action(422, "tts_source_too_large"))