401 invalid_developer_key with a valid provider key
The gateway needs its own ACE developer key on every call; a provider key alone leaves the request with no ACE identity.
Symptom
Calls fail with HTTP 401 and x-ace-error: invalid_developer_key, although the OpenAI, Anthropic or other provider key you sent works when you call the provider directly.
Cause
ACE uses two credentials. The ACE developer key identifies your org to ACE; the provider key says which upstream account to bill. Only ace_dev_ and ace_tok_ prefixes count as an ACE key: a credential starting with neither is treated as a provider key, which leaves the request with no ACE identity — a 401. There is no anonymous fallback.
Fix
Send the ACE key as Authorization: Bearer ace_dev_... and the provider key on its pass-through header (x-ace-openai-key, x-ace-anthropic-key, …). On a vendor-shaped surface the ACE key goes on the header that vendor's SDK already sends: x-api-key on /anthropic/v1/messages, api-key on /azure/openai/….