OpenAI Codex · tool · fg-0499

Codex fails to load its config when a model provider still sets wire_api = "chat"

failed to load Codex config, and codex doctor reports config could not be loaded

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

Current Codex releases support only Responses API endpoints for custom providers; wire_api chat and Chat Completions-only gateways are no longer accepted.

Fix

Point the provider at a Responses-compatible endpoint with wire_api responses, put a Responses-compatible gateway in front of the old one, or delete the stale provider entry.

Apply

[model_providers.proxy]
name = "Company proxy"
base_url = "https://proxy.example.com/v1"
wire_api = "responses"

Affects: Codex CLI 0.59 and later dropped chat for most uses; config load failure reported on 0.151.0; as of 2026-10

Sources

Have your agent know this before it fails

claude mcp add --transport http footgun https://getfootgun.com/api/mcp