bug: From Codex CLI: `Support for the "chat" wire API is deprecated and will soon be removed. Update your model provider definition in config.toml to use wire_api = "responses".`

[jeremyckahn]

Version: v0.7.5

Describe the Bug

When using Jan's API server via Codex CLI, this deprecation notice is shown:

⚠ Support for the "chat" wire API is deprecated and will soon be removed. Update your model provider definition in config.toml to use wire_api = "responses".

This appears to be related to openai/codex#7782. Notably, from that issue:

In February 2026, this will transition to a hard error as support is fully removed.

Steps to Reproduce

1. Install Codex CLI
2. Configure Codex to use Jan as a model provider
3. Observe the deprecation notice

Sample Codex config:

profile = "jan"
model = "gpt-oss-120b-Q4_K_M.gguf"
model_provider = "jan"
show_raw_agent_reasoning = true
model_context_window = 131072

[model_providers.jan]
name = "Jan"
base_url = "http://localhost:1337/v1"
env_key = "JAN_API_KEY"
# When this line is uncommented, Codex errors out because Jan's API is incompatible
#wire_api = "responses"

[profiles.jan]
name = "Jan"
model_provider = "jan"
model_reasoning_effort = "high"

Screenshots / Logs

Operating System

• MacOS
• Windows
• Linux

[jeremyckahn]

In case it's helpful, support for the "responses" API is being implemented in llama.cpp: ggml-org/llama.cpp#18486