Run OpenAI Codex CLI on any model

OpenAI's official CLI coding agent - use antseed codex for per-run proxy config.

Coding agentsOpenAI Chat Completions~2 min

Codex is OpenAI's terminal coding agent. Recent versions ignore OPENAI_BASE_URL and instead read provider config from Codex settings.

antseed codex supplies that provider config for one run with Codex -c overrides, points it at the active buyer proxy, sets the placeholder API key, and leaves your real CODEX_HOME untouched.

If you prefer a persistent manual setup, create ~/.codex/antseed.config.toml and launch Codex with codex --profile antseed; the wrapper is still the shortest path for one-off sessions.

Run AntSeed first

Every integration assumes a buyer proxy at http://localhost:8377. One-time setup, ~2 minutes.

Step 1

Install OpenAI Codex CLI

Install Codex globally
npm install -g @openai/codex
Verify it runs
codex --version

Step 2

Point OpenAI Codex CLI at AntSeed

antseed codex --model deepseek-v4-flash

Recommended: the wrapper resolves the proxy URL, injects an AntSeed model provider with wire_api = "responses", sets ANTSEED_API_KEY=antseed, and forwards extra Codex args. Put child flags after -- when they look like wrapper flags. To route to a specific peer, prefix the model with its peer id: antseed codex --model <peerId>@deepseek-v4-flash.

~/.codex/antseed.config.toml

# Loaded by: codex --profile antseed # Set this to a service id returned by http://localhost:8377/v1/models # after pinning an AntSeed peer. model = "deepseek-v4-flash" model_provider = "antseed" [model_providers.antseed] name = "AntSeed" base_url = "http://localhost:8377/v1" wire_api = "responses"

Manual profile only: this must be your **user-level** ~/.codex/antseed.config.toml, then launch with codex --profile antseed. If your buyer proxy uses a non-default port, update base_url to match it. Project-local ./.codex/config.toml provider blocks are ignored by Codex.

No real OpenAI key is needed. The AntSeed proxy authenticates with your local buyer identity; the wrapper and manual profile both point Codex at the local proxy instead of OpenAI.

Step 3

Pick a model

deepseek-v4-flashkimi-k2.6qwen3-coder-480bminimax-m2.7

Pass the peer service id to antseed codex --model <service-id>. For a manual profile, set top-level model = "<service-id>" in ~/.codex/antseed.config.toml or override with codex --profile antseed --model <service-id>. Route to a specific peer by prefixing the model: <peerId>@<service-id>.

The exact list of models depends on which peer you pin. Run antseed network browse or open the live network page to see what's available right now.

Verify

Test it

See which service ids your pinned peer exposes
curl -s http://localhost:8377/v1/models | jq '.data[].id'
Example response
"deepseek-v4-flash" "gpt-oss-120b" "kimi-k2.6" "minimax-m2.7"
Whatever appears here is a valid value for top-level model = ... in ~/.codex/antseed.config.toml (or for codex --profile antseed --model <id>).
Run Codex through the wrapper
antseed codex --model deepseek-v4-flash
Manual profile equivalent: codex --profile antseed --model deepseek-v4-flash.
Verify inference is actually paid through AntSeed
open http://localhost:3118 # or: antseed buyer status
What to look for after one real prompt
Deposits available: 4.289391 USDC → 3.289391 USDC Deposits reserved: 0 USDC → 1 USDC
The buyer dashboard at http://localhost:3118 is the authoritative real-time signal: a non-zero Reserved (channel opened) and/or a drop in Available (settled spend) after a real prompt confirms AntSeed served the request. The antseed buyer status CLI output is cached and may lag the dashboard - refresh the web view for confirmation. Do not rely on lsof -i | grep codex or ~/.codex/log/codex-tui.log: Codex keeps persistent TCP connections to Cloudflare/ChatGPT IPs (e.g. 172.64.0.0/13) for non-inference purposes (the cause was not isolated during testing), and the provider=OpenAI lines in the TUI log are not a reliable indicator that inference went to OpenAI - the on-chain numbers can show AntSeed served the request despite that log line.

How OpenAI Codex CLI talks to AntSeed

Wire format sent by OpenAI Codex CLI: OpenAI Chat Completions (hits /v1/chat/completions on the buyer proxy)
Best-fit services: any service whose protocols array contains openai-chat-completions. That's what the peer advertises as natively-supported - zero translation overhead, no transform edge cases.
How to check a peer: run antseed network peer <peerId> --json and look at providerServiceApiProtocols[provider].services[service]. The browse command exposes the same field per peer.
What happens when protocols don't match: AntSeed's @antseed/api-adapter translates between OpenAI Chat Completions and the service's native protocol on the fly. So a request from OpenAI Codex CLI can still reach a service that only advertises anthropic-messages - just with a small transform step.
One known caveat: services whose only advertised protocol is openai-responses require streaming. If OpenAI Codex CLI sends a non-streaming request and the proxy routes it to one of those services, the call fails with HTTP 400: Stream must be set to true. Pick a service whose protocols includes openai-chat-completions (or another non-responses protocol) to avoid this.

If it goes wrong

Troubleshooting

OPENAI_BASE_URL / OPENAI_API_KEY are being ignoredExpected on recent Codex builds. Use antseed codex --model <service-id> so the wrapper injects the provider config for the current run, or use the manual ~/.codex/antseed.config.toml profile above.
How can I tell if Codex is actually routing through AntSeed?Check the buyer dashboard at http://localhost:3118 (or antseed buyer status) after sending a test prompt. Reserved going from $0 to a non-zero value (a channel was opened) and/or Available dropping (spend settled) confirms AntSeed served the request. If both stay flat after a real prompt, the profile is not being applied. Do not trust lsof connections to Cloudflare IPs or provider=OpenAI lines in ~/.codex/log/codex-tui.log - neither is a reliable routing signal.
Codex prints Ignored unsupported project-local config keys … model_provider, model_providersProvider settings must live in your **user-level** Codex profile file. For this manual flow, put the top-level model, model_provider, and [model_providers.antseed] block in ~/.codex/antseed.config.toml, then relaunch with codex --profile antseed. Codex silently rejects provider blocks in project-local ./.codex/config.toml and falls back to its default provider.
Hand-written Codex -c provider overrides behave inconsistentlyUse antseed codex --model <service-id> so AntSeed supplies the complete provider block (base_url, wire_api, and model_provider) for the current run. If managing config yourself, keep the full provider/profile in user-level ~/.codex/antseed.config.toml.
Streaming stops after the first chunk with a manual profileUse antseed codex, or set wire_api = "responses" in the manual [model_providers.antseed] block.
unknown profile: antseedCodex caches profile config on launch. Make sure you saved ~/.codex/antseed.config.toml, then start a fresh codex --profile antseed session.
Hangs forever on first messageNo peer is pinned. Run antseed network browse, then antseed buyer connection set --peer <peerId>.

Reference

Links

Codex repo Codex sample config

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