Use OpenAI Codex / ChatGPT as a Home Assistant Assist conversation agent.
Codex Assist signs in with Codex-style ChatGPT device-code auth, adds Codex as a selectable Assist conversation agent, and keeps device control inside Home Assistant's normal exposed-entity safety model.
Experimental: this project is not affiliated with OpenAI or Home Assistant. Codex backend compatibility may change with upstream Codex updates.
Requirements: Home Assistant 2026.5.0 or newer, HACS, and a ChatGPT account/plan with Codex access.
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In Home Assistant, open HACS → Custom repositories.
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Add this repository as an Integration:
https://github.com/itsreverence/ha-codex-assist -
Install Codex Assist.
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Restart Home Assistant.
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In ChatGPT, enable Settings → Security → Enable device code authorization for Codex if it is available on your account.
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Go to Settings → Devices & services → Add integration, or use the button above.
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Search for Codex Assist and complete device-code sign-in.
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Select Codex Assist in your Assist pipeline.
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Test with a harmless exposed entity first, like a single light.
- Use eligible ChatGPT/Codex subscription access instead of wiring Home Assistant to OpenAI API billing.
- Pick Codex as a normal Home Assistant Assist conversation agent.
- Let Home Assistant's Assist exposed-entity controls define what the agent can see or control.
- Ask about exposed entity state and request simple actions in the same Assist chat.
- Stream replies in Assist while Codex is answering.
- Configure model, prompt, reasoning effort, reasoning summary, and text verbosity from the integration options flow.
- Use Home Assistant AI Task for structured data generation, attachment-aware prompts, and subscription-backed image generation with curated image quality and size controls.
Codex Assist does not expose a raw “call any Home Assistant service” bridge. It routes control through Home Assistant's Assist LLM API, so your Assist exposed entities list is the practical safety boundary.
Start with harmless lights or read-only questions. Keep locks, alarms, garage doors, water shutoff valves, covers, and other sensitive devices unexposed unless you deliberately want Assist control there.
The GitHub Wiki is the main user manual: