Adam SmithandClaude Opus 5
b79164b60c
Writes up what is still OpenAI-specific in this fork, since the base URL being configurable is what makes it reach a compatible endpoint, not what makes it behave correctly against one. Four findings, each with what it actually costs: 1. service_tier, store and prompt_cache_retention are sent on every request whatever the provider is (entity.py:515-563); reasoning, include and text.verbosity are gated on OpenAI name prefixes. 2. 23 startswith() model-name gates plus the UNSUPPORTED_* lists infer capability from OpenAI naming, which fails in both directions: service tier, code interpreter and web search are offered to providers that cannot honour them, while reasoning effort/summary and verbosity are withheld from any model whose name does not look like OpenAI's. 3. manufacturer="OpenAI" and the "Error talking to OpenAI" error text. 4. Repair issues citing core's 2026.9.0 removal schedule, which has passed and was never this fork's commitment, and an OpenAI-only organization-verification repair. Two things worth having written down beyond the list itself: - A proxy set to drop incompatible parameters hides finding 1 entirely and makes finding 2 worse, because a dropped parameter turns a misconfigured option into a silent no-op rather than an error. Testing only against such a proxy therefore says nothing about portability, and a strict server is the honest target. This reorders the priorities: finding 2 first, since it is what the user sees and the failure is silent; finding 1 matters for setups without a normalising proxy. - The prerequisite decision is recorded rather than assumed. There is no capability discovery in the OpenAI API -- GET /v1/models returns ids, not feature support -- so the three candidates (per-entry capability toggle, host detection, per-endpoint checkboxes) are laid out with their trade-offs and explicitly marked unsettled. No behaviour change; the README links it from a short "known OpenAI-specific behaviour" section so it is findable from the front page. Local: 170 passed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NxJYWgGJtCw13qUHZtG8ki
OpenAI Compatible for Home Assistant
Home Assistant's built-in OpenAI integration, with one change that matters: the
API base URL is configurable. Point Home Assistant's conversation agent, AI Task,
speech-to-text and text-to-speech at any OpenAI-compatible endpoint — LiteLLM, vLLM,
OpenRouter, a gateway of your own — instead of only api.openai.com.
Everything else is upstream Home Assistant code, vendored unmodified, so behavior and options match the core integration you already know.
Why this exists
Core's openai_conversation hardcodes OpenAI's endpoint. If you run a proxy for cost
control, routing, key management or privacy, or you self-host models, there is no way to
tell the core integration about it. This fork adds a Base URL field to the config
flow and threads it to every client it creates.
How it is organised
One entry per server or provider, and one endpoint per model underneath it. Setup asks only for the connection; nothing is created on your behalf. You then add endpoints yourself, picking the type and the model each time — so a single LiteLLM entry can carry a conversation agent on one model, another on a second, and a TTS endpoint on a third.
Each endpoint is one of four types, and each becomes its own Home Assistant entity:
- Conversation agent — an Assist conversation entity, with the LLM Assist API, tool calling, and the full upstream option set (model, temperature, top-p, max tokens, reasoning effort, verbosity, web search, code interpreter, service tier, …)
- AI Task — for
ai_task.generate_data/ image generation - Speech-to-text — an STT entity
- Text-to-speech — a TTS entity, with speed control
Plus two actions on the entry itself: openai_compatible.generate_content and
openai_compatible.generate_image.
Requirements
- Home Assistant 2026.9.0 or newer
- An OpenAI-compatible endpoint (see Endpoint compatibility)
Installation
HACS (custom repository)
- HACS → ⋮ → Custom repositories
- Add
https://github.com/adamjs83/ha-openai-compatible, category Integration - Find OpenAI Compatible in HACS, download it, and restart Home Assistant
- Settings → Devices & services → Add integration → OpenAI Compatible
Manual
Copy custom_components/openai_compatible/ into your Home Assistant
config/custom_components/ directory and restart.
Configuration
1. Add the provider
| Field | Notes |
|---|---|
| Name | Label for this provider, e.g. LiteLLM. Leave blank to use the endpoint's host. |
| Base URL | Full URL including any version path, e.g. https://api.openai.com/v1. Passed to the OpenAI SDK as-is. |
| API key | Optional — leave blank for an endpoint that does not authenticate. |
Submitting it checks the connection with GET /v1/models and creates the entry. No
entities are created yet, deliberately: guessing them would mean pointing STT and TTS at
OpenAI model names your provider probably does not serve.
You can add several entries for the same server — one per provider-side key, say. Upstream refuses this as a duplicate; this fork does not.
2. Add endpoints for the models you want
On the entry, use Add conversation agent / Add AI task / Add speech-to-text /
Add text-to-speech. Each flow offers a model dropdown populated from that
provider's own GET /v1/models, read when you open the form, so it lists what is
actually available right then. The dropdown also accepts a typed-in name, for a provider
that routes models it does not advertise (LiteLLM wildcard routes, for instance), and
falls back to a plain text box if the endpoint will not list models at all.
Repeat per model. Name each endpoint something you will recognise in Assist — the subentry title becomes the entity name.
Base URL rules
- Only
httpandhttpsare accepted; the URL must include a host. - Whitespace and trailing slashes are stripped.
- Include the version path if your server expects one. Most do:
/v1. - Credentials embedded in the URL (
https://user:pass@host/v1) are rejected. Put the token in the API key field — it is stored as a secret and kept out of logs, while a base URL is echoed back in error and log messages. - Re-authenticating (rotating the API key) keeps your configured base URL.
Empty API keys
Local endpoints often require no auth. Leave the API key blank and the integration sends
the placeholder not-required — the OpenAI SDK refuses to build a client with no key at
all, so something has to be sent, and servers that ignore auth ignore it.
Endpoint examples
| Server | Typical base URL |
|---|---|
| OpenAI | https://api.openai.com/v1 |
| LiteLLM | http://litellm.local:4000/v1 |
| vLLM | http://vllm.local:8000/v1 |
| OpenRouter | https://openrouter.ai/api/v1 |
| Azure OpenAI (via a proxy) | your proxy's URL |
Endpoint compatibility
This is the important caveat. Upstream uses OpenAI's Responses API, not Chat
Completions, so a server that only implements /v1/chat/completions will not work
for conversation or AI Task.
| Feature | Endpoint the server must implement |
|---|---|
| Setup / connection test | GET /v1/models |
| Conversation, AI Task | POST /v1/responses |
| Text-to-speech | POST /v1/audio/speech |
| Speech-to-text | POST /v1/audio/transcriptions |
generate_image action |
POST /v1/images/generations |
You only need the endpoints for the subentries you actually add. Check your server's docs for Responses API support before filing a bug — LiteLLM and vLLM have it in recent versions; several popular local servers still do not.
Model names
Pick from the dropdown and this mostly takes care of itself. Two upstream behaviours to know about anyway:
- The fallback defaults are OpenAI's (
gpt-4o-mini,gpt-4o-mini-tts,gpt-4o-mini-transcribe), used only if you never choose a model. A new endpoint starts with Recommended settings unticked so the flow always asks. - Upstream's lists of models that don't support web search, image generation, reasoning effort and so on are keyed to OpenAI names, so they won't match a third-party model string. Options are offered based on those name patterns, and the endpoint's own error is what you'll see if you ask for something it can't do.
Known OpenAI-specific behaviour
The base URL is configurable, but much of the rest is still upstream's OpenAI-shaped logic: some request parameters are sent to every provider, and which options the config flow offers is inferred from OpenAI model-name prefixes. That means options can appear for endpoints that cannot honour them, and be withheld from endpoints that could.
docs/provider-genericity.md has the full audit, what
each item costs, and the design decision that has to be made first.
Relationship to Home Assistant core
custom_components/openai_compatible/ is derived from
homeassistant/components/openai_conversation/ at core tag 2026.9.2
(commit recorded in UPSTREAM_COMMIT),
with the domain renamed to openai_compatible and the base URL made configurable.
Base-URL handling lives in its own module,
url_util.py, deliberately separate
from the vendored files so re-syncing with core stays a clean merge.
Installing this alongside core's OpenAI integration is fine — different domain, separate config entries. This is not an official Home Assistant integration and is not affiliated with or endorsed by OpenAI.
Development
Requires Python 3.14+ (Home Assistant 2026.9's floor).
pip install -r requirements_test.txt
pytest tests/ -v
The suite is core's openai_conversation test suite, ported as a regression net, plus
tests for the base-URL behavior this fork adds.
Releases
HACS falls back to serving the default branch when a repository has no releases, so
every download looks identical and there is no way to tell what is installed. Tagged
releases fix that, and Home Assistant shows manifest.json's version on the
integration page.
Versions are 0.x while the config entry shape is still changing; 1.0.0 when it
settles.
To cut one:
python scripts/release.py 0.2.0
git push origin main --follow-tags
The script bumps manifest.json, commits, and creates the annotated tag v0.2.0. It
deliberately does not push — pushing the tag is what publishes. That triggers
release.yaml, which refuses to publish if the tag
and the manifest version disagree (HACS reads the tag, HA reads the manifest; when they
drift you install "v0.2.0" and it reports 0.1.0) and then creates the GitHub release.
License
Apache-2.0, inherited from Home Assistant core. See NOTICE for attribution.