# Move from the OpenAI API The exchange serves Chat Completions and a stateless part of Responses. Most OpenAI code changes in two places: the base URL and the API key. Model names, and features that need OpenAI to keep state, need more work. For setup, see [OpenAI SDK](https://inference.ai.exchange/docs/connect-openai-sdk.md). ## Change these three things 1. Issue a `spend` key on the **API keys** page. See [API keys](https://inference.ai.exchange/docs/keys.md). 2. Set the base URL to `https://router.inference.ai.exchange/v1` (or `OPENAI_BASE_URL`). Send the key as `Authorization: Bearer sk-liquid-…` (or `OPENAI_API_KEY`). 3. Change each `model` to a name that `GET /v1/models` lists. See [Model names](#model-names). Then check these: - Remove each parameter that the exchange refuses. See [OpenAI features](#openai-features). - Run a dry run. See [Check a request without a purchase](https://inference.ai.exchange/docs/move-from-openrouter.md#check-a-request-without-a-purchase). - Read [What is different about money](https://inference.ai.exchange/docs/move-from-openrouter.md#what-is-different-about-money). The exchange never lowers an output limit that you set. See [Output limits](https://inference.ai.exchange/docs/errors.md#output-limits). ## What differs - **Model names.** An unknown name, or a fine-tuned model, returns `404 model_not_found`. - **`n` greater than 1.** Refused. OpenAI bills every choice, and the exchange serves one. - **State in Responses.** `previous_response_id`, `conversation` and `background: true` are refused. Send the full conversation in `input`. - **Hosted tools.** The exchange runs none. It removes `web_search` with the header `x-liquid-notice: web_search_dropped` and refuses the others. To search the web, add `:web` (beta) to the model name. - **Not available.** The Batch, Files, Assistants and Moderations APIs, and image edits. - **Retries.** The SDK retries a `5xx` response, and each try is a new request. To get the first response again, send the same `idempotency-key` header. See [Purchasing rules](https://inference.ai.exchange/docs/rules.md#headers). With `with_raw_response`, the SDK returns the headers, including `x-liquid-cap-usd`. ## Example An OpenAI request, then the same request for the exchange. The new request changes the client and the model, removes `n=2` (refused) and `store` and `service_tier` (ignored), and adds a cap and a data rule. `user` stays, because it names the end user for guardrail limits. The model name is an illustration. ```python from openai import OpenAI client = OpenAI() response = client.chat.completions.create( model="gpt-4o", messages=[{"role": "user", "content": "Say hello."}], max_completion_tokens=500, n=2, store=True, service_tier="auto", user="user-123", ) ``` ```python import os from openai import OpenAI client = OpenAI( base_url="https://router.inference.ai.exchange/v1", api_key=os.environ["LIQUID_API_KEY"], ) response = client.chat.completions.create( model="gpt-oss-120b", messages=[{"role": "user", "content": "Say hello."}], max_completion_tokens=500, user="user-123", extra_body={"exchange": {"cap_usd": 0.05, "privacy": {"retention": "none"}}}, ) ``` ## Reference ### Model names Send a name that `GET /v1/models` returns. The `model` field accepts a model, a router model, a basket or a preset. See [Model names](https://inference.ai.exchange/docs/move-from-openrouter.md#model-names). The exchange never uses a different model. `max_completion_tokens`, `max_tokens` and `max_output_tokens` (Responses) are all accepted. Reasoning tokens count toward the limit. ### OpenAI features | OpenAI feature | What the exchange does | | -------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `stream`, `stream_options` | Applied. Set `stream_options: {"include_usage": true}` to get token usage in a stream. | | `tools`, `tool_choice` | Applied. Only an offer that declares tool support can win. | | `parallel_tool_calls`, `service_tier`, `include`, `truncation`, `safety_identifier`, `metadata` | Ignored. For `metadata`, send `x-liquid-tag` to label spend. See [Cost tags](https://inference.ai.exchange/docs/rules.md#cost-tags). An input too long for an offer excludes it. | | `response_format` | Applies `json_schema` and `json_object`. Only an offer that declares support can win. See [Structured output](https://inference.ai.exchange/docs/errors.md#structured-output). | | `reasoning_effort`, `reasoning.effort` (Responses) | Applied to offers that support the level, or `unsupported_parameter`. | | `temperature` | Applied. | | `top_p`, `top_k`, `min_p`, `repetition_penalty`, `stop`, `seed`, `logprobs`, `top_logprobs`, `logit_bias`, `frequency_penalty`, `presence_penalty` | Passed to a provider that declares support. If no offer supports one, `unsupported_parameter`. `/v1/responses` refuses `logprobs` and `top_logprobs`. | | `n` greater than 1 | `400 unsupported_parameter`, `param` is `n`. | | `store` | Ignored. The exchange keeps no response. To limit what a provider keeps, send `exchange.privacy.retention: "none"`. See [Data handling](https://inference.ai.exchange/docs/data-handling.md). | | `user` | Names the end user for the limits of a [guardrail](https://inference.ai.exchange/docs/guardrails.md#end-users). The `X-Liquid-End-User` header wins. | | `prompt_cache_key` | Read into the cache plan of the job. See [Prompt caching](https://inference.ai.exchange/docs/caching.md). | | `previous_response_id`, `conversation`, `background: true` (Responses) | `400 unsupported_parameter`. Send the full conversation in `input`. | | Hosted tool `web_search` (Responses) | Removed, with `x-liquid-notice: web_search_dropped`. No search runs. Add `:web` (beta) to the model name. See [Quickstart](https://inference.ai.exchange/docs/quickstart.md#web-access). | | Other hosted tools: `file_search`, `code_interpreter`, `mcp` | `400 unsupported_parameter`, `param` such as `tools[1]`. Declare your own function. | | Embeddings, image generation, speech and video endpoints | Served. See [Embeddings](https://inference.ai.exchange/docs/embeddings.md), [Modalities](https://inference.ai.exchange/docs/modalities.md) and [Move from the Sora API](https://inference.ai.exchange/docs/move-from-sora.md). | | Batch, Files, Assistants, Moderations, image edits, fine-tuning (`ft:` names) | Not available. Send each request on its own. | ### Troubleshooting For `402 insufficient_balance` and `400 no_eligible_offer` with `param` set to `exchange.cap_usd`, see [What is different about money](https://inference.ai.exchange/docs/move-from-openrouter.md#what-is-different-about-money). | Error | Cause | Fix | | -------------------------------------------------------------- | ------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | | `404 model_not_found` | The `model` is an OpenAI name that the exchange does not list. | Pick a name from `GET /v1/models`. | | `400 unsupported_parameter`, `param` is `n` | The request asks for more than one choice. | Remove `n`. | | `400 unsupported_parameter`, `param` is `previous_response_id` | The Responses request asks the exchange to keep state. | Send the full conversation in `input`. | | `400 unsupported_parameter`, `param` is `tools[...]` | The request has a hosted tool that the exchange does not run. | Remove the tool, or declare your own function. | | `400 unsupported_parameter`, `param` is another field | No offer for the model supports that parameter. | Remove the parameter, or select another model. See [Errors](https://inference.ai.exchange/docs/errors.md). | | `402 insufficient_balance` | The cheapest eligible cap is more than the balance. | Add funds, or send a lower output limit. | | `429 rate_limited` | Too many requests from the address, or a guardrail rate limit refused the call. | Wait for `Retry-After`. OpenAI limits do not apply here. See [Guardrails](https://inference.ai.exchange/docs/guardrails.md#rate-limits). | | `503 provider_failed` or `503 model_unavailable` | The awarded provider failed, or no seller can serve the model now. | Set `max_retries` yourself, and send the same `idempotency-key` on a retry. See [Purchasing rules](https://inference.ai.exchange/docs/rules.md#headers). |