Quickstart

Send an ordinary OpenAI or Anthropic request to the exchange. Providers compete to answer it. You pay for the tokens that the job used, and never more than a price cap that the exchange fixes before the first token.

This page is for buyers. To sell inference, start with Become a provider.

To make your first request, follow steps 1 and 2. They need a key and one curl command.

1. Get a key

1. Sign up. Sign-up creates a workspace. A workspace holds your balance, your API keys and your receipts.
2. Open the API keys page and choose Create key.
3. Copy the key. The page shows it one time only.

A new workspace gets a starting credit, so you can send your first requests without a card. Your first top-up of $10 or more adds $2 of free credit. The Credits page shows your balance.

A key looks like sk-liquid-<key-id>-<secret>. See API keys for scopes and spending limits.

2. Send a request

curl https://router.inference.ai.exchange/v1/chat/completions \
  -H "Authorization: Bearer $LIQUID_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-oss-120b",
    "messages": [{"role": "user", "content": "Say hello."}]
  }'

The response is a normal chat completion with one more field, exchange. It tells you what the job cost.

3. Read what you paid

Each provider posts standing offers: a price for each model. The exchange picks the best offer for your request, holds the price cap from your balance, and charges the tokens that the job used. It returns the rest of the cap to your balance.

A receipt records each settled job. It does not change after settlement. The Overview and Credits pages list your receipts.

To read a receipt in code, use a key with the read scope or higher:

curl https://router.inference.ai.exchange/v1/exchange/jobs/<job_id> \
  -H "Authorization: Bearer $LIQUID_API_KEY"

The exchange writes the receipt just after it answers. A call at once can return 404. Try again after a moment.

To set your own price cap, add "exchange": {"cap_usd": 0.05} to the request body. To choose models, regions or a ranking, see Purchasing rules.

4. Point your tool at the exchange

A tool needs a base URL and your key. The two formats use different base URLs, because each client adds its own path.

The Connection guides give the steps for Claude Code, Codex, Cursor, Cline, the official SDKs and many other tools. If your code now sends requests to another product, use its guide: OpenRouter, LiteLLM, the OpenAI API, the Anthropic API or Portkey. To start a coding agent from the terminal, use the Liquid CLI.

Next steps

• API keys: scopes, spending limits and expiry.
• Purchasing rules: choose the models, the ranking and the limits for each request.
• Market data: read the book, the list of current offers, before you send a request.
• Modalities: send an image, an audio clip or a document.
• Errors: the error format and the error codes.

Reference

Endpoints

The exchange also serves images, speech, video and embeddings. See Modalities and Embeddings. The API reference lists every endpoint.

Choose a model

The model field accepts these kinds of name:

To rank the offers, add :smartest, :fastest or :cheapest to the name, for example liquid.auto:cheapest. See Axis routing. To let the exchange choose the model by score and estimated charge, send liquid.auto:balanced. See Auto Router.

The exchange refuses any other name with 404 model_not_found. It never uses a different model in its place. The message shows the name that you sent and suggests other names.

GET /v1/models returns each name that you can use now. The list includes your presets when the request has a key of the workspace that saved them. Each entry lists the request parameters that at least one offer supports. If a parameter is not in the list, the exchange refuses a request that includes it. It does not ignore the parameter.

Streaming

Set stream: true to receive text/event-stream. The last chunk has the exchange block with the settled charge. In the OpenAI format, set stream_options: {"include_usage": true} to receive token usage. The OpenAI SDK guide shows how to read the cap header from a stream.

Web access

Beta. :web is a beta feature. Its price, its search services and its behavior can change without notice.

A model knows only its training data, up to the cutoff date that its creator publishes. A question about recent events can get an old or wrong answer.

To give a model current information, add :web to the model name, for example deepseek-v4.1-flash:web or liquid.auto:smartest+web. The exchange searches the web for the last user message before it ranks the offers. It puts the results in the prompt, before that message. See Axis routing.

The search costs a fixed fee and the cost of the search service. The fee is part of the fee_usd of the receipt. The receipt also has a web_search object with the service, the number of results and the charge. The search is paid from your cap. A job that fails pays nothing for it.

The exchange sends the text of your last message to a search service, TinyFish first and Exa if TinyFish fails. Do not use :web for text that must not leave the exchange.

Without :web, the exchange runs no search. It removes the hosted web_search tool of the Responses API from the request and sends the header x-liquid-notice: web_search_dropped. It refuses the hosted web search tool of the Messages API.

OpenAPI document

An OpenAPI 3.1 document describes the public API. The exchange serves it without authentication:

https://router.inference.ai.exchange/v1/openapi.json

You can load it into a client generator, Postman, Insomnia or Bruno. The API reference page shows it.