For agents

How an agent finds OpenAgents, says who it is, and pays. Every step is one request or one command.

Beta.

Find us

Start from any of these. None needs a key.

What	Where
A short index of the site and its docs	`https://openagents.com/llms.txt`
Every doc in one file	`https://openagents.com/llms-full.txt`
The API, described in OpenAPI 3.1	`https://api.openagents.com/v1/openapi.json`
The API catalog	`https://openagents.com/.well-known/api-catalog`
The AI catalog (MCP, agent card, skills, API)	`https://openagents.com/.well-known/ai-catalog.json`
The docs as an MCP server	`https://openagents.com/mcp/docs`
How keys work	`https://openagents.com/auth.md`
Models and prices as JSON	`https://api.openagents.com/v1/rates`

Any page is also Markdown: add .md to its address, or send Accept: text/markdown.

curl -s https://openagents.com/llms.txt

Say who you are

You don't have to. A call paid per request needs no account. When you do want one:

How	What to send	Status
An API key	`Authorization: Bearer oak_...`. A person makes it at Settings, API keys.	Works now
Sign in for a person (OAuth)	For MCP clients and agents acting for someone	Coming (#11084)
Your Nostr key	A signed `Authorization: Nostr ...` header (NIP-98)	Coming

curl https://api.openagents.com/v1/responses \
  -H "Authorization: Bearer $OPENAGENTS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "openagents/chat", "input": "Say hello."}'

Pay

With a key

Calls on a key are paid from its credit, at each answer's actual cost. When the credit runs out the answer is 402 with the type insufficient_balance. Add credit at Settings, then retry.

Per request, with no key

Send the call with no Authorization header. The answer is 402 Payment Required with the price and one Lightning invoice for exactly that request, written once for each way to pay listed below. Pay it once, then send the same request again with the proof in the header your method uses. Each step is in Pay per request.

Paying per request is off on this API right now; use an API key.

The openagents command does all of it from your wallet:

openagents inference google/gemini-3.8-flash "Say hello." --pay x402 --max-msat 10000

Ways to pay

Method	Challenge	You send	You get back	Status
A key with credit, bought by card	`401` without one	`Authorization: Bearer oak_...`	the answer	Works now
x402 on Lightning (`PAYMENT-REQUIRED`, `PAYMENT-SIGNATURE`)				Coming
The `Payment` scheme on Lightning, as used by MPP (`WWW-Authenticate: Payment`)				Coming
L402 (`WWW-Authenticate: L402`)				Coming
Cashu ecash (`X-Cashu`)				Coming
Dollar stablecoins through x402 and MPP				Coming
Agent checkout for credits and Pro: ACP, UCP, AP2				Coming

This table is read from the API itself, so it lists a way to pay only while the API takes it. The 402 answer lists the same ways (its methods field), and so do the OpenAPI description (x-payment-info on each paid route), the API catalog, and the docs MCP server's list_payment_methods tool. Follow the plan in #11085.

What you get back

A paid answer carries a receipt header from the method you used (PAYMENT-RESPONSE for x402, Payment-Receipt for the Payment scheme), our own receipt id in x-openagents-receipt, and the answer's actual cost in x-openagents-cost-usd. Errors are listed in Errors.