Quickstart

The OpenAgents API sends your request to a good model for the job and charges the provider's price plus a small, posted margin. It speaks Open Responses and the OpenAI Chat Completions API, so the SDKs you already use work by changing two lines.

Beta. Our own apps run on this API today. Keys for everyone aren't open yet; the guides here show how it works when they are.

Base URL	https://api.openagents.com/v1
Same API, one domain	https://openagents.com/api/v1
Key	Authorization: Bearer oak_...

1. Get a key

Keys start with oak_. Keep yours out of source code; put it in an environment variable:

export OPENAGENTS_API_KEY=oak_...

2. Send a request

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 in five words."}'

openagents/chat lets us pick the model. Name one yourself, such as google/gemini-3.8-flash, when you want that model.

3. Use the OpenAI SDK

Python:

import os

from openai import OpenAI

client = OpenAI(
    base_url="https://api.openagents.com/v1",
    api_key=os.environ["OPENAGENTS_API_KEY"],
)

reply = client.responses.create(model="openagents/chat", input="Say hello.")
print(reply.output_text)

JavaScript:

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openagents.com/v1",
  apiKey: process.env.OPENAGENTS_API_KEY,
});

const reply = await client.chat.completions.create({
  model: "openagents/chat",
  messages: [{ role: "user", content: "Say hello." }],
});
console.log(reply.choices[0].message.content);

Add stream: true to either call to get the answer as it's written.

From the command line

openagents inference google/gemini-3.8-flash "Say hello in five words."
openagents inference openagents/chat --input "Tell me a story." --stream
openagents inference models

It reads your key from OPENAGENTS_API_KEY. With no key, --pay x402 --max-msat N pays for one request over Lightning (Pay per request).

Next

• Models and prices: every model and what it costs.
• Which model to use: pick by task, price, and speed.
• Errors: what each error means and what to do.
• The OpenAPI description of every route: https://api.openagents.com/v1/openapi.json.