ai.image

Generate images from a text prompt across the gateway’s image models (gpt-image, Gemini image, FLUX, Grok Imagine, …) on one endpoint. POST { model, prompt, n?, size? } → OpenAI-style { created, data: [{ b64_json }] }. Pay per call in USDC via x402 — no accounts or provider keys. Priced per model from $0.03/image (quoted in the 402). List models at GET /api/ai/models.

Overview

The image API is a pay-per-call ai endpoint built for AI agents and autonomous software. Generate images from a text prompt across the gateway’s image models (gpt-image, Gemini image, FLUX, Grok Imagine, …) on one endpoint.

There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in image data source for an agent tool-use loop, an MCP host, or a backend that needs ai data on demand without onboarding to yet another vendor portal.

Use cases

• Give an AI agent live image lookups as a tool, with no API key to provision or rotate — the agent pays per call from a wallet you fund.
• Enrich records in a data pipeline with ai data, paying only for the calls you actually make instead of a monthly seat.
• Ground LLM answers in authoritative ai data to cut hallucination, then optionally request a signed response for verifiability.
• Prototype against the live image API in minutes using the free trial call, then flip to per-call x402 payment for production with no code change.

Parameters

Code samples

# 1. Probe the endpoint with no auth — receive 402 with PaymentRequirements
curl -sS -X POST 'https://2s.io/api/ai/image' \
  -H 'Content-Type: application/json' \
  -d '{"model":"example","prompt":"example","n":1,"size":"example"}'

# 2. Sign the EIP-3009 transferWithAuthorization for the advertised price +
#    payTo from the 402 envelope, then retry with PAYMENT-SIGNATURE:
curl -sS -X POST 'https://2s.io/api/ai/image' \
  -H 'Content-Type: application/json' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>' \
  -d '{"model":"example","prompt":"example","n":1,"size":"example"}'

# Or just use the canonical runner — it handles the whole loop:
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/ai/image'

import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.ai.image({
  "model": "example",
  "prompt": "example",
  "n": 1,
  "size": "example"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.ai.image(model="example", prompt="example", n=1, size="example")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "ai.image",
    "arguments": {
      "model": "example",
      "prompt": "example",
      "n": 1,
      "size": "example"
    }
  }
}

FAQ

Do I need an API key to use the image API?

No. ai.image is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.

How much does the image API cost?

Pricing is dynamic: the exact amount is computed per request and quoted in the 402 challenge before you pay (from $0.0360 USDC). There are no monthly fees, seats, or minimums — you pay only for the calls you make.

Which networks and tokens are supported?

USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.

How do I call ai.image from an AI agent or MCP host?

Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

• /api/directory — full catalog of every endpoint
• /openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
• /.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
• /.well-known/mcp/server-card.json — MCP SEP-1649 server card
• /llms.txt — plain-text manifest for LLM ingestion