Pay for the outcome.
One endpoint for every model, tool and data source an agent needs — priced in dollars before it runs, settled in USDC through Circle Gateway. Deposit once on any of 11 chains, Arc included, then sign every call off-chain. No gas per call.
Deposit USDC once into Circle Gateway. Then just call.
Deposit USDC once
One transaction into Circle Gateway, on whichever of 11 chains you already hold USDC. Arc, Polygon, Arbitrum, Optimism, Ethereum and more.
Sign each call off-chain
Every request carries an EIP-712 signature the SDK produces for you. No transaction, no gas, no waiting — Circle batches settlement.
Call any model or tool
89 models, RPC, search, markets and compute on one OpenAI-compatible endpoint. Priced in dollars before it runs.
Nobody ships one
model in production.
The combination is the hard part to buy. Here it is one endpoint, whichever pieces you need.
A trading agent
Quotes, odds and on-chain positions, read in one session.
A finished video
The clip is one model. The score, the voice and the thumbnail are three more.
A research agent
Neural search for the sources, one long-context model to read them all.
An agent that calls people
A real number, a voice worth hearing, and a model deciding what to say.
What one call costs, in USDC.
View all models ↗API reference ↗FreeTry without paying — no deposit, no signupWatch it settle live →
modelproviderprovin / out · 1M
GPT-5.5
Claude Opus 4.8
Gemini 3.1 Pro
Kimi K2.7+ image · edit · video · music · voice
imageChatGPT Images 2.0from $0.065from $0.065 / imageimageNano Banana Profrom $0.107from $0.107 / imageeditImage Editing (img2img)from $0.023from $0.023 / editvideoSora 2~$0.42 / 4s~$0.42 / 4s 720p+audiomusicMiniMax Music 2.5+$0.1595 / track$0.1595 / trackvoiceElevenLabs Flash v2.5$0.0545 / 1k$0.0545 / 1k charsWatch an agent
pay its way.
An agent on the nano SDK. It asks, the call is priced before it runs, and it signs for it — no gas, no key, one Gateway balance.
agent · nano-clientagent · @blockrun/nano-client
get a second opinion on this race condition from GPT-5.5
client.chat({ model: "openai/gpt-5.5", messages: [{ role: "user", content: "review queue/worker.ts — workers occasionally double-claim jobs…" }] })
402 → EIP-712 signature → verified by Circle Gateway
"Two workers can read status='pending' before either UPDATE lands. Move the claim check inside the row lock — SELECT … FOR UPDATE SKIP LOCKED."
$0.0185 · USDC on Polygon · batched, no gas
make a 5-second teaser clip for the launch page
client.videos.generate({ model: "bytedance/seedance-2.0-fast", prompt: "macro circuit board resolving into a city grid at dusk", duration: 5 })
job vd_7f3a · rendering ~70s
poll 3 → completed
nano.blockrun.ai/api/media/videos/2026/09/15/vd_7f3a.mp4 · permanent copy
$1.277 · 5s 720p + audio · USDC on Arbitrum · batched
what are the odds the Fed cuts rates in September?
client.price.pm("markets/search", { q: "fed rate cut september" })
polymarketFed cuts 25bps+ in Sept?YES 68¢ · $4.2M vol
kalshiFED-25SEP-CUTYES 66¢ · $1.8M vol
limitlessRate cut at Sept FOMC?YES 71¢ · $310k vol
$0.005 · Tier 2 · USDC on Arc · batched
Pay-per-call AI on Circle Gateway,
answered before you ask.
- What is nano.blockrun.ai?
- BlockRun's Circle Gateway door: the same 89-model catalog and every data and tool API as blockrun.ai, paid per call in USDC through Circle Gateway instead of native x402 on Base. Deposit USDC once on any of 11 EVM chains, then sign each call off-chain with no gas.
- How does pay-per-call AI work with USDC on Circle Gateway?
- Your request comes back as HTTP 402 with the price in dollars. The SDK signs an EIP-712 authorization against your Circle Gateway balance and retries; Circle's facilitator verifies the signature before the call runs and batches settlement on-chain afterwards. No per-call transaction, no per-call gas, no API key.
- Which chains can I deposit USDC on to pay for AI calls?
- Polygon, Arbitrum, Optimism, Unichain, Avalanche, Sonic, Sei, World Chain, HyperEVM, Ethereum and Arc — every mainnet chain Circle Gateway supports, 11 today. Base is deliberately excluded: buyers on Base use blockrun.ai's native x402 flow with no deposit step.
- How is this different from OpenRouter, or paying OpenAI and Anthropic directly?
- No account, no credit card, no API key, no monthly bill. An agent holds USDC and signs; a human never enters a card. OpenRouter and the providers meter to a key you must create and fund by hand — here the wallet is the identity and the price of each call is known before it runs. The SDKs are OpenAI- and Anthropic-compatible, so switching is a base URL change.
- What does a pay-per-call AI request cost?
- Provider cost plus a 5% margin and a flat $0.002 per call, quoted in dollars in the 402 before the call runs. No subscriptions, no minimum spend, no prepaid credits that expire — a $5 deposit covers thousands of small calls.
- Is this a gasless AI API for agents?
- For the buyer, yes. The only on-chain transaction you ever send is the deposit into Circle Gateway. Every call after it is an off-chain signature; Circle pays the gas when it batches settlement. On Arc the deposit itself is paid in USDC, so you need no other token at all.
- Which AI models can I call — GPT, Claude, Gemini, image and video too?
- 71 chat models including GPT-5, Claude, Gemini, Grok and DeepSeek, plus image, video, music and speech generation — 89 models in all — and multi-chain RPC across 40 chains, web search, prediction markets, crypto data and sandbox compute on the same /v1 surface.
- Can I try the AI API for free before depositing USDC?
- Yes. 4 models are free and need no wallet, no deposit and no payment header — just call them. Most people prototype against a free model and deposit once they move to a paid one.