HTTP/1.1 402 PAYMENT REQUIRED agent402.base.eth · BASE · SOLANA · POLYGON · ARBITRUM · MONAD · CELO · AVALANCHE · STELLAR · ALGORAND · ROBINHOOD · USDC · USDG
402
open source · x402 · mcp-native · settle in seconds

Where agents
pay agents.

Your AI agent calls and pays for tools by the request. Web search, market data, PDF & OCR, on-chain reads, an OpenAI-compatible LLM gateway. No signup, no API keys. The wallet is the identity.

516
tools
101
skill packs
220
free · pow
$0.001
per call
10
chains
live · 28,826 calls settled to date
~ / agent402SH
# 516 x402 tools in Claude Code.
# no signup, no API key.
$ claude mcp add agent402 -s user \
    -- npx -y agent402-mcp@latest

# then ask Claude:
# "quote AAPL and its 52-week range"
# "run financial-research on NVDA"
# "audit example.com for SEO"
# free tier pays in compute -
# USDC on Base + 8 more chains, or USDG on Robinhood Chain when you scale.
PAYMENT REQUIRED
· 402 · agent402.tools ·
Settles natively on ten networks - USDC on nine chains plus USDG on Robinhood
BaseSolanaPolygonArbitrumMonadCeloAvalancheStellarAlgorandRobinhood
$ POST /api/skill/{slug}

A whole job, one payment.

101 packs · $0.05–$1.50 · partial-success per step

One payment runs a whole job: a pack orchestrates the right tools server-side and returns every step's result in one envelope. Callable as MCP prompts too.

browse all 101 skill packs →
$ POST /connect

Three ways in.

Same surface underneath - payment handled automatically: proof-of-work for free tools, your x402 wallet for paid.

01 / YOUR AGENT

Pay in code with any x402 client - @x402/fetch, axios, or your framework.

// signs USDC, retries on 402
await payFetch(
  "…/api/extract", { url })
read the docs →
02 / CLAUDE · MCP

Paste the hosted connector URL - zero install. Pure-CPU tools run free, rate-limited.

# Settings → Connectors
https://agent402.tools/mcp
add connector →
03 / YOUR CODE

The agent402-client SDK resolves a task to a tool and pays automatically.

// free tier, zero deps
await a.call("hash",
  { text, algo:"sha256" })
install the SDK →
+ zero-dep adapters: openai · anthropic · langchain · llamaindex · vercel-ai · google-adk · aws-strands
$ GET /catalog

The index - 516 tools.

deterministic · flat-priced · no LLM in the path

415 tools + 101 skill packs, each tested against its own example on every deploy and priced to market. It grows only when a tool is worth calling.

Web & documents
Read the live web: browser rendering, screenshots,…
36$0.001
Agent memory & coordination
The stateful layer a stateless agent can't build f…
11$0.001
Network & domains
DNS, TLS certificates, WHOIS/RDAP, uptime checks, …
18$0.001
Live public data
Keyless real-time government and market data: data…
111$0.001
Payments & x402
Non-custodial x402 tooling: decode HTTP 402 quotes…
17$0.001
Data conversion
JSON ⇄ CSV/YAML/XML, markdown ⇄ HTML, diffs and qu…
30$0.001
Text processing
Slugs, case conversion, diffs, regex, keywords, to…
27$0.001
Math & finance
Safe expression calculator, statistics, unit conve…
13$0.001
Encoding & crypto
Hashes, HMAC signatures, base64/hex, JWT decoding,…
20$0.001
Generators & IDs
UUIDs, ULIDs, passwords, secure randomness, QR cod…
6$0.001
Time & scheduling
Timezone-aware clocks, epoch conversion, cron pars…
10$0.001
Validation & parsing
Emails (with MX), URLs, IPs, user agents, colors, …
23$0.001
LLM gateway
OpenAI-compatible pay-per-call inference over x402…
8$0.002
Browse all 516 tools →+101 skill packs
$ GET /api/leaderboard

Not just a seller -
the neutral index.

An open index and Smart Order Router, ranked by real on-chain USDC volume. Route a task across every x402 seller, not just ours.

SELLERS · BY USDC SETTLED LIVE
#sellerusdcbuyers
01BlockRun.AI$23778.74553
02StableEnrich$352.65193
03x402.twit.sh$174.8155
04agents.chain.link$137.974
05StableSocial$129.5455
hourly on-chain snapshot · ?include=external
$ POST /sell

The other side of the ledger.

no signup · non-custodial · your wallet, your funds

Agents are buying. If you run an API - or a site AI crawlers keep hitting - the same rails pay you.

01 / LIST YOUR API

Serve x402 challenges and list it on /sell (free) and the index crawler picks it up - free, health-ranked, routed by the Smart Order Router next to 516 of our own tools.

# we probe, you appear
POST /api/index/register
  { "origin": "https://api.you.com" }
list your API →
02 / TOLLBOOTH YOUR SITE

Humans browse free; known AI crawlers get 402 and pay in USDC - or solve proof-of-work. Express, edge, proxy, or WordPress. MIT, no CDN lock-in.

# one middleware
npm i agent402-tollbooth
gate your crawlers →
everything for sellers → /sell
$ GET /verify

Every claim, checkable.

No sales calls, no contracts. Deterministic outputs, flat prices, a named maintainer, fully open source - asserted by nobody, verifiable by anybody.

On-chain settlements
Every paid call lands at agent402.base.eth on Base USDC - verifiable on Basescan.0xaBF4…a9D0
Open source
Read every line that serves and prices your call. Self-host the whole thing free.github.com/…/Agent402
Deterministic
No LLM in the deterministic tool path. Same input, same bytes - no token spend. (/v1 is a separate, opt-in LLM gateway.)re-tested per deploy
CDP Bazaar
Discoverable on the index AI agents browse for x402 services, keyed to our payTo.x402/discovery
Self-describing
Full OpenAPI 3.1 spec and machine-readable pricing for the entire catalog.GET /openapi.json
$ GET /faq

Questions.

What is Agent402?+

A place where software buys small jobs, one at a time. 415 web tools and 101 skill packs - read a page, decode a barcode, check a domain, run a query - each with a price and each callable without a signup. The customers are mostly AI agents rather than people, so there is no account to create and no API key to manage.

What is x402?+

When the web was designed, HTTP set aside a response for "payment required" - status code 402 - and then left it unused for about thirty years. x402 finally fills it in: ask for something, get a price back, pay, and the same request goes through. It is an open standard rather than anything we invented, and it is what lets a program buy one thing in one round trip with no subscription and no checkout page. There is a plain-English explainer on the what-is-x402 page.

Why would software need to buy anything?+

An AI agent working on a real task keeps running into things it cannot answer from memory: fetch a live page, pull a filing, convert a file, look up an address on a blockchain. Signing up for twenty different APIs is not something an agent can do on its own - it has no email, no credit card, and no way to agree to terms. Paying a fraction of a cent per call is something it can do.

Do I need crypto or a wallet to try it?+

No. 220 of the 516 tools run free on proof-of-work: your own computer solves a short puzzle instead of paying, which costs a second of CPU and nothing else. A wallet only matters for tools that cost real money to run, and those quote their price before anything is charged.

How do I know the money side is honest?+

The whole server is open source, so the payment code can be read line by line. Settlement happens on a public blockchain, so every payment is independently verifiable. And a failed call is never charged - payment only completes on a successful response, so if a tool breaks, no money moves.

I have a website or an API. Is there anything here for me?+

Yes, it runs in both directions. If you have an API, you can charge for it the same way and buyers pay straight into your wallet with nothing taken in between. If you have a website that AI crawlers keep hitting, agent402-tollbooth is an open-source gate that charges them per page instead of blocking them. Listing is free.

402

No signup. No API keys.
Just pay-per-call.

Add 516 tools to your agent in 60 seconds. Free tier, no wallet - settle in USDC when you scale.

ADD TO CLAUDE → READ THE DOCS