2s.io SDK

Client SDK + MCP server for 2s.io — the (most) everything API. One pay-per-call API giving AI agents ground-truth data across hundreds of endpoints, paid per call in USDC on Base or Solana via x402.

This repo ships SDKs for every major agent-development language plus an MCP server for any MCP-aware host:

Language	Package	Install	Status
TypeScript / Node	@2sio/sdk	npm install @2sio/sdk	✅ x402
TypeScript / Node	@2sio/mcp	npx @2sio/mcp	✅ MCP server, x402
Python	2sio	pip install 2sio	✅ x402
Python / LangChain	langchain-twosio	pip install langchain-twosio	✅ Tool adapters
Python / LlamaIndex	llama-index-tools-twosio	pip install llama-index-tools-twosio	✅ Tool adapters
Go	github.com/2s-io/sdk/packages/go	go get github.com/2s-io/sdk/packages/go	🚧 x402 wire-up pending
Rust	twosio	cargo add twosio	🚧 x402 wire-up pending

No accounts. No API keys. No credit cards. Buyers sign an EIP-3009 USDC authorization (Base) or an SPL USDC transfer (Solana) on-the-fly, the facilitator verifies + settles in ~2 seconds on mainnet, and the API returns typed data. Prices start at $0.001/call.

🎁 Try before you buy — free, no wallet

Want to confirm an endpoint actually works before funding anything? Every endpoint serves one free real call per endpoint per hour — no key, no wallet, no signup. Add ?trial=1 (or header X-2s-Trial: 1), or flip the SDK into trial mode:

import { TwoS } from '@2sio/sdk'
const trial = new TwoS({ trial: true })            // no key required
const { data } = await trial.validate.iban({ iban: 'GB82WEST12345698765432' })
console.log(data.items[0].valid)                    // real result; response meta.trial = { free: true, ... }

from twosio import TwoS
trial = TwoS(trial=True)                            # no key required
print(trial.validate.iban(iban="GB82WEST12345698765432").data["items"][0]["valid"])

curl "https://2s.io/api/validate/iban?iban=GB82WEST12345698765432&trial=1"

npx -y @2sio/mcp --trial      # MCP host with free trial calls; or set TWOS_TRIAL=1

The trial runs the real handler and returns real data. Once the hourly trial is used, the endpoint returns the normal 402 — drop trial and pass a privateKey/signer to pay per call for unlimited access.

🔔 Watchers — get woken up, don't poll

Most endpoints are reads. Watchers flip that: arm one once and 2s pushes you a signed callback the instant something happens — a wallet moves on Base/Ethereum/Bitcoin, a US stock crosses your price, a company reports earnings. No polling loop, no wasted calls. Flat $0.05 to arm; callbacks are EIP-191-signed (verify offline), retried with exponential backoff, with a pull backstop via watchers.status. A new class of stateful, agent-native primitives.

const client = new TwoS({ privateKey: process.env.EVM_PRIVATE_KEY })
const { data } = await client.watchers.stockPrice({
  ticker: 'AAPL', conditionType: 'above', threshold: 250,
  callbackUrl: 'https://your-agent.app/hooks/aapl',
})
// also: watchers.cryptoAddressActivity, watchers.earnings — see https://2s.io/watchers

Hosted MCP (connect by URL)

Don't want to install anything? Point any MCP host at the hosted server:

https://2s.io/mcp

Streamable-HTTP; set header X-EVM-Private-Key: 0x… (USDC on Base) and 2s signs + settles x402 per call. Tradeoff: a hosted signer means your private key transits 2s's infrastructure — for keys that never leave your machine, run npx @2sio/mcp locally or use the SDK above (the more private, secure path).

30-second demo

TypeScript:

import { TwoS } from '@2sio/sdk'
import { privateKeyToAccount } from 'viem/accounts'

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

const { data } = await client.patents.search({ q: 'neural network', limit: 5 })
console.log(data.items[0].title) // normalized envelope: { ok, items, total, source, meta? }

Python:

from eth_account import Account
from twosio import TwoS

client = TwoS(signer=Account.from_key(os.environ["EVM_PRIVATE_KEY"]))
r = client.patents.search(q="neural network", limit=5)
print(r.data["hits"][0]["title"])

30-second Claude Desktop install

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

Restart Claude. The model can now call patents.search, law.sanctions-check, ai.summarize, geocode.address, vehicle.vin-decode, agent.knowledge-delta, security.cve, and 340+ other paid tools — paying per call, no human in the loop.

What's behind the API

575+ endpoints across 113+ groups (live count in the directory) across:

• AI: webpage summarization, translation, typed extraction, image description, transcription, screenshots
• Agent primitives: persistent key-value memory, agent-to-agent marketplace (register / discover / review), knowledge-delta ("what changed in X since date Y"), atomic batch settlement
• Control plane: wallet-scoped agent infrastructure — distributed locks/leases, durable message queues, cron-style scheduled callbacks, pub/sub topics with fan-out
• Storage: pay-per-call wallet-keyed persistence — key-value, documents, vector / full-text search, private blob upload
• Watchers (push, not poll): arm once, get a signed callback the instant a wallet moves, a stock crosses a price, or a company reports earnings
• Security: CVE lookup (NVD + CISA KEV + EPSS), email-security, HTTP security headers, password-exposure (HIBP), RPKI, CT logs, IOC reputation, CWE / ATT&CK / CAPEC, exploit availability
• Patents & trademarks: USPTO Open Data Portal search + full file-wrapper detail + document list; trademark full-text search + status
• Law: federal/state case search, citation verification, OFAC sanctions screening, Federal Register, CFR & USC, opinions, dockets
• Government: Congress bills/votes/members, FEC campaign finance, FDA drug/device/food events + recalls, OSHA/MSHA, USAspending, EPA facilities, USGS water (50+ endpoints)
• Finance & treasury: SEC EDGAR company facts, filings, insider trades, 13F holdings; US Treasury debt + cash; stock quotes; FX rates
• Vehicles & aviation: VIN decode, recalls, complaints, investigations (NHTSA); aircraft registry, airports, flight data
• Health & medical: ICD-10 / HCPCS / RxNorm, hospital quality, Medicare provider + open-payments, clinical trials, drug pricing
• Business & registries: Secretary-of-State entity search, GLEIF LEI entity-match, KYB screening, IRS nonprofit search, bank routing
• Energy, agriculture, maritime & telecom: energy prices & production, USDA agriculture, soil surveys, vessel & port data, phone/number intelligence
• Geo / weather / earth: forward + reverse geocoding, US weather by ZIP, NOAA tides, sunrise/sunset, climate stations, recent earthquakes, IP geolocation (single + bulk)
• Space: launches, close approaches, satellites, exoplanets, sky-tonight, space weather
• Internet: DNS lookup, RDAP whois, TLS inspection, URL unfurl (Open Graph), URL → clean Markdown
• Wikipedia / academic papers: summaries, multi-source paper search (arXiv + PubMed + Semantic Scholar)
• Crypto: multi-chain address validation (BTC, ETH, SOL, LTC, TRX, XRP, BCH), live EVM gas oracle
• Economics & labor: BLS series, inflation, World Bank indicators, ACS demographics, occupations, USAJOBS, College Scorecard
• Data & utilities: 10+ validators (IBAN, email, phone, VAT…), EDI parsing, ISO codes, unit/currency conversion, hashing, image compression, barcode/QR, countdown GIFs

Live catalog: https://2s.io/api/directory. OpenAPI 3.1: https://2s.io/api/openapi. Machine-discovery manifest: https://2s.io/.well-known/x402.

Safety

• The SDK refuses to sign payments above a configurable maxPriceUsd. There is no default cap (maxPriceUsd defaults to Infinity) — set it to opt into a ceiling.
• Every x402 payment is a single-use EIP-3009 authorization with a 60-second deadline. No allowances are issued; a leaked key can only spend what's in the wallet at the moment of signing, only at advertised prices.
• Optional onPaymentRequested hook lets callers approve/deny each call programmatically.

Repo layout

packages/
├── 2s-sdk/             @2sio/sdk — typed TypeScript client
├── 2s-mcp/             @2sio/mcp — MCP server (depends on 2s-sdk)
├── python/             2sio — Python client
├── python-langchain/   langchain-twosio — LangChain tool adapters
├── python-llamaindex/  llama-index-tools-twosio — LlamaIndex tool adapters
├── go/                 Go client (x402 wire-up pending)
└── rust/               Rust client (x402 wire-up pending)
examples/sdk/   minimal paying-agent samples + Claude Desktop wiring

License

MIT. See LICENSE.

Links

• API site: https://2s.io
• npm:
  • https://www.npmjs.com/package/@2sio/sdk
  • https://www.npmjs.com/package/@2sio/mcp
• x402 protocol: https://x402.org
• MCP protocol: https://modelcontextprotocol.io