watchers.ipo

WATCHER: get a signed callback when a new US IPO appears on the calendar. Arm once, pay once. Optionally pass keyword to only fire when the company name/symbol matches. Fires once per new IPO (deduped by symbol); bounded by maxFires/expiry. Existing entries at arm time are baselined. Calendar via Finnhub. Signed (verify offline) + retried; recoverable via watchers.status. Returns a watcherId.

price
$0.0500 USDC per call
method
POST/api/watchers/ipo
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.

Overview

The ipo API is a pay-per-call watchers endpoint built for AI agents and autonomous software. WATCHER: get a signed callback when a new US IPO appears on the calendar.

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 ipo data source for an agent tool-use loop, an MCP host, or a backend that needs watchers data on demand without onboarding to yet another vendor portal.

Use cases

Parameters

NameTypeDescription
keywordstringOptional: only fire when the IPO name contains this text (case-insensitive).
max 64 chars
callbackUrlrequiredstringSigned event POSTed here (verify X-2s-Signature). Any http(s) URL.
max 2048 chars · uri
payloadobjectArbitrary JSON echoed back in every callback.
expiresInSecondsintegerActive window in seconds (default 30d, max 90d).
min 60 · max 7776000
maxFiresintegerStop after this many IPOs (default 25).
min 1 · max 1000
labelstringOptional free-text tag.
max 64 chars

Code samples

cURLbash
# 1. Probe the endpoint with no auth — receive 402 with PaymentRequirements
curl -sS -X POST 'https://2s.io/api/watchers/ipo' \
  -H 'Content-Type: application/json' \
  -d '{"keyword":"example","callbackUrl":"https://example.com","payload":{},"expiresInSeconds":60,"maxFires":1,"label":"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/watchers/ipo' \
  -H 'Content-Type: application/json' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>' \
  -d '{"keyword":"example","callbackUrl":"https://example.com","payload":{},"expiresInSeconds":60,"maxFires":1,"label":"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/watchers/ipo'
TypeScript / Node — @2sio/sdktypescript
import { TwoS } from '@2sio/sdk'

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

const result = await client.watchers.ipo({
  "keyword": "example",
  "callbackUrl": "https://example.com",
  "payload": {},
  "expiresInSeconds": 60,
  "maxFires": 1,
  "label": "example"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)
Python — 2siopython
import os
from twosio import TwoS

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

result = client.watchers.ipo(keyword="example", callbackUrl="https://example.com", payload={}, expiresInSeconds=60, maxFires=1, label="example")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)
MCP — Claude Desktop / AgentKit / any MCP hostjson
// 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": "watchers.ipo",
    "arguments": {
      "keyword": "example",
      "callbackUrl": "https://example.com",
      "payload": {},
      "expiresInSeconds": 60,
      "maxFires": 1,
      "label": "example"
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
Example response datajson
{
  "ok": true,
  "items": [
    {}
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

FAQ

Do I need an API key to use the ipo API?
No. watchers.ipo 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 ipo API cost?
$0.0500 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.
Can I try the ipo API for free first?
Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.
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 watchers.ipo 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

Related: ipo api · watchers ipo api · ipo api for ai agents · x402 watchers api · ipo api no api key · pay per call ipo api · watchers api