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.
/api/watchers/ipoPAYMENT-SIGNATURE.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.
| Name | Type | Description |
|---|---|---|
keyword | string | Optional: only fire when the IPO name contains this text (case-insensitive). max 64 chars |
callbackUrlrequired | string | Signed event POSTed here (verify X-2s-Signature). Any http(s) URL. max 2048 chars · uri |
payload | object | Arbitrary JSON echoed back in every callback. |
expiresInSeconds | integer | Active window in seconds (default 30d, max 90d). min 60 · max 7776000 |
maxFires | integer | Stop after this many IPOs (default 25). min 1 · max 1000 |
label | string | Optional free-text tag. max 64 chars |
# 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'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)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)// 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"
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object |
{
"ok": true,
"items": [
{}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
}
}