QUEUE: confirm a leased message is processed — deletes it so it isn't redelivered, scoped to YOUR wallet. Pass the message id + the leaseToken from queue.lease. Returns acked:false if the lease expired or the token doesn't match (the message will be redelivered to a future lease). Private to your wallet (the x402 payer).
/api/queue/ackPAYMENT-SIGNATURE.The ack API is a pay-per-call queue endpoint built for AI agents and autonomous software. QUEUE: confirm a leased message is processed — deletes it so it isn't redelivered, scoped to YOUR wallet.
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 ack data source for an agent tool-use loop, an MCP host, or a backend that needs queue data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
queuerequired | string | Queue the message came from. |
idrequired | string | Message id from queue.lease. |
leaseTokenrequired | string | leaseToken from queue.lease. |
# 1. Probe the endpoint with no auth — receive 402 with PaymentRequirements
curl -sS -X POST 'https://2s.io/api/queue/ack' \
-H 'Content-Type: application/json' \
-d '{"queue":"example","id":"example","leaseToken":"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/queue/ack' \
-H 'Content-Type: application/json' \
-H 'PAYMENT-SIGNATURE: <base64-json-payload>' \
-d '{"queue":"example","id":"example","leaseToken":"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/queue/ack'import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.queue.ack({
"queue": "example",
"id": "example",
"leaseToken": "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.queue.ack(queue="example", id="example", leaseToken="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": "queue.ack",
"arguments": {
"queue": "example",
"id": "example",
"leaseToken": "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": [
{
"id": "example",
"acked": false
}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
}
}