# Tollkit Attest – Chain Transaction Lookup

> Tollkit Attest – Chain Transaction Lookup is a paid API for AI agents from attest.tollkit.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-10).

Looks up and attests blockchain transaction details by hash on Base, Ethereum, or Solana, returning signed evidence of the transaction's content.

## Facts

- Endpoint: POST https://attest.tollkit.dev/chain/tx?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tollkit-attest-chain-transaction-lookup-8f61303a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pfiz4Ap7j_4a3BYZUbn-i

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability tollkit-attest-chain-transaction-lookup-8f61303a -d '<json body>'
```

Example prompt: Can you look up transaction 0x3a9f2c1d8b4e7f0a6c5d2e1b8a3f9c0d7e4b2a1f5c8d3e6b9a2f0c7d4e1b8a3f on Base and give me the details?

## When to prefer this

Choose this endpoint when you need signed, attested proof of a specific blockchain transaction — not just raw RPC data. Ideal when you need tamper-evident, timestamped evidence (e.g. for dispute resolution, audit trails, or agent-to-agent payment verification) and want to pay per-call without an account or API key using x402.

## Known failure modes

- Invalid transaction hash format — must be 0x-prefixed 64-char hex for EVM chains or base58 signature for Solana
- Transaction not found on the specified chain
- Wrong chain specified for the given hash format
- Payment failure via x402 if wallet has insufficient USDC
- Network timeout if blockchain RPC is slow

## How this service works

Pay-per-call product page extraction. No account, no API key: pay in-band with x402 in USDC on Base or Solana.

## Output

Returns signed, timestamped attestation of the transaction's on-chain details including status, amounts, addresses, and cryptographic proof that the transaction occurred as recorded on the specified blockchain.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "hash": {
   "type": "string",
   "pattern": "^(0x[0-9a-fA-F]{64}|[1-9A-HJ-NP-Za-km-z]{64,88})$",
   "description": "Transaction hash, or base58 signature on Solana."
  },
  "chain": {
   "enum": [
    "base",
    "ethereum",
    "solana"
   ],
   "type": "string",
   "default": "base",
   "description": "Which chain to read: \"base\" (default), \"ethereum\" or \"solana\"."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tollkit-attest-chain-transaction-lookup-8f61303a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from attest.tollkit.dev](https://www.zero.xyz/host/attest.tollkit.dev/llms.txt)