# Transaction Evidence Brief

> Transaction Evidence Brief is a paid API for AI agents from transaction-evidence-brief-2026.bowu365.chatgpt.site, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-16).

Retrieves deterministic on-chain evidence for a Base blockchain transaction by hash, suitable for agent audit trails.

## Facts

- Endpoint: GET https://transaction-evidence-brief-2026.bowu365.chatgpt.site/api/v1/tx-brief/paid
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/transaction-evidence-brief-1b849f42
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pSOuoskjbJzEN6_5rnKhA

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 transaction-evidence-brief-1b849f42
```

Example prompt: Can you verify that Base transaction 0x904a17eb77255e1208eea43f3519ec6e5c04c417a21453bb239e1a6de0c8a797 went through successfully and give me a confirmation I can use for my audit trail?

## When to prefer this

Choose this endpoint when you need lightweight, deterministic on-chain evidence for a specific Base transaction hash — especially in agent workflows that require audit trails or payment confirmation before proceeding. Prefer it over full block explorers when you only need status and hash confirmation without full transaction decode.

## Known failure modes

- Invalid transaction hash format (not matching 0x[64 hex chars]) returns a validation error
- Transaction hash not found on Base returns a not-found or null status
- Network or RPC timeouts may cause intermittent failures
- Payment not received (402) if the x402 micropayment header is missing or insufficient

## How this service works

Deterministic Base transaction evidence for agents and audit trails.

## Output

Returns a JSON object containing the chain name ('Base'), transaction status ('success' or failure state), and the canonical transaction hash, providing deterministic proof of the transaction's on-chain outcome.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "hash"
     ],
     "properties": {
      "hash": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{64}$",
       "description": "Base transaction hash"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "Base",
  "status": "success",
  "transactionHash": "0x904a17eb77255e1208eea43f3519ec6e5c04c417a21453bb239e1a6de0c8a797"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/transaction-evidence-brief-1b849f42/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from transaction-evidence-brief-2026.bowu365.chatgpt.site](https://www.zero.xyz/host/transaction-evidence-brief-2026.bowu365.chatgpt.site/llms.txt)