# Northline ChainKit Transaction Explainer

> Northline ChainKit Transaction Explainer is a paid API for AI agents from northline-chainkit.northline-c86.workers.dev, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-30).

Fetches and explains a blockchain transaction (Base or Arc) by hash, returning status, gas fees, and token transfers in human-readable form

## Facts

- Endpoint: GET https://northline-chainkit.northline-c86.workers.dev/v1/tx/explain?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/northline-chainkit-transaction-explainer-75e29529
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lXrWJgpPf_rwpqoRfjga7

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 northline-chainkit-transaction-explainer-75e29529
```

Example prompt: Can you explain what happened in this Base transaction — 0x3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b — what tokens moved and what was the fee?

## When to prefer this

Choose this endpoint when you need a quick, structured explanation of a specific transaction on Base or Arc, particularly when you need token transfer details and fee breakdown without running your own node. Best for agents that need to confirm payment receipt, audit gas costs, or summarize onchain activity for end users on Base or Arc specifically.

## Known failure modes

- Invalid or malformed transaction hash (must be 0x-prefixed 64 hex characters) returns a validation error
- Transaction hash not found on the specified chain returns empty or error response
- Unsupported chain value (only 'base' and 'arc' are valid) returns an error
- Network/RPC timeout if the chain node is unreachable
- Payment not processed (x402 payment required, insufficient USDC)

## How this service works

x402 pay-per-call onchain API (Base + Arc).

## Output

Returns a JSON object with transaction status (success/failure), fee details (amount and symbol, e.g. 0.0000021 ETH), and an array of token transfers (each with amount and symbol, e.g. 5 USDC). Provides a human-readable breakdown of what occurred onchain.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "tx"
     ],
     "properties": {
      "tx": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{64}$"
      },
      "chain": {
       "enum": [
        "base",
        "arc"
       ],
       "type": "string",
       "default": "base"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "fee": {
   "amount": "0.0000021",
   "symbol": "ETH"
  },
  "status": "success",
  "tokenTransfers": [
   {
    "amount": "5",
    "symbol": "USDC"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/northline-chainkit-transaction-explainer-75e29529/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from northline-chainkit.northline-c86.workers.dev](https://www.zero.xyz/host/northline-chainkit.northline-c86.workers.dev/llms.txt)