# TraceFast Ethereum Transaction Call Trace

> TraceFast Ethereum Transaction Call Trace is a paid API for AI agents from mpp.tracefast.xyz, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-12).

Returns every call frame a specific Ethereum transaction executed, including caller, target, call type, value, gas, outcome, and revert reason for each frame.

## Facts

- Endpoint: GET https://mpp.tracefast.xyz/api/v1/chains/1/traces/:hash?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tracefast-ethereum-transaction-call-trace-983012bc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SsvMSmuCzZW8Xqdw-VrIK

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 tracefast-ethereum-transaction-call-trace-983012bc
```

Example prompt: Show me the full call trace for Ethereum transaction 0x4e3a3754410177e6937ef1f84bba68ea139e8d1a8863f77b8de6a12e551e19d — I want every call frame including the caller, target, call type, value moved, gas, and any revert reason.

## When to prefer this

Choose this endpoint when you need internal execution detail for a specific Ethereum transaction — especially for debugging reverts, auditing multi-contract flows, or verifying value transfers across call frames. Prefer this over event log endpoints when you need call-level granularity (not just emitted events) or need to see failed internal calls that emit no logs.

## Known failure modes

- Transaction hash not found or not yet indexed — returns 404 or empty result
- Invalid transaction hash format (not 0x-prefixed 64 hex chars) — returns 400 validation error
- Transaction is pending and not yet mined — trace unavailable
- Network timeout for deeply nested call trees with many frames
- Rate limit exceeded — returns 429

## How this service works

TraceFast live Ethereum data: every call frame a transaction executed, the order it ran — the caller and target of each, the kind of call, the value and gas it moved, its own outcome, and why it reverted where it did. Path hash: Transaction hash, `0x`-prefixed, 64 hex characters, any case. Query: includeCalldata, limit (see docs). Docs: https://docs.tracefast.xyz/api/trace.md

## Output

A list of call frames in execution order, each containing: caller address, target address, call type (CALL, DELEGATECALL, STATICCALL, etc.), value transferred, gas supplied and used, outcome (success/failure), and revert reason where applicable.

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "required": [
    "method"
   ],
   "properties": {
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tracefast-ethereum-transaction-call-trace-983012bc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mpp.tracefast.xyz](https://www.zero.xyz/host/mpp.tracefast.xyz/llms.txt)