# TraceFast Address Attribute Proof

> TraceFast Address Attribute Proof is a paid API for AI agents from mpp.tracefast.xyz, paid per call via x402, $0.025/call, status unknown (last checked 2026-10-19).

Returns the knowledge-graph evidence behind one proven attribute of an Ethereum address — facts checked, expected vs. observed values, falsified conditions, sources, and the pinned block.

## Facts

- Endpoint: GET https://mpp.tracefast.xyz/api/v1/chains/1/entities/:address/attributes/:attribute_id/proof?utm_source=zero.xyz
- Price: $0.025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tracefast-address-attribute-proof-ac880861
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sjrspSkGGW4F79Jx1kD5w

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-address-attribute-proof-ac880861
```

Example prompt: Show me the TraceFast knowledge graph proof for Ethereum address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 and attribute entity:is_contract — I want to see the facts that were checked, the expected vs observed values, the conditions that had to be false, and which block the evaluation was pinned to.

## When to prefer this

Use this endpoint when you need to understand the evidence and provenance behind a specific TraceFast address attribute — not just the attribute value itself, but the facts checked, the sources consulted, and the block at which it was evaluated. Prefer this over the general attributes listing endpoint when doing compliance audits, provenance tracing, or when you need to challenge or validate a specific classification.

## Known failure modes

- Address not found or not indexed — 404 with no proof available
- Invalid address format (not 0x-prefixed 40 hex chars) — 400 bad request
- Unknown attribute_id not listed by attributes method — 400 or 404
- Attribute exists but has not been proven for this address — empty or null proof response
- Payment not completed (x402 protocol failure) — 402 Payment Required
- Network timeout or upstream chain node unavailable — 503

## How this service works

TraceFast knowledge graph: the evidence behind one proven attribute of an address — the facts that were checked with their expected and observed values, the conditions that had to be false, the sources the evidence was read from, and the block the evaluation was pinned to. Path address: The address, `0x`-prefixed, 40 hex characters, any case; attribute_id: The attribute id, `family:name`, as listed by the attributes method. Docs: https://docs.tracefast.xyz/api/address-attribute-proof.md

## Output

A knowledge-graph proof object containing: the list of facts that were checked (each with expected and observed values), the conditions that had to be false for the attribute to hold, the source references the evidence was read from, and the Ethereum block number at which the evaluation was pinned.

## 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-address-attribute-proof-ac880861/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)