# Atlas Keccak Merkle Proof Verifier

> Atlas Keccak Merkle Proof Verifier is a paid API for AI agents from chain-tools.use.x402atlas.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Validates Keccak Merkle inclusion proofs against the Atlas sorted-pair tree profile, verifying leaf index, leaf count, and proof shape.

## Facts

- Endpoint: POST https://chain-tools.use.x402atlas.com/merkle/verify
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/atlas-keccak-merkle-proof-verifier-8218ecc6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wzuSKSuM9QwKIMXPYrXrC

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 atlas-keccak-merkle-proof-verifier-8218ecc6 -d '<json body>'
```

Example prompt: Verify this Merkle inclusion proof for me — the leaf value is 0xabc123, it's at index 3 out of 8 total leaves, and here's the proof path with the root 0xdeadbeef. Use the Atlas sorted-pair Keccak tree profile to confirm the proof shape and inclusion are valid.

## When to prefer this

Use this endpoint when you need to verify Keccak Merkle inclusion proofs specifically generated against the Atlas sorted-pair tree profile, particularly when you also need to validate the exact leaf index and total leaf count as part of the proof. Prefer this over generic Merkle verifiers when working with proofs built by the sibling Atlas Merkle tree builder endpoint, or when your application requires domain-separated sorted-pair tree semantics.

## Known failure modes

- Invalid proof path length not matching claimed leaf count
- Root mismatch — computed root differs from provided root
- Leaf index out of range for given leaf count
- Malformed proof elements (non-hex or wrong byte length)
- Proof shape inconsistency with Atlas sorted-pair profile
- Missing required fields in request body

## How this service works

Keccak Merkle proof verifier — validate inclusion plus exact leaf index and count proof shape for the Atlas sorted-pair tree profile.

## Output

Returns a boolean indicating whether the inclusion proof is valid, along with confirmation of the verified leaf index, total leaf count, and whether the proof shape matches the Atlas sorted-pair Keccak tree profile. May include details on which part of the proof failed if invalid.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/atlas-keccak-merkle-proof-verifier-8218ecc6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chain-tools.use.x402atlas.com](https://www.zero.xyz/host/chain-tools.use.x402atlas.com/llms.txt)