Sarek MCP Tools

The server exposes three tools, advertised through tools/list. Names are snake_case and action-oriented. Every input is validated against a strict schema before anything reaches Sarek: unknown fields are rejected, and malformed input comes back as an actionable error instead of a failed upstream call.

sarek_stamp

Stamps a pre-computed SHA3-256 hash on-chain and returns a verifiable proof.

This tool takes a hash, not raw data. The agent hashes its data locally first so that raw data never leaves its environment in cleartext.

Parameters

Name	Type	Required	Description
`hash`	`string`	Yes	The SHA3-256 hash of your data as 64 lowercase hex characters. This is the data to be stamped on-chain.

Returns

Field	Type	Description
`tx_hash`	`string`	On-chain transaction hash of the stamp.
`ldgp`	`string`	Base64-encoded .ldgp proof for the stamped hash.
`mmr_root`	`string`	The root that was stamped on-chain.
`block_number`	`number`	Block the stamp landed in, when known.
`on_chain`	`boolean`	Whether the stamp is confirmed on-chain.

Example


// input
{
  "hash": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"
}


// result
{
  "tx_hash": "0x4a7c2f...e91b",
  "ldgp": "VEVSSFVB...base64...",
  "mmr_root": "c1d2e3...f0",
  "block_number": 10789522,
  "on_chain": true
}

Errors

Sending anything other than a 64-character lowercase hex hash returns an actionable validation error telling the agent to hash its data locally first, without ever contacting Sarek. Re-stamping a hash that already exists returns The resource already exists.

sarek_stamp is the one write operation. It is marked idempotent (the same hash resolves to the same stamp) and is not read-only.

sarek_verify

Verifies a .ldgp proof against the on-chain record and returns a layered result.

Parameters

Name	Type	Required	Description
`ldgp`	`string`	Yes	The base64-encoded .ldgp proof, exactly as returned by `sarek_stamp` or `sarek_get_proof`.
`data`	`string`	No	Base64-encoded raw data. When provided, adds the data-integrity layer: Sarek checks that this data hashes to the proof leaf.
`hash`	`string`	No	A leaf hash (64 lowercase hex) to check for membership in the proof. This is an existing leaf to look for, not data to be stamped.

Returns

Field	Type	Description
`valid`	`boolean`	Overall verdict across all checked layers.
`layers`	`object`	Per-layer breakdown (see below).
`leaf`	`string`	The leaf hash the proof resolves to, when known.
`mmr_root`	`string`	The root the proof resolves to, when known.

The layers object contains:

Field	Type	Description
`data_integrity`	`boolean`	Raw data hashes to the proof leaf. Present only when `data` was supplied.
`tree_integrity`	`boolean`	The proof’s path reconstructs the stamped root.
`on_chain`	`boolean`	The root is anchored on-chain.
`on_chain_leaf`	`boolean`	The specific leaf is provably included on-chain, when known.
`block_number`	`number`	Block the stamp was anchored in, when known.
`block_date`	`string`	ISO timestamp of the anchoring block, when known.

Example


// input
{
  "ldgp": "VEVSSFVB...base64...",
  "data": "TG9hbiAjNDgyMSBhcHByb3ZlZA=="
}


// result
{
  "valid": true,
  "layers": {
    "data_integrity": true,
    "tree_integrity": true,
    "on_chain": true,
    "on_chain_leaf": true,
    "block_number": 10789522,
    "block_date": "2026-06-12T00:00:00.000Z"
  },
  "leaf": "9f86d081...0a08",
  "mmr_root": "c1d2e3...f0"
}

See Verification for what each layer proves and when valid is true.

Errors

A malformed or non-base64 ldgp returns a validation error before any upstream call. sarek_verify is read-only and idempotent.

sarek_get_proof

Fetches the .ldgp proof for a previously stamped hash, base64-encoded and ready to pass to sarek_verify.

Parameters

Name	Type	Required	Description
`hash`	`string`	Yes	The 64 lowercase hex SHA3-256 hash of a stamped leaf.

Returns

Field	Type	Description
`hash`	`string`	The leaf hash the proof belongs to.
`ldgp`	`string`	Base64-encoded binary .ldgp proof.

Example


// input
{
  "hash": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"
}


// result
{
  "hash": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
  "ldgp": "VEVSSFVB...base64..."
}

Errors

A hash that was never stamped returns The requested resource was not found. sarek_get_proof is read-only and idempotent.