---
title: "Consistency proof that the log grew by append only."
method: GET
path: "/transparency/consistency"
tags: ["Transparency"]
---

# Consistency proof that the log grew by append only.

`GET /transparency/consistency`

## Request

- Base URL: `https://api.mnemom.ai/v1`
- URL: `https://api.mnemom.ai/v1/transparency/consistency`
- Auth: none required

Returns an RFC 6962 / RFC 9162 §2.1.4 consistency proof that the tree of size `second` contains the tree of size `first` as a prefix — i.e. the first `first` entries were not reordered, altered, or removed. `second` defaults to the log's current size.

This is the only endpoint that can distinguish "the log grew" from "the log was rewritten and re-signed": an inclusion proof verifies against whatever root it is given, so it cannot detect a wholesale reissue. Chain these proofs across successive signed roots from `GET /v1/transparency/root` and the append-only claim becomes checkable rather than promised.

What it does NOT prove: that Mnemom published every root it computed. A consistent chain of roots shown to you could coexist with a different, internally-consistent chain shown to somebody else (a "split view"). Detecting that requires gossip between independent monitors. MNE-6384.

## Query parameters

- `first` integer, required
- `second` integer

## Response `200`

Consistency proof between the two tree sizes.

- object
  - `construction` 'mnemom.transparency.rfc6962/v1', required: Named construction the proof is built against. Versioned wire string — a new construction mints a new identity rather than editing this one, so a verifier can never silently apply the wrong rules.
  - `first` integer, required: The earlier tree_size.
  - `second` integer, required: The later tree_size.
  - `first_root` string, required: Merkle root at tree_size = first. Compare this against the signed root you already hold for that size — if it differs, the log was rewritten.
  - `second_root` string, required: Merkle root at tree_size = second.
  - `hashes` string[], required: RFC 6962 §2.1.2 consistency path, in the order the §2.1.4.2 verification algorithm consumes it. Empty ONLY when first === second (nothing was appended). Note that when `first` is an exact power of two the generator omits MTH(D[0:first]) because the verifier re-derives it from first_root.

## Other responses

- `400`: Bad request
- `404`: The log is empty, or one of the requested sizes exceeds the log's current size. The latter is worth investigating: if you hold a signed root for a larger size than the log now reports, the log shrank.
- `429`: Rate-limit exceeded. The global per-IP limiter (100 requests/minute, applied to every `/v1/*` route) rejected this request. Back off until the window resets — `Retry-After` carries the cooldown in seconds and `X-RateLimit-Reset` the absolute reset time.
- `500`: Server error — request was well-formed but the server failed to fulfill it. Typically a downstream dependency (DB / RPC / external API) returned an unexpected error.
- `503`: An upstream dependency is currently unavailable. The request was not processed; retry after the cooldown window.

---

[API](https://skmtc.dev/mnemom/apis/mnemom-api.md) · [All operations](https://skmtc.dev/mnemom/apis/mnemom-api/llms.txt) · [OpenAPI document](https://skmtc.dev/mnemom/apis/mnemom-api/revisions/274b7a6ea182?raw)