# `MetamorphicLog`
[🔗](https://github.com/moss-piglet/metamorphic_log/blob/main/lib/metamorphic_log.ex#L1)

Elixir client for the **metamorphic-log** transparency-log engine.

`MetamorphicLog` wraps the audited `metamorphic-log` Rust crate via precompiled
Rust NIFs — no Rust toolchain, no C compiler, no system packages required. It
surfaces the engine's **verification + monitor SDK** plus the deterministic
**ingestion primitives**, byte-for-byte compatible with the browser WASM SDK
and the native core.

> #### Verification-focused {: .info}
>
> This package verifies and recomputes; it does not run a hosted log. All
> cryptography is the single-source-of-truth `metamorphic-crypto` core.

## Modules

- `MetamorphicLog.Proof` — RFC 6962/9162 inclusion & consistency proofs
- `MetamorphicLog.Checkpoint` — signed tree heads (parse/verify + proofs)
- `MetamorphicLog.Note` — C2SP signed-note verification (Ed25519 + hybrid PQ)
- `MetamorphicLog.Coniks` — CONIKS key-transparency lookup/absence proofs
- `MetamorphicLog.Commitment` — SHA3-512 commitment verification
- `MetamorphicLog.Keytrans` — IETF KEYTRANS combined-tree verification
  (search / fixed-version / monitor; experimental, suite-aware)
- `MetamorphicLog.Policy` — signed namespace policy + declared==observed
- `MetamorphicLog.Leaf` — canonical `mosslet/key-history/v1` leaf encoding
- `MetamorphicLog.Ingest` — dedup keys, flush geometry, Merkle recomputation

## Wire format

Binary values (hashes, roots, proof nodes, keys, openings) are **base64-encoded**
strings; checkpoint/note bodies and verifier keys are UTF-8 text. This matches
the WASM SDK and is what makes cross-target digests identical.

## Quick start

    # Verify an inclusion proof against a verified checkpoint
    {:ok, %MetamorphicLog.Checkpoint{}} =
      MetamorphicLog.Checkpoint.verify(note_text, [vkey])

    :ok =
      MetamorphicLog.Checkpoint.verify_inclusion(
        note_text, [vkey], leaf_index, leaf_hash, proof
      )

# `verify_consistency`

```elixir
@spec verify_consistency(
  non_neg_integer(),
  non_neg_integer(),
  [String.t()],
  String.t(),
  String.t()
) :: :ok | {:error, String.t()}
```

Convenience delegate for `MetamorphicLog.Proof.verify_consistency/5`.

# `verify_inclusion`

```elixir
@spec verify_inclusion(
  non_neg_integer(),
  non_neg_integer(),
  String.t(),
  [String.t()],
  String.t()
) :: :ok | {:error, String.t()}
```

Convenience delegate for `MetamorphicLog.Proof.verify_inclusion/5`.

---

*Consult [api-reference.md](api-reference.md) for complete listing*