Feature description

Add Proof of Inclusion (PoI) support to the IOTA Notarization Toolkit.

PoI should provide portable evidence that a specific IOTA transaction, object, or event is included in authenticated chain data. This issue is the top-level epic for the feature. Follow-up implementation issues will be created separately and handled one by one.

Motivation

The current light-client-shaped work should evolve into a product-level Proof of Inclusion capability for the toolkit.

PoI lets applications construct inclusion evidence from an available data source while preserving local cryptographic verification. The design keeps data availability separate from trust: a full node, archive-backed source, or indexer can provide witness data, but the verifier must authenticate the packaged proof locally against the expected committee trust path.

This gives the toolkit a clearer product boundary for transaction, object, and event inclusion proofs without requiring every caller to run or trust a full node for verification.

Requirements

1. Establish Proof of Inclusion as a toolkit feature for transaction, object, and event inclusion proofs.
2. Keep proof construction separate from proof verification.
3. Support local verification of packaged proof data against committee trust.
4. Support explicit committee trust modes, including trusted-node mode and anchored verification from the genesis blob.
5. Cache only verified committee material and avoid treating cache entries as an independent trust source.
6. Treat full nodes, archive-backed sources, and indexers as proof-input data sources, not verifier trust sources.
7. Track implementation through separate follow-up issues created one by one.

Open questions

N/A

Are you planning to do it yourself in a pull request?

Yes