TON Overlays

Overlays are logical peer groups over ADNL. They are used by validators and full nodes for shardchain communication, broadcasts, and peer exchange.

Why Overlays Matter

LiteAPI is request/response. Mempool and pending-message observation requires more direct network participation, which usually means DHT discovery and overlays.

Concepts

overlay id,
overlay node,
overlay peer list,
random peer exchange,
broadcast,
certificates,
validator group overlays,
shard overlays.

Implementation Requirements

An overlay implementation needs:

ADNL UDP transport,
DHT peer discovery,
overlay TL types,
peer score and expiration,
query routing,
broadcast validation,
deduplication.

Mempool Relation

Pending external messages are propagated before final block inclusion. A scanner must distinguish:

observed broadcast,
candidate block data,
included transaction,
finalized transaction.

Missing Work

Extract overlay constructors from ton_api.tl.
Document overlay id derivation.
Study validator shard overlays relevant to pending messages.
Add captured fixtures.