Breaking changes & protocol notes

Short log of protocol and API changes that affect upgrades. Prefer matching lib and node versions (Operate & Troubleshoot).

0.27 — First-class module deploys

Wire format

Module deploys are not smart-object transitions.

Storage	On-chain shape
multisig	Cleartext metadata { ept: string } in bare-multisig data outputs (no exp / env / mod / v, no encryption on modules yet)
taproot	Reveal-input witness envelope with protocol id BC, content type text/javascript

Legacy shapes that stored modules as transition exp fields or non-BC inscription envelopes are not read.

Client API

• deploy / load — write and evaluate modules
• decode — throws ModuleDecodeError on module deploys; use load. Import { ModuleDecodeError } from @bitcoin-computer/lib for instanceof.
• getModules / getModule — list/fetch indexed source without evaluating
• Static getInscription — parse a BC witness from raw hex
• txIdToBlockTime now returns Promise<bigint | undefined> (was number). Mixing bigint with number arithmetic throws.

Node

• Module table + GET /modules and GET /module/:mod
• Existing databases must apply the Module DDL if they predate this feature — see schema upgrade
• ZMQ/sync index module deploys; reorg clears module confirmation fields; mempool cleanup can delete unconfirmed module rows

Docs / migration tips

1. Upgrade node, apply Module table if needed, restart.
2. Upgrade @bitcoin-computer/lib to the same version.
3. Replace any code that treated module txs as transitions (decode / fake exp).
4. After deploy, call waitForIndexed before relying on getModules / object queries.
5. Prefer getOUTXOs over deprecated query for listing smart objects.

Deprecated client APIs (still present)

Deprecated	Prefer
computer.query	computer.getOUTXOs
export / import	deploy / load
Wallet getUtxos (lowercase)	getUTXOs({ address, isObject: false })

See the Computer index for the full list.