SmartLedger-BSV 9.42.0 Adds Compact Covenant Scripts

Developer Infrastructure Watch / Developer Tools

In Brief

SmartLedger-BSV has published version 9.42.0 of its JavaScript library, adding a compact script component for checking transaction data and building covenant constraints on BSV Blockchain.

The new OP_PUSH_TX authenticator is 89 bytes, compared with 377 bytes for the library’s existing version. A related helper produces a 135-byte script that requires a specified set of outputs in the transaction spending it.

The additions use existing Bitcoin Script operations and preserve the library’s older implementations.

News Report

The npm registry records publication of @smartledger/bsv version 9.42.0 on October 17, 2026, at 17:55 UTC.

The release adds compact transaction-preimage verification and an output-constraining covenant helper. The relevant implementation is present in the published package and matches the source in the release commit.

This is a separate development from the signature-hashing corrections BSV TIMES reported on October 16.

Those updates addressed agreement between library and node software over the data covered by a signature. Version 9.42.0 adds a smaller way to construct certain transaction constraints.

What the Script Component Does

A covenant restricts how a transaction output can be spent. One example is a rule requiring the spending transaction to create a particular set of outputs.

To enforce that kind of condition, a script needs a trustworthy connection between the transaction data presented to it and the transaction actually being validated.

OP_PUSH_TX is a scripting technique used to establish that connection. Despite its name, it is not a newly introduced network opcode.

The technique checks supplied transaction-signing data, known as a preimage, using existing hashing and signature operations. A covenant can then inspect information committed to by that preimage and apply its conditions.

Version 9.42.0 adds a compact implementation of that checking component.

Smaller Scripts and Less Preparation Work

The published reference scripts show the compact authenticator at 89 bytes, compared with 377 bytes for the classic form—a reduction of approximately 76% for that component.

The compact construction removes the classic implementation’s byte-reversal sequences and large-number arithmetic, replacing them with a simpler calculation.

The size comparison concerns the authenticator itself. A complete application may require additional script conditions, unlocking data and transaction fields.

The release also changes the preparation process for the compact form.

OP_PUSH_TX construction involves trying transaction variations until the resulting signing data satisfies the script’s requirements. The project reports that approximately 49.6% of candidates satisfy the compact form’s conditions, compared with roughly 2% for the classic construction.

That corresponds to around two attempts on average instead of approximately fifty.

These figures describe transaction preparation. They are not a measurement of network throughput or end-to-end application speed.

A Compact Rule for the Entire Output Set

The new valueCovenantPortable() helper combines the compact authenticator with a method for extracting the transaction’s output commitment.

The resulting script is 135 bytes, compared with 419 bytes for the library’s classic valueCovenant() implementation.

It constrains the complete output set, including output order, amounts and locking scripts. Any required change output must therefore be included in the committed set.

The portable implementation also avoids operations whose restored behavior depends on Chronicle.

The project’s tests exercise it under current mainnet validation flags and under historical configurations without Genesis or Chronicle enabled. The construction still depends on operations introduced in the 2018 Monolith upgrade.

This is a compatibility property of the tested script construction. Larger contracts built around it can encounter additional limits and require their own validation.

Published Evidence and Integration Limits

The repository includes a reference vector containing the compact script’s exact bytes, its SHA-256 hash, a sample spending transaction and the corresponding preimage.

Tests cover acceptance of the intended preimage and rejection of altered data. Separate covenant tests check that changing the required output set causes validation to fail.

These are script-validation results. They do not establish that a commercial application has deployed the new construction.

The maintainer also documents the technique’s cryptographic assumptions and distinguishes test coverage from a formal security proof.

The update is additive: the classic authenticator remains available, its published script bytes remain unchanged, and existing calls retain their previous defaults. Developers must explicitly select the compact form when adopting it.

BSV TIMES Read

The practical improvement is a smaller reusable component for applications that enforce transaction conditions through Bitcoin Script.

Reducing the script’s size can reduce the amount of data a particular construction places on-chain. Reducing the number of preparation attempts can also simplify work performed before a transaction is submitted.

The benefit to an application depends on its complete contract and transaction structure. An 89-byte authenticator is one component within that larger design.

What makes this release reportable is the availability of the implementation in a published package, accompanied by concrete script bytes and reproducible reference data.

It is a developer-tooling improvement built with existing protocol capabilities.

Developer Context

The npm package identifies SmartLedger Technology as its author and smartledger as its maintainer account.

Development is published in the codenlighten/smartledger-bsv repository. The version 9.42.0 release commit and accompanying documentation updates are credited to the public GitHub account codenlighten.

Source Links

Posted on October 18, 2026 (UTC)