Bitcoin Cash activated the "Layla" network upgrade on May 15, 2026, when Median Time Past reached the specified activation time. The upgrade bundled four CashVM and standardness proposals.
The network upgrade specification is the primary reference. This article explains the practical effect without treating every possible application as a delivered product.
Loops
Bounded loops let a script repeat logic without copying the same bytecode for every iteration. The loop operations are constrained by CashVM resource limits, so they provide compact expression rather than unbounded execution.
Loops are useful for algorithms that process a list, repeat hashing steps, or verify a variable number of items. They also create new review obligations: developers must prove the exit condition, maximum work, and behavior at every boundary.
Functions
OP_DEFINE and OP_INVOKE let scripts define and call reusable function bodies. Factoring repeated logic can reduce contract size and make generated bytecode easier to reason about.
Functions do not introduce persistent global state or dynamic package imports. They are a CashVM code-reuse mechanism within the validating script.
Pay to Script
Pay to Script, or P2S, made a direct script form standard for relay and mining while increasing several standard transaction-component limits. A P2S output commits to a script through the transaction structure defined by the proposal, and the spending transaction reveals the relevant program.
This can reduce indirection for some larger contracts and post-upgrade constructions. Consensus validity and standard relay policy remain distinct: a transaction can satisfy consensus while still depending on node and miner policy for ordinary propagation.
Bitwise operations
The upgrade re-enabled bitwise operations for AND, OR, XOR, and related binary-data work under the modern VM limits. Contracts can manipulate bit fields and binary encodings more directly instead of replacing every operation with arithmetic or lookup logic.
The benefit is expressiveness and byte efficiency, not a new cryptographic assumption.
Node and infrastructure status
Bitcoin Cash Node v29.0.0 introduced the activation rules. The current BCHN maintenance release at this review is v29.1.0; operators should follow their implementation's supported-release guidance rather than treating the activation version as permanently current.
Wallet users did not need to move ordinary funds solely because of Layla. Exchanges, miners, indexers, and node operators did need compatible validation software before activation.
What Layla does not establish
The upgrade makes some contracts smaller or newly practical. It does not:
- convert BCH to an account-based execution model;
- make contracts safe without testing and review;
- provide trustworthy off-chain data without an oracle design;
- guarantee wallet adoption or application demand;
- remove block, transaction, or VM resource limits.
The useful post-activation question is no longer whether the rules will activate. It is which applications use them, how their risks are documented, and whether independent implementations agree on the resulting transactions.