semaphore

Semaphore v4 anonymous signaling for EVML scripts: wallet-derived zero-knowledge identities, on-chain group management against the canonical singleton, and membership proofs with the production ceremony artifacts, built on the circom module.

⚗️ Experimental — available at next.evmcrispr.com.

load semaphore

Configuration variables

Config variables are set with set (fully qualified, including the module prefix) and are only readable by their own module and the user script.

Variable	Type	Default	Description
$semaphore:address	address	—	Semaphore v4 contract address override (default: the canonical singleton, same address on every supported chain).
$semaphore:deployBlock	number	—	Block the Semaphore contract was deployed at, bounding member event scans on chains without a built-in entry.

Commands

Command	Description
semaphore:add-member	Add an identity commitment (or an array of them) to a Semaphore group. Only the group admin can execute the resulting transaction.
semaphore:create-group	Create a Semaphore group on the canonical contract and bind the predicted group id to . Without --admin the transaction sender becomes the admin (correct through Safes and forwarders).
semaphore:identity	Derive a Semaphore v4 identity and bind its public commitment to . The connected wallet signs a fixed message and the signature seeds the identity - deterministic per wallet, recoverable anywhere by re-signing. The secret never leaves module memory.
semaphore:prove	Prove membership in a Semaphore group anonymously, signaling a message nullified per scope, and bind the proof JSON to . Uses the production ceremony artifacts for the group's tree depth. Requires an identity derived this session (semaphore:identity).
semaphore:remove-member	Remove an identity commitment from a Semaphore group (the leaf becomes 0; the tree keeps its size). Computes the required Merkle siblings from the reconstructed member set — they go stale if the group changes before execution.
semaphore:validate	Validate a Semaphore membership proof on-chain. The contract records the nullifier, so a second proof with the same identity and scope reverts.

Helpers

Helper	Returns	Description
@semaphore:depth	number	The current depth of a Semaphore group's member tree.
@semaphore:members	array	The ordered member commitments of a Semaphore group, reconstructed from contract events and checked against the on-chain root. Removed members appear as 0.
@semaphore:nullifier	number	The nullifier a stored identity produces for a scope (poseidon of the hashed scope and the identity secret), what the contract records on validateProof; useful to check whether a signal was already sent.
@semaphore:root	number	The current Merkle root of a Semaphore group's member tree.
@semaphore:size	number	The number of leaves in a Semaphore group's member tree (removed members keep their slot as 0).
@semaphore:verify	bool	Check a Semaphore membership proof against a group with the contract's view verifier: no transaction and no nullifier recording.