| name | compact-core:standard-library |
| description | Use when importing from CompactStandardLibrary, working with crypto functions (persistentHash, persistentCommit, ecAdd, ecMul), utility types (Maybe, Either), token operations (mintToken, send, receive, mergeCoin), or time functions (blockTime, blockTimeBefore, blockTimeAfter). |
Compact Standard Library
Complete reference for CompactStandardLibrary - the built-in module providing cryptographic functions, utility types, token operations, and time functions.
Import
import { persistentHash, Maybe, mintToken, blockTime } from "CompactStandardLibrary";
Quick Reference
Cryptographic Functions
| Function | Safe? | Purpose |
|---|
persistentCommit(value) | Yes | Create hiding commitment with nonce (cross-transaction stable) |
transientCommit(value) | Yes | Create hiding commitment with nonce (transaction-local) |
persistentHash(domain, value) | No | Domain-separated hash (cross-transaction stable) |
transientHash(domain, value) | No | Domain-separated hash (transaction-local) |
ecAdd(p1, p2) | - | Elliptic curve point addition |
ecMul(scalar, point) | - | Elliptic curve scalar multiplication |
Safe vs Unsafe: Commit functions include a random nonce, making them hiding. Hash functions do not include a nonce - if the input has low entropy, the hash can be brute-forced.
Utility Types
| Type | Purpose | Variants |
|---|
Maybe<T> | Optional value | Some(T), None |
Either<L, R> | Result/choice | Left(L), Right(R) |
Token Operations
| Function | Purpose |
|---|
mintToken(info) | Create new tokens |
send(coin, recipient) | Send tokens to address |
receive() | Receive tokens in circuit |
mergeCoin(coins) | Combine multiple coins |
Time Functions
| Function | Purpose |
|---|
blockTime() | Current block timestamp |
blockTimeBefore(time) | Assert current time < time |
blockTimeAfter(time) | Assert current time > time |
Common Patterns
Safe Commitment
import { persistentCommit } from "CompactStandardLibrary";
witness get_secret(): Field;
export circuit commit_secret(): Bytes<32> {
const secret = get_secret();
// Safe: commitment hides the secret
return persistentCommit(secret);
}
Nullifier Generation
import { persistentHash } from "CompactStandardLibrary";
witness get_secret(): Field;
export circuit generate_nullifier(): Bytes<32> {
const secret = get_secret();
// Unsafe but intentional: nullifier should be deterministic
return persistentHash("nullifier", secret);
}
Optional Value Handling
import { Maybe } from "CompactStandardLibrary";
ledger values: Map<Bytes<32>, Field>;
export circuit get_or_default(key: Bytes<32>): Field {
const result = values.lookup(key);
return if result is Maybe::Some(v) { v } else { 0 };
}
Time-Locked Action
import { blockTime, blockTimeAfter } from "CompactStandardLibrary";
ledger unlock_time: Cell<Uint<64>>;
export circuit withdraw(): [] {
// Fails if current block time <= unlock_time
blockTimeAfter(unlock_time.read());
// Perform withdrawal...
}
References
Examples
