LockScript Built-in Functions

Overview

Nine built-in functions are registered by engine.RegisterBuiltinFunctions(). They are called from LockScript via OpCallBuiltin and bridge the script environment to real cryptographic and system operations.

Time Functions

now() → int64

Returns the current Unix timestamp (seconds since epoch).

now()  // e.g. 1717200000

after(ts int64) → bool

Returns true if the current time is strictly greater than ts.

after(1700000000)        // true if current time > 2023-11-14
after(unlock_time)       // true if the lock's configured unlock time has passed

before(ts int64) → bool

Returns true if the current time is strictly less than ts.

before(1800000000)       // true if before 2027-01-15

Cryptographic Functions

sha256(data string) → string

Returns the hex-encoded SHA-256 hash of the input string.

sha256("hello")  // "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"

verify_sig(pk string, msg string, sig string) → bool

Verifies an Ed25519 signature. All three arguments are hex-encoded strings.

• pk — 32-byte Ed25519 public key (hex)
• msg — message that was signed (hex or plain string)
• sig — 64-byte Ed25519 signature (hex)

verify_sig(owner, asset_id, signature)

Returns true if the signature is valid for the given key and message. Returns false (not an error) for invalid signatures — allowing scripts to branch on verification result rather than hard-fail.

require_sigs(pks []string, msg string, sigs []string, n int) → bool

Ed25519 m-of-n multi-signature verification. Returns true if at least n of the signatures in sigs are valid Ed25519 signatures over msg by one of the keys in pks.

• Each signature is matched against the key at the same index position.
• n must be ≤ len(pks).

// 2-of-3 multi-sig
require_sigs(pubkeys, message, signatures, 2)

Important: Prior to the v2 fix, require_sigs counted non-empty strings rather than verifying actual cryptographic signatures. The current implementation performs real Ed25519 verification for each pair.

Geographic Function

check_geo(region string) → bool

Returns true if the node's configured geographic region matches the provided region identifier.

check_geo("us-east")
check_geo("eu-west")

Region strings are matched against the node's runtime configuration. This is primarily used in enterprise/compliance scenarios where assets should only be accessible from specific jurisdictions.

Math Functions

min(a, b, ...) → int

Returns the minimum of the provided integer arguments.

min(3, 7, 2)   // 2
min(a, b)       // lesser of two context variables

max(a, b, ...) → int

Returns the maximum of the provided integer arguments.

max(3, 7, 2)   // 7

Usage Patterns

Time-lock with single signature

after(unlock_time) && verify_sig(owner, asset_id, signature)

Multi-sig OR owner unlock

verify_sig(owner, message, signature) ||
require_sigs(backup_keys, message, backup_sigs, 2)

Commitment check

sha256(preimage) == expected_hash && after(unlock_time)

Geo-gated access

check_geo("eu-west") && verify_sig(owner, asset_id, signature)