@circom:field

Reduce a value into the BN254 scalar field: values >= the field prime wrap around and negative values wrap to p - |x| (the circom convention).

⚗️ Experimental — available at next.evmcrispr.com.

Returns: number

Syntax

@circom:field(value)

Arguments

Name	Type	Description
value	any	Number, decimal string, or hex/bytes32 value to reduce into the field

Examples

# Fit a keccak256 hash into the BN254 field before using it as a circuit input
set $leaf @circom:field(@hash("my secret"))
print "Leaf:" $leaf

Notes

• Reduction follows the circom convention: values wrap modulo the prime p = 21888242871839275222246405745257275088548364400416034343698204186575808495617, and negatives map to p - |x|.
• Every circom helper applies this reduction to its inputs implicitly; use @circom:field when you need the reduced value itself (e.g. to compare against a public signal).

See Also

• @circom:field.hash — keccak256-then-reduce for arbitrary bytes
• @circom:poseidon — hash field elements