CEL API Reference

elide:cel compiles and evaluates CEL expressions. Expressions have no side effects and always terminate, so they suit user-supplied rules, filters and policies.

import { compile } from "elide:cel";

const rule = compile("user.age >= 18 && 'admin' in user.roles");
rule.variables; // ["user"]
rule.test({ user: { age: 30, roles: ["admin"] } }); // true
compile("xs.filter(x, x % 2 == 0)").evaluate({ xs: [1, 2, 3, 4] }); // [2, 4]

• compile(expression) parses and type-checks once and returns a reusable program. Free identifiers become variables, typed dyn. Invalid expressions throw an Error with the CEL diagnostic.
• program.evaluate(variables?) returns the result; program.test(variables?) requires a boolean. Evaluation failures throw an Error.
• The standard library and macros (has, all, exists, exists_one, map, filter) are available. CEL extension libraries are not.

Values

Results convert back the same way. An int beyond Number.MAX_SAFE_INTEGER returns as a bigint; a timestamp or duration returns as its string form. Comparisons mix int and double freely, arithmetic does not: write double(x) / 2.0 when x may be integral.

Samples

• Access rules with CEL