different-ai/openwork · error · InterpreterRuntimeError

Number method '${name}' is not available in CodeMode.

Error message

Number method '${name}' is not available in CodeMode.

What it means

invokeNumberMethod supports a fixed switch of Number.prototype methods (toFixed, toPrecision, toString, etc.). Any other method name hits the default branch and throws this error. The library makes unsupported method surface explicit rather than allowing a runtime 'not a function' failure deep in sandbox code.

Source

Thrown at packages/codemode/src/stdlib/number.ts:36

      break
    case "toExponential":
      result = value.toExponential(optNum(0))
      break
    case "toPrecision": {
      const digits = optNum(0)
      result = digits === undefined ? value.toString() : value.toPrecision(digits)
      break
    }
    case "toString": {
      const radix = optNum(0)
      if (radix !== undefined && (radix < 2 || radix > 36)) {
        throw new InterpreterRuntimeError("Number.toString radix must be between 2 and 36.", node)
      }
      result = value.toString(radix)
      break
    }
    default:
      throw new InterpreterRuntimeError(`Number method '${name}' is not available in CodeMode.`, node)
  }
  return boundedData(result, `Number.${name} result`)
}

export const invokeNumberStatic = (name: string, args: Array<unknown>, node: AstNode): unknown => {
  const value = args[0]
  switch (name) {
    case "isInteger":
      return Number.isInteger(value)
    case "isFinite":
      return Number.isFinite(value)
    case "isNaN":
      return Number.isNaN(value)
    case "isSafeInteger":
      return Number.isSafeInteger(value)
    case "parseInt": {
      const radix = args[1]
      if (radix !== undefined && typeof radix !== "number") {

View on GitHub (pinned to 2b7df46e8a)

Solutions

  1. Use supported methods only: toFixed, toPrecision, toString (see the switch in packages/codemode/src/stdlib/number.ts).
  2. For locale formatting, pre-format the string outside CodeMode or format manually with toFixed.
  3. For toExponential, approximate via toPrecision or implement conversion in sandbox JS.

Example fix

// before
const s = value.toLocaleString("de-DE")
// after
const s = value.toFixed(2).replace(".", ",")
Defensive patterns

Strategy: validation

Validate before calling

const allowedNumberMethods = new Set(["toFixed", "toPrecision", "toString"])
if (!allowedNumberMethods.has(methodName)) throw new Error(`Number.${methodName} is not whitelisted in CodeMode`)

Type guard

const isNumberMethod = (n: string): n is "toFixed" | "toPrecision" | "toString" => allowedNumberMethods.has(n)

Try / catch

try { return value[methodName](...args) } catch (e) { if (/is not available in CodeMode/.test(String(e))) return numberFallback(value, methodName, args); throw e }

Prevention

When it happens

Trigger: Calling unsupported Number.prototype methods on sandbox numbers, e.g. value.toLocaleString("de-DE"), value.toExponential(2), or typos like value.toFixd(2).

Common situations: Locale-aware formatting in generated code (toLocaleString) — CodeMode does not support it; porting numeric formatting code that used toExponential; simple typos in method names.

Related errors

AI-assisted analysis of different-ai/openwork@2b7df46e8a (2026-09-01). Data as JSON: /api/errors/0af45206adac0abd. Report an issue: GitHub.