different-ai/openwork · error · InterpreterRuntimeError

Object.${name} expects a data object.

Error message

Object.${name} expects a data object.

What it means

The requireObject helper inside invokeObjectMethod validates that the first argument is a plain data object (not null, not an array, not a primitive, not a sandbox value). It throws this when Object.values, Object.entries, Object.hasOwn, or Object.fromEntries prechecks receive something else.

Source

Thrown at packages/codemode/src/stdlib/object.ts:14

import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
import { isBlockedMember } from "../tool-runtime.js"
import { isSandboxValue, SandboxMap, SandboxURLSearchParams } from "../values.js"
import { boundedData, coerceToString } from "./value.js"

export const objectStatics = new Set(["keys", "values", "entries", "hasOwn", "assign", "fromEntries"])

export const invokeObjectMethod = (name: string, args: Array<unknown>, node: AstNode): unknown => {
  if (!objectStatics.has(name)) throw new InterpreterRuntimeError(`Object.${name} is not available in CodeMode.`, node)
  const requireObject = (): Record<string, unknown> => {
    const value = boundedData(args[0], `Object.${name} input`)
    if (isSandboxValue(value)) return {}
    if (value === null || typeof value !== "object" || Array.isArray(value)) {
      throw new InterpreterRuntimeError(`Object.${name} expects a data object.`, node)
    }
    return value as Record<string, unknown>
  }
  const guardedSet = (out: Record<string, unknown>, key: string, item: unknown): void => {
    if (isBlockedMember(key)) throw new InterpreterRuntimeError(`Property '${key}' is not available in CodeMode.`, node)
    out[key] = item
  }
  switch (name) {
    case "keys": {
      const value = boundedData(args[0], "Object.keys input")
      if (isSandboxValue(value)) return []
      if (Array.isArray(value)) return Object.keys(value)
      if (value === null || typeof value !== "object") {
        throw new InterpreterRuntimeError("Object.keys expects a data object or array.", node)
      }
      return Object.keys(value)
    }
    case "values":

View on GitHub (pinned to 2b7df46e8a)

Solutions

1. Ensure the first argument is a plain object: wrap construction as data ?? {} before calling
2. Convert arrays to keyed objects via Object.fromEntries(entries) when key/index mapping is needed
3. Check API responses for null before passing to Object.values/entries
4. Use Object.keys (which accepts arrays) instead of values/entries when the input may be an array

Example fix

// before
const counts = Object.entries(data)
// after
if (data && typeof data === 'object' && !Array.isArray(data)) {
  const counts = Object.entries(data)
}

function assertPlainObject(v: unknown): asserts v is Record<string, unknown> {
  if (v === null || typeof v !== 'object' || Array.isArray(v)) {
    throw new Error('Object statics require a plain data object')
  }
}

const isPlainObject = (v: unknown): v is Record<string, unknown> =>
  v !== null && typeof v === 'object' && !Array.isArray(v)

try {
  return Object.entries(input)
} catch (e) {
  if (e instanceof InterpreterRuntimeError && e.message.includes('expects a data object')) {
    return Object.entries(input && typeof input === 'object' && !Array.isArray(input) ? input : {})
  }
  throw e
}

When it happens

Trigger: Object.values(null), Object.entries([1,2,3]) (array passed to entries/values), Object.hasOwn('str', 'k'), Object.values(42), or passing a sandbox opaque value that was mapped to {} and then a non-object second call path receives a primitive.

Common situations: Passing JSON.parse results that turned out to be null (JSON 'null'); passing arrays where the API demands a record; handling API responses that may be scalar in edge cases.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Object.keys expects a data object or array.
• Object.assign expects data objects.
• Object.fromEntries expects an array of [key, value] pairs.
• Object.fromEntries expects [key, value] pairs.
• String.${name} expects argument ${index + 1} to be a number.

AI-assisted analysis of different-ai/openwork@2b7df46e8a (2026-09-01). Data as JSON: /api/errors/ca1df32d8fac1fdc. Report an issue: GitHub.