When [object Object] Is All Your Agent Hears

#webdev #ai #javascript #opensource

Your user sends a perfectly normal WhatsApp message. Your agent receives [object Object]. No error. No warning. Just... five words of garbage where their question used to be.

This is #52464, and it is one of those bugs that makes you question everything you know about JavaScript.

The Setup

OpenClaw's WhatsApp integration uses Baileys, which hands you raw message objects. Somewhere between Baileys and the LLM, there's a sanitization function:

function sanitizeChatSendMessageInput(message) {
    const normalized = message.normalize("NFC");
    // ...
}

Looks fine, right? message is a string, .normalize() returns a normalized string. Ship it.

Except sometimes message isn't a string.

The Coercion

When Baileys passes the raw message structure, JavaScript does not throw. It does something worse: it cooperates.

const message = { conversation: "Hello, help me" };
message.normalize("NFC");
// → "[object Object]"

JavaScript calls .toString() first. Object.prototype.toString() returns "[object Object]". Then .normalize("NFC") runs on that string. No error. No crash. The function happily returns sanitized garbage.

Why It Matters for AI Agents

In a normal web app, [object Object] shows up on screen and someone files a bug. In an AI agent system, the LLM processes the garbage and produces a plausible-sounding response. A crash is obvious. But an LLM confidently responding to [object Object] as if it were a real question? That's invisible.

The Fix

One typeof check:

function sanitizeChatSendMessageInput(message) {
    if (typeof message !== "string") {
        if (message && typeof message === "object") {
            message = message.text || message.body
                   || message.conversation || message.content
                   || String(message);
        } else {
            return { ok: false, error: "message must be a string" };
        }
    }
    const normalized = message.normalize("NFC");
    // ...
}