# Why Your OpenAI JSON Calls Randomly Fail with "could not parse JSON body" (And How to Fix It)

> Source: <https://dev.to/zey-smith/why-your-openai-json-calls-randomly-fail-with-could-not-parse-json-body-and-how-to-fix-it-2nip>
> Published: 2026-09-18 03:28:36+00:00

``You're calling OpenAI from Node.js. 99% of requests work. Then randomly:

BadRequestError: 400 could not parse JSON body

Or:

SyntaxError: Invalid JSON: EOF while parsing an object

Or, if you're using tool calling:

Invalid JSON in tool call arguments

You check your code. Nothing changed. You retry manually — it works. You deploy again. It breaks again.

These errors are NOT your bugs. They're transient artifacts from:

Every one of these is intermittent. So you can't debug it with a stack trace. You just suffer.

People usually do this:

``` js
try {
  const res = await client.chat.completions.create({...});
} catch (e) {
  const res = await client.chat.completions.create({...});
}
```

Problems:

Different errors need different handling:

| Error | Correct action | 
|---|---|
| Transient 400 (could not parse JSON body) | Retry with backoff + jitter | 
| Truncated stream (EOF while parsing) | Retry, possibly with higher max_tokens | 
| Malformed tool args | Sanitize inline, no retry needed | 
| Invalid API key | Fail fast, do NOT retry | 
| Rate limit | Retry with longer backoff | 

Doing this manually is ~150 lines of code you'll write badly. Or:

``` js
npm install @coder12-z/llm-shield

import { shield } from "@coder12-z/llm-shield";
import OpenAI from "openai";

const client = new OpenAI();

const safeCall = shield(async (prompt) =>
  client.chat.completions.create({
    model: "gpt-4o-mini",
    messages: [{ role: "user", content: prompt }],
    response_format: { type: "json_object" },
  }),
  {
    maxRetries: 3,
    onRetry: ({ attempt, kind }) => console.log(`retry #${attempt} (${kind})`),
  }
);
```

Three lines of config. Zero dependencies. Works with OpenAI, Anthropic, Gemini, or anything that throws Error objects with status and message.

MIT licensed. Feedback welcome.