fetchOptions - Type '{ dispatcher: any; }' is not assignable to type 'undefined'.

[Cerlancism]

Confirm this is a Node library issue and not an underlying OpenAI API issue

• This is an issue with the Node library

Describe the bug

Type error when configuring fetchOptions of new OpenAI instance

Type '{ dispatcher: ProxyAgent; }' is not assignable to type 'undefined'.ts(2322)
client.d.mts(64, 5): The expected type comes from property 'fetchOptions' which is declared here on type 'ClientOptions'
(property) ClientOptions.fetchOptions?: undefined
Additional RequestInit options to be passed to fetch calls. Properties will be overridden by per-request fetchOptions.

To Reproduce

1. Follow "Configuring proxies" from README https://github.com/openai/openai-node?tab=readme-ov-file#configuring-proxies
2. Observe TypeScript errors

Code snippets

import OpenAI from 'openai';
import * as undici from 'undici';

const proxyAgent = new undici.ProxyAgent('http://localhost:8888');
const client = new OpenAI({
  fetchOptions: {
    dispatcher: proxyAgent,
  },
});

OS

Windows

Node version

Node v22.12.0

Library version

openai v5.7.0

[RobertCraigie]

Thanks for the report, what does your tsconfig.json and package.json look like?

[Cerlancism]

Thank you for the response.

I am using jsconfig.json instead.

{
    "compilerOptions": {
        "target": "ESNext",
        "module": "NodeNext",
        "moduleResolution": "NodeNext",
        "lib": [
            "ESNext"
        ],
        "checkJs": true
    },
    "exclude": [
        "./web"
    ]
}

package.json

{
  "name": "chatgpt-subtitle-translator",
  "version": "2.19.0",
  "description": "Translation tool based on ChatGPT API",
  "main": "src/main.mjs",
  "type": "module",
  "scripts": {
    "test": "node --test"
  },
  "author": "Cerlancism",
  "license": "MIT",
  "dependencies": {
    "@types/node": "^20.15.0",
    "commander": "^13.1.0",
    "dotenv": "^16.5.0",
    "JSONStream": "^1.3.5",
    "loglevel": "^1.9.2",
    "openai": "^5.7.0",
    "proxy-agent": "^6.5.0",
    "readline": "^1.3.0",
    "srt-parser-2": "^1.2.3",
    "undici": "^7.10.0",
    "zod": "^3.25.63"
  },
  "engines": {
    "node": ">=16.13.0"
  },
  "bin": {
    "chatgpt-subtitle-translator": "./cli/translator.mjs"
  }
}

[RobertCraigie]

@Cerlancism please try v5.8.2!