For some reason getting "400" bad request

Bug Reports
1

Hi folks,

Might be stupid and silly question.. but that’s my first time playing with API..

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image732×700 21.9 KB

I am trying to connect to API and I am getting..

“URL Called:

https://api.perplexity.ai/chat/completions

Full Response:

{
  "status": 400,
  "reason": "Bad Request"
}

What I am doing wrong?

I’ve copied the API key directly from the settings, so have no clue why it is not getting response back.

2

Hey @Piotr_Krol — welcome to the API! A 400 Bad Request usually means there is a formatting issue with your request payload.

The most common causes:

  1. Wrong endpoint or base URL — For Sonar models, use https://api.perplexity.ai/v1/sonar

  2. Missing or malformed messages array — The payload needs to look like:

{
  "model": "sonar-pro",
  "messages": [
    {"role": "user", "content": "Your question here"}
  ]
}

  1. Invalid model name — Use sonar, sonar-pro, or sonar-reasoning-pro. Old model names like llama-3.1-sonar-small-128k-online are deprecated.

  2. Auth header format — Should be Authorization: Bearer pplx-xxxxx (not Api-Key or other formats)

Here is a minimal working curl you can test with:

curl https://api.perplexity.ai/v1/sonar \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "sonar", "messages": [{"role": "user", "content": "Hello"}]}'

If you are still hitting issues, share your request code (with the API key redacted) and I can spot the problem. Docs: Sonar Quickstart