---
title: "OpenAI (ChatGPT) API key"
description: "Add your OpenAI API key to score mentions with GPT: where to get the key, model options and costs, and troubleshooting."
source: https://backtalk.sh/docs/openai
---
# OpenAI (ChatGPT) key

Bring your own [OpenAI](https://openai.com/) key to score and categorise mentions with **GPT**. Without an AI key, BackTalk uses a free offline word-list scorer; a GPT key upgrades every new signal to AI sentiment, categories, and priority.

## What it unlocks

- AI sentiment (positive / neutral / negative) instead of the offline lexicon.
- Category and priority tagging on each mention.
- A one-time background **re-score** of your existing mentions when you save the key.

You can save **a key per provider**. Left untouched, your first key powers filtering (sentiment, relevance, priority) and every saved key's model joins the AI share-of-voice comparison. Point either job at any saved key and model, including several models from one provider, under **What runs each task** in Settings.

## Get your API key

1. Sign in to the [OpenAI Platform](https://platform.openai.com/).
2. Add a payment method under **Billing**. API access is separate from a ChatGPT Plus subscription and needs its own credit.
3. Open [**API keys**](https://platform.openai.com/api-keys) and choose **Create new secret key**.
4. Copy the key. New keys start with `sk-proj-…` (older ones, `sk-…`) and it's shown only once.

## Add it in BackTalk

1. Go to [**Settings**](/app/settings/ai) and find the **OpenAI** card under AI providers.
2. Pick a model (see below) and paste your `sk-proj-…` key.
3. **Save.** BackTalk sends one tiny test request to confirm the key and model, then stores the key encrypted and starts the background re-score.

## Models & cost

Billed by OpenAI directly at their token rates, with no markup from BackTalk. Sentiment prompts are short, so cost per mention is usually a fraction of a cent. List prices (USD per million input / output tokens):

- **GPT-5.4 nano**: ~$0.20 / $1.25. Fastest and cheapest; the right default for sentiment.
- **GPT-5.4**: ~$2.50 / $15. More nuance.
- **GPT-5.5**: ~$5 / $30. Most capable; rarely needed just for scoring.

## Troubleshooting

- **"The provider rejected that API key."** Wrong, revoked, or project-scoped key that lacks model access. Create a fresh key and re-paste.
- **"That model isn't available on this key."** Your account/project can't use that model. Add billing or pick GPT-5.4 nano.
- **Key check failed.** Most often no billing credit on the OpenAI account. Add credit, then retry.

> **Your key stays private.** It's encrypted at rest and only decrypted server-side when a scoring call runs. It is never returned to your browser and never logged. Settings shows only a masked hint.
>
> **Rotating your key:** create a new key in the OpenAI Platform, paste it into Settings to replace the old one, then revoke the previous key.