Powered by OpenAI's GPT models, this integration lets you summarize messages, translate content, rewrite drafts, generate replies, and automate repetitive tasks — all without leaving your inbox. Use it on demand from any message or draft, or set up rules to let AI handle incoming messages automatically.
The integration supports GPT-5 mini (fast and cost-effective for most tasks), GPT-5 (for complex reasoning and detailed analysis), and GPT-4o mini (previous generation, still reliable).
On messages: Click the AI icon on any incoming message to summarize, translate, or generate a reply.
In drafts: Select text to rewrite, fix grammar, or change tone. Or generate an entire draft from scratch. You can also use the [documentation] variable to let AI reference your canned responses when generating replies — so the output is grounded in your actual business knowledge, not generic filler.
Via rules: Automate AI actions on incoming messages. Auto-summarize long threads, auto-label conversations by topic, extract action items as tasks, or create draft replies for common inquiries — all before a human even opens the message. Learn more about AI Rules.
To use the OpenAI integration in Missive, you need an OpenAI API account, not a ChatGPT subscription. These are different products. A ChatGPT Plus subscription ($20/month) gives you access to ChatGPT's web interface, but it won't work with Missive. You need an OpenAI platform account with API access and pay-as-you-go billing.
Each user in your organization can add their own OpenAI API key if preferred.
The integration is fully customizable. Create your own prompts using variables like [message] (the last message in the thread), [selection] (text you've highlighted in your draft), and [documentation] (your canned responses).
Save prompts you use often, and they'll appear as quick actions on your messages and drafts.
Manage which quick actions show up from Settings > Preferences > Appearance — especially useful if your organization shares many prompts and you only want the ones relevant to your workflow.
Data submitted through the OpenAI API is not used to train OpenAI models or improve OpenAI's service offering. See openai.com/security for more information.
