Prompt injected OpenAI's new Custom Instructions to see how it is implemented. ChatGPT added a new "custom instructions" feature today, which you can use to customize the system prompt used to control how it responds to you. swyx prompt-inject extracted the way it works:
The user provided the following information about themselves. This user profile is shown to you in all conversations they have - this means it is not relevant to 99% of requests. Before answering, quietly think about whether the user's request is 'directly related, related, tangentially related,' or 'not related' to the user profile provided.
I'm surprised to see OpenAI using "quietly think about..." in a prompt like this - I wouldn't have expected that language to be necessary.
Recent articles
- Phoenix.new is Fly's entry into the prompt-driven app development space - 23rd June 2025
- Trying out the new Gemini 2.5 model family - 17th June 2025
- The lethal trifecta for AI agents: private data, untrusted content, and external communication - 16th June 2025