Deprecation notice and the replacement
OpenAI has deprecated custom prompts and directs developers toward skills as the replacement. Skills serve as reusable instructions that Codex can invoke explicitly or implicitly, providing a more integrated mechanism for embedding repeatable behavior into the Codex workflow.
This transition mirrors the same shift implemented by amp last week.
What custom prompts provided
Historically, custom prompts allowed Markdown files to be turned into reusable prompts. These could be invoked as slash commands in both the Codex CLI and the Codex IDE extension, enabling quick access to predefined prompts from within those tools.
Implications for projects
- Existing projects that relied on custom prompts should plan to transition to skills, since the older mechanism is deprecated.
For any further details, refer to the official note on custom prompts deprecation: https://developers.openai.com/codex/custom-prompts/