Release Notes - Phoenix

Delete Prompts and Prompt Version Tags via REST API

March 30, 2026 Available in arize-phoenix 13.20.0+

Two new REST endpoints let you delete prompts and remove tags from prompt versions programmatically.

DELETE /v1/prompts/{prompt_identifier} deletes a prompt and all of its versions, tags, and labels in one operation. The prompt_identifier can be the prompt name or its numeric ID.

DELETE /v1/prompt_versions/{prompt_version_id}/tags/{tag_name} removes a single named tag from a specific prompt version. The tag is resolved within the scope of the prompt linked to that version.

• DELETE /v1/prompts/{prompt_identifier} — permanently deletes the prompt and every version, tag, and label associated with it
• DELETE /v1/prompt_versions/{prompt_version_id}/tags/{tag_name} — removes a tag from a prompt version without affecting other tags or the version itself
• Both endpoints return 204 No Content on success; attempting to delete a non-existent tag returns 404 Not Found