Text feeds send two different kinds of instruction to Anthropic.
System Prompt: How To Behave #
Use the System Prompt for standing rules that should govern every request made by this feed:
- The AI’s role or perspective.
- Audience and tone.
- Accuracy and safety boundaries.
- Required style or response constraints.
- What to do when information is missing.
Example:
You are an internal case-note assistant. Be neutral and concise. Use only supplied facts. Do not
offer legal advice. If the request is unclear, state that in the summary.User Prompt: What To Do This Time #
Use the User Prompt for the actual task and entry-specific content:
Write a case summary under 120 words from the following submission.
Issue: {Issue:3}
Actions already taken: {Actions:4}
Desired outcome: {Outcome:5}The name “User Prompt” describes its provider message role; it does not mean visitors necessarily type the whole prompt. Administrators configure it, and merge tags insert visitor values.
Why Separate Them #
Separation makes the prompt easier to maintain. Stable behavior remains in one place while the task and submitted data remain explicit. It also helps avoid mixing a visitor’s untrusted content with the highest-level instructions.
The system prompt is not magical security. Models can still misunderstand conflicting or adversarial content. Validate outputs and avoid using AI alone for high-impact decisions.
Both fields support merge tags, but use a merge tag in System Prompt only when that value truly changes the standing behavior. Most form data belongs in User Prompt.
