Skip to main content
The system prompt is what tells the model what kind of agent it is. HasteKit lets you write it inline on the agent, or reference an immutable version of a prompt template from your project’s prompt library so the same prompt can power many agents.

​
Two ways to configure

​
Use raw prompt text

Write the prompt directly on the agent. The editor supports multi-line text and syntax highlighting.
System Prompt Raw Text
Best when:
  • The prompt is unique to this agent.
  • You’re iterating quickly and don’t yet want to version it.

​
Use prompt reference

Reference a prompt from your project’s Prompts library.
  1. Select Reference.
  2. Pick a prompt from the Select Prompt dropdown.
  3. Optionally pin to a specific version (or leave on $LATEST).
System Prompt Reference
Each prompt version is immutable — referencing version 3 of a prompt guarantees the exact same text forever, even if a teammate later publishes version 4. This is the recommended path for production agents. Best when:
  • Multiple agents share a prompt.
  • You want to version the prompt independently of the agent.
  • You want a non-engineer to be able to edit the prompt without touching the agent config.

​
Variables

Prompt templates can use {{variable}} interpolation. Variables are resolved from the agent’s runtime context (passed via the chat UI’s Add Context dialog or the HTTP request body). This lets one prompt template adapt to per-user or per-tenant data without spinning up a separate agent for each.