Prompt files

Flary prompt files are Markdown files with YAML front matter. Store them in Git and review them like source code.

File and slug

prompts/support/answer.prompt.md

The path becomes the slug support/answer.

Complete example

---
model: inherit
thinking: medium
tools:
  - docs.search
  - account.read

input:
  customer.name: string
  customer.plan: string
  question: string

limits:
  steps: 12
  tools: 20
---

You are a product support agent.

Answer {{customer.name}} about the {{customer.plan}} plan.
Use a tool for product facts. Do not invent policy.

Question:
{{question}}

model: inherit uses the model selected by the application. A prompt can also pin a provider and model:

model: anthropic/claude-sonnet-4-5

Compile

import { compilePrompt } from "flary/prompts";

const compiled = await compilePrompt(
  {
    path: "prompts/support/answer.prompt.md",
    content: promptSource,
  },
  {
    callerModel: "openai/gpt-5.6",
    values: {
      customer: { name: "Ada", plan: "Pro" },
      question: "Can I add another workspace?",
    },
  },
);

Templates support strict {{value.path}} interpolation. Compilation fails on missing values, unknown values, or secret-like paths. Provider credentials do not enter the prompt.