PromptScript Language Guide

PromptScript is a domain-specific language that compiles .prs files into native instruction formats for AI coding assistants (GitHub Copilot, Claude Code, Cursor, Antigravity, Factory AI, OpenCode, Gemini CLI). One source of truth, multiple outputs.

File Structure

A .prs file is made of blocks. Order doesn't matter except @meta should come first by convention.

# Comments start with #

@meta { ... }           # Required metadata
@inherit @path          # Single inheritance (optional)
@use @path [as alias]   # Imports/mixins (optional, multiple)

@identity { ... }       # AI persona
@context { ... }        # Project context
@standards { ... }      # Coding conventions
@restrictions { ... }   # Hard rules
@shortcuts { ... }      # Command aliases
@knowledge { ... }      # Reference documentation
@skills { ... }         # Reusable skill definitions
@agents { ... }         # Subagent definitions
@params { ... }         # Template parameters
@guards { ... }         # File globs and priorities
@local { ... }          # Private config (not committed)
@extend path { ... }    # Modify imported blocks
@custom-name { ... }    # Arbitrary named blocks

Content Types

PromptScript has three content types inside blocks:

Text Content

Use triple quotes (three double-quote characters) to wrap multiline text.
Text is automatically dedented - leading whitespace from source indentation is stripped.
Use for prose, markdown, or freeform content.

Example: @identity with a text block describing an AI persona starting with "You are..."

Object Content (key-value pairs)

@context {
  project: "My App"
  team: "Frontend"
  monorepo: {
    tool: "Nx"
    packageManager: "pnpm"
  }
}

Values can be strings (quoted or unquoted), numbers, booleans, nested objects, or arrays.

Array Content

@standards {
  code: [
    "Use strict TypeScript",
    "Named exports only"
  ]
}

@restrictions {
  - "Never use any type"
  - "Never commit secrets"
}

Mixed Content

Blocks can contain both object properties and text in the same block.
Place the triple-quoted text block alongside key-value pairs.

Block Reference

@meta (required)

@meta {
  id: "project-id"        # Required: unique identifier
  syntax: "1.0.0"         # Required: syntax version (semver)
  org: "Company Name"     # Optional
  team: "Frontend"        # Optional
  tags: [react, ts]       # Optional
  params: {               # Optional: template parameters
    projectName: string
    port: number = 3000
    debug?: boolean
    framework: enum("react", "vue") = "react"
  }
}

@identity

Defines AI persona. Start with "You are..." for consistent output across all formatters.
Contains a triple-quoted text block with the persona description.

@context

Project context with structured properties (project, team, languages, runtime)
plus optional triple-quoted text for architecture details, diagrams, etc.

@standards

Category-based conventions. Any category name is valid:

@standards {
  typescript: ["Strict mode", "No any type"]
  naming: ["Files: kebab-case.ts", "Classes: PascalCase"]
  git: {
    format: "Conventional Commits"
    types: [feat, fix, docs, refactor, test, chore]
  }
}

@restrictions

Hard rules as a list of dash-prefixed strings:

@restrictions {
  - "Never expose API keys"
  - "Never commit secrets to version control"
  - "Always validate user input"
}

@shortcuts

Simple strings appear as documentation. Objects with prompt: true generate
executable prompt/command files for GitHub Copilot and Cursor:

@shortcuts {
  "/review": "Review code for quality"
  "/test": {
    prompt: true
    description: "Write unit tests"
    content: (triple-quoted text with instructions)
  }
}

@skills

Reusable skill definitions with metadata:

@skills {
  commit: {
    description: "Create git commits"
    trigger: "commit, git commit"
    disableModelInvocation: true
    userInvocable: true
    allowedTools: ["Bash", "Read"]
    content: (triple-quoted text with skill instructions)
  }
}

Properties: description (required), content (required), trigger, disableModelInvocation,
userInvocable, allowedTools, context ("fork" or "inherit"), agent.

@agents

Custom subagent definitions:

@agents {
  code-reviewer: {
    description: "Reviews code quality"
    tools: ["Read", "Grep", "Glob", "Bash"]
    model: "sonnet"
    permissionMode: "default"
    content: (triple-quoted text with agent instructions)
  }
}

@knowledge

Reference documentation as triple-quoted text. Used for command references,
API docs, and other material that should appear in the output.

@params

Template parameter definitions with types: string, number, boolean, enum("a", "b").
Optional parameters use ? suffix. Defaults use = value.

@guards

File glob patterns and priority rules for path-specific instructions.

@local

Private local configuration. Not included in compiled output or committed to git.

Inheritance and Composition

@inherit (single, linear)

One per file. Child blocks merge on top of parent:

@inherit @company/frontend-team
@inherit ./parent
@inherit @stacks/react-app(projectName: "my-app", port: 3000)

@use (multiple, mixins)

Import and merge fragments:

@use @core/security
@use @core/quality
@use ./local-config
@use @core/typescript as ts   # alias enables @extend access

Merge rules:

• Text: concatenated with deduplication
• Objects: deep merged (target wins on conflicts)
• Arrays: unique concatenation

@extend (modify imported blocks)

Requires an aliased @use:

@use @core/typescript as ts

@extend ts.standards {
  testing: { coverage: 95 }
}

Configuration: promptscript.yaml

version: '1'
input:
  entry: .promptscript/project.prs
  include: ['.promptscript/**/*.prs']
targets:
  github:
    version: full      # simple | multifile | full
  claude:
    version: full
  cursor:
    version: standard
  antigravity:
    version: frontmatter
  factory:
    version: full
registry:
  git: https://github.com/org/registry.git
  ref: main

CLI Commands

prs init                    # Initialize project
prs init --migrate          # Initialize + migration skills
prs compile                 # Compile to all targets
prs compile --watch         # Watch mode
prs validate --strict       # Validate syntax
prs pull                    # Update registry
prs diff --target claude    # Show compilation diff

Output Targets

Target	Main File	Skills
GitHub	.github/copilot-instructions.md	.github/skills/*/SKILL.md
Claude	CLAUDE.md	.claude/skills/*/SKILL.md
Cursor	.cursor/rules/project.mdc	.cursor/commands/*.md
Antigravity	.agent/rules/project.md	.agent/rules/*.md
Factory	AGENTS.md	.factory/skills/*/SKILL.md
OpenCode	agents.yaml	-
Gemini	GEMINI.md	-

Project Organization

Typical modular structure:

.promptscript/
  project.prs      # Entry: @meta, @inherit, @use, @identity, @agents
  context.prs      # @context (architecture, tech stack)
  standards.prs    # @standards (coding conventions)
  restrictions.prs # @restrictions (hard rules)
  commands.prs     # @shortcuts and @knowledge

The entry file uses @use ./context, @use ./standards, etc. to compose them.

Common Mistakes

1. Missing @meta block - every .prs file needs @meta with id and syntax
2. Multiple @inherit - only one per file; use @use for additional imports
3. @extend without alias - requires prior @use ... as alias
4. Unquoted strings with special chars - quote strings containing :, #, {, }
5. Forgetting to compile - .prs changes need prs compile to take effect
6. Triple quotes inside triple quotes - not supported; describe content textually instead