Scoped Rules

What are Rules?

Rules are markdown files with YAML frontmatter that inject project-specific guidance into agent prompts. Every rule you add makes all future agents smarter about your codebase.

Rules are scoped by file patterns — an agent working on src/payments/** gets payment-specific rules, while an agent on src/ui/** gets UI rules.

Creating Rules

Place rule files in .tack/rules/:

---
scope: "src/payments/**"
priority: high
---

## Payment Module Conventions

- Use integer cents for all monetary amounts, never floating point
- All payment mutations must be wrapped in a database transaction
- Log every payment state change to the audit table

Rule Fields

Field	Type	Description
`scope`	glob	File pattern this rule applies to (e.g., `src/*`, `.ts`)
`priority`	string	`high` or `normal` (default). High-priority rules are injected first.
`tools`	object	Optional tool restrictions (`include`/`exclude` lists)

Tool Restrictions

Rules can restrict which tools agents have access to:

---
scope: "src/database/**"
tools:
  include:
    - "mcp:postgres:*"
  exclude:
    - "mcp:filesystem:delete"
---

Database modules should use the Postgres MCP tools.

How Rules Are Applied

When an agent spawns, Tack collects all rules whose scope matches the stream's file scope
Rules are sorted by priority (high first), then by source path
Rule bodies are injected into the agent's system prompt
Tool restrictions are applied to the agent's available tool set