## Definition
**BMAD-METHOD** (Breakthrough Method for Agile AI-Driven Development) is an open-source SDD framework that orchestrates multiple specialised AI agents across an SDLC workflow using named personas, file-based context passing, and strict role boundaries.
## Roles (typical)
- **PM agent** — turns user input into stories.
- **Architect agent** — decomposes stories into tasks.
- **Builder agent** — implements.
- **Reviewer agent** — checks against the original story.
Each role has its own system prompt, model choice, and tool set.
## File-Based Context Passing
The artifact handed between roles is **structured** — typically YAML or JSON — so the next role can parse it deterministically.
```yaml
story:
id: 184
as: registered user
i_want: to sign in without a password
architect:
tasks:
- id: 184-1
summary: Add magic-link request endpoint
files_touched: [src/auth/magic_link.ts]
builder:
assigned: 184-1
status: in_progress
```
## When to Use
- Features that need traceability from user goal to commit.
- Regulated environments.
- Teams onboarding new engineers who need to *see* the process.
## Trade-offs
The most architecturally complex of major SDD frameworks. Earns its overhead on enterprise-scale projects; over-engineered for small teams.
## Related
- [[Spec-Driven Development]]
- [[OpenSpec]]
- [[Specialized Agent]]
- [[Sequential Pipeline]]