Monorepo Support

Boundary supports analyzing monorepos with multiple services, shared modules, and per-service architecture rules.

Per-Service Analysis

Use the --per-service flag to analyze each service independently:

boundary analyze . --per-service

This produces a separate report for each service discovered under the configured services pattern, plus an aggregate summary.

Configuring the Services Pattern

Tell Boundary where your services live:

[project]
services_pattern = "services/*"

This matches directories like services/auth/, services/billing/, services/notifications/, etc. Each is analyzed as an independent unit with its own scores.

Per-Service Layer Overrides

Each service may have its own internal structure. Use layer overrides to configure patterns per-service:

# Global defaults
[layers]
domain = ["**/domain/**"]
application = ["**/application/**"]
infrastructure = ["**/infrastructure/**"]

# Auth service has a different structure
[[layers.overrides]]
scope = "services/auth/**"
domain = ["services/auth/core/**"]
infrastructure = ["services/auth/server/**", "services/auth/adapters/**"]

# Shared modules
[[layers.overrides]]
scope = "common/modules/*/**"
domain = ["common/modules/*/domain/**"]
application = ["common/modules/*/app/**"]

Cross-Service Dependencies

When analyzing the full monorepo (without --per-service), Boundary tracks dependencies between services. Cross-service dependencies that violate layer rules are flagged, helping enforce clean boundaries at service boundaries.

Shared Modules

Shared modules (e.g., common/, pkg/) that are used across multiple services can be configured as cross-cutting concerns if they don’t belong to any specific layer:

[layers]
cross_cutting = ["common/utils/**", "pkg/logger/**"]

Or given their own layer overrides if they contain domain logic:

[[layers.overrides]]
scope = "common/modules/users/**"
domain = ["common/modules/users/domain/**"]
application = ["common/modules/users/app/**"]