Configuration: .boundary.toml

Boundary is configured via a .boundary.toml file. Run boundary init to generate a starter config.

Config Discovery

Boundary searches for .boundary.toml starting from the analysis target directory and walking up parent directories (similar to how Git finds .git). The first config file found is used. If no config is found, built-in defaults are used.

This means you can place .boundary.toml at the repository root and analyze any subdirectory — the config will be discovered automatically.

Full Reference

[project]
languages = ["go"]
exclude_patterns = ["vendor/**", "**/*_test.go", "**/testdata/**"]
# services_pattern = "services/*"   # For monorepo per-service analysis

[layers]
# Glob patterns to classify files into architectural layers.
domain = ["**/domain/**", "**/entity/**", "**/model/**"]
application = ["**/application/**", "**/usecase/**", "**/service/**"]
infrastructure = ["**/infrastructure/**", "**/adapter/**", "**/repository/**", "**/persistence/**"]
presentation = ["**/presentation/**", "**/handler/**", "**/api/**", "**/cmd/**"]

# Paths exempt from layer violation checks (cross-cutting concerns)
# cross_cutting = ["common/utils/**", "pkg/logger/**", "pkg/errors/**"]

# Global architecture mode: "ddd" (default), "active-record", or "service-oriented"
# architecture_mode = "ddd"

[scoring]
# Weights for score components (should sum to 1.0)
layer_isolation_weight = 0.4
dependency_direction_weight = 0.4
interface_coverage_weight = 0.2

[rules]
# Minimum severity to cause failure: "error", "warning", or "info"
fail_on = "error"
# min_score = 70.0   # Optional minimum architecture score
# detect_init_functions = true   # Detect Go init() side effects

[rules.severities]
layer_boundary = "error"
circular_dependency = "error"
missing_port = "warning"
init_coupling = "warning"

Sections

[project]

[layers]

Each layer accepts a list of glob patterns. Files matching a pattern are classified into that layer.

Additional fields:

[[layers.overrides]]

Per-module overrides for layer classification. The first matching scope wins.

[[layers.overrides]]
scope = "services/auth/**"
domain = ["services/auth/core/**"]
infrastructure = ["services/auth/server/**", "services/auth/adapters/**"]
# architecture_mode = "active-record"   # Optional per-module mode

Omitted layers fall back to the global patterns.

[scoring]

Weights should sum to 1.0.

[rules]

[rules.severities]

Override the default severity for built-in violation types. Both category names and rule IDs are accepted as keys. Rule IDs take precedence over category names.

Category Names

Rule IDs

You can also use specific rule IDs (e.g., L001, PA001) for more granular control:

[rules.severities]
missing_port = "warning"   # Category-wide default
PA001 = "info"             # Override just missing-port-interface to info

See Rules & Rule IDs for the full rule catalog.

[[rules.ignore]]

Suppress specific rules for files matching glob patterns:

[[rules.ignore]]
rule = "PA001"
paths = ["infrastructure/**/*document.go"]

[[rules.ignore]]
rule = "L005"
paths = ["legacy/**"]

Custom Rules

Define custom dependency rules:

[[rules.custom_rules]]
name = "no-http-in-domain"
from_pattern = "**/domain/**"
to_pattern = "**/net/http**"
action = "deny"
severity = "error"
message = "Domain layer must not import HTTP packages"