feat(config): Add support for config subsection injection in skills (#92)

edenreich · claude · web-flow · commit 6e8ff1a4df33 · 2025-11-16T10:04:14.000+02:00
Enable skills to inject specific configuration subsections using dotted notation (e.g., config.email, config.database) instead of requiring the entire config object. This provides better scoped access, type safety, and separation of concerns by allowing skills to declare explicit dependencies on only the configuration they need. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude <noreply@anthropic.com>
diff --git a/README.md b/README.md
@@ -576,6 +576,104 @@ type CacheConfig struct {
 - `CACHE_MAX_ENTRIES="1000"`
 - `CACHE_TTL="3600"`
 
+### Config Subsection Injection
+
+In addition to injecting entire configuration objects, you can inject specific config subsections directly into skills using dotted notation. This provides type-safe access to focused configuration scopes.
+
+**Example ADL Configuration:**
+
+```yaml
+spec:
+  config:
+    database:
+      connectionString: "postgresql://localhost:5432/db"
+      maxConnections: "10"
+      timeout: "30s"
+    email:
+      apiKey: ""
+      fromAddress: "noreply@example.com"
+      provider: "sendgrid"
+  services:
+    database:
+      type: service
+      interface: DatabaseService
+      factory: NewDatabaseService
+      description: PostgreSQL database service
+  skills:
+    - name: export_report
+      description: "Export data and email report"
+      inject:
+        - logger
+        - database
+        - config.email  # Inject only the email config subsection
+      schema:
+        type: object
+        properties:
+          recipient:
+            type: string
+        required: [recipient]
+```
+
+**Generated Skill Code:**
+
+```go
+type ExportReportSkill struct {
+    logger   *zap.Logger
+    database database.DatabaseService
+    email    *config.EmailConfig  // Type-safe access to email config only
+}
+
+func NewExportReportSkill(
+    logger *zap.Logger,
+    database database.DatabaseService,
+    email *config.EmailConfig,
+) server.Tool {
+    skill := &ExportReportSkill{
+        logger:   logger,
+        database: database,
+        email:    email,
+    }
+    // ...
+}
+
+func (s *ExportReportSkill) ExportReportHandler(ctx context.Context, args map[string]any) (string, error) {
+    // Direct access to email config subsection
+    apiKey := s.email.APIKey
+    fromAddress := s.email.FromAddress
+    provider := s.email.Provider
+
+    // ... implementation
+}
+```
+
+**Main Registration:**
+
+```go
+// In main.go - config subsection is passed directly
+exportReportSkill := skills.NewExportReportSkill(l, databaseSvc, &cfg.Email)
+toolBox.AddTool(exportReportSkill)
+```
+
+**Benefits of Config Subsection Injection:**
+
+- **Scoped Access**: Skills only receive the configuration they need, following principle of least privilege
+- **Type Safety**: Compile-time validation ensures config fields exist
+- **Clear Dependencies**: Explicit declaration of which config sections each skill requires
+- **Easier Testing**: Mock specific config subsections without full config object
+- **Better Separation**: Skills don't have access to unrelated configuration
+- **Auto-Validation**: ADL CLI validates that injected config sections exist in `spec.config`
+
+**Injection Patterns:**
+
+```yaml
+inject:
+  - logger                 # Built-in logger service
+  - config                 # Entire config object (*config.Config)
+  - config.database        # Database config subsection (*config.DatabaseConfig)
+  - config.email           # Email config subsection (*config.EmailConfig)
+  - myService              # Custom service from spec.services
+```
+
 ### Service Architecture
 
 The service injection system generates:
diff --git a/internal/schema/validator.go b/internal/schema/validator.go
@@ -79,10 +79,21 @@ func (v *Validator) validateServiceReferences(adl *ADL) error {
 	}
 
 	definedServices["logger"] = true
+	definedServices["config"] = true
+
+	definedConfigSections := make(map[string]bool)
+	for configSection := range adl.Spec.Config {
+		definedConfigSections[configSection] = true
+	}
 
 	for _, skill := range adl.Spec.Skills {
 		for _, injectedService := range skill.Inject {
-			if !definedServices[injectedService] {
+			if len(injectedService) > 7 && injectedService[:7] == "config." {
+				configSection := injectedService[7:]
+				if !definedConfigSections[configSection] {
+					return fmt.Errorf("skill '%s' injects config section '%s' that is not defined in spec.config", skill.ID, configSection)
+				}
+			} else if !definedServices[injectedService] {
 				return fmt.Errorf("skill '%s' injects service '%s' that is not defined in spec.services", skill.ID, injectedService)
 			}
 		}
@@ -327,7 +338,7 @@ const adlSchema = `{
                 "type": "array",
                 "items": {
                   "type": "string",
-                  "pattern": "^[a-zA-Z_][a-zA-Z0-9_]*$"
+                  "pattern": "^[a-zA-Z_][a-zA-Z0-9_]*(\\.[a-zA-Z_][a-zA-Z0-9_]*)*$"
                 }
               }
             }
diff --git a/internal/templates/languages/go/main.go.tmpl b/internal/templates/languages/go/main.go.tmpl
@@ -94,7 +94,7 @@ func main() {
 	{{- range .ADL.Spec.Skills }}
 
 	// Register {{ .Name }} skill
-	{{ .Name | toCamelCase }}Skill := skills.New{{ .Name | toPascalCase }}Skill({{ range $index, $svc := .Inject }}{{ if $index }}, {{ end }}{{ if eq $svc "logger" }}l{{ else }}{{ $svc | toCamelCase }}Svc{{ end }}{{ end }})
+	{{ .Name | toCamelCase }}Skill := skills.New{{ .Name | toPascalCase }}Skill({{ range $index, $svc := .Inject }}{{ if $index }}, {{ end }}{{ if eq $svc "logger" }}l{{ else if eq $svc "config" }}&cfg{{ else if hasPrefix "config." $svc }}&cfg.{{ $svc | trimPrefix "config." | toPascalCase }}{{ else }}{{ $svc | toCamelCase }}Svc{{ end }}{{ end }})
 	toolBox.AddTool({{ .Name | toCamelCase }}Skill)
 	l.Info("registered skill: {{ .Name }} ({{ .Description }})")
 	{{- end }}
diff --git a/internal/templates/languages/go/skill.go.tmpl b/internal/templates/languages/go/skill.go.tmpl
@@ -8,6 +8,10 @@ import (
 {{- range $depID := .Inject }}
 {{- if eq $depID "logger" }}
 	zap "go.uber.org/zap"
+{{- else if eq $depID "config" }}
+	config "{{ $.GoModule }}/config"
+{{- else if hasPrefix "config." $depID }}
+	config "{{ $.GoModule }}/config"
 {{- else }}
 	{{ $depID | toCamelCase }} "{{ $.GoModule }}/internal/{{ $depID | toSnakeCase }}"
 {{- end }}
@@ -19,6 +23,10 @@ type {{ .Name | toPascalCase }}Skill struct {
 {{- range $depID := .Inject }}
 {{- if eq $depID "logger" }}
 	{{ $depID | toCamelCase }} *zap.Logger
+{{- else if eq $depID "config" }}
+	{{ $depID | toCamelCase }} *config.Config
+{{- else if hasPrefix "config." $depID }}
+	{{ $depID | trimPrefix "config." | toCamelCase }} *config.{{ $depID | trimPrefix "config." | toPascalCase }}Config
 {{- else }}
 {{- $svc := index $.ServiceMap $depID }}
 	{{ $depID | toCamelCase }} {{ $depID | toCamelCase }}.{{ $svc.Interface }}
@@ -27,10 +35,14 @@ type {{ .Name | toPascalCase }}Skill struct {
 }
 
 // New{{ .Name | toPascalCase }}Skill creates a new {{ .Name }} skill
-func New{{ .Name | toPascalCase }}Skill({{ range $index, $depID := .Inject }}{{ if $index }}, {{ end }}{{- if eq $depID "logger" }}{{ $depID | toCamelCase }} *zap.Logger{{- else }}{{- $svc := index $.ServiceMap $depID }}{{ $depID | toCamelCase }} {{ $depID | toCamelCase }}.{{ $svc.Interface }}{{- end }}{{ end }}) server.Tool {
+func New{{ .Name | toPascalCase }}Skill({{ range $index, $depID := .Inject }}{{ if $index }}, {{ end }}{{- if eq $depID "logger" }}{{ $depID | toCamelCase }} *zap.Logger{{- else if eq $depID "config" }}{{ $depID | toCamelCase }} *config.Config{{- else if hasPrefix "config." $depID }}{{ $depID | trimPrefix "config." | toCamelCase }} *config.{{ $depID | trimPrefix "config." | toPascalCase }}Config{{- else }}{{- $svc := index $.ServiceMap $depID }}{{ $depID | toCamelCase }} {{ $depID | toCamelCase }}.{{ $svc.Interface }}{{- end }}{{ end }}) server.Tool {
 	skill := &{{ .Name | toPascalCase }}Skill{
 {{- range $depID := .Inject }}
+{{- if hasPrefix "config." $depID }}
+		{{ $depID | trimPrefix "config." | toCamelCase }}: {{ $depID | trimPrefix "config." | toCamelCase }},
+{{- else }}
 		{{ $depID | toCamelCase }}: {{ $depID | toCamelCase }},
+{{- end }}
 {{- end }}
 	}
 	return server.NewBasicTool(

Original file line number	Diff line number	Diff line change
`@@ -79,10 +79,21 @@ func (v Validator) validateServiceReferences(adl ADL) error {`
`79`	`79`	`}`
`80`	`80`
`81`	`81`	`definedServices["logger"] = true`
	`82`	`+ definedServices["config"] = true`
	`83`	`+`
	`84`	`+ definedConfigSections := make(map[string]bool)`
	`85`	`+ for configSection := range adl.Spec.Config {`
	`86`	`+ definedConfigSections[configSection] = true`
	`87`	`+ }`
`82`	`88`
`83`	`89`	`for _, skill := range adl.Spec.Skills {`
`84`	`90`	`for _, injectedService := range skill.Inject {`
`85`		`- if !definedServices[injectedService] {`
	`91`	`+ if len(injectedService) > 7 && injectedService[:7] == "config." {`
	`92`	`+ configSection := injectedService[7:]`
	`93`	`+ if !definedConfigSections[configSection] {`
	`94`	`+ return fmt.Errorf("skill '%s' injects config section '%s' that is not defined in spec.config", skill.ID, configSection)`
	`95`	`+ }`
	`96`	`+ } else if !definedServices[injectedService] {`
`86`	`97`	`return fmt.Errorf("skill '%s' injects service '%s' that is not defined in spec.services", skill.ID, injectedService)`
`87`	`98`	`}`
`88`	`99`	`}`
@@ -327,7 +338,7 @@ const adlSchema = `{
`327`	`338`	`"type": "array",`
`328`	`339`	`"items": {`
`329`	`340`	`"type": "string",`
`330`		`- "pattern": "^[a-zA-Z_][a-zA-Z0-9_]*$"`
	`341`	`+ "pattern": "^[a-zA-Z_][a-zA-Z0-9_](\\.[a-zA-Z_][a-zA-Z0-9_])*$"`
`331`	`342`	`}`
`332`	`343`	`}`
`333`	`344`	`}`