developer-internals

# gh-aw Internal Architecture Use this reference when working on the gh-aw compiler internals, validation system, safe output processing, or MCP server features. ## Table of Contents - [Validation Architecture](#validation-architecture) - [Safe Output Messages](#safe-output-messages) - [Schema Validation](#schema-validation) - [YAML Compatibility](#yaml-compatibility) - [MCP Logs Guardrail](#mcp-logs-guardrail) ## Validation Architecture The validation system ensures workflow configurations are correct, secure, and compatible with GitHub Actions before compilation. ### Architecture Overview ```mermaid graph LR WF[Workflow] --> CV[Centralized Validation] WF --> DV[Domain-Specific Validation] CV --> validation.go DV --> strict_mode_validation.go DV --> strict_mode_permissions_validation.go DV --> pip.go DV --> npm.go DV --> expression_safety_validation.go DV --> engine.go DV --> mcp-config.go ``` ### Centralized Validation **Location:** `pkg/workflow/validation.go` (core compile-time checks) **Purpose:** General-purpose validation that applies across the entire workflow system **Key Functions:** - `validateExpressionSizes()` - Ensures GitHub Actions expression size limits - `validateContainerImages()` - Verifies Docker images exist and are accessible - `validateRuntimePackages()` - Validates runtime package dependencies - `validateGitHubActionsSchema()` - Validates against GitHub Actions YAML schema - `validateNoDuplicateCacheI...