Remove mode field from custom MCP servers schema and add migration codemod

[Copilot]

The main workflow schema defined both mode and type properties with identical enums for custom MCP server configuration. Investigation shows mode is only meaningful for built-in tools (GitHub, Serena) where it controls execution mode ("local"/"remote" for GitHub, "docker"/"local" for Serena). For custom MCP servers, only type is used by the parser to determine connection protocol ("stdio", "http").

Changes

• Removed mode property entirely from custom MCP servers in main_workflow_schema.json

  • The deprecated field has been completely removed (not just marked as deprecated)
  • GitHub/Serena tools continue using mode for their specific purposes (unchanged)

• Enhanced type property description

  • Documented connection protocol semantics (stdio/http)
  • Noted "local" is normalized to "stdio" during parsing

• Added migration codemod (codemod_mcp_mode_to_type.go)

  • Automatically renames mode to type in mcp-servers: section
  • Preserves GitHub and Serena tool mode fields (not affected)
  • Handles multiple MCP servers and preserves comments/formatting
  • Registered in codemod registry with ID mcp-mode-to-type-migration

• Added comprehensive tests (codemod_mcp_mode_to_type_test.go)

  • 6 test cases covering all migration scenarios
  • Verifies GitHub/Serena fields remain unchanged
  • Tests multiple servers and formatting preservation

Migration Path

Users can automatically migrate workflows using:

gh aw compile --fix

The codemod will transform:

Before:

mcp-servers:
  my-server:
    mode: stdio  # ❌ No longer supported
    command: node

After:

mcp-servers:
  my-server:
    type: stdio  # ✅ Correct
    command: node

Built-in tools remain unchanged:

tools:
  github:
    mode: remote  # ✅ Still valid - controls local vs hosted execution

Testing

• ✅ All codemod tests pass (6/6)
• ✅ All codemod registry tests pass (5/5)
• ✅ Manual workflow migration confirmed working
• ✅ Format and lint checks pass
• ✅ Binary rebuilt with updated schema
• ✅ Code review passed with no issues

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[plan] Clarify or deprecate "mode" property in main schema</issue_title>
<issue_description>## Objective

Determine the purpose of the mode property in main schema and either document it clearly or deprecate it.

Context

From discussion #11706: The main schema defines both mode and type with identical enum values, but MCP config schema only has type. It's unclear if mode is:

• An alias for type
• A deprecated field
• A workflow-specific property

Approach

1. Search codebase for usage of mode field in MCP context
2. Check if parser/compiler treats mode and type differently
3. Review git history to understand when/why mode was added
4. Either:
   • Document mode as an alias (if intentional)
   • Mark as deprecated with migration guide
   • Remove if unused

Files to Investigate

• pkg/parser/mcp.go - Check parsing logic
• pkg/workflow/mcp-config-*.go - Check compilation logic
• .github/workflows/*.md - Check for usage in workflows
• Git history of main_workflow_schema.json

Acceptance Criteria

• Usage of mode vs type is clarified
• Decision documented in schema description or comments
• If deprecated: Add deprecation notice with migration path
• If alias: Add clear documentation explaining relationship
• If unused: Remove from schema
• Update docs if needed

AI generated by Plan Command for discussion #11706

Comments on the Issue (you are @copilot in this section)

• Fixes [plan] Clarify or deprecate "mode" property in main schema #11712

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[pelikhan]

@copilot remove deprecated features from the schema and add codemods as needed

[Copilot]

@copilot remove deprecated features from the schema and add codemods as needed

Done! Removed the deprecated mode field from the schema and added a migration codemod.

Changes in commit 2f35101:

1. Removed mode field entirely from pkg/parser/schemas/main_workflow_schema.json
2. Added migration codemod (codemod_mcp_mode_to_type.go) that:
   • Automatically renames mode to type in custom MCP servers (mcp-servers: section)
   • Preserves GitHub and Serena tool mode fields (unaffected)
   • Handles multiple servers and preserves comments/formatting
3. Added tests with 100% pass rate covering all scenarios

Users can migrate with: gh aw compile --fix

The codemod only affects custom MCP servers - GitHub and Serena tool mode fields remain valid and unchanged.