whetstone_DSL/progress.md

Sprint 9 Progress — Agent-First Tooling

Phase 9a: Standalone MCP Server

Step 245: HeadlessEditorState (no ImGui dependency)

Status: PASS (20/20 tests)

Created the headless agent API surface — same method interface as EditorState but with zero GUI dependencies (no ImGui, no SDL, no WebSocket).

Files created:

• editor/src/ASTUtils.h — Pure AST utility functions extracted from EditorUtils.h (cloneModule, isAnnotationNode, countAnnotationNodes, findNodeById, findNodeAtPosition)
• editor/src/HeadlessEditorState.h — Lightweight state: HeadlessAgentState, HeadlessLibraryState, HeadlessBufferState, buffer management, orchestrator sync
• editor/src/HeadlessAgentRPCHandler.h — Full RPC dispatch mirroring AgentRPCHandler.h (20+ methods: getAST, parseSource, runPipeline, applyMutation, applyBatch, projectLanguage, generateCode, workflow recording, etc.)
• editor/tests/step245_test.cpp — 20 test cases covering construction, buffer management, RPC dispatch, permission enforcement, pipeline execution

Key design decisions:

• JSON roundtrip cloning (matching EditorUtils.h) instead of manual deep copy
• Separate HeadlessAgentState (no AgentMarketplace/WebSocket dependency chain)
• All files under 600-line architecture limit

Step 246: mcp_main.cpp — Standalone MCP Server Entry Point

Status: PASS (12/12 tests)

Wires HeadlessEditorState + MCPBridge into a standalone whetstone_mcp binary that any MCP client (Claude Code, Cursor, etc.) can launch over stdio.

Files created:

• editor/src/mcp_main.cpp — Standalone MCP server entry point with CLI arg parsing (--workspace, --language, --verbose), signal handling, resource reader lambda routing whetstone:// URIs, and MCPBridge stdio loop
• editor/tests/step246_test.cpp — 12 test cases: initialize, notifications, tools/list (10+), resources/list (5), prompts/list (4), tools/call pipeline, tools/call get_ast, resources/read ast, resources/read diagnostics, ping, resources/read settings, CLI arg parsing

Key design decisions:

• No SDL, no ImGui, no OpenGL — headless only binary
• Fixed "mcp-session" session ID (MCP stdio is single-client)
• Default Refactor role for full MCP access
• Empty scratch buffer on startup so getAST works immediately
• All logging to stderr (stdout is the MCP transport)

Step 247: File Operation Tools for MCP

Status: PASS (12/12 tests)

Adds 5 file I/O tools to the MCP server so agents can create, read, write, diff, and list files without a GUI. All operations respect the --workspace root with path-escape security checks.

Files created:

• editor/src/FileOperations.h — Standalone file ops: resolve path, read, write, create (with templates), unified diff, workspace listing via FileTree
• editor/tests/step247_test.cpp — 12 test cases: path resolution, path escape rejection, file create/read/write via RPC, line range, diff, workspace list, glob filter, language templates, parent dir creation, permission denial

Files modified:

• editor/src/AgentPermissionPolicy.h — fileRead/workspaceList/fileDiff read-only; fileWrite/fileCreate require Refactor/Generator
• editor/src/HeadlessAgentRPCHandler.h — 5 new RPC handlers
• editor/src/HeadlessEditorState.h — include FileOperations.h
• editor/src/MCPServer.h — registerFileTools() with 5 MCP tool definitions
• editor/CMakeLists.txt — step247_test target

Key design decisions:

• Path security: all paths resolved against workspaceRoot, escape rejected
• Simple line-by-line unified diff (no external dependency)
• Language templates for Python, C++, Rust, Go, Java, JS/TS
• FileTree.h reuse for .gitignore-aware workspace listing
• tools/list now returns 15 tools (was 10)

Step 248: Compact AST Response Format

Status: PASS (12/12 tests)

Adds token-efficient AST responses so agents waste fewer tokens on large ASTs. Compact mode returns a flat list of {id, type, name, line, children} nodes at <30% the size of full AST. Subtree extraction and AST diff (version-based) let agents query only what changed.

Files created:

• editor/src/CompactAST.h — toJsonCompact, toJsonCompactTree, toJsonSubtree, getNodeName, tokenEstimate, ASTVersionTracker (recordMutation, changedSince, buildDiff, pruneOlderThan)
• editor/tests/step248_test.cpp — 12 test cases: full backward compat, compact flat list, <30% size ratio, compact field validation, tokenEstimate, version counter, subtree extraction, invalid nodeId error, empty diff, version increment on mutation, diff after mutation, subtree vs full tokenEstimate

Files modified:

• editor/src/HeadlessEditorState.h — include CompactAST.h, add ASTVersionTracker to HeadlessBufferState
• editor/src/HeadlessAgentRPCHandler.h — getAST compact param, version and tokenEstimate in responses, getASTSubtree and getASTDiff methods, version recording in applyMutation/applyBatch
• editor/src/AgentPermissionPolicy.h — getASTSubtree/getASTDiff read-only
• editor/src/MCPServer.h — whetstone_get_ast compact param, new whetstone_get_ast_subtree and whetstone_get_ast_diff tools
• editor/CMakeLists.txt — step248_test target

Key design decisions:

• Compact mode: flat array of abbreviated nodes (not nested tree)
• Version counter per buffer, incremented on each mutation
• ASTVersionTracker stores affected nodeIds per version for diff
• tokenEstimate = json.dump().size() / 4 (rough LLM token approx)
• tools/list returns 17 tools (was 15): +whetstone_get_ast_subtree, +whetstone_get_ast_diff

Step 249: MCP Server Integration Tests

Status: PASS (8/8 tests)

End-to-end integration tests exercising the full MCP server stack through MCPBridge. Simulates a realistic agent session from handshake through tool discovery, AST queries, pipeline execution, resource reads, and file I/O.

Files created:

• editor/tests/step249_test.cpp — 8 integration test cases:
  1. MCP handshake (initialize + notifications/initialized, verify protocol version, server info, capabilities)
  2. tools/list returns all 17 tools with valid schemas (name, description, inputSchema with type field)
  3. tools/call whetstone_get_ast on active buffer returns valid AST
  4. tools/call whetstone_run_pipeline: Python → C++ code generation (5393 chars)
  5. resources/read whetstone://diagnostics returns valid JSON array
  6. prompts/list returns all 4 prompts (annotate_module, cross_language_projection, security_audit, refactor_memory)
  7. File operations cycle: create → write → read → verify on disk (full CRUD through MCP tools/call layer)
  8. Compact AST vs full AST size comparison via MCP (3% ratio — 1,469 vs 39,446 chars)

Files modified:

• editor/CMakeLists.txt — step249_test target

Key results:

• Phase 9a complete: all 5 steps pass (64/64 tests across steps 245–249)
• Full MCP stack validated end-to-end: handshake → tools → resources → prompts → file ops
• Compact AST achieves 97% token savings through MCP layer (3% of full size)
• 17 tools, 5 resources, 4 prompts all verified with correct schemas

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Phase 9b: Agent-Optimized Diagnostics

Step 250: Structured Diagnostic Format

Status: PASS (12/12 tests)

Unified diagnostic format for agent consumption. Merges tree-sitter parse errors, annotation validation diagnostics, and strategy validation violations into a single stream with error codes, severity levels, AST node references, and machine-applicable fix mutations.

Files created:

• editor/src/StructuredDiagnostics.h — Unified diagnostic format:
  • StructuredDiagnostic struct: code, severity, nodeId, line, col, message, source, fix (optional mutation object)
  • Error code scheme: E01xx (parser), E02xx (annotation), E03xx (strategy)
  • Severity enum: Error(1), Warning(2), Info(3), Hint(4)
  • Collectors: collectParseDiagnostics, collectAnnotationDiagnostics, collectStrategyDiagnostics, collectAllDiagnostics, collectPipelineDiagnostics
  • Fix builders: suggest concrete mutations (deleteNode, setProperty, insertNode)
  • Filters: filterBySeverity, filterBySource
  • JSON serialization: diagnosticToJson, diagnosticsToJson
• editor/tests/step250_test.cpp — 12 test cases: valid code (zero diags), parse error codes (E01xx), parse location/severity, annotation validation (E02xx), nodeId presence, fix suggestions, getDiagnostics RPC, severity filter, JSON field validation, MCP tool registration, pipeline diagnostics, source filter

Files modified:

• editor/src/HeadlessEditorState.h — include StructuredDiagnostics.h
• editor/src/HeadlessAgentRPCHandler.h — getDiagnostics RPC method with optional severity and source filters
• editor/src/AgentPermissionPolicy.h — getDiagnostics as read-only
• editor/src/MCPServer.h — whetstone_get_diagnostics tool registration
• editor/CMakeLists.txt — step250_test target

Key design decisions:

• Error codes are hierarchical: E01xx=parser, E02xx=annotation, E03xx=strategy
• Fix suggestions are concrete mutation objects (same format as applyMutation)
• Severity filtering uses numeric comparison (lower = more severe)
• Source filtering allows isolating parser vs annotation vs strategy diagnostics
• tools/list now returns 18 tools (was 17): +whetstone_get_diagnostics

Step 251: Quick-Fix Actions as RPC Mutations

Status: PASS (12/12 tests)

Turns diagnostic fix suggestions into one-shot RPC calls. getQuickFixes returns concrete mutation objects the agent can review; applyQuickFix takes a diagnostic code + nodeId, applies the fix, and reports whether the diagnostic cleared.

Files created:

• editor/tests/step251_test.cpp — 12 test cases: fix discovery, required fields, mutation structure, nodeId filtering, apply fix, diagnostic clearing report, invalid diagCode error, missing param error, permission enforcement, MCP tool registration, missing-return heuristic, category validation

Files modified:

• editor/src/StructuredDiagnostics.h — QuickFix struct, getQuickFixesForNode, getQuickFixesAll, findQuickFix, heuristic fixes (unused variable removal, missing return statement)
• editor/src/HeadlessAgentRPCHandler.h — getQuickFixes and applyQuickFix RPC methods
• editor/src/AgentPermissionPolicy.h — getQuickFixes read-only, applyQuickFix requires Refactor/Generator
• editor/src/MCPServer.h — whetstone_get_quick_fixes and whetstone_apply_quick_fix tool registration
• editor/CMakeLists.txt — step251_test target

Key design decisions:

• QuickFix has unique id, diagCode, nodeId, description, category, mutation
• Fix categories: remove-annotation, change-strategy, resolve-conflict, remove-use-after-free, add-deallocation, remove-unused, missing-return
• applyQuickFix delegates to existing applyMutation path for consistency
• After applying, re-runs diagnostics to report if the error cleared
• tools/list now returns 20 tools (was 18): +whetstone_get_quick_fixes, +whetstone_apply_quick_fix

Step 252: Diagnostic Delta Streaming

Status: PASS (12/12 tests)

Efficient delta computation so agents only see what changed since their last diagnostic query. getDiagnosticsDelta returns added/removed diagnostics based on a version number, enabling fast mutate → check loops.

Files created:

• editor/tests/step252_test.cpp — 12 test cases: version tracking, empty delta, addition detection, removal detection, response structure, version increment, DiagnosticKey comparison, tracker reset, MCP tool, structured format in delta, Linter role access

Files modified:

• editor/src/StructuredDiagnostics.h — DiagnosticKey (code, nodeId, line), DiagnosticDelta (added, removed, version), DiagnosticVersionTracker (recordSnapshot, getDelta, reset), deltaToJson
• editor/src/HeadlessEditorState.h — DiagnosticVersionTracker in HeadlessBufferState
• editor/src/HeadlessAgentRPCHandler.h — getDiagnosticsDelta RPC method, getDiagnostics now records snapshots for delta tracking
• editor/src/AgentPermissionPolicy.h — getDiagnosticsDelta as read-only
• editor/src/MCPServer.h — whetstone_get_diagnostics_delta tool
• editor/CMakeLists.txt — step252_test target

Key design decisions:

• DiagnosticKey tuple (code, nodeId, line) uniquely identifies a diagnostic
• Version bumps on each getDiagnostics/getDiagnosticsDelta call
• Delta computed by set difference between previous and current snapshots
• Response includes addedCount/removedCount for quick checks without parsing
• tools/list now returns 21 tools (was 20): +whetstone_get_diagnostics_delta

Step 253: Diagnostic and Delta Integration Tests

Status: PASS (8/8 tests)

Comprehensive end-to-end tests for the full diagnostic pipeline: structured diagnostics, quick fixes, delta streaming, and filtering. Exercises the complete flow: introduce error → diagnose → fix → verify clearing.

Files created:

• editor/tests/step253_test.cpp — 8 integration test cases:
  1. Valid Python → zero diagnostics
  2. Annotation error → structured diagnostics with nodeIds and codes
  3. Quick fixes include concrete mutation objects
  4. applyQuickFix resolves diagnostic (cleared=true, remaining=0)
  5. Delta after fix shows removal (removed=1, added=0)
  6. Delta after new error shows addition (added=1, removed=0)
  7. Combined parser + annotation diagnostics in streams
  8. Severity filtering across the pipeline

Files modified:

• editor/CMakeLists.txt — step253_test target

Key results:

• Phase 9b complete: all 4 steps pass (44/44 tests across steps 250–253)
• Full diagnostic pipeline validated: diagnose → fix → verify → delta
• 21 MCP tools, structured error codes (E01xx/E02xx/E03xx), delta streaming

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Phase 9c: Token-Efficient Agent Protocol

Step 254: Response Budget System

Status: PASS (12/12 tests)

Optional budget parameter on query methods. If the response exceeds the budget, it's truncated with truncated: true and a continuation token for paginated follow-up. Arrays are shrunk via binary search; responses sorted by priority (errors first).

Files created:

• editor/src/ResponseBudget.h — applyBudget (binary search truncation of arrays), applyContinuation (resume from offset), sortDiagnosticsByPriority
• editor/tests/step254_test.cpp — 12 test cases: no-budget backward compat, compact AST truncation, totalCount/returnedCount, continuation pagination, full-mode truncated flag, diagnostics with budget, non-array truncation, large budget passthrough, invalid continuation error, priority sorting, budget=0 unlimited, multi-page coverage

Files modified:

• editor/src/HeadlessEditorState.h — include ResponseBudget.h
• editor/src/HeadlessAgentRPCHandler.h — getAST and getDiagnostics gain optional budget parameter with truncation
• editor/CMakeLists.txt — step254_test target

Key design decisions:

• Budget in chars (not tokens) — simple, predictable, cheap to compute
• Binary search finds max array elements that fit within budget
• Continuation token format: "field:offset:total" (opaque to agent)
• Diagnostics sorted by severity before truncation (errors first)
• budget=0 or omitted → unlimited (backward compatible)

Step 255: Symbol-Only Mode for Scope Queries

Status: PASS (12/12 tests)

Lean vs detailed mode for getInScopeSymbols, getCallHierarchy, and getDependencyGraph. Default (lean) mode returns minimal symbol data (name, kind, nodeId); detailed: true includes full node JSON.

Files created:

• editor/tests/step255_test.cpp — 12 test cases: lean scope (no node data), detailed scope (with node JSON), count field, size comparison, lean call hierarchy (names + IDs), detailed call hierarchy (node arrays), lean deps (ID list + count), detailed deps (full nodes), both modes valid output, field validation (name/kind/nodeId), node concept field, functionName

Files modified:

• editor/src/HeadlessAgentRPCHandler.h — getInScopeSymbols, getCallHierarchy, getDependencyGraph gain detailed parameter; lean mode returns symbols-only, detailed mode includes full node JSON via toJson()
• editor/CMakeLists.txt — step255_test target

Key design decisions:

• Default mode is "symbols" (lean) — agents get names/IDs without node JSON
• detailed: true adds full node serialization for each symbol/caller/callee/dep
• Lean scope responses ~7% the size of detailed (302 vs 4329 chars)
• getDependencyGraph lean mode converts vector IDs to JSON array
• Uses getNodeName() from CompactAST.h for cross-type name extraction