feat(metrics): score Cursor sessions like Claude Code

[afeddersen]

Add per-session usage accounting for Cursor — graft vs source reads and token savings — via repo-local .cursor hooks, a graft stats readout, and host-attributed session_summary telemetry.

• consolidate the Codex/Cursor/MCP config writers onto a shared ConfigWrite type and a readJsonObject load-or-skip helper (src/hosts/config-write.ts)
• force-close the just-ended conversation on Cursor's sessionEnd instead of waiting for the idle sweep, and stamp the recording host on each session
• anchor graft MCP-tool detection to the real tool-name list rather than a loose "graft" substring (src/mcp/tool-names.ts)

[github-actions]

🌱 graft blast radius

5 areas changed → 3 areas can be affected. 5 dependent symbols, depth 2.
Tests: Tool Registry has tests the diff did not touch; 3 areas updated their tests.
Tag: @anirudhkumar-nanonets — 8 of 8 areas · @shhdwi — 5 of 8 areas

flowchart TB
  A0(("Claude Initialization<br/>2 symbols"))
  A1(("MCP Server<br/>2 symbols"))
  A2(("Wiring Configuration<br/>1 symbol"))
  classDef reached fill:#D9EDF3,stroke:#3AA7C9,stroke-width:1.5px,color:#0E313C;
  class A0,A1,A2 reached;

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Can be affected	Symbols	Nearest hop	Reached from
Claude Initialization	2	src/claude/init.ts:L59-L90 runInit — calls, depth 1	Session State Management, Host Integration
MCP Server	2	src/mcp/server.ts:L1-L125 server.ts — imports, depth 1	Tool Registry, Telemetry
Wiring Configuration	1	src/upkeep-run.ts:L41-L46 rewriteWiring — calls, depth 1	Session State Management, Host Integration

Who knows this code — 2 people across 8 areas

Area	Who knows it
Host Integration · changed	@shhdwi — 11 commits, last 16d ago · @anirudhkumar-nanonets — 4 commits, last 2d ago
Session State Management · changed	@shhdwi — 14 commits, last 17d ago · @anirudhkumar-nanonets — 13 commits, last 2d ago
Tool Registry · changed	@anirudhkumar-nanonets — 36 commits, last 2d ago · @shhdwi — 28 commits, last 16d ago
Telemetry · changed	@anirudhkumar-nanonets — 2 commits, last 2d ago
Test Runner · changed	@anirudhkumar-nanonets — 1 commit, last 26d ago
Claude Initialization · affected	@anirudhkumar-nanonets — 7 commits, last 17d ago · @shhdwi — 4 commits, last 1mo ago
MCP Server · affected	@anirudhkumar-nanonets — 4 commits, last 8d ago · @shhdwi — 2 commits, last 1mo ago
Wiring Configuration · affected	@anirudhkumar-nanonets — 1 commit, last 16d ago

Ownership is git history over each area's own files, weighted towards recent work (120-day half-life). Merge commits and bots are dropped, and you are dropped from your own PR. A name with no @ has no GitHub handle in its commit email — tag them by hand, or add a .mailmap entry. A suggestion from history, not a CODEOWNERS rule.

All 5 dependent symbols, grouped by area

Claude Initialization — 2 symbols in 2 files

• src/claude/init.ts:L59-L90 — runInit (calls, depth 1)
  67: try { existing = JSON.parse(readFileSync(settingsPath, 'utf8')); } catch { /* none/invalid → start fresh */ }
• src/claude/statusline.ts:L24-L35 — main (calls, depth 2)
  24: export function main(): void {

MCP Server — 2 symbols in 1 file

• src/mcp/server.ts:L1-L125 — server.ts (imports, depth 1)
  6: import { TOOLS, callTool } from './tools.js';
• src/mcp/server.ts:L44-L124 — startMcpServer (calls, depth 2)
  47: // refreshes rule files an older `graft init` wrote, and kicks off the cached

Wiring Configuration — 1 symbol in 1 file

• src/upkeep-run.ts:L41-L46 — rewriteWiring (calls, depth 1)
  45: runHostsInit(repo, { agents: others, global: opts.global, mcp: opts.mcp, hooks: opts.hooks });

Test signal per changed area — 3 ✓ · 1 ⚠ · 1 –

Reached = a node under a test path has a resolved edge into the changed symbol. It undercounts anything called indirectly — through a CLI, a spawned process or a dynamic import — so read a low ratio as “look here”, never as a coverage gate.

• ✓ Host Integration — 8 of 13 reached · 2 test files changed here: test/hosts-config-write.test.ts, test/hosts-cursor-hooks.test.ts
  • not reached: writeOwned, configPathFor, desiredEntries, shimPathFor, mergeJsonKey
• ✓ Session State Management — 9 of 20 reached · 2 test files changed here: test/claude-settings-merge.test.ts, test/session-metrics.test.ts
  • not reached: classifyAndScore, cursorSessionId, handleCursorMcp, handleCursorPostTool, handleToolUse, main, isShellTool, graftBlocks, …3 more
• ⚠ Tool Registry — 1 of 2 reached · 5 test files reach it, none changed here
  • not reached: sumSavingsFooters
• ✓ Telemetry — 2 of 2 reached · 1 test file changed here: test/telemetry-sessions.test.ts
• – Test Runner — no function, method or class changed here

15 test suites also reference this code

17 symbols, kept out of the diagram and the table so they cannot crowd out the areas a reviewer has to look at.

• test/claude-init.test.ts
• test/claude-state.test.ts
• test/claude-tally.test.ts
• test/cli-picker.test.ts
• test/graph-follow-submodules.test.ts
• test/graph-load.test.ts
• test/graph-refresh.test.ts
• test/graph-seed.test.ts
• test/hosts-antigravity.test.ts
• test/hosts-codex-hooks.test.ts
• test/hosts-init.test.ts
• test/hosts-mcp-config.test.ts
• test/hosts-plan.test.ts
• test/hosts-retract.test.ts
• test/mcp-tools.test.ts

⚠️ 1 changed file not in the graph (.gitignore) — no parser claims the extension, or the index predates the file.

_{graft blast · origin/main...HEAD · depth 2 · 25 changed files}

Open the interactive graph → — click an area to see its dependent symbols at file:line.

[shhdwi]

Verified locally on top of current main (clean merge; build clean; 95/95 across session-metrics, cursor-hooks, claude-hooks, telemetry-sessions).

Real session scoring for Cursor, mirroring Claude Code: cursor-hooks.ts writes .cursor/hooks.json wiring postToolUse/afterMCPExecution/sessionEnd to shared classify+record in session-metrics.ts (previously graftReads/sourceReads were never incremented, so Cursor session_summary shipped 0/0). Live demo through the hook: before → "no session recorded"; after a Cursor Read + a graft MCP call + a graft ask: graft reads 2, source reads 1, 67% graft, ~6,600 saved, attributed to host cursor. MCP double-count is correctly guarded, and the new graft stats reads the local mix. Nice, complete piece of work — thanks! Merging.