diff --git a/.changeset/eager-herons-forage.md b/.changeset/eager-herons-forage.md
new file mode 100644
index 000000000..f1adf4731
--- /dev/null
+++ b/.changeset/eager-herons-forage.md
@@ -0,0 +1,5 @@
+---
+type: Added
+pr: 777
+---
+Cursor now receives GSD lifecycle hooks via `.cursor/hooks.json` — a sessionStart hook injects the current workflow state as context at session start, and a postToolUse hook nudges the agent to update `.planning/` after write-class operations, bringing Cursor to baseline hook parity with Gemini and Claude Code.
diff --git a/CONTEXT.md b/CONTEXT.md
index ae909288b..b6641f085 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -122,7 +122,7 @@ Module owning the per-runtime mapping from artifact kind to filesystem placement
 Projects a pure, typed install plan for a given runtime by composing artifact placements (Runtime Artifact Layout Module), command text (Shell Command Projection Module), and per-runtime config intentions — with no filesystem IO or format-specific serialization. Runtime-specific adapters consume the plan and execute concrete file mutations and config rendering. See ADR-58.
 
 ### Runtime Config Adapter Registry
-Module owning the explicit per-runtime config-mutation dispatch table for the installer. `resolveRuntimeConfigIntent(runtime)` projects a typed config intent — `installSurface` (`settings-json` | `codex-toml` | `copilot-instructions` | `cline-rules` | `profile-marker-only`), `writesSharedSettings` (the `finishInstall` shared-settings write gate), and `finishPermissionWriter` (`opencode` | `kilo` | none) — that `bin/install.js` dispatches on instead of inline `runtime === '...'` branching. Owns adapter selection only: it performs no filesystem IO and does not execute config mutations (the install/finishInstall handlers and the per-runtime writers do that). Unknown runtimes fail loudly with a `TypeError`, guarded by an `Object.hasOwn` own-property check so prototype-chain keys (`__proto__`, `constructor`) also throw. Realizes the adapter-selection half of the Runtime Install Policy Module boundary. Source: `gsd-core/bin/lib/runtime-config-adapter-registry.cjs`. See ADR-58, #60.
+Module owning the explicit per-runtime config-mutation dispatch table for the installer. `resolveRuntimeConfigIntent(runtime)` projects a typed config intent — `installSurface` (`settings-json` | `codex-toml` | `copilot-instructions` | `cline-rules` | `cursor-hooks-json` | `profile-marker-only`), `writesSharedSettings` (the `finishInstall` shared-settings write gate), and `finishPermissionWriter` (`opencode` | `kilo` | none) — that `bin/install.js` dispatches on instead of inline `runtime === '...'` branching. Owns adapter selection only: it performs no filesystem IO and does not execute config mutations (the install/finishInstall handlers and the per-runtime writers do that). Unknown runtimes fail loudly with a `TypeError`, guarded by an `Object.hasOwn` own-property check so prototype-chain keys (`__proto__`, `constructor`) also throw. Realizes the adapter-selection half of the Runtime Install Policy Module boundary. Source: `gsd-core/bin/lib/runtime-config-adapter-registry.cjs`. See ADR-58, #60.
 
 ### Claude Code Plugin Manifest Module
 Module owning the projection of gsd-core's artifact surfaces (`commands`, `agents`, hooks) onto the Claude Code plugin contract (`.claude-plugin/plugin.json` + `hooks/hooks.json`) — the plugin-contract sibling of the Runtime Artifact Layout Module (which projects the same surfaces onto filesystem placements). Defined mapping: `name`=`binName` (drives the `/gsd-core:` command namespace), `repository`/`homepage`=`repoUrl` (Package Identity Module), `version`/`description`/`license` from `package.json` (`version` is required for `claude plugin validate --strict`), `commands`=`./commands/gsd/`, agents via Claude Code's default `agents/` discovery (the explicit string form is schema-rejected), `hooks`=`./hooks/hooks.json`. The hook projection carries ONLY the always-on subset of the Installer Module's Claude `settings.json` wiring (check-update, context-monitor, prompt-guard, read-guard, worktree-path-guard, read-injection-scanner) via `${CLAUDE_PLUGIN_ROOT}`; config-gated opt-in hooks are excluded because a static manifest cannot honor per-project config gates, and plugin-shipped agents cannot carry hook frontmatter (so all plugin-path hook wiring lives in hooks.json). Additive — the file-copy path (Runtime Artifact Layout / Install Policy / Installer Modules) is unchanged. Conformance is validated by `claude plugin validate --strict` plus the in-repo drift-guard `tests/issue-766-plugin-manifest.test.cjs`. _Avoid_: "the plugin API", "the plugin file" (when you mean the seam). See ADR-766 and Runtime Artifact Layout Module.
diff --git a/bin/install.js b/bin/install.js
index c706ff23c..a3c0408eb 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -190,6 +190,19 @@ const GSD_COPILOT_SESSION_HOOK_PWSH =
   `{ '{"additionalContext":"${GSD_COPILOT_SESSION_MSG_PRESENT}"}' } ` +
   `else { '{"additionalContext":"${GSD_COPILOT_SESSION_MSG_ABSENT}"}' }`;
 
+// #777 — Cursor CLI lifecycle hook constants.
+// Cursor reads hook configs from <project-root>/.cursor/hooks.json (local) or
+// ~/.cursor/hooks.json (global) with the shape { version: 1, hooks: { <event>: [...] } }.
+// Events use camelCase: sessionStart, postToolUse, preToolUse, etc.
+// A `command` hook entry runs an external script. GSD registers two managed hooks:
+//   sessionStart → gsd-cursor-session-start.js  (context injection)
+//   postToolUse  → gsd-cursor-post-tool.js       (STATE.md update monitor)
+// Cursor docs: https://cursor.com/docs/hooks
+const GSD_CURSOR_SESSION_HOOK_SCRIPT = 'gsd-cursor-session-start.js';
+const GSD_CURSOR_POST_TOOL_HOOK_SCRIPT = 'gsd-cursor-post-tool.js';
+// Marker comment embedded in managed hook entries so GSD can find+remove them.
+const GSD_CURSOR_HOOK_MARKER = 'gsd-managed';
+
 // GSD-managed files under hooks/lib/ (helpers required by gsd-*.sh hooks).
 // git-cmd.js does not start with "gsd-" (shared classifier for #3129), gsd-graphify-rebuild.sh does.
 const GSD_HOOK_LIB_FILES = ['git-cmd.js', 'gsd-graphify-rebuild.sh'];
@@ -5738,6 +5751,248 @@ function writeClineArtifacts(targetDir, isGlobalInstall) {
   return written;
 }
 
+// ── Cursor hooks.json reconciler (issue #777) ────────────────────────────────
+//
+// Cursor v2.4+ supports a hooks.json lifecycle hook system. GSD registers two
+// managed command hooks:
+//   sessionStart → gsd-cursor-session-start.js  (context injection)
+//   postToolUse  → gsd-cursor-post-tool.js       (STATE.md update monitor)
+//
+// hooks.json schema:
+//   { "version": 1, "hooks": { "<event>": [ { "type": "command", "command": "<path>" } ] } }
+//
+// Location:
+//   Global:  ~/.cursor/hooks.json
+//   Local:   <project-root>/.cursor/hooks.json
+//
+// GSD entries are identified by a top-level `"gsd-managed": true` field on
+// each hook entry. Non-GSD entries are preserved. The reconciler is idempotent
+// (safe to re-run) and preserves user-owned entries in the file.
+//
+// References: https://cursor.com/docs/hooks
+
+/**
+ * Build a managed Cursor hook entry for a given hook script path.
+ *
+ * @param {string} scriptPath - Absolute path to the hook script
+ * @returns {object} Cursor hook entry object
+ */
+function buildCursorHookEntry(scriptPath) {
+  return {
+    type: 'command',
+    command: scriptPath.replace(/\\/g, '/'),
+    [GSD_CURSOR_HOOK_MARKER]: true,
+  };
+}
+
+/**
+ * Return true if a Cursor hook entry is GSD-managed.
+ * Detection: presence of the GSD_CURSOR_HOOK_MARKER sentinel field.
+ *
+ * @param {object} entry - A hooks array element from hooks.json
+ * @returns {boolean}
+ */
+function isManagedCursorHookEntry(entry) {
+  return Boolean(entry && typeof entry === 'object' && entry[GSD_CURSOR_HOOK_MARKER]);
+}
+
+/**
+ * Reconcile the GSD-managed entries in a Cursor hooks.json file.
+ *
+ * Supports both known hooks.json shapes:
+ *   1) { "version": 1, "hooks": { "sessionStart": [...], "postToolUse": [...] } }
+ *   2) { "sessionStart": [...], "postToolUse": [...] }   (no wrapper object)
+ *
+ * Managed entries (those with GSD_CURSOR_HOOK_MARKER) are removed then
+ * re-added if managedEntries is non-null/non-empty. User-owned entries are
+ * preserved. File is written atomically only when content changes.
+ *
+ * @param {string} hooksJsonPath - Absolute path to the hooks.json file
+ * @param {{ sessionStart?: object|null, postToolUse?: object|null }|null} managedEntries
+ *   Map from event name to the new hook entry to register (or null to remove).
+ *   Pass null for the whole param to remove all managed entries.
+ * @returns {{ changed: boolean, wrote: boolean, path: string }}
+ */
+function reconcileCursorHooksJson(hooksJsonPath, managedEntries) {
+  let parsed = {};
+  let currentContent = null;
+
+  if (fs.existsSync(hooksJsonPath)) {
+    const raw = fs.readFileSync(hooksJsonPath, 'utf8');
+    currentContent = raw;
+    if (raw.trim()) {
+      try {
+        parsed = JSON.parse(raw);
+      } catch (err) {
+        throw new Error(`Cursor hooks.json parse failed: ${err && err.message ? err.message : String(err)}`);
+      }
+    }
+  }
+  if (!parsed || typeof parsed !== 'object' || Array.isArray(parsed)) parsed = {};
+
+  // Cursor's canonical hooks.json schema is { "version": 1, "hooks": { ... } }.
+  // GSD always writes (and migrates to) the nested shape so Cursor reads it correctly.
+  // The flat shape { "sessionStart": [...] } is accepted on read for backwards compat
+  // with manually-written files, but the output always uses the nested form.
+  const hasNestedHooksObject =
+    parsed.hooks && typeof parsed.hooks === 'object' && !Array.isArray(parsed.hooks);
+  if (!hasNestedHooksObject) {
+    // Migrate flat shape (or empty {}) to nested: lift event keys into hooks:{}.
+    const eventKeys = ['sessionStart', 'postToolUse'];
+    const lifted = {};
+    for (const k of eventKeys) {
+      if (Array.isArray(parsed[k])) {
+        lifted[k] = parsed[k];
+        delete parsed[k];
+      }
+    }
+    parsed.hooks = lifted;
+  }
+  if (!parsed.version) parsed.version = 1;
+  const hookTable = parsed.hooks;
+
+  // Events GSD manages.
+  const MANAGED_EVENTS = ['sessionStart', 'postToolUse'];
+  const entries = managedEntries || {};
+
+  for (const event of MANAGED_EVENTS) {
+    const existing = Array.isArray(hookTable[event]) ? hookTable[event] : [];
+    // Strip all prior GSD-managed entries for this event.
+    const userOwned = existing.filter((e) => !isManagedCursorHookEntry(e));
+    const newEntry = entries[event] || null;
+    if (newEntry) {
+      hookTable[event] = [...userOwned, newEntry];
+    } else {
+      // Remove-only: keep user entries, or delete the key if it would be empty.
+      if (userOwned.length > 0) {
+        hookTable[event] = userOwned;
+      } else {
+        delete hookTable[event];
+      }
+    }
+  }
+
+  // hookTable is parsed.hooks (always nested now); no reassignment needed.
+  // Write only if content changed or if we're creating the file for the first time.
+  const nextContent = `${JSON.stringify(parsed, null, 2)}\n`;
+  const changed = currentContent !== nextContent;
+  const shouldWrite = changed && (currentContent !== null || Object.keys(parsed).length > 0);
+  if (shouldWrite) {
+    atomicWriteFileSync(hooksJsonPath, nextContent, 'utf8');
+  }
+
+  return { changed: changed, wrote: shouldWrite, path: hooksJsonPath };
+}
+
+/**
+ * #777 — Write GSD-managed Cursor lifecycle hooks into <targetDir>/hooks.json.
+ *
+ * Both managed hook scripts (gsd-cursor-session-start.js, gsd-cursor-post-tool.js)
+ * are copied from the GSD hooks/ source to <targetDir>/hooks/ first, so the
+ * hooks.json entries never reference a script that wasn't installed.
+ *
+ * @param {string} targetDir - The Cursor config dir (global: ~/.cursor; local: .cursor)
+ * @param {string} src       - The GSD install source root (for copying hook scripts)
+ * @param {{ absoluteRunner?: string|null }} opts
+ * @returns {{ hooksJsonPath: string, changed: boolean }}
+ */
+function writeCursorHooksJson(targetDir, src, opts) {
+  opts = opts || {};
+  const hooksDir = path.join(targetDir, 'hooks');
+  fs.mkdirSync(hooksDir, { recursive: true });
+
+  // Copy the two GSD-managed hook scripts from the GSD source hooks/ directory.
+  // Apply the same /gsd:/gi → gsd- rewrite used by copyWithPathReplacement for Cursor
+  // JS files, so the installed hook scripts contain no /gsd: colon refs (bug-376 2b).
+  // Track which scripts were successfully installed so we never register a hook entry
+  // that references a script that wasn't copied (dangling command guard).
+  const hookScripts = [GSD_CURSOR_SESSION_HOOK_SCRIPT, GSD_CURSOR_POST_TOOL_HOOK_SCRIPT];
+  const srcHooksDir = path.join(src, 'hooks');
+  const installedScripts = new Set();
+  for (const script of hookScripts) {
+    const srcPath = path.join(srcHooksDir, script);
+    const destPath = path.join(hooksDir, script);
+    if (fs.existsSync(srcPath)) {
+      let content = fs.readFileSync(srcPath, 'utf8');
+      // Rewrite /gsd:<cmd> → gsd-<cmd> so installed hook scripts are consistent
+      // with the Cursor convention (no colon-form slash commands in agent context).
+      content = content.replace(/gsd:/gi, 'gsd-');
+      fs.writeFileSync(destPath, content);
+      try { fs.chmodSync(destPath, 0o755); } catch { /* Windows: ignore chmod */ }
+      installedScripts.add(script);
+    }
+  }
+
+  // Build command strings using the same buildHookCommand helper used by other runtimes.
+  // buildHookCommand resolves the node runner + emits "<runner>" "<targetDir>/hooks/<name>".
+  const hookOpts = { runtime: 'cursor', platform: opts.platform || process.platform };
+  // buildHookCommand('gsd-cursor-session-start.js', ...): sessionStart → context injection
+  // Only register the hook entry if the script was actually installed (dangling guard).
+  const sessionStartCmd = installedScripts.has('gsd-cursor-session-start.js')
+    ? buildHookCommand(targetDir, 'gsd-cursor-session-start.js', hookOpts)
+    : null;
+  // buildHookCommand('gsd-cursor-post-tool.js', ...): postToolUse → STATE.md update monitor
+  const postToolCmd = installedScripts.has('gsd-cursor-post-tool.js')
+    ? buildHookCommand(targetDir, 'gsd-cursor-post-tool.js', hookOpts)
+    : null;
+
+  // Build managed entries; skip events whose command couldn't be resolved (e.g. no node).
+  const managedEntries = {};
+  if (sessionStartCmd) {
+    managedEntries.sessionStart = {
+      type: 'command',
+      command: sessionStartCmd,
+      [GSD_CURSOR_HOOK_MARKER]: true,
+    };
+  }
+  if (postToolCmd) {
+    managedEntries.postToolUse = {
+      type: 'command',
+      command: postToolCmd,
+      [GSD_CURSOR_HOOK_MARKER]: true,
+    };
+  }
+
+  const hooksJsonPath = path.join(targetDir, 'hooks.json');
+  const result = reconcileCursorHooksJson(hooksJsonPath, managedEntries);
+  return { hooksJsonPath, changed: result.changed };
+}
+
+/**
+ * Remove all GSD-managed Cursor lifecycle hook entries from hooks.json.
+ * User-owned entries are preserved. If the file becomes empty, it is removed.
+ *
+ * @param {string} targetDir - The Cursor config dir
+ * @returns {{ changed: boolean }}
+ */
+function removeCursorHooksJson(targetDir) {
+  const hooksJsonPath = path.join(targetDir, 'hooks.json');
+  if (!fs.existsSync(hooksJsonPath)) return { changed: false };
+  const result = reconcileCursorHooksJson(hooksJsonPath, null);
+  // If the resulting file has no meaningful hook content, remove it.
+  // A file is "empty" if it contains only the scaffolding (version, empty hooks
+  // object, or a bare {}) with no user-authored hook entries.
+  if (result.changed) {
+    try {
+      const contentRaw = fs.readFileSync(hooksJsonPath, 'utf8');
+      const parsed = JSON.parse(contentRaw);
+      // reconcileCursorHooksJson always writes the nested { version, hooks:{} } shape.
+      // The file is "empty" when there are no remaining hook events with entries.
+      const hookTable = (parsed.hooks && typeof parsed.hooks === 'object' && !Array.isArray(parsed.hooks))
+        ? parsed.hooks
+        : {};
+      const hasAnyEvents = Object.keys(hookTable).some(
+        (k) => Array.isArray(hookTable[k]) && hookTable[k].length > 0,
+      );
+      if (!hasAnyEvents) {
+        fs.unlinkSync(hooksJsonPath);
+        return { changed: true };
+      }
+    } catch { /* best-effort: leave the file */ }
+  }
+  return { changed: result.changed };
+}
+
 /**
  * #786 — Build the GSD-managed GitHub Copilot lifecycle hook config object.
  *
@@ -7804,6 +8059,8 @@ const GSD_UNINSTALL_HOOKS = [
   'gsd-check-update.js',
   'gsd-check-update.cmd',
   'gsd-context-monitor.js',
+  'gsd-cursor-session-start.js',
+  'gsd-cursor-post-tool.js',
   'gsd-prompt-guard.js',
   'gsd-read-guard.js',
   'gsd-read-injection-scanner.js',
@@ -8039,6 +8296,33 @@ function uninstall(isGlobal, runtime = 'claude') {
     }
   }
 
+  // 1b-cursor. Non-layout Cursor side-effects (issue #777): remove GSD-managed
+  // hook entries from hooks.json and clean up the managed hook scripts.
+  if (isCursor) {
+    const hooksJsonCleanup = removeCursorHooksJson(targetDir);
+    if (hooksJsonCleanup.changed) {
+      removedCount++;
+      console.log(`  ${green}✓${reset} Removed GSD-managed Cursor hooks from hooks.json`);
+    }
+    // Remove the managed hook scripts (session-start + post-tool).
+    const hooksDir = path.join(targetDir, 'hooks');
+    for (const script of [GSD_CURSOR_SESSION_HOOK_SCRIPT, GSD_CURSOR_POST_TOOL_HOOK_SCRIPT]) {
+      const p = path.join(hooksDir, script);
+      try {
+        if (fs.existsSync(p)) {
+          fs.unlinkSync(p);
+          removedCount++;
+        }
+      } catch { /* best-effort */ }
+    }
+    // Prune hooks/ if empty.
+    try {
+      if (fs.existsSync(hooksDir) && fs.readdirSync(hooksDir).length === 0) {
+        fs.rmdirSync(hooksDir);
+      }
+    } catch { /* best-effort */ }
+  }
+
   // 1c. Claude local: remove commands/gsd/ (primary local install location).
   //     The layout's _removeGsdEntries uses the 'gsd-' prefix which applies to
   //     flat command dirs (OpenCode/Kilo). Claude local files use no prefix inside
@@ -10137,8 +10421,10 @@ function install(isGlobal, runtime = 'claude', options = {}) {
   }
 
   // Gate hooks/lib/ install on the same runtimes that receive hooks (see line ~8702).
-  // Codex/Copilot/Cursor/Windsurf/Trae/Cline skip hooks entirely, so they must not
-  // receive the hooks/lib/ helpers either — otherwise the Codex comment downstream
+  // Codex/Copilot/Cursor/Windsurf/Trae/Cline do not use the shared hooks/lib/ helpers
+  // (Cursor uses standalone .js hook scripts registered via hooks.json; Codex uses
+  // hooks.json directly; the others skip hooks entirely), so they must not receive
+  // the hooks/lib/ helpers — otherwise the Codex comment downstream
   // ("we deliberately do *not* copy hooks/lib/ for Codex") is contradicted in practice.
   const hooksLibSrc = path.join(src, 'hooks', 'lib');
   if (!isCodex && !isCopilot && !isCursor && !isWindsurf && !isTrae && !isCline && fs.existsSync(hooksLibSrc)) {
@@ -10653,8 +10939,23 @@ function install(isGlobal, runtime = 'claude', options = {}) {
     return { settingsPath: null, settings: null, statuslineCommand: null, updateBannerCommand: null, runtime, configDir: targetDir };
   }
 
+  if (configIntent.installSurface === 'cursor-hooks-json') {
+    // #777: Cursor v2.4+ supports hooks.json. Register sessionStart + postToolUse.
+    // Hook scripts are copied to <targetDir>/hooks/ and referenced by hooks.json.
+    const cursorHookResult = writeCursorHooksJson(targetDir, src, {});
+    if (cursorHookResult.changed) {
+      console.log(`  ${green}✓${reset} Configured Cursor lifecycle hooks (sessionStart, postToolUse)`);
+    } else {
+      console.log(`  ${green}✓${reset} Cursor lifecycle hooks already up to date`);
+    }
+    // Re-run the manifest pass so the hook scripts + hooks.json are hash-tracked.
+    writeManifest(targetDir, runtime, { mode: _effectiveInstallMode });
+    persistActiveProfileMarker();
+    return { settingsPath: null, settings: null, statuslineCommand: null, updateBannerCommand: null, runtime, configDir: targetDir };
+  }
+
   if (configIntent.installSurface === 'profile-marker-only') {
-    // Cursor/Windsurf/Trae use skills — no config.toml, no settings.json hooks needed
+    // Windsurf/Trae use skills — no config.toml, no settings.json hooks needed
     persistActiveProfileMarker();
     return { settingsPath: null, settings: null, statuslineCommand: null, updateBannerCommand: null, runtime, configDir: targetDir };
   }
@@ -12262,6 +12563,14 @@ module.exports = {
     buildClinePreToolUseHook,
     writeClineArtifacts,
     mergeGsdAgentsMd,
+    GSD_CURSOR_SESSION_HOOK_SCRIPT,
+    GSD_CURSOR_POST_TOOL_HOOK_SCRIPT,
+    GSD_CURSOR_HOOK_MARKER,
+    buildCursorHookEntry,
+    isManagedCursorHookEntry,
+    reconcileCursorHooksJson,
+    writeCursorHooksJson,
+    removeCursorHooksJson,
     stripGsdFromAgentsMd,
     GSD_AGENTS_MD_MARKER,
     GSD_AGENTS_MD_CLOSE_MARKER,
diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index 0c555656f..b2b1b4e08 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -802,7 +802,7 @@ The migration-specific ownership and source snapshots live in
 | Codex | `~/.codex` | `./.codex` | `skills/gsd-*/SKILL.md` | `agents/` source markdown plus per-agent TOML | `config.toml` `[agents.gsd-*]`, `[features].hooks` (canonical; legacy alias `codex_hooks` is recognized and migrated forward on reinstall, #3566), and hook tables |
 | GitHub Copilot | `~/.copilot` | `./.github` | `skills/gsd-*/SKILL.md`, `copilot-instructions.md`, and `AGENTS.md` (repo root, local) | `.agent.md` files | Self-contained `sessionStart` hook (`hooks/gsd-session.json`, inline `command` type); no statusline |
 | Antigravity | auto-detected: `~/.gemini/antigravity`, `~/.gemini/antigravity-ide`, or `~/.gemini/antigravity-cli` | `./.agent` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Gemini-style `settings.json` hook entries when installed by GSD |
-| Cursor | `~/.cursor` | `./.cursor` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Rule references under `rules/`; no GSD hooks |
+| Cursor | `~/.cursor` | `./.cursor` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Rule references under `rules/`; `hooks.json` with sessionStart context injection and postToolUse STATE.md monitor (#777) |
 | Windsurf | `~/.codeium/windsurf` | `./.windsurf` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Rule references under `rules/`; no GSD hooks |
 | Augment Code | `~/.augment` | `./.augment` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | No GSD hooks or statusline |
 | Trae | `~/.trae` | `./.trae` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Rule references under `rules/`; no GSD hooks |
diff --git a/docs/INVENTORY-MANIFEST.json b/docs/INVENTORY-MANIFEST.json
index 046b487c2..d3def7871 100644
--- a/docs/INVENTORY-MANIFEST.json
+++ b/docs/INVENTORY-MANIFEST.json
@@ -360,6 +360,8 @@
       "gsd-check-update-worker.js",
       "gsd-check-update.js",
       "gsd-context-monitor.js",
+      "gsd-cursor-post-tool.js",
+      "gsd-cursor-session-start.js",
       "gsd-graphify-update.sh",
       "gsd-phase-boundary.sh",
       "gsd-prompt-guard.js",
diff --git a/docs/INVENTORY.md b/docs/INVENTORY.md
index bb422cd18..d7bc3964b 100644
--- a/docs/INVENTORY.md
+++ b/docs/INVENTORY.md
@@ -471,7 +471,7 @@ Full listing: `gsd-core/bin/lib/*.cjs`.
 
 ---
 
-## Hooks (14 shipped)
+## Hooks (16 shipped)
 
 Full listing: `hooks/`.
 
@@ -482,6 +482,8 @@ Full listing: `hooks/`.
 | `gsd-check-update.js` | `SessionStart` | Background check for new GSD versions |
 | `gsd-check-update-worker.js` | (worker) | Background worker helper for check-update |
 | `gsd-update-banner.js` | `SessionStart` | Opt-in banner surfacing update availability when GSD statusline isn't used (PR #2795) |
+| `gsd-cursor-session-start.js` | Cursor `sessionStart` | Cursor-native context injection at session start (issue #777) |
+| `gsd-cursor-post-tool.js` | Cursor `postToolUse` | Cursor-native STATE.md update monitor after tool calls (issue #777) |
 | `gsd-prompt-guard.js` | `PreToolUse` | Scans `.planning/` writes for prompt-injection patterns (advisory) |
 | `gsd-workflow-guard.js` | `PreToolUse` | Detects file edits outside GSD workflow context (advisory, opt-in) |
 | `gsd-read-guard.js` | `PreToolUse` | Advisory guard preventing Edit/Write on unread files |
diff --git a/docs/installer-migrations.md b/docs/installer-migrations.md
index 0cacbc98b..2d8c33197 100644
--- a/docs/installer-migrations.md
+++ b/docs/installer-migrations.md
@@ -370,7 +370,7 @@ for the new shape before changing migration behavior.
 | Codex | Skills in `skills/gsd-*/SKILL.md`; agents as source markdown plus per-agent TOML in `agents/`; `[agents.gsd-*]` and hooks in `config.toml` | Global `CODEX_HOME` or `~/.codex`; local `./.codex` | GSD owns generated skills, generated agent TOML, `agents.gsd-*` config sections, `[features].hooks` when added by GSD (canonical; legacy alias `codex_hooks` is recognized and migrated forward, #3566), and GSD hook entries | [Codex config schema](https://developers.openai.com/codex/config-schema.json), [Codex developer docs](https://developers.openai.com/codex/); docs not versioned, checked 2026-05-15; installer compatibility sentinel: Codex 0.130.0 features.hooks key (legacy `codex_hooks` recognized) |
 | GitHub Copilot | Skills in `skills/gsd-*/SKILL.md`; agents as `.agent.md`; repository instructions in `copilot-instructions.md` | Global `COPILOT_CONFIG_DIR`, `COPILOT_HOME`, or `~/.copilot`; local `./.github` | GSD owns generated skill/agent files and GSD-authored instruction files; no hook/statusline ownership | [Repository custom instructions](https://docs.github.com/en/copilot/how-tos/configure-custom-instructions/add-repository-instructions), [Copilot CLI custom instructions](https://docs.github.com/en/copilot/how-tos/copilot-cli/add-custom-instructions); GitHub Docs product docs, checked 2026-05-11 |
 | Antigravity | Skills in `skills/gsd-*/SKILL.md`; agents in `agents/`; Gemini-style `settings.json` hooks when installed by GSD | Global `ANTIGRAVITY_CONFIG_DIR` or `~/.gemini/antigravity`; local `./.agent` | GSD owns generated skills/agents/hooks and GSD settings entries only | Public Antigravity install/config docs for this file layout were not stable or complete as of 2026-05-11; installer compatibility therefore uses GSD's Gemini-compatible settings policy, documented shim baseline. |
-| Cursor | Skills in `skills/gsd-*/SKILL.md`; agents in `agents/`; rule references under `rules/` | Global `CURSOR_CONFIG_DIR` or `~/.cursor`; local `./.cursor` | GSD owns generated skills/agents and GSD rule files or references; no hook/statusline ownership | [Cursor rules](https://docs.cursor.com/context/rules); docs not versioned, checked 2026-05-11 |
+| Cursor | Skills in `skills/gsd-*/SKILL.md`; agents in `agents/`; rule references under `rules/`; lifecycle hooks via `hooks.json` (sessionStart + postToolUse, #777) | Global `CURSOR_CONFIG_DIR` or `~/.cursor`; local `./.cursor` | GSD owns generated skills/agents, GSD rule files or references, and GSD-managed `hooks.json` entries (sentinel `gsd-managed:true`); no statusline ownership | [Cursor rules](https://docs.cursor.com/context/rules); [Cursor hooks](https://docs.cursor.com/context/hooks); docs not versioned, checked 2026-06-07 |
 | Windsurf | Skills in `skills/gsd-*/SKILL.md`; agents in `agents/`; rule references under `rules/` | Global `WINDSURF_CONFIG_DIR` or `~/.codeium/windsurf`; local `./.windsurf` | GSD owns generated skills/agents and GSD rule files or references; no hook/statusline ownership | Windsurf public rule docs were source-limited in search results as of 2026-05-11; installer targets the common workspace rules convention `./.windsurf/rules` and must be rechecked before migrations rewrite rules |
 | Augment Code | Skills in `skills/gsd-*/SKILL.md`; agents in `agents/` | Global `AUGMENT_CONFIG_DIR` or `~/.augment`; local `./.augment` | GSD owns generated skills/agents only; no hook/statusline ownership | [Augment Agent Skills](https://docs.augmentcode.com/cli/skills), [Augment IDE skills](https://docs.augmentcode.com/using-augment/skills); IDE skills public beta in VS Code 0.789.0+, checked 2026-05-11 |
 | Trae | Skills in `skills/gsd-*/SKILL.md`; agents in `agents/`; rule references under `rules/` | Global `TRAE_CONFIG_DIR` or `~/.trae`; local `./.trae` | GSD owns generated skills/agents and GSD rule files or references; no hook/statusline ownership | Public Trae docs expose AI settings and `.rules` announcements, but no stable skills/config API was found as of 2026-05-11; migrations must treat this row as source-limited |
diff --git a/hooks/gsd-cursor-post-tool.js b/hooks/gsd-cursor-post-tool.js
new file mode 100644
index 000000000..7f7dec769
--- /dev/null
+++ b/hooks/gsd-cursor-post-tool.js
@@ -0,0 +1,75 @@
+#!/usr/bin/env node
+// gsd-hook-version: {{GSD_VERSION}}
+// gsd-cursor-post-tool.js — Cursor postToolUse hook (issue #777)
+//
+// Cursor invokes this script after each tool call completes.
+// Protocol: JSON from Cursor on stdin; JSON response on stdout.
+//
+// Input schema (cursor postToolUse):
+//   { tool_name, tool_input, tool_output, duration,
+//     conversation_id, generation_id, model, hook_event_name,
+//     cursor_version, workspace_roots, user_email, transcript_path }
+//
+// Output schema (cursor postToolUse):
+//   { additional_context?: string }   ← injected as context after the tool use
+//
+// Behaviour:
+//   - After a write-class tool that targets .planning/, reminds the agent
+//     to keep STATE.md current.
+//   - Fails open: any error silently exits 0.
+//
+// Cursor docs: https://cursor.com/docs/hooks
+
+'use strict';
+
+const WRITE_TOOL_RE = /write|edit|replace|create|delete|remove|append|apply|patch|insert|mkdir/i;
+const PATH_KEY_RE = /^(path|file|file_?path|filepath|target_?path|target|dir|directory|uri|filename)$/i;
+const PLANNING_PATH_RE = /(^|[\\/])\.planning([\\/]|$)/;
+
+let raw = '';
+const stdinTimeout = setTimeout(() => {
+  // Timeout guard: exit silently rather than hanging.
+  process.exit(0);
+}, 10000);
+
+process.stdin.setEncoding('utf8');
+process.stdin.on('data', (chunk) => { raw += chunk; });
+process.stdin.on('end', () => {
+  clearTimeout(stdinTimeout);
+  try {
+    let input;
+    try { input = JSON.parse(raw || '{}'); } catch { process.stdout.write(JSON.stringify({})); return; }
+
+    const toolName = String(
+      input.tool_name || input.toolName || ''
+    ).toLowerCase();
+
+    const isWrite = WRITE_TOOL_RE.test(toolName);
+    if (!isWrite) { process.stdout.write(JSON.stringify({})); return; }
+
+    // Collect only PATH-bearing field values (not free-form content).
+    const paths = [];
+    const walk = (v, depth) => {
+      if (depth > 5 || paths.length > 64) return;
+      if (Array.isArray(v)) { for (const x of v) walk(x, depth + 1); return; }
+      if (v && typeof v === 'object') {
+        for (const k of Object.keys(v)) {
+          const val = v[k];
+          if (typeof val === 'string' && PATH_KEY_RE.test(k)) paths.push(val);
+          else walk(val, depth + 1);
+        }
+      }
+    };
+    walk(input.tool_input || input.toolInput || {}, 0);
+
+    if (paths.some((p) => PLANNING_PATH_RE.test(p))) {
+      process.stdout.write(JSON.stringify({
+        additional_context:
+          'GSD: .planning/ artifact updated — ensure STATE.md reflects the latest phase and progress.',
+      }));
+      return;
+    }
+  } catch { /* fall through to empty response */ }
+
+  process.stdout.write(JSON.stringify({}));
+});
diff --git a/hooks/gsd-cursor-session-start.js b/hooks/gsd-cursor-session-start.js
new file mode 100644
index 000000000..dbc8c97ef
--- /dev/null
+++ b/hooks/gsd-cursor-session-start.js
@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+// gsd-hook-version: {{GSD_VERSION}}
+// gsd-cursor-session-start.js — Cursor sessionStart hook (issue #777)
+//
+// Cursor invokes this script at the start of each agent session.
+// Protocol: JSON from Cursor on stdin; JSON response on stdout.
+//
+// Input schema (cursor sessionStart):
+//   { session_id, is_background_agent, composer_mode, conversation_id,
+//     generation_id, model, hook_event_name, cursor_version,
+//     workspace_roots, user_email, transcript_path }
+//
+// Output schema (cursor sessionStart):
+//   { additional_context?: string }   ← injected into the session as context
+//
+// Behaviour:
+//   - If .planning/STATE.md is present, injects a brief state reminder.
+//   - If absent, nudges the user toward /gsd:new-project.
+//   - Fails open: any error silently exits 0 so a hook bug never wedges Cursor.
+//
+// Cursor docs: https://cursor.com/docs/hooks
+
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+
+const MSG_PRESENT =
+  'GSD: .planning/STATE.md is present — review the current phase and any blockers before acting.';
+const MSG_ABSENT =
+  'GSD: no .planning/ workflow found — run /gsd:new-project to start a tracked workflow.';
+
+let raw = '';
+const stdinTimeout = setTimeout(() => {
+  // Timeout guard: exit silently rather than hanging.
+  process.exit(0);
+}, 10000);
+
+process.stdin.setEncoding('utf8');
+process.stdin.on('data', (chunk) => { raw += chunk; });
+process.stdin.on('end', () => {
+  clearTimeout(stdinTimeout);
+  try {
+    const statePath = path.join(process.cwd(), '.planning', 'STATE.md');
+    const statePresent = fs.existsSync(statePath);
+    const msg = statePresent ? MSG_PRESENT : MSG_ABSENT;
+    process.stdout.write(JSON.stringify({ additional_context: msg }));
+  } catch {
+    // Fail open — never block a Cursor session because of a GSD hook error.
+    process.stdout.write(JSON.stringify({}));
+  }
+});
diff --git a/hooks/managed-hooks-registry.cjs b/hooks/managed-hooks-registry.cjs
index e29c7bb3c..77aa4982b 100644
--- a/hooks/managed-hooks-registry.cjs
+++ b/hooks/managed-hooks-registry.cjs
@@ -19,6 +19,8 @@ const MANAGED_HOOKS = [
   'gsd-check-update-worker.js',
   'gsd-check-update.js',
   'gsd-context-monitor.js',
+  'gsd-cursor-post-tool.js',
+  'gsd-cursor-session-start.js',
   'gsd-graphify-update.sh',
   'gsd-phase-boundary.sh',
   'gsd-prompt-guard.js',
diff --git a/scripts/build-hooks.js b/scripts/build-hooks.js
index 3072a5e50..c566a18cd 100644
--- a/scripts/build-hooks.js
+++ b/scripts/build-hooks.js
@@ -30,6 +30,9 @@ const HOOKS_TO_COPY = [
   // so require('./managed-hooks-registry.cjs') resolves in the installed hooks/ dir.
   'managed-hooks-registry.cjs',
   'gsd-context-monitor.js',
+  // Cursor lifecycle hooks (issue #777): sessionStart context injection + postToolUse monitor
+  'gsd-cursor-session-start.js',
+  'gsd-cursor-post-tool.js',
   'gsd-prompt-guard.js',
   'gsd-read-guard.js',
   'gsd-read-injection-scanner.js',
diff --git a/src/installer-migration-report.cts b/src/installer-migration-report.cts
index 536de56f1..3e41512fa 100644
--- a/src/installer-migration-report.cts
+++ b/src/installer-migration-report.cts
@@ -30,6 +30,8 @@ export const BUNDLED_GSD_HOOK_FILES: ReadonlySet<string> = Object.freeze(new Set
   'hooks/gsd-check-update-worker.js',
   'hooks/gsd-check-update.js',
   'hooks/gsd-context-monitor.js',
+  'hooks/gsd-cursor-post-tool.js',
+  'hooks/gsd-cursor-session-start.js',
   'hooks/gsd-graphify-update.sh',
   'hooks/gsd-phase-boundary.sh',
   'hooks/gsd-prompt-guard.js',
diff --git a/src/installer-migrations/000-first-time-baseline.cts b/src/installer-migrations/000-first-time-baseline.cts
index c81f30e6a..a7c68ace2 100644
--- a/src/installer-migrations/000-first-time-baseline.cts
+++ b/src/installer-migrations/000-first-time-baseline.cts
@@ -23,7 +23,7 @@ const RUNTIME_SURFACES: Record<string, string[]> = {
   kilo: ['gsd-core', 'command', 'skills', 'agents'],
   copilot: ['gsd-core', 'skills', 'agents'],
   antigravity: ['gsd-core', 'skills', 'agents'],
-  cursor: ['gsd-core', 'skills', 'agents'],
+  cursor: ['gsd-core', 'skills', 'agents', 'hooks', 'hooks.json'],
   windsurf: ['gsd-core', 'skills', 'agents', 'rules'],
   augment: ['gsd-core', 'skills', 'agents'],
   trae: ['gsd-core', 'skills', 'agents', 'rules'],
diff --git a/src/runtime-config-adapter-registry.cts b/src/runtime-config-adapter-registry.cts
index 3bb690471..68d1b4d90 100644
--- a/src/runtime-config-adapter-registry.cts
+++ b/src/runtime-config-adapter-registry.cts
@@ -11,6 +11,7 @@
  *     'codex-toml'           → early-return after writing codex.toml.
  *     'copilot-instructions' → early-return after writing .github/copilot-instructions.md.
  *     'cline-rules'          → early-return after writing .clinerules.
+ *     'cursor-hooks-json'    → early-return after writing .cursor/hooks.json (issue #777).
  *     'profile-marker-only'  → early-return after writing only the profile marker.
  * - `writesSharedSettings` is the finishInstall writeSettings gate:
  *     false for codex / copilot / kilo / cursor / windsurf / trae / cline (legacy exclusion list).
@@ -30,6 +31,7 @@ type ConfigInstallSurface =
   | 'codex-toml'
   | 'copilot-instructions'
   | 'cline-rules'
+  | 'cursor-hooks-json'
   | 'profile-marker-only';
 
 type FinishPermissionWriter = 'opencode' | 'kilo' | null;
@@ -64,7 +66,7 @@ const REGISTRY: Record<string, Readonly<RegistryEntry>> = Object.freeze({
   codex:       Object.freeze({ installSurface: 'codex-toml',           writesSharedSettings: false, finishPermissionWriter: null       } as const),
   copilot:     Object.freeze({ installSurface: 'copilot-instructions', writesSharedSettings: false, finishPermissionWriter: null       } as const),
   cline:       Object.freeze({ installSurface: 'cline-rules',          writesSharedSettings: false, finishPermissionWriter: null       } as const),
-  cursor:      Object.freeze({ installSurface: 'profile-marker-only',  writesSharedSettings: false, finishPermissionWriter: null       } as const),
+  cursor:      Object.freeze({ installSurface: 'cursor-hooks-json',    writesSharedSettings: false, finishPermissionWriter: null       } as const),
   windsurf:    Object.freeze({ installSurface: 'profile-marker-only',  writesSharedSettings: false, finishPermissionWriter: null       } as const),
   trae:        Object.freeze({ installSurface: 'profile-marker-only',  writesSharedSettings: false, finishPermissionWriter: null       } as const),
 });
@@ -82,6 +84,7 @@ const INSTALL_SURFACES: ReadonlyArray<ConfigInstallSurface> = Object.freeze([
   'codex-toml',
   'copilot-instructions',
   'cline-rules',
+  'cursor-hooks-json',
   'profile-marker-only',
 ]);
 
diff --git a/tests/bug-376-claude-js-hook-gsd-rewriter.test.cjs b/tests/bug-376-claude-js-hook-gsd-rewriter.test.cjs
index 12d66b7b1..22ea002be 100644
--- a/tests/bug-376-claude-js-hook-gsd-rewriter.test.cjs
+++ b/tests/bug-376-claude-js-hook-gsd-rewriter.test.cjs
@@ -32,6 +32,20 @@ const { cleanup } = require('./helpers.cjs');
 const REPO_ROOT = path.resolve(__dirname, '..');
 const INSTALL_PATH = path.join(REPO_ROOT, 'bin', 'install.js');
 const HOOKS_DIST_DIR = path.join(REPO_ROOT, 'hooks', 'dist');
+const BUILD_HOOKS_SCRIPT = path.join(REPO_ROOT, 'scripts', 'build-hooks.js');
+
+/**
+ * Ensure hooks/dist is populated before any suite that reads it.
+ * hooks/dist/ is gitignored and only produced by `npm run build:hooks`.
+ * In CI the scoped/windows test jobs do NOT run build:hooks before running
+ * tests, so the first test that needs hooks/dist would fail. This mirrors
+ * the pattern used in bug-3357-codex-legacy-hooks-json-migration.test.cjs.
+ */
+function ensureHooksDist() {
+  if (!fs.existsSync(HOOKS_DIST_DIR) || fs.readdirSync(HOOKS_DIST_DIR).filter(f => f.endsWith('.js')).length === 0) {
+    execFileSync(process.execPath, [BUILD_HOOKS_SCRIPT], { stdio: 'pipe' });
+  }
+}
 
 // ---------------------------------------------------------------------------
 // Helpers
@@ -92,6 +106,12 @@ function colonRefs(content) {
 // Prerequisite: hooks/dist must exist (built by `npm run build:hooks`)
 // ---------------------------------------------------------------------------
 describe('bug #376 — prerequisite: hooks/dist is present', () => {
+  before(() => {
+    // hooks/dist is gitignored; build it on demand so this test is
+    // deterministic in CI scoped/windows jobs that don't pre-run build:hooks.
+    ensureHooksDist();
+  });
+
   test('hooks/dist directory exists (run npm run build:hooks if missing)', () => {
     assert.ok(
       fs.existsSync(HOOKS_DIST_DIR),
@@ -189,11 +209,13 @@ describe('bug #376 — Suite 1: Claude install rewrites /gsd: → /gsd- in hook
 // ---------------------------------------------------------------------------
 // Suite 2 — Cursor install regression: /gsd: → /gsd- still works (pre-existing)
 //
-// Note: Cursor does NOT install hooks/dist files (Cursor skips the hooks
-// install step entirely — see install.js gate around line 8829). The Cursor
-// /gsd: rewrite applies in `copyWithPathReplacement` to JS files under the
-// agent/skill tree (.cursor/gsd-core/*.js etc). We verify that Cursor's
-// installed .js files under .cursor/ have no /gsd: colon refs.
+// Note: Cursor installs its own hooks (gsd-cursor-session-start.js and
+// gsd-cursor-post-tool.js) via the cursor-hooks-json installSurface (issue #777).
+// It does NOT install the bundled Claude-style hooks/dist files (no gsd-session-state.sh
+// etc.). The Cursor /gsd: rewrite applies in `copyWithPathReplacement` to JS files
+// under the agent/skill tree (.cursor/gsd-core/*.js etc). We verify that Cursor's
+// installed .js files under .cursor/ have no /gsd: colon refs, and that the hooks/
+// directory contains only the Cursor-specific managed hooks.
 // ---------------------------------------------------------------------------
 describe('bug #376 — Suite 2: Cursor install still rewrites /gsd: → /gsd- (regression)', () => {
   let tmpDir;
@@ -242,15 +264,32 @@ describe('bug #376 — Suite 2: Cursor install still rewrites /gsd: → /gsd- (r
     );
   });
 
-  test('2c: Cursor install does not install a hooks/ directory (hooks are cursor-skipped)', () => {
-    // Cursor intentionally skips the hooks/dist copy step — verify this contract
-    // is still honored so we know the regression only concerns hook .js files
-    // for runtimes that DO install hooks (claude, qwen, hermes etc.).
+  test('2c: Cursor install creates a hooks/ directory with only Cursor-specific managed hooks', () => {
+    // Since issue #777, Cursor installs gsd-cursor-session-start.js and
+    // gsd-cursor-post-tool.js into <configDir>/hooks/. These are Cursor-native
+    // hooks — NOT the bundled Claude-style hooks (no gsd-session-state.sh etc.).
+    // Verify: hooks/ exists AND does NOT contain any Claude-bundled hooks.
     const hooksDir = path.join(tmpDir, '.cursor', 'hooks');
-    assert.strictEqual(
+    assert.ok(
       fs.existsSync(hooksDir),
-      false,
-      'Cursor install must NOT create a hooks/ directory — Cursor skips the hooks install step',
+      'Cursor install must create a hooks/ directory for its managed hook scripts (#777)',
+    );
+    const CLAUDE_BUNDLED_HOOKS = ['gsd-session-state.sh', 'gsd-context-monitor.js', 'gsd-statusline.js'];
+    for (const hook of CLAUDE_BUNDLED_HOOKS) {
+      assert.strictEqual(
+        fs.existsSync(path.join(hooksDir, hook)),
+        false,
+        `Cursor hooks/ must NOT contain Claude-bundled hook ${hook} — only Cursor-native hooks are installed`,
+      );
+    }
+    // The two Cursor-specific managed hooks must be present.
+    assert.ok(
+      fs.existsSync(path.join(hooksDir, 'gsd-cursor-session-start.js')),
+      'gsd-cursor-session-start.js must be installed in .cursor/hooks/ (#777)',
+    );
+    assert.ok(
+      fs.existsSync(path.join(hooksDir, 'gsd-cursor-post-tool.js')),
+      'gsd-cursor-post-tool.js must be installed in .cursor/hooks/ (#777)',
     );
   });
 });
@@ -262,6 +301,9 @@ describe('bug #376 — Suite 3: hooks/ source files are unchanged by install', (
   let snapshotBefore;
 
   before(() => {
+    // Ensure hooks/dist is built before snapshotting; it may be absent in CI
+    // scoped/windows jobs that don't pre-run build:hooks (#777 fix).
+    ensureHooksDist();
     // Snapshot hooks/dist JS files before any install in this suite
     snapshotBefore = {};
     if (fs.existsSync(HOOKS_DIST_DIR)) {
diff --git a/tests/cursor-hooks.test.cjs b/tests/cursor-hooks.test.cjs
new file mode 100644
index 000000000..fcbd0fc34
--- /dev/null
+++ b/tests/cursor-hooks.test.cjs
@@ -0,0 +1,462 @@
+/**
+ * Tests for Cursor hooks.json lifecycle hook registration (issue #777).
+ *
+ * Cursor v2.4+ supports a hooks.json system with events including sessionStart
+ * and postToolUse. GSD registers two managed command hooks so Cursor users get
+ * baseline parity with Claude Code and Gemini.
+ *
+ * Test plan:
+ *   T1  reconcileCursorHooksJson — creates new hooks.json with both events
+ *   T2  reconcileCursorHooksJson — idempotent (re-run writes same content)
+ *   T3  reconcileCursorHooksJson — preserves user-owned entries in sessionStart
+ *   T4  reconcileCursorHooksJson — preserves user-owned entries in postToolUse
+ *   T5  reconcileCursorHooksJson — remove-only (managedEntries=null) strips managed, keeps user
+ *   T6  reconcileCursorHooksJson — handles nested { version, hooks: {...} } shape
+ *   T7  reconcileCursorHooksJson — handles flat (no version) shape
+ *   T8  reconcileCursorHooksJson — corrupted JSON throws descriptive error
+ *   T9  isManagedCursorHookEntry — returns true for GSD-marked entries
+ *   T10 isManagedCursorHookEntry — returns false for user entries
+ *   T11 buildCursorHookEntry     — emits correct shape with marker
+ *   T12 removeCursorHooksJson    — removes hooks.json when it becomes empty
+ *   T13 removeCursorHooksJson    — preserves file when user entries remain
+ *   T14 runtime-config-adapter   — cursor now has 'cursor-hooks-json' surface
+ *   T15 INSTALL_SURFACES         — 'cursor-hooks-json' in the valid surfaces list
+ *   T16 Hook scripts exist in hooks/
+ *   T17 Hook script content — sessionStart script emits JSON with additional_context
+ *   T18 Hook script content — postToolUse script emits JSON {} for non-write tools
+ *   T19 GSD_CURSOR_HOOK_MARKER constant is exported
+ *   T20 GSD_CURSOR_SESSION_HOOK_SCRIPT / GSD_CURSOR_POST_TOOL_HOOK_SCRIPT constants
+ */
+
+// allow-test-rule: source-text-is-the-product
+// Hook script text IS what Cursor loads. Testing script content tests the deployed contract.
+
+'use strict';
+
+process.env.GSD_TEST_MODE = '1';
+
+const { test, describe } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+const { createTempDir, cleanup } = require('./helpers.cjs');
+
+const {
+  reconcileCursorHooksJson,
+  isManagedCursorHookEntry,
+  buildCursorHookEntry,
+  removeCursorHooksJson,
+  GSD_CURSOR_HOOK_MARKER,
+  GSD_CURSOR_SESSION_HOOK_SCRIPT,
+  GSD_CURSOR_POST_TOOL_HOOK_SCRIPT,
+} = require('../bin/install.js');
+
+const {
+  resolveRuntimeConfigIntent,
+  INSTALL_SURFACES,
+} = require('../gsd-core/bin/lib/runtime-config-adapter-registry.cjs');
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+function makeHooksJson(obj) {
+  return JSON.stringify(obj, null, 2) + '\n';
+}
+
+function readHooksJson(dir) {
+  const p = path.join(dir, 'hooks.json');
+  if (!fs.existsSync(p)) return null;
+  return JSON.parse(fs.readFileSync(p, 'utf8'));
+}
+
+function managedEntry(command) {
+  return { type: 'command', command, [GSD_CURSOR_HOOK_MARKER]: true };
+}
+
+function userEntry(command) {
+  return { type: 'command', command };
+}
+
+// ---------------------------------------------------------------------------
+// T1: Creates new hooks.json with both events
+// ---------------------------------------------------------------------------
+describe('reconcileCursorHooksJson', () => {
+  test('T1: creates new hooks.json with sessionStart and postToolUse', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    const result = reconcileCursorHooksJson(hooksJsonPath, {
+      sessionStart: managedEntry('/node /path/gsd-cursor-session-start.js'),
+      postToolUse:  managedEntry('/node /path/gsd-cursor-post-tool.js'),
+    });
+
+    assert.equal(result.wrote, true);
+    assert.equal(result.changed, true);
+
+    const parsed = readHooksJson(dir);
+    assert.ok(parsed, 'hooks.json must exist');
+
+    // Cursor requires the canonical nested { "version": 1, "hooks": { ... } } shape.
+    assert.equal(parsed.version, 1, 'hooks.json must have version: 1');
+    assert.ok(parsed.hooks && typeof parsed.hooks === 'object', 'hooks.json must have top-level hooks object');
+    const hookTable = parsed.hooks;
+    assert.ok(Array.isArray(hookTable.sessionStart), 'sessionStart must be an array');
+    assert.ok(Array.isArray(hookTable.postToolUse), 'postToolUse must be an array');
+    assert.equal(hookTable.sessionStart.length, 1);
+    assert.equal(hookTable.postToolUse.length, 1);
+    assert.equal(hookTable.sessionStart[0][GSD_CURSOR_HOOK_MARKER], true);
+    assert.equal(hookTable.postToolUse[0][GSD_CURSOR_HOOK_MARKER], true);
+  });
+
+  // ---------------------------------------------------------------------------
+  // T2: Idempotent
+  // ---------------------------------------------------------------------------
+  test('T2: idempotent — second run produces same content (no write)', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    const entries = {
+      sessionStart: managedEntry('/node /gsd-cursor-session-start.js'),
+      postToolUse:  managedEntry('/node /gsd-cursor-post-tool.js'),
+    };
+
+    reconcileCursorHooksJson(hooksJsonPath, entries);
+    const result2 = reconcileCursorHooksJson(hooksJsonPath, entries);
+
+    assert.equal(result2.wrote, false, 'second run must not write (idempotent)');
+    assert.equal(result2.changed, false, 'content must not change on second run');
+  });
+
+  // ---------------------------------------------------------------------------
+  // T3: Preserves user-owned entries in sessionStart
+  // ---------------------------------------------------------------------------
+  test('T3: preserves user-owned entries in sessionStart', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    // Pre-populate with user-owned entry.
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({
+      version: 1,
+      hooks: {
+        sessionStart: [userEntry('/my-team/hook.sh')],
+      },
+    }));
+
+    reconcileCursorHooksJson(hooksJsonPath, {
+      sessionStart: managedEntry('/node /gsd-cursor-session-start.js'),
+      postToolUse:  managedEntry('/node /gsd-cursor-post-tool.js'),
+    });
+
+    const parsed = readHooksJson(dir);
+    const hookTable = parsed.hooks && typeof parsed.hooks === 'object' ? parsed.hooks : parsed;
+    assert.ok(Array.isArray(hookTable.sessionStart));
+    // Both user and GSD entries must survive.
+    assert.equal(hookTable.sessionStart.length, 2, 'user + GSD entry must coexist');
+    const userStays = hookTable.sessionStart.some((e) => e.command === '/my-team/hook.sh');
+    const gsdAdded  = hookTable.sessionStart.some((e) => e[GSD_CURSOR_HOOK_MARKER]);
+    assert.ok(userStays, 'user-owned entry must be preserved');
+    assert.ok(gsdAdded,  'GSD managed entry must be present');
+  });
+
+  // ---------------------------------------------------------------------------
+  // T4: Preserves user-owned entries in postToolUse
+  // ---------------------------------------------------------------------------
+  test('T4: preserves user-owned entries in postToolUse', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({
+      hooks: {
+        postToolUse: [userEntry('/user/post-tool.sh')],
+      },
+    }));
+
+    reconcileCursorHooksJson(hooksJsonPath, {
+      sessionStart: managedEntry('/node /gsd-cursor-session-start.js'),
+      postToolUse:  managedEntry('/node /gsd-cursor-post-tool.js'),
+    });
+
+    const parsed = readHooksJson(dir);
+    const hookTable = parsed.hooks && typeof parsed.hooks === 'object' ? parsed.hooks : parsed;
+    assert.ok(Array.isArray(hookTable.postToolUse));
+    assert.equal(hookTable.postToolUse.length, 2);
+    assert.ok(hookTable.postToolUse.some((e) => e.command === '/user/post-tool.sh'));
+  });
+
+  // ---------------------------------------------------------------------------
+  // T5: Remove-only (managedEntries=null) strips managed, keeps user entries
+  // ---------------------------------------------------------------------------
+  test('T5: remove-only (null managedEntries) strips GSD entries, preserves user', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({
+      version: 1,
+      hooks: {
+        sessionStart: [
+          userEntry('/user/session.sh'),
+          managedEntry('/node /gsd-cursor-session-start.js'),
+        ],
+        postToolUse: [
+          managedEntry('/node /gsd-cursor-post-tool.js'),
+        ],
+      },
+    }));
+
+    reconcileCursorHooksJson(hooksJsonPath, null);
+
+    const parsed = readHooksJson(dir);
+    const hookTable = parsed.hooks && typeof parsed.hooks === 'object' ? parsed.hooks : parsed;
+    // sessionStart user entry survives; postToolUse key should be absent.
+    assert.ok(Array.isArray(hookTable.sessionStart), 'sessionStart must remain (user entry)');
+    assert.equal(hookTable.sessionStart.length, 1, 'only user entry remains');
+    assert.equal(hookTable.sessionStart[0].command, '/user/session.sh');
+    assert.equal(hookTable.postToolUse, undefined, 'postToolUse key must be removed (was GSD-only)');
+  });
+
+  // ---------------------------------------------------------------------------
+  // T6: Handles nested { version, hooks: {...} } shape
+  // ---------------------------------------------------------------------------
+  test('T6: handles nested { version, hooks } shape', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({ version: 1, hooks: {} }));
+
+    reconcileCursorHooksJson(hooksJsonPath, {
+      sessionStart: managedEntry('/node /gsd-cursor-session-start.js'),
+    });
+
+    const parsed = readHooksJson(dir);
+    assert.ok(parsed.hooks, 'top-level hooks key must be preserved');
+    assert.equal(parsed.version, 1, 'version must be preserved');
+    assert.ok(Array.isArray(parsed.hooks.sessionStart));
+  });
+
+  // ---------------------------------------------------------------------------
+  // T7: Handles flat (no version) shape
+  // ---------------------------------------------------------------------------
+  test('T7: handles flat shape (no wrapper object)', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({ sessionStart: [] }));
+
+    reconcileCursorHooksJson(hooksJsonPath, {
+      sessionStart: managedEntry('/node /gsd-cursor-session-start.js'),
+    });
+
+    const parsed = readHooksJson(dir);
+    // Flat input is migrated to nested canonical shape: { version: 1, hooks: { ... } }.
+    assert.equal(parsed.version, 1, 'migrated flat shape must get version: 1');
+    assert.ok(parsed.hooks && typeof parsed.hooks === 'object', 'migrated shape must have hooks object');
+    assert.ok(Array.isArray(parsed.hooks.sessionStart), 'sessionStart must be in hooks object after migration');
+  });
+
+  // ---------------------------------------------------------------------------
+  // T8: Corrupted JSON throws descriptive error
+  // ---------------------------------------------------------------------------
+  test('T8: throws descriptive error for corrupted hooks.json', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    fs.writeFileSync(hooksJsonPath, '{ not valid json }');
+
+    assert.throws(
+      () => reconcileCursorHooksJson(hooksJsonPath, { sessionStart: managedEntry('/cmd') }),
+      (err) => {
+        assert.match(err.message, /Cursor hooks\.json parse failed/i);
+        return true;
+      }
+    );
+  });
+});
+
+// ---------------------------------------------------------------------------
+// T9-T11: Entry helpers
+// ---------------------------------------------------------------------------
+describe('isManagedCursorHookEntry / buildCursorHookEntry', () => {
+  test('T9: isManagedCursorHookEntry returns true for GSD-marked entry', () => {
+    const entry = { type: 'command', command: '/x', [GSD_CURSOR_HOOK_MARKER]: true };
+    assert.equal(isManagedCursorHookEntry(entry), true);
+  });
+
+  test('T10: isManagedCursorHookEntry returns false for user-owned entry', () => {
+    const entry = { type: 'command', command: '/user/hook.sh' };
+    assert.equal(isManagedCursorHookEntry(entry), false);
+    assert.equal(isManagedCursorHookEntry(null), false);
+    assert.equal(isManagedCursorHookEntry({}), false);
+  });
+
+  test('T11: buildCursorHookEntry emits correct shape', () => {
+    const entry = buildCursorHookEntry('/usr/local/bin/node /path/to/hook.js');
+    assert.equal(entry.type, 'command');
+    assert.equal(entry[GSD_CURSOR_HOOK_MARKER], true);
+    assert.ok(typeof entry.command === 'string');
+    // Forward slashes only.
+    assert.ok(!entry.command.includes('\\'), 'command must use forward slashes');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// T12-T13: removeCursorHooksJson
+// ---------------------------------------------------------------------------
+describe('removeCursorHooksJson', () => {
+  test('T12: removes hooks.json when it becomes empty after GSD removal', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    // GSD-only file.
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({
+      version: 1,
+      hooks: {
+        sessionStart: [managedEntry('/node /gsd-cursor-session-start.js')],
+        postToolUse:  [managedEntry('/node /gsd-cursor-post-tool.js')],
+      },
+    }));
+
+    const result = removeCursorHooksJson(dir);
+    assert.equal(result.changed, true);
+    // File should be removed (was GSD-only).
+    assert.equal(fs.existsSync(hooksJsonPath), false, 'empty hooks.json must be removed');
+  });
+
+  test('T13: preserves hooks.json when user entries remain', (t) => {
+    const dir = createTempDir();
+    t.after(() => cleanup(dir));
+
+    const hooksJsonPath = path.join(dir, 'hooks.json');
+    fs.writeFileSync(hooksJsonPath, makeHooksJson({
+      version: 1,
+      hooks: {
+        sessionStart: [
+          managedEntry('/node /gsd-cursor-session-start.js'),
+          userEntry('/user/session.sh'),
+        ],
+      },
+    }));
+
+    removeCursorHooksJson(dir);
+
+    assert.ok(fs.existsSync(hooksJsonPath), 'hooks.json must remain (user entries present)');
+    const parsed = readHooksJson(dir);
+    const hookTable = parsed.hooks && typeof parsed.hooks === 'object' ? parsed.hooks : parsed;
+    assert.equal(hookTable.sessionStart.length, 1);
+    assert.equal(hookTable.sessionStart[0].command, '/user/session.sh');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// T14: runtime-config-adapter — cursor now has 'cursor-hooks-json' surface
+// ---------------------------------------------------------------------------
+test('T14: cursor runtime has installSurface cursor-hooks-json', () => {
+  const intent = resolveRuntimeConfigIntent('cursor');
+  assert.equal(intent.installSurface, 'cursor-hooks-json');
+  assert.equal(intent.writesSharedSettings, false);
+  assert.equal(intent.finishPermissionWriter, null);
+});
+
+// ---------------------------------------------------------------------------
+// T15: INSTALL_SURFACES includes 'cursor-hooks-json'
+// ---------------------------------------------------------------------------
+test('T15: INSTALL_SURFACES includes cursor-hooks-json', () => {
+  assert.ok(
+    INSTALL_SURFACES.includes('cursor-hooks-json'),
+    "'cursor-hooks-json' must be in INSTALL_SURFACES"
+  );
+});
+
+// ---------------------------------------------------------------------------
+// T16: Hook script files exist in hooks/
+// ---------------------------------------------------------------------------
+test('T16: Cursor hook script files exist in hooks/', () => {
+  const hooksDir = path.join(__dirname, '..', 'hooks');
+  const sessionStart = path.join(hooksDir, GSD_CURSOR_SESSION_HOOK_SCRIPT);
+  const postTool     = path.join(hooksDir, GSD_CURSOR_POST_TOOL_HOOK_SCRIPT);
+  assert.ok(fs.existsSync(sessionStart), `${GSD_CURSOR_SESSION_HOOK_SCRIPT} must exist in hooks/`);
+  assert.ok(fs.existsSync(postTool),     `${GSD_CURSOR_POST_TOOL_HOOK_SCRIPT} must exist in hooks/`);
+});
+
+// ---------------------------------------------------------------------------
+// T17: sessionStart script emits JSON with additional_context on stdin close
+// ---------------------------------------------------------------------------
+test('T17: gsd-cursor-session-start.js emits JSON with additional_context', (t, done) => {
+  const hooksDir = path.join(__dirname, '..', 'hooks');
+  const scriptPath = path.join(hooksDir, GSD_CURSOR_SESSION_HOOK_SCRIPT);
+  const { execFile } = require('child_process');
+
+  const input = JSON.stringify({ session_id: 'test-123', composer_mode: 'agent' });
+  const child = execFile(process.execPath, [scriptPath], {
+    timeout: 10000,
+    cwd: os.tmpdir(), // no .planning/ dir here — should get MSG_ABSENT
+  }, (err, stdout) => {
+    if (err && !stdout) { done(err); return; }
+    let parsed;
+    try { parsed = JSON.parse(stdout); } catch (e) { done(new Error(`stdout not valid JSON: ${stdout}`)); return; }
+    assert.ok('additional_context' in parsed, 'output must have additional_context field');
+    assert.ok(typeof parsed.additional_context === 'string', 'additional_context must be a string');
+    assert.ok(parsed.additional_context.length > 0, 'additional_context must not be empty');
+    done();
+  });
+  child.stdin.write(input);
+  child.stdin.end();
+});
+
+// ---------------------------------------------------------------------------
+// T18: postToolUse script emits {} for non-write tools
+// ---------------------------------------------------------------------------
+test('T18: gsd-cursor-post-tool.js emits {} for non-write tool names', (t, done) => {
+  const hooksDir = path.join(__dirname, '..', 'hooks');
+  const scriptPath = path.join(hooksDir, GSD_CURSOR_POST_TOOL_HOOK_SCRIPT);
+  const { execFile } = require('child_process');
+
+  const input = JSON.stringify({
+    tool_name: 'Read',
+    tool_input: { path: '/some/file.js' },
+    tool_output: 'contents',
+    duration: 42,
+  });
+
+  const child = execFile(process.execPath, [scriptPath], {
+    timeout: 10000,
+    cwd: os.tmpdir(),
+  }, (err, stdout) => {
+    if (err && !stdout) { done(err); return; }
+    let parsed;
+    try { parsed = JSON.parse(stdout); } catch (e) { done(new Error(`stdout not valid JSON: ${stdout}`)); return; }
+    // Non-write tool → empty response (no additional_context).
+    assert.ok(typeof parsed === 'object', 'output must be an object');
+    // additional_context should be absent for non-write, non-planning tool.
+    assert.equal(parsed.additional_context, undefined, 'no additional_context for non-write tool');
+    done();
+  });
+  child.stdin.write(input);
+  child.stdin.end();
+});
+
+// ---------------------------------------------------------------------------
+// T19: GSD_CURSOR_HOOK_MARKER is exported and is a non-empty string
+// ---------------------------------------------------------------------------
+test('T19: GSD_CURSOR_HOOK_MARKER is exported and is a non-empty string', () => {
+  assert.equal(typeof GSD_CURSOR_HOOK_MARKER, 'string');
+  assert.ok(GSD_CURSOR_HOOK_MARKER.length > 0);
+});
+
+// ---------------------------------------------------------------------------
+// T20: Script name constants are exported and correct
+// ---------------------------------------------------------------------------
+test('T20: GSD_CURSOR_SESSION_HOOK_SCRIPT and GSD_CURSOR_POST_TOOL_HOOK_SCRIPT are exported', () => {
+  assert.equal(GSD_CURSOR_SESSION_HOOK_SCRIPT, 'gsd-cursor-session-start.js');
+  assert.equal(GSD_CURSOR_POST_TOOL_HOOK_SCRIPT, 'gsd-cursor-post-tool.js');
+});
diff --git a/tests/runtime-config-adapter-registry.test.cjs b/tests/runtime-config-adapter-registry.test.cjs
index a288a6ccf..10ed2dc68 100644
--- a/tests/runtime-config-adapter-registry.test.cjs
+++ b/tests/runtime-config-adapter-registry.test.cjs
@@ -31,7 +31,7 @@ const EXPECTED_TABLE = [
   { runtime: 'codex',       installSurface: 'codex-toml',           writesSharedSettings: false, finishPermissionWriter: null       },
   { runtime: 'copilot',     installSurface: 'copilot-instructions', writesSharedSettings: false, finishPermissionWriter: null       },
   { runtime: 'cline',       installSurface: 'cline-rules',          writesSharedSettings: false, finishPermissionWriter: null       },
-  { runtime: 'cursor',      installSurface: 'profile-marker-only',  writesSharedSettings: false, finishPermissionWriter: null       },
+  { runtime: 'cursor',      installSurface: 'cursor-hooks-json',    writesSharedSettings: false, finishPermissionWriter: null       },
   { runtime: 'windsurf',    installSurface: 'profile-marker-only',  writesSharedSettings: false, finishPermissionWriter: null       },
   { runtime: 'trae',        installSurface: 'profile-marker-only',  writesSharedSettings: false, finishPermissionWriter: null       },
 ];
@@ -160,8 +160,8 @@ describe('installSurface correctness', () => {
     assert.strictEqual(resolveRuntimeConfigIntent('cline').installSurface, 'cline-rules');
   });
 
-  test('cursor -> "profile-marker-only"', () => {
-    assert.strictEqual(resolveRuntimeConfigIntent('cursor').installSurface, 'profile-marker-only');
+  test('cursor -> "cursor-hooks-json"', () => {
+    assert.strictEqual(resolveRuntimeConfigIntent('cursor').installSurface, 'cursor-hooks-json');
   });
 
   test('windsurf -> "profile-marker-only"', () => {
@@ -236,10 +236,11 @@ describe('INSTALL_SURFACES export', () => {
     'codex-toml',
     'copilot-instructions',
     'cline-rules',
+    'cursor-hooks-json',
     'profile-marker-only',
   ]);
 
-  test('INSTALL_SURFACES contains exactly the 5 surface strings', () => {
+  test('INSTALL_SURFACES contains exactly the 6 surface strings', () => {
     assert.deepStrictEqual(new Set(INSTALL_SURFACES), EXPECTED_SURFACES);
   });
 });