diff --git a/.claude/hooks/check-cycles.sh b/.claude/hooks/check-cycles.sh
new file mode 100644
index 00000000..3885c407
--- /dev/null
+++ b/.claude/hooks/check-cycles.sh
@@ -0,0 +1,94 @@
+#!/usr/bin/env bash
+# check-cycles.sh — PreToolUse hook for Bash (git commit)
+# Blocks commits if circular dependencies involve files edited in this session.
+
+set -euo pipefail
+
+INPUT=$(cat)
+
+# Extract the command from tool_input JSON
+COMMAND=$(echo "$INPUT" | node -e "
+  let d='';
+  process.stdin.on('data',c=>d+=c);
+  process.stdin.on('end',()=>{
+    const p=JSON.parse(d).tool_input?.command||'';
+    if(p)process.stdout.write(p);
+  });
+" 2>/dev/null) || true
+
+if [ -z "$COMMAND" ]; then
+  exit 0
+fi
+
+# Only trigger on git commit commands
+if ! echo "$COMMAND" | grep -qE '(^|\s|&&\s*)git\s+commit\b'; then
+  exit 0
+fi
+
+# Guard: codegraph DB must exist
+WORK_ROOT=$(git rev-parse --show-toplevel 2>/dev/null) || WORK_ROOT="${CLAUDE_PROJECT_DIR:-.}"
+if [ ! -f "$WORK_ROOT/.codegraph/graph.db" ]; then
+  exit 0
+fi
+
+# Guard: must have staged changes
+STAGED=$(git diff --cached --name-only 2>/dev/null) || true
+if [ -z "$STAGED" ]; then
+  exit 0
+fi
+
+# Load session edit log
+LOG_FILE="$WORK_ROOT/.claude/session-edits.log"
+if [ ! -f "$LOG_FILE" ] || [ ! -s "$LOG_FILE" ]; then
+  exit 0
+fi
+EDITED_FILES=$(awk '{print $2}' "$LOG_FILE" | sort -u)
+
+# Run check with cycles predicate on staged changes
+RESULT=$(node "$WORK_ROOT/src/cli.js" check --staged --json -T 2>/dev/null) || true
+
+if [ -z "$RESULT" ]; then
+  exit 0
+fi
+
+# Check if cycles predicate failed — but only block if a cycle involves
+# a file that was edited in this session
+CYCLES_FAILED=$(echo "$RESULT" | EDITED="$EDITED_FILES" node -e "
+  let d='';
+  process.stdin.on('data',c=>d+=c);
+  process.stdin.on('end',()=>{
+    try {
+      const data=JSON.parse(d);
+      const cyclesPred=(data.predicates||[]).find(p=>p.name==='cycles');
+      if(!cyclesPred || cyclesPred.passed) return;
+      const edited=new Set(process.env.EDITED.split('\\n').filter(Boolean));
+      // Filter to cycles that involve at least one file we edited
+      const relevant=(cyclesPred.cycles||[]).filter(
+        cycle=>cycle.some(f=>edited.has(f))
+      );
+      if(relevant.length===0) return;
+      const summary=relevant.slice(0,5).map(c=>c.join(' -> ')).join('\\n  ');
+      const extra=relevant.length>5?'\\n  ... and '+(relevant.length-5)+' more':'';
+      process.stdout.write(summary+extra);
+    }catch{}
+  });
+" 2>/dev/null) || true
+
+if [ -n "$CYCLES_FAILED" ]; then
+  REASON="BLOCKED: Circular dependencies detected involving files you edited:
+  $CYCLES_FAILED
+Fix the cycles before committing."
+
+  node -e "
+    console.log(JSON.stringify({
+      hookSpecificOutput: {
+        hookEventName: 'PreToolUse',
+        permissionDecision: 'deny',
+        permissionDecisionReason: process.argv[1]
+      }
+    }));
+  " "$REASON"
+  exit 0
+fi
+
+exit 0
diff --git a/.claude/hooks/warn-signature-changes.sh b/.claude/hooks/warn-signature-changes.sh
new file mode 100644
index 00000000..6ad9b65f
--- /dev/null
+++ b/.claude/hooks/warn-signature-changes.sh
@@ -0,0 +1,130 @@
+#!/usr/bin/env bash
+# warn-signature-changes.sh — PreToolUse hook for Bash (git commit)
+# Warns when staged changes modify function signatures, highlighting risk
+# level based on the symbol's role (core > utility > others).
+# Informational only — never blocks.
+
+set -euo pipefail
+
+INPUT=$(cat)
+
+# Extract the command from tool_input JSON
+COMMAND=$(echo "$INPUT" | node -e "
+  let d='';
+  process.stdin.on('data',c=>d+=c);
+  process.stdin.on('end',()=>{
+    const p=JSON.parse(d).tool_input?.command||'';
+    if(p)process.stdout.write(p);
+  });
+" 2>/dev/null) || true
+
+if [ -z "$COMMAND" ]; then
+  exit 0
+fi
+
+# Only trigger on git commit commands
+if ! echo "$COMMAND" | grep -qE '(^|\s|&&\s*)git\s+commit\b'; then
+  exit 0
+fi
+
+# Guard: codegraph DB must exist
+WORK_ROOT=$(git rev-parse --show-toplevel 2>/dev/null) || WORK_ROOT="${CLAUDE_PROJECT_DIR:-.}"
+if [ ! -f "$WORK_ROOT/.codegraph/graph.db" ]; then
+  exit 0
+fi
+
+# Guard: must have staged changes
+STAGED=$(git diff --cached --name-only 2>/dev/null) || true
+if [ -z "$STAGED" ]; then
+  exit 0
+fi
+
+# Run check --staged to get signature violations, then enrich with role + caller count
+WARNING=$(echo "" | node --input-type=module -e "
+  import path from 'path';
+  const workRoot = process.argv[2];
+  const { checkData } = await import(path.join(workRoot, 'src/check.js'));
+  const { openReadonlyOrFail } = await import(path.join(workRoot, 'src/db.js'));
+
+  const result = checkData(undefined, { staged: true, noTests: true });
+  if (!result || result.error) process.exit(0);
+
+  const sigPred = (result.predicates || []).find(p => p.name === 'signatures');
+  if (!sigPred || sigPred.passed || !sigPred.violations.length) process.exit(0);
+
+  const db = openReadonlyOrFail();
+  const lines = [];
+
+  for (const v of sigPred.violations) {
+    // Get role from DB
+    const node = db.prepare(
+      'SELECT role FROM nodes WHERE name = ? AND file = ? AND line = ?'
+    ).get(v.name, v.file, v.line);
+    const role = node?.role || 'unknown';
+
+    // Count transitive callers (BFS, depth 3)
+    const defNode = db.prepare(
+      'SELECT id FROM nodes WHERE name = ? AND file = ? AND line = ?'
+    ).get(v.name, v.file, v.line);
+
+    let callerCount = 0;
+    if (defNode) {
+      const visited = new Set([defNode.id]);
+      let frontier = [defNode.id];
+      for (let d = 0; d < 3; d++) {
+        const next = [];
+        for (const fid of frontier) {
+          const callers = db.prepare(
+            'SELECT DISTINCT n.id FROM edges e JOIN nodes n ON e.source_id = n.id WHERE e.target_id = ? AND e.kind = \\'calls\\''
+          ).all(fid);
+          for (const c of callers) {
+            if (!visited.has(c.id)) {
+              visited.add(c.id);
+              next.push(c.id);
+              callerCount++;
+            }
+          }
+        }
+        frontier = next;
+        if (!frontier.length) break;
+      }
+    }
+
+    const risk = role === 'core' ? 'HIGH' : role === 'utility' ? 'MEDIUM' : 'low';
+    lines.push(risk + ': ' + v.name + ' (' + v.kind + ') [' + role + '] at ' + v.file + ':' + v.line + ' — ' + callerCount + ' transitive callers');
+  }
+
+  db.close();
+
+  if (lines.length > 0) {
+    process.stdout.write(lines.join('\\n'));
+  }
+" -- "$WORK_ROOT" 2>/dev/null) || true
+
+if [ -z "$WARNING" ]; then
+  exit 0
+fi
+
+# Escape for JSON
+ESCAPED=$(printf '%s' "$WARNING" | node -e "
+  let d='';
+  process.stdin.on('data',c=>d+=c);
+  process.stdin.on('end',()=>process.stdout.write(JSON.stringify(d)));
+" 2>/dev/null) || true
+
+if [ -z "$ESCAPED" ]; then
+  exit 0
+fi
+
+# Inject as additionalContext — informational, never blocks
+node -e "
+  console.log(JSON.stringify({
+    hookSpecificOutput: {
+      hookEventName: 'PreToolUse',
+      permissionDecision: 'allow',
+      additionalContext: '[codegraph] Signature changes detected in staged files:\\n' + JSON.parse(process.argv[1])
+    }
+  }));
+" "$ESCAPED" 2>/dev/null || true
+
+exit 0
diff --git a/commitlint.config.js b/commitlint.config.js
index c4340a23..2e77d9c3 100644
--- a/commitlint.config.js
+++ b/commitlint.config.js
@@ -1,5 +1,6 @@
 export default {
   extends: ["@commitlint/config-conventional"],
+  ignores: [(msg) => /^merge[:\s]/i.test(msg)],
   rules: {
     "type-enum": [
       2,
diff --git a/docs/guides/recommended-practices.md b/docs/guides/recommended-practices.md
index 02a90a21..5b28f721 100644
--- a/docs/guides/recommended-practices.md
+++ b/docs/guides/recommended-practices.md
@@ -335,6 +335,12 @@ You can configure [Claude Code hooks](https://docs.anthropic.com/en/docs/claude-
 
 **Graph update hook** (PostToolUse on Edit/Write): keeps the graph incrementally updated after each file edit. Only changed files are re-parsed.
 
+**Cycle check hook** (PreToolUse on Bash): when Claude runs `git commit`, the hook runs `codegraph check --staged --json -T` and checks if any circular dependencies involve files edited in this session. If found, blocks the commit with a `deny` decision listing the cycles. Uses the session edit log to scope checks — pre-existing cycles in untouched files don't trigger.
+
+**Dead export check hook** (PreToolUse on Bash): when Claude runs `git commit`, the hook runs `codegraph exports <file> --unused --json -T` for each staged `src/` file that was edited in this session. If any export has zero consumers (dead code), blocks the commit. This catches accidentally introduced dead exports before they reach a PR.
+
+**Signature change warning hook** (PreToolUse on Bash): when Claude runs `git commit`, the hook runs `codegraph check --staged` to detect modified function declaration lines, then enriches each violation with the symbol's role (`core`, `utility`, etc.) and transitive caller count from the graph. Injects a risk-rated summary via `additionalContext` — `HIGH` for core symbols, `MEDIUM` for utility, `low` for others. Non-blocking — the agent sees the warning and can decide whether the signature change is intentional.
+
 **Git operation hook** (PostToolUse on Bash): detects `git rebase`, `git revert`, `git cherry-pick`, `git merge`, and `git pull` commands and automatically: (1) rebuilds the codegraph so dependency context stays fresh, (2) logs all files changed by the operation to `session-edits.log` so commit validation doesn't block rebase-modified files, and (3) clears stale entries from `codegraph-checked.log` so the edit reminder re-fires for affected files. Uses `ORIG_HEAD` (set by all these git operations) to detect which files changed. If the operation failed (e.g. merge conflicts), the diff safely returns nothing.
 
 > **Windows note:** If your hooks use bash scripts, normalize backslashes inside `node -e` rather than bash (`${VAR//\\//}` fails on Git Bash). See this repo's `.claude/hooks/enrich-context.sh` for the pattern.
diff --git a/src/cli.js b/src/cli.js
index 8734bc02..3df60e50 100644
--- a/src/cli.js
+++ b/src/cli.js
@@ -266,10 +266,10 @@ QUERY_OPTS(
     fileExports(file, opts.db, {
       noTests: resolveNoTests(opts),
       json: opts.json,
+      unused: opts.unused || false,
       limit: opts.limit ? parseInt(opts.limit, 10) : undefined,
       offset: opts.offset ? parseInt(opts.offset, 10) : undefined,
       ndjson: opts.ndjson,
-      unused: opts.unused || false,
     });
   });
 
diff --git a/src/flow.js b/src/flow.js
index 6c8fa559..0ca1d212 100644
--- a/src/flow.js
+++ b/src/flow.js
@@ -99,10 +99,10 @@ export function flowData(name, dbPath, opts = {}) {
   try {
     const maxDepth = opts.depth || 10;
     const noTests = opts.noTests || false;
+    const flowOpts = { ...opts, kinds: opts.kind ? [opts.kind] : CORE_SYMBOL_KINDS };
 
     // Phase 1: Direct LIKE match on full name (use all 10 core symbol kinds,
     // not just FUNCTION_KINDS, so flow can trace from interfaces/types/structs/etc.)
-    const flowOpts = { ...opts, kinds: opts.kind ? [opts.kind] : CORE_SYMBOL_KINDS };
     let matchNode = findMatchingNodes(db, name, flowOpts)[0] ?? null;
 
     // Phase 2: Prefix-stripped matching — try adding framework prefixes
diff --git a/src/queries.js b/src/queries.js
index a1f8094e..4c839366 100644
--- a/src/queries.js
+++ b/src/queries.js
@@ -18,6 +18,10 @@ import { debug } from './logger.js';
 import { ownersForFiles } from './owners.js';
 import { paginateResult } from './paginate.js';
 import { LANGUAGE_REGISTRY } from './parser.js';
+import { isTestFile } from './test-filter.js';
+
+// Re-export from dedicated module for backward compat
+export { isTestFile, TEST_PATTERN } from './test-filter.js';
 
 /**
  * Resolve a file path relative to repoRoot, rejecting traversal outside the repo.
@@ -29,11 +33,6 @@ function safePath(repoRoot, file) {
   return resolved;
 }
 
-// Re-export from dedicated module for backward compat
-export { isTestFile, TEST_PATTERN } from './test-filter.js';
-
-import { isTestFile } from './test-filter.js';
-
 export const FALSE_POSITIVE_NAMES = new Set([
   'run',
   'get',
diff --git a/tests/unit/queries-unit.test.js b/tests/unit/queries-unit.test.js
index 939ece00..db188420 100644
--- a/tests/unit/queries-unit.test.js
+++ b/tests/unit/queries-unit.test.js
@@ -23,7 +23,6 @@ import {
   fnImpact,
   impactAnalysis,
   moduleMap,
-  queryName,
 } from '../../src/queries-cli.js';
 
 // ─── Helpers ───────────────────────────────────────────────────────────
@@ -380,34 +379,6 @@ describe('diffImpactMermaid', () => {
 
 // ─── Display wrappers ─────────────────────────────────────────────────
 
-describe('queryName (display)', () => {
-  it('outputs JSON when opts.json is true', () => {
-    const spy = vi.spyOn(console, 'log').mockImplementation(() => {});
-    queryName('handleRequest', dbPath, { json: true });
-    expect(spy).toHaveBeenCalledTimes(1);
-    const output = JSON.parse(spy.mock.calls[0][0]);
-    expect(output).toHaveProperty('query', 'handleRequest');
-    expect(output).toHaveProperty('results');
-    spy.mockRestore();
-  });
-
-  it('outputs human-readable format', () => {
-    const spy = vi.spyOn(console, 'log').mockImplementation(() => {});
-    queryName('handleRequest', dbPath);
-    const allOutput = spy.mock.calls.map((c) => c[0]).join('\n');
-    expect(allOutput).toContain('handleRequest');
-    spy.mockRestore();
-  });
-
-  it('outputs "No results" for unknown name', () => {
-    const spy = vi.spyOn(console, 'log').mockImplementation(() => {});
-    queryName('zzzzNotExist', dbPath);
-    const allOutput = spy.mock.calls.map((c) => c[0]).join('\n');
-    expect(allOutput).toContain('No results');
-    spy.mockRestore();
-  });
-});
-
 describe('impactAnalysis (display)', () => {
   it('outputs JSON when opts.json is true', () => {
     const spy = vi.spyOn(console, 'log').mockImplementation(() => {});