diff --git a/scripts/review_pr.py b/scripts/review_pr.py
index fca864a..b15b1c5 100644
--- a/scripts/review_pr.py
+++ b/scripts/review_pr.py
@@ -317,9 +317,11 @@ def build_prompt(meta, files, diff_path, agent_md, impact_report_path=None):
 
 
 def run_claude(claude_bin, project_root, prompt, extra_dir=None):
-    """Run claude -p, return stdout."""
+    """Run claude with stream-json output, return all text lines."""
     cmd = [
         claude_bin, "-p",
+        "--output-format", "stream-json",
+        "--include-partial-messages",
         "--permission-mode", "acceptEdits",
         "--verbose",
     ]
@@ -327,7 +329,7 @@ def run_claude(claude_bin, project_root, prompt, extra_dir=None):
         cmd += ["--add-dir", extra_dir]
     cmd.append(prompt)
 
-    print(f"[review_pr] Running: {' '.join(cmd[:4])} ...", file=sys.stderr)
+    print(f"[review_pr] Command: {' '.join(cmd)}", file=sys.stderr)
     proc = subprocess.Popen(
         cmd,
         cwd=project_root,
@@ -340,19 +342,45 @@ def run_claude(claude_bin, project_root, prompt, extra_dir=None):
     def _stream(pipe, label, dest_lines):
         for line in pipe:
             line = line.rstrip("\n")
-            if line:
-                print(f"[{label}] {line}", file=sys.stderr)
+            if not line:
+                continue
             dest_lines.append(line)
-
-    stderr_lines = []
-    t = threading.Thread(target=_stream, args=(proc.stderr, "claude:stderr", stderr_lines))
-    t.start()
+            # Pretty-print stream-json events for progress visibility
+            try:
+                msg = json.loads(line)
+                t = msg.get("type", "")
+                if t == "assistant":
+                    text = ""
+                    for block in msg.get("message", {}).get("content", []):
+                        if block.get("type") == "text":
+                            text = block.get("text", "")
+                    if text:
+                        print(f"[claude] {text}", file=sys.stderr)
+                elif t == "tool_use":
+                    name = msg.get("message", {}).get("name", "?")
+                    inp = msg.get("message", {}).get("input", {})
+                    print(f"[claude] tool: {name}({json.dumps(inp, ensure_ascii=False)})", file=sys.stderr)
+                elif t == "tool_result":
+                    print(f"[claude] tool: result", file=sys.stderr)
+                elif t == "system":
+                    subtype = msg.get("subtype", "")
+                    if subtype == "init":
+                        print(f"[claude] system: init", file=sys.stderr)
+                # skip heartbeat/user/other events to avoid noise
+            except (json.JSONDecodeError, KeyError, TypeError):
+                print(f"[claude] {line}", file=sys.stderr)
 
     stdout_lines = []
-    _stream(proc.stdout, "claude", stdout_lines)
+    stderr_lines = []
 
-    t.join(timeout=10)
-    proc.wait(timeout=600)
+    t_out = threading.Thread(target=_stream, args=(proc.stdout, "claude", stdout_lines))
+    t_err = threading.Thread(target=_stream, args=(proc.stderr, "claude:stderr", stderr_lines))
+    t_out.start()
+    t_err.start()
+
+    t_out.join(timeout=600)
+    t_err.join(timeout=10)
+    proc.wait(timeout=10)
 
     if proc.returncode != 0:
         print(f"Claude exited with code {proc.returncode}", file=sys.stderr)
@@ -363,30 +391,67 @@ def run_claude(claude_bin, project_root, prompt, extra_dir=None):
 
 
 def extract_json_from_output(stdout):
-    """Extract the review JSON from Claude's output."""
-    match = re.search(r"```json\s*([\s\S]*)\s*```", stdout)
-    if not match:
-        print("ERROR: No ```json block found in Claude output.", file=sys.stderr)
-        print(stdout[:3000], file=sys.stderr)
-        sys.exit(1)
+    """Extract the review JSON from Claude's output.
 
+    Handles both stream-json lines and plain-text ```json blocks.
+    """
+    # ── Try stream-json: collect assistant text ──
+    assistant_text = _extract_stream_json_text(stdout)
+    if assistant_text:
+        obj = _find_review_json(assistant_text)
+        if obj:
+            return obj
+        print("[review_pr] stream-json text gathered but no review JSON found; trying raw ...",
+              file=sys.stderr)
+
+    # ── Fall back to plain-text ```json block ──
+    obj = _find_review_json(stdout)
+    if obj:
+        return obj
+
+    print("ERROR: No valid review JSON found in Claude output.", file=sys.stderr)
+    print(stdout[-3000:], file=sys.stderr)
+    sys.exit(1)
+
+
+def _extract_stream_json_text(stdout):
+    """Parse stdout as stream-json lines and return concatenated assistant text."""
+    texts = []
+    for line in stdout.splitlines():
+        line = line.strip()
+        if not line or not line.startswith("{"):
+            continue
+        try:
+            msg = json.loads(line)
+        except json.JSONDecodeError:
+            continue
+        if msg.get("type") != "assistant":
+            continue
+        for block in msg.get("message", {}).get("content", []):
+            if block.get("type") == "text":
+                texts.append(block.get("text", ""))
+    return "\n".join(texts) if texts else ""
+
+
+def _find_review_json(text):
+    """Find and parse a review JSON object in *text*.
+
+    Returns the parsed dict, or None.
+    """
+    match = re.search(r"```json\s*([\s\S]*)\s*```", text)
+    if not match:
+        return None
     try:
         obj = json.loads(match.group(1))
-    except json.JSONDecodeError as e:
-        print(f"ERROR: Invalid JSON in Claude output: {e}", file=sys.stderr)
-        print(match.group(1)[:2000], file=sys.stderr)
-        sys.exit(1)
-
+    except json.JSONDecodeError:
+        return None
+    if not isinstance(obj, dict):
+        return None
     # Unwrap {review: {...}} envelope if present
-    if isinstance(obj, dict) and "review" in obj and isinstance(obj["review"], dict):
+    if "review" in obj and isinstance(obj["review"], dict):
         obj = obj["review"]
-
-    if not isinstance(obj, dict) or "body" not in obj:
-        print(f"ERROR: JSON missing required 'body' field. "
-              f"Keys: {list(obj.keys()) if isinstance(obj, dict) else type(obj).__name__}",
-              file=sys.stderr)
-        sys.exit(1)
-
+    if "body" not in obj:
+        return None
     return obj