daaain · cboos · May 7, 2026 · May 8, 2026
diff --git a/claude_code_log/factories/task_notification_factory.py b/claude_code_log/factories/task_notification_factory.py
@@ -50,9 +50,13 @@
     re.DOTALL,
 )
 
-# Single-tag fields inside the notification.
+# Single-tag fields inside the notification. ``tool-use-id`` is the
+# originating ``toolu_...`` id from the spawning tool_use; surfaced here
+# so the renderer can backlink the notification's Task ID value to the
+# original tool_use card (#142). Older notifications didn't carry it,
+# so the absence is benign — the dict get below returns None.
 _FIELD_RE = re.compile(
-    r"<(?P<tag>task-id|status|summary)>(?P<body>.*?)</(?P=tag)>",
+    r"<(?P<tag>task-id|tool-use-id|status|summary)>(?P<body>.*?)</(?P=tag)>",
     re.DOTALL,
 )
 _RESULT_RE = re.compile(r"<result>\s*(?P<body>.*?)\s*</result>", re.DOTALL)
@@ -153,4 +157,5 @@ def create_task_notification_message(
         usage=usage,
         transcript_path=transcript_path,
         raw_text=text,
+        tool_use_id=fields.get("tool-use-id") or None,
     )
diff --git a/claude_code_log/factories/tool_factory.py b/claude_code_log/factories/tool_factory.py
@@ -45,6 +45,7 @@
     ToolUseContent,
     ToolUseMessage,
     ToolUseResult,
+    MonitorInput,
     SkillInput,
     WebSearchInput,
     WebFetchInput,
@@ -55,6 +56,7 @@
     BashOutput,
     EditOutput,
     ExitPlanModeOutput,
+    MonitorOutput,
     ReadOutput,
     SendMessageOutput,
     TaskCreateOutput,
@@ -99,6 +101,7 @@
     "ExitPlanMode": ExitPlanModeInput,
     "WebSearch": WebSearchInput,
     "WebFetch": WebFetchInput,
+    "Monitor": MonitorInput,
     "Skill": SkillInput,
     # Teammates feature tools
     "TeamCreate": TeamCreateInput,
@@ -705,6 +708,34 @@ def parse_webfetch_output(
     return None
 
 
+# Match ``Monitor started (task <id>, …)`` so the task id is available
+# to downstream consumers without re-parsing the full body. The id is
+# the short alphanumeric form (e.g. ``b07h5t4ng``) the harness echoes
+# back; not load-bearing for rendering today (the body text is shown
+# verbatim) but useful for the task-end backlink (#142) and any future
+# UI that wants to cross-reference the originating Monitor card.
+_MONITOR_TASK_ID_RE = re.compile(r"Monitor started \(task ([A-Za-z0-9]+)")
+
+
+def parse_monitor_output(
+    tool_result: ToolResultContent,
+    file_path: Optional[str],
+) -> Optional[MonitorOutput]:
+    """Parse Monitor tool's start-confirmation result.
+
+    The harness emits a single paragraph confirming the monitor was
+    armed and naming the task id. Capture the raw text for rendering
+    and extract the task id when the format matches; both fields are
+    optional from the renderer's perspective.
+    """
+    del file_path  # Unused — Monitor's result text is self-contained.
+    text = _extract_tool_result_text(tool_result).strip()
+    if not text:
+        return None
+    task_match = _MONITOR_TASK_ID_RE.search(text)
+    return MonitorOutput(text=text, task_id=task_match.group(1) if task_match else None)
+
+
 # =============================================================================
 # Teammates feature tool output parsers
 # =============================================================================
@@ -1004,6 +1035,7 @@ def parse_taskoutput_output(
     "ExitPlanMode": parse_exitplanmode_output,
     "WebSearch": parse_websearch_output,
     "WebFetch": parse_webfetch_output,
+    "Monitor": parse_monitor_output,
     # Teammates feature tools
     "TeamCreate": parse_teamcreate_output,
     "TeamDelete": parse_teamdelete_output,

diff --git a/claude_code_log/html/async_formatter.py b/claude_code_log/html/async_formatter.py
@@ -129,7 +129,22 @@ def format_task_notification_content(content: TaskNotificationMessage) -> str:
     """
     rows: list[str] = []
     if content.task_id:
-        rows.append(_row("Task ID", _code(content.task_id)))
+        if content.spawning_task_message_index is not None:
+            # Backlink anchor format matches the rest of the renderer
+            # ("d-{N}" → "msg-d-{N}"; the template emits the corresponding
+            # id on every message div). Wrapping the Task ID itself in
+            # the anchor (rather than a separate "Spawn" row) keeps the
+            # affordance close to the value the reader is looking up
+            # — matches issue #142's spec for the Monitor backlink and
+            # is a cleaner shape for the agent-spawn case too.
+            anchor = f"msg-d-{content.spawning_task_message_index}"
+            task_id_html = (
+                f"<a class='task-notification-backlink' href='#{anchor}'>"
+                f"<code>{escape_html(content.task_id)}</code></a>"
+            )
+        else:
+            task_id_html = _code(content.task_id)
+        rows.append(_row("Task ID", task_id_html))
     if content.status:
         status_class = (
             f"status-{content.status}"
@@ -146,18 +161,6 @@ def format_task_notification_content(content: TaskNotificationMessage) -> str:
     rows.extend(_format_usage_rows(content.usage))
     if content.transcript_path:
         rows.append(_row("Transcript", _code(content.transcript_path)))
-    if content.spawning_task_message_index is not None:
-        # Backlink anchor format matches the rest of the renderer
-        # ("d-{N}" → "msg-d-{N}"; the template emits the corresponding
-        # id on every message div).
-        anchor = f"msg-d-{content.spawning_task_message_index}"
-        rows.append(
-            _row(
-                "Spawn",
-                f"<a class='task-notification-backlink' href='#{anchor}'>"
-                f"&#x21b1; Task</a>",
-            )
-        )
 
     parts: list[str] = []
     if rows:

diff --git a/claude_code_log/html/renderer.py b/claude_code_log/html/renderer.py
@@ -53,6 +53,8 @@
     SkillInput,
     WebSearchInput,
     WebFetchInput,
+    MonitorInput,
+    MonitorOutput,
     WriteInput,
     # Tool output types
     AskUserQuestionOutput,
@@ -150,6 +152,8 @@
     format_websearch_output,
     format_webfetch_input,
     format_webfetch_output,
+    format_monitor_input,
+    format_monitor_output,
     format_write_input,
     format_write_output,
     render_params_table,
@@ -589,6 +593,14 @@ def format_WebFetchOutput(self, output: WebFetchOutput, _: TemplateMessage) -> s
         """Format → collapsible markdown with metadata badge."""
         return format_webfetch_output(output)
 
+    def format_MonitorInput(self, input: MonitorInput, _: TemplateMessage) -> str:
+        """Format → 4-row params table with collapsible command."""
+        return format_monitor_input(input)
+
+    def format_MonitorOutput(self, output: MonitorOutput, _: TemplateMessage) -> str:
+        """Format → start-confirmation paragraph verbatim."""
+        return format_monitor_output(output)
+
     # -------------------------------------------------------------------------
     # Tool Input Title Methods (for Renderer.title_ToolUseMessage dispatch)
     # -------------------------------------------------------------------------
@@ -699,6 +711,10 @@ def title_WebFetchInput(
         """Title → '🌐 WebFetch <url>'."""
         return self._tool_title(message, "🌐", input.url)
 
+    def title_MonitorInput(self, input: MonitorInput, message: TemplateMessage) -> str:
+        """Title → '🔭 Monitor <description>'."""
+        return self._tool_title(message, "🔭", input.description)
+
     def title_SkillInput(self, input: SkillInput, message: TemplateMessage) -> str:
         """Title → '💡 Skill <skill_name>'."""
         return self._tool_title(message, "💡", input.skill)

diff --git a/claude_code_log/html/tool_formatters.py b/claude_code_log/html/tool_formatters.py
@@ -22,6 +22,7 @@
 
 from .utils import (
     escape_html,
+    render_collapsible_code,
     render_file_content_collapsible,
     render_markdown_collapsible,
 )
@@ -37,6 +38,8 @@
     ExitPlanModeInput,
     ExitPlanModeOutput,
     GrepInput,
+    MonitorInput,
+    MonitorOutput,
     MultiEditInput,
     ReadInput,
     ReadOutput,
@@ -680,6 +683,70 @@ def format_webfetch_output(output: WebFetchOutput) -> str:
     return f"{badge_html}{content_html}"
 
 
+# -- Monitor Tool -------------------------------------------------------------
+
+
+def format_monitor_input(monitor_input: MonitorInput) -> str:
+    """Format Monitor tool use as a key-value grid.
+
+    Renders four rows — ``description``, ``command``, ``timeout_ms``,
+    ``persistent`` — using the same ``tool-params-table`` shape as
+    other multi-field tool inputs. The ``command`` value (often a
+    multi-line bash poll-loop) renders inside a collapsible block so
+    a long script doesn't dominate the card.
+
+    The ``description`` is shown both in the title and the body; the
+    body row anchors the rendering to the harness's exact field name
+    and keeps the card useful when a future title format changes.
+    """
+    command = monitor_input.command
+    line_count = command.count("\n") + 1
+    escaped_command = escape_html(command)
+    if line_count > 5 or len(command) > 300:
+        # Use the collapsible-code helper for the same visual treatment
+        # other multi-line tool bodies get (line-count badge + preview).
+        preview_lines = "\n".join(command.splitlines()[:3])
+        preview_html = f"<pre>{escape_html(preview_lines)}</pre>"
+        full_html = f"<pre>{escaped_command}</pre>"
+        command_cell = render_collapsible_code(preview_html, full_html, line_count)
+    else:
+        command_cell = f"<pre class='monitor-command'>{escaped_command}</pre>"
+
+    # Compose the table by hand so the ``command`` row carries the
+    # specialised cell instead of a generic stringification.
+    rows: list[str] = []
+    rows.append(
+        f"<tr><td class='tool-param-key'>description</td>"
+        f"<td class='tool-param-value'>{escape_html(monitor_input.description)}</td></tr>"
+    )
+    rows.append(
+        f"<tr><td class='tool-param-key'>command</td>"
+        f"<td class='tool-param-value'>{command_cell}</td></tr>"
+    )
+    if monitor_input.timeout_ms is not None:
+        rows.append(
+            f"<tr><td class='tool-param-key'>timeout_ms</td>"
+            f"<td class='tool-param-value'>{escape_html(str(monitor_input.timeout_ms))}</td></tr>"
+        )
+    if monitor_input.persistent is not None:
+        rows.append(
+            f"<tr><td class='tool-param-key'>persistent</td>"
+            f"<td class='tool-param-value'>{escape_html(str(monitor_input.persistent))}</td></tr>"
+        )
+    return f"<table class='tool-params-table monitor-input'>{''.join(rows)}</table>"
+
+
+def format_monitor_output(output: MonitorOutput) -> str:
+    """Format Monitor tool result — the start-confirmation paragraph.
+
+    The harness emits a single paragraph confirming the monitor was
+    armed and naming the task id. Render verbatim inside a paragraph
+    block; the body is short enough that no collapsibility is worth
+    the chrome.
+    """
+    return f"<div class='monitor-output'>{escape_html(output.text)}</div>"
+
+
 # -- Generic Parameter Table --------------------------------------------------
 
 
@@ -871,6 +938,7 @@ def format_tool_result_content_raw(tool_result: ToolResultContent) -> str:
     "format_grep_input",
     "format_websearch_input",
     "format_webfetch_input",
+    "format_monitor_input",
     # Tool output formatters (called by HtmlRenderer.format_{OutputClass})
     "format_read_output",
     "format_write_output",
@@ -881,6 +949,7 @@ def format_tool_result_content_raw(tool_result: ToolResultContent) -> str:
     "format_exitplanmode_output",
     "format_websearch_output",
     "format_webfetch_output",
+    "format_monitor_output",
     # Fallback for ToolResultContent
     "format_tool_result_content_raw",
     # Legacy formatters (still used)

diff --git a/claude_code_log/markdown/renderer.py b/claude_code_log/markdown/renderer.py
@@ -61,6 +61,8 @@
     SkillInput,
     WebSearchInput,
     WebFetchInput,
+    MonitorInput,
+    MonitorOutput,
     WriteInput,
     # Tool output types
     AskUserQuestionOutput,
@@ -837,6 +839,28 @@ def format_WebFetchInput(self, input: WebFetchInput, _: TemplateMessage) -> str:
             return self._code_fence(input.prompt)
         return ""
 
+    def format_MonitorInput(self, input: MonitorInput, _: TemplateMessage) -> str:
+        """Format → bullet list of fields with the command in a fenced block.
+
+        Mirrors the HTML 4-row grid in plain Markdown. The command's
+        adaptive fence width comes from ``_code_fence``; the description
+        is also in the title but kept here so the body stands alone.
+        """
+        lines: list[str] = [f"- **description:** {input.description}"]
+        if input.timeout_ms is not None:
+            lines.append(f"- **timeout_ms:** {input.timeout_ms}")
+        if input.persistent is not None:
+            lines.append(f"- **persistent:** {input.persistent}")
+        lines.append("")
+        lines.append("**command:**")
+        lines.append("")
+        lines.append(self._code_fence(input.command, "bash"))
+        return "\n".join(lines)
+
+    def format_MonitorOutput(self, output: MonitorOutput, _: TemplateMessage) -> str:
+        """Format → start-confirmation paragraph verbatim."""
+        return output.text
+
     def format_SkillInput(self, _input: SkillInput, _: TemplateMessage) -> str:
         """Format → '' (skill name in title; body folded in via skill_body)."""
         return ""
@@ -1394,6 +1418,18 @@ def title_WebFetchInput(self, input: WebFetchInput, _: TemplateMessage) -> str:
         url = input.url[:60] + "…" if len(input.url) > 60 else input.url
         return f"🌐 WebFetch `{url}`"
 
+    def title_MonitorInput(self, input: MonitorInput, _: TemplateMessage) -> str:
+        """Title → '🔭 Monitor `<description>`'.
+
+        Wraps the description in inline code via ``_inline_code`` —
+        same recipe as ``title_WebSearchInput`` / ``title_WebFetchInput``
+        / ``title_SkillInput``. The helper widens the fence past any
+        backtick run in the value and escapes the value from
+        Markdown emphasis / heading metacharacters that would otherwise
+        leak into the rendered title (e.g. ``*`` / ``_`` / ``[``).
+        """
+        return f"🔭 Monitor {_inline_code(input.description)}"
+
     def title_SkillInput(self, input: SkillInput, _: TemplateMessage) -> str:
         """Title → '💡 Skill `<skill_name>`'."""
         return f"💡 Skill `{input.skill}`"