feat: emergent narrative engine from agent interactions (#1607)

Add nexus/chronicle.py — a living chronicle that watches fleet events
(dispatches, commits, errors, recoveries, collaborations) and renders
them as narrative prose.

- AgentEvent dataclass captures every fleet signal with kind, agent,
  detail, timestamp, and metadata
- ChronicleWriter ingests events, persists to daily JSONL, and renders
  prose via rotating template banks
- Arc detection finds dramatic patterns (struggle-and-recovery, solo
  sprint, fleet convergence, silent grind, abandon-then-retry) and
  appends arc-level commentary to the rendered chronicle
- render() and render_markdown() produce human-readable output;
  summary() returns structured stats
- Convenience constructors (event_from_gitea_issue, event_from_heartbeat,
  event_from_commit) bridge existing fleet signals into the chronicle
- 22 tests cover ingestion, persistence, template rotation, arc
  detection, markdown rendering, and edge cases

Fixes #1607

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nexus/__init__.py

@@ -14,6 +14,7 @@ from nexus.perception_adapter import (
 )
 from nexus.experience_store import ExperienceStore
 from nexus.trajectory_logger import TrajectoryLogger
+from nexus.chronicle import ChronicleWriter, AgentEvent, EventKind
 
 try:
     from nexus.nexus_think import NexusMind
@@ -29,4 +30,7 @@ __all__ = [
     "ExperienceStore",
     "TrajectoryLogger",
     "NexusMind",
+    "ChronicleWriter",
+    "AgentEvent",
+    "EventKind",
 ]

nexus/chronicle.py

@@ -0,0 +1,387 @@
+"""
+Nexus Chronicle — Emergent Narrative from Agent Interactions
+
+Watches the fleet's activity (dispatches, errors, recoveries,
+collaborations) and transforms raw event data into narrative prose.
+The system finds the dramatic arc in real work and produces a living
+chronicle. The story writes itself from the data.
+
+Usage:
+    from nexus.chronicle import ChronicleWriter, AgentEvent, EventKind
+
+    writer = ChronicleWriter()
+
+    writer.ingest(AgentEvent(kind=EventKind.DISPATCH, agent="claude", detail="took issue #42"))
+    writer.ingest(AgentEvent(kind=EventKind.ERROR, agent="claude", detail="rate limit hit"))
+    writer.ingest(AgentEvent(kind=EventKind.RECOVERY, agent="claude", detail="retried after backoff"))
+    writer.ingest(AgentEvent(kind=EventKind.COMMIT, agent="claude", detail="feat: add narrative engine"))
+
+    prose = writer.render()
+    print(prose)
+"""
+
+from __future__ import annotations
+
+import json
+import time
+from dataclasses import dataclass, field
+from enum import Enum
+from pathlib import Path
+from typing import Optional
+
+
+# ---------------------------------------------------------------------------
+# Event model
+# ---------------------------------------------------------------------------
+
+class EventKind(str, Enum):
+    """The kinds of agent events the chronicle recognises."""
+
+    DISPATCH = "dispatch"         # agent claimed / was assigned work
+    COMMIT = "commit"             # agent produced a commit
+    PUSH = "push"                 # agent pushed a branch
+    PR_OPEN = "pr_open"           # agent opened a pull request
+    PR_MERGE = "pr_merge"         # PR was merged
+    ERROR = "error"               # agent hit an error / exception
+    RECOVERY = "recovery"         # agent recovered from a failure
+    ABANDON = "abandon"           # agent abandoned a task (timeout / giving up)
+    COLLABORATION = "collab"      # two agents worked on the same thing
+    HEARTBEAT = "heartbeat"       # agent reported a heartbeat (alive signal)
+    IDLE = "idle"                 # agent is waiting for work
+    MILESTONE = "milestone"       # notable achievement (e.g. 100th issue closed)
+
+
+@dataclass
+class AgentEvent:
+    """One discrete thing that happened in the fleet."""
+
+    kind: EventKind
+    agent: str                          # who did this (e.g. "claude", "mimo-v2-pro")
+    detail: str = ""                    # free-text description
+    timestamp: float = field(default_factory=time.time)
+    metadata: dict = field(default_factory=dict)
+
+    def to_dict(self) -> dict:
+        return {
+            "kind": self.kind.value,
+            "agent": self.agent,
+            "detail": self.detail,
+            "timestamp": self.timestamp,
+            "metadata": self.metadata,
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict) -> "AgentEvent":
+        return cls(
+            kind=EventKind(data["kind"]),
+            agent=data["agent"],
+            detail=data.get("detail", ""),
+            timestamp=data.get("timestamp", time.time()),
+            metadata=data.get("metadata", {}),
+        )
+
+
+# ---------------------------------------------------------------------------
+# Narrative templates — maps event kinds to prose fragments
+# ---------------------------------------------------------------------------
+
+# Each entry is a list so we can rotate through variants.
+_TEMPLATES: dict[EventKind, list[str]] = {
+    EventKind.DISPATCH: [
+        "{agent} stepped forward and claimed the work: {detail}.",
+        "{agent} took on the challenge — {detail}.",
+        "The task landed on {agent}'s desk: {detail}.",
+    ],
+    EventKind.COMMIT: [
+        '{agent} sealed a commit into the record: "{detail}".',
+        '{agent} committed "{detail}" — progress crystallised.',
+        "{agent} carved a new ring into the trunk: {detail}.",
+    ],
+    EventKind.PUSH: [
+        "{agent} pushed the work upstream.",
+        "The branch rose into the forge — {agent}'s changes were live.",
+        "{agent} sent their work into the wider current.",
+    ],
+    EventKind.PR_OPEN: [
+        "{agent} opened a pull request: {detail}.",
+        "A proposal surfaced — {agent} asked the fleet to review {detail}.",
+        "{agent} laid their work before the reviewers: {detail}.",
+    ],
+    EventKind.PR_MERGE: [
+        "{agent}'s branch folded into the whole: {detail}.",
+        "Consensus reached — {agent}'s changes were merged: {detail}.",
+        "{detail} joined the canon. {agent}'s contribution lives on.",
+    ],
+    EventKind.ERROR: [
+        "{agent} ran into an obstacle: {detail}.",
+        "Trouble. {agent} encountered {detail} and had to pause.",
+        "The path grew difficult — {agent} hit {detail}.",
+    ],
+    EventKind.RECOVERY: [
+        "{agent} regrouped and pressed on: {detail}.",
+        "After the setback, {agent} found a way through: {detail}.",
+        "{agent} recovered — {detail}.",
+    ],
+    EventKind.ABANDON: [
+        "{agent} released the task, unable to finish: {detail}.",
+        "Sometimes wisdom is knowing when to let go. {agent} abandoned {detail}.",
+        "{agent} stepped back from {detail}. Another will carry it forward.",
+    ],
+    EventKind.COLLABORATION: [
+        "{agent} and their peers converged on the same problem: {detail}.",
+        "Two minds touched the same work — {agent} in collaboration: {detail}.",
+        "The fleet coordinated — {agent} joined the effort on {detail}.",
+    ],
+    EventKind.HEARTBEAT: [
+        "{agent} checked in — still thinking, still present.",
+        "A pulse from {agent}: the mind is alive.",
+        "{agent} breathed through another cycle.",
+    ],
+    EventKind.IDLE: [
+        "{agent} rested, waiting for the next call.",
+        "Quiet descended — {agent} held still between tasks.",
+        "{agent} stood ready, watchful in the lull.",
+    ],
+    EventKind.MILESTONE: [
+        "A moment worth noting — {agent}: {detail}.",
+        "The chronicle marks a milestone. {agent}: {detail}.",
+        "History ticked over — {agent} reached {detail}.",
+    ],
+}
+
+# Arc-level commentary triggered by sequences of events
+_ARC_TEMPLATES = {
+    "struggle_and_recovery": (
+        "There was a struggle here. {agent} hit trouble and came back stronger — "
+        "the kind of arc that gives a chronicle its texture."
+    ),
+    "silent_grind": (
+        "No drama, just steady work. {agents} moved through the backlog with quiet persistence."
+    ),
+    "abandon_then_retry": (
+        "{agent} let go once. But the work called again, and this time it was answered."
+    ),
+    "solo_sprint": (
+        "{agent} ran the whole arc alone — dispatch to merge — without breaking stride."
+    ),
+    "fleet_convergence": (
+        "The fleet converged. Multiple agents touched the same thread and wove it tighter."
+    ),
+}
+
+
+# ---------------------------------------------------------------------------
+# Chronicle writer
+# ---------------------------------------------------------------------------
+
+class ChronicleWriter:
+    """Accumulates agent events and renders them as narrative prose.
+
+    The writer keeps a running log of events.  Call ``ingest()`` to add new
+    events as they arrive, then ``render()`` to produce a prose snapshot of
+    the current arc.
+
+    Events are also persisted to JSONL so the chronicle survives restarts.
+    """
+
+    def __init__(self, log_path: Optional[Path] = None):
+        today = time.strftime("%Y-%m-%d")
+        self.log_path = log_path or (
+            Path.home() / ".nexus" / "chronicle" / f"chronicle_{today}.jsonl"
+        )
+        self.log_path.parent.mkdir(parents=True, exist_ok=True)
+
+        self._events: list[AgentEvent] = []
+        self._template_counters: dict[EventKind, int] = {}
+
+        # Load any events already on disk for today
+        self._load_existing()
+
+    # ------------------------------------------------------------------
+    # Public API
+    # ------------------------------------------------------------------
+
+    def ingest(self, event: AgentEvent) -> None:
+        """Add an event to the chronicle and persist it to disk."""
+        self._events.append(event)
+        with open(self.log_path, "a") as f:
+            f.write(json.dumps(event.to_dict()) + "\n")
+
+    def render(self, max_events: int = 50) -> str:
+        """Render the recent event stream as narrative prose.
+
+        Returns a multi-paragraph string suitable for display or logging.
+        """
+        events = self._events[-max_events:]
+        if not events:
+            return "The chronicle is empty. No events have been recorded yet."
+
+        paragraphs: list[str] = []
+
+        # Opening line with timestamp range
+        first_ts = time.strftime("%H:%M", time.localtime(events[0].timestamp))
+        last_ts = time.strftime("%H:%M", time.localtime(events[-1].timestamp))
+        paragraphs.append(
+            f"The chronicle covers {len(events)} event(s) between {first_ts} and {last_ts}."
+        )
+
+        # Event-by-event prose
+        sentences: list[str] = []
+        for evt in events:
+            sentences.append(self._render_event(evt))
+        paragraphs.append("  ".join(sentences))
+
+        # Arc-level commentary
+        arc = self._detect_arc(events)
+        if arc:
+            paragraphs.append(arc)
+
+        return "\n\n".join(paragraphs)
+
+    def render_markdown(self, max_events: int = 50) -> str:
+        """Render as a Markdown document."""
+        events = self._events[-max_events:]
+        if not events:
+            return "# Chronicle\n\n*No events recorded yet.*"
+
+        today = time.strftime("%Y-%m-%d")
+        lines = [f"# Chronicle — {today}", ""]
+
+        for evt in events:
+            ts = time.strftime("%H:%M:%S", time.localtime(evt.timestamp))
+            prose = self._render_event(evt)
+            lines.append(f"**{ts}** — {prose}")
+
+        arc = self._detect_arc(events)
+        if arc:
+            lines += ["", "---", "", f"*{arc}*"]
+
+        return "\n".join(lines)
+
+    def summary(self) -> dict:
+        """Return a structured summary of the current session."""
+        agents: dict[str, dict] = {}
+        kind_counts: dict[str, int] = {}
+
+        for evt in self._events:
+            agents.setdefault(evt.agent, {"events": 0, "kinds": []})
+            agents[evt.agent]["events"] += 1
+            agents[evt.agent]["kinds"].append(evt.kind.value)
+            kind_counts[evt.kind.value] = kind_counts.get(evt.kind.value, 0) + 1
+
+        return {
+            "total_events": len(self._events),
+            "agents": agents,
+            "kind_counts": kind_counts,
+            "log_path": str(self.log_path),
+        }
+
+    # ------------------------------------------------------------------
+    # Internal
+    # ------------------------------------------------------------------
+
+    def _render_event(self, evt: AgentEvent) -> str:
+        """Turn a single event into a prose sentence."""
+        templates = _TEMPLATES.get(evt.kind, ["{agent}: {detail}"])
+        counter = self._template_counters.get(evt.kind, 0)
+        template = templates[counter % len(templates)]
+        self._template_counters[evt.kind] = counter + 1
+        return template.format(agent=evt.agent, detail=evt.detail or evt.kind.value)
+
+    def _detect_arc(self, events: list[AgentEvent]) -> Optional[str]:
+        """Scan the event sequence for a recognisable dramatic arc."""
+        if not events:
+            return None
+
+        kinds = [e.kind for e in events]
+        agents = list({e.agent for e in events})
+
+        # struggle → recovery
+        if EventKind.ERROR in kinds and EventKind.RECOVERY in kinds:
+            err_idx = kinds.index(EventKind.ERROR)
+            rec_idx = kinds.index(EventKind.RECOVERY)
+            if rec_idx > err_idx:
+                agent = events[err_idx].agent
+                return _ARC_TEMPLATES["struggle_and_recovery"].format(agent=agent)
+
+        # abandon → dispatch (retry): find first ABANDON, then any DISPATCH after it
+        if EventKind.ABANDON in kinds and EventKind.DISPATCH in kinds:
+            ab_idx = kinds.index(EventKind.ABANDON)
+            retry_idx = next(
+                (i for i, k in enumerate(kinds) if k == EventKind.DISPATCH and i > ab_idx),
+                None,
+            )
+            if retry_idx is not None:
+                agent = events[retry_idx].agent
+                return _ARC_TEMPLATES["abandon_then_retry"].format(agent=agent)
+
+        # solo sprint: single agent goes dispatch→commit→pr_open→pr_merge
+        solo_arc = {EventKind.DISPATCH, EventKind.COMMIT, EventKind.PR_OPEN, EventKind.PR_MERGE}
+        if solo_arc.issubset(set(kinds)) and len(agents) == 1:
+            return _ARC_TEMPLATES["solo_sprint"].format(agent=agents[0])
+
+        # fleet convergence: multiple agents, collaboration event
+        if len(agents) > 1 and EventKind.COLLABORATION in kinds:
+            return _ARC_TEMPLATES["fleet_convergence"]
+
+        # silent grind: only commits / heartbeats, no drama
+        drama = {EventKind.ERROR, EventKind.ABANDON, EventKind.RECOVERY, EventKind.COLLABORATION}
+        if not drama.intersection(set(kinds)) and EventKind.COMMIT in kinds:
+            return _ARC_TEMPLATES["silent_grind"].format(agents=", ".join(agents))
+
+        return None
+
+    def _load_existing(self) -> None:
+        """Load events persisted from earlier in the same session."""
+        if not self.log_path.exists():
+            return
+        with open(self.log_path) as f:
+            for line in f:
+                line = line.strip()
+                if not line:
+                    continue
+                try:
+                    self._events.append(AgentEvent.from_dict(json.loads(line)))
+                except (json.JSONDecodeError, KeyError, ValueError):
+                    continue  # skip malformed lines
+
+
+# ---------------------------------------------------------------------------
+# Convenience: build events from common fleet signals
+# ---------------------------------------------------------------------------
+
+def event_from_gitea_issue(payload: dict, agent: str) -> AgentEvent:
+    """Build a DISPATCH event from a Gitea issue assignment payload."""
+    issue_num = payload.get("number", "?")
+    title = payload.get("title", "")
+    return AgentEvent(
+        kind=EventKind.DISPATCH,
+        agent=agent,
+        detail=f"issue #{issue_num}: {title}",
+        metadata={"issue_number": issue_num},
+    )
+
+
+def event_from_heartbeat(hb: dict) -> AgentEvent:
+    """Build a HEARTBEAT event from a nexus heartbeat dict."""
+    agent = hb.get("model", "unknown")
+    status = hb.get("status", "thinking")
+    cycle = hb.get("cycle", 0)
+    return AgentEvent(
+        kind=EventKind.HEARTBEAT,
+        agent=agent,
+        detail=f"cycle {cycle}, status={status}",
+        metadata=hb,
+    )
+
+
+def event_from_commit(commit: dict, agent: str) -> AgentEvent:
+    """Build a COMMIT event from a git commit dict."""
+    message = commit.get("message", "").split("\n")[0]  # subject line only
+    sha = commit.get("sha", "")[:8]
+    return AgentEvent(
+        kind=EventKind.COMMIT,
+        agent=agent,
+        detail=message,
+        metadata={"sha": sha},
+    )

tests/test_chronicle.py

@@ -0,0 +1,211 @@
+"""
+Tests for nexus.chronicle — emergent narrative from agent interactions.
+"""
+
+import json
+import time
+from pathlib import Path
+
+import pytest
+
+from nexus.chronicle import (
+    AgentEvent,
+    ChronicleWriter,
+    EventKind,
+    event_from_commit,
+    event_from_gitea_issue,
+    event_from_heartbeat,
+)
+
+
+# ---------------------------------------------------------------------------
+# AgentEvent
+# ---------------------------------------------------------------------------
+
+class TestAgentEvent:
+    def test_roundtrip(self):
+        evt = AgentEvent(
+            kind=EventKind.DISPATCH,
+            agent="claude",
+            detail="took issue #42",
+        )
+        assert AgentEvent.from_dict(evt.to_dict()).kind == EventKind.DISPATCH
+        assert AgentEvent.from_dict(evt.to_dict()).agent == "claude"
+        assert AgentEvent.from_dict(evt.to_dict()).detail == "took issue #42"
+
+    def test_default_timestamp_is_recent(self):
+        before = time.time()
+        evt = AgentEvent(kind=EventKind.IDLE, agent="mimo")
+        after = time.time()
+        assert before <= evt.timestamp <= after
+
+    def test_all_event_kinds_are_valid_strings(self):
+        for kind in EventKind:
+            evt = AgentEvent(kind=kind, agent="test-agent")
+            d = evt.to_dict()
+            assert d["kind"] == kind.value
+            restored = AgentEvent.from_dict(d)
+            assert restored.kind == kind
+
+
+# ---------------------------------------------------------------------------
+# ChronicleWriter — basic ingestion and render
+# ---------------------------------------------------------------------------
+
+class TestChronicleWriter:
+    @pytest.fixture
+    def writer(self, tmp_path):
+        return ChronicleWriter(log_path=tmp_path / "chronicle.jsonl")
+
+    def test_empty_render(self, writer):
+        text = writer.render()
+        assert "empty" in text.lower()
+
+    def test_single_event_render(self, writer):
+        writer.ingest(AgentEvent(kind=EventKind.DISPATCH, agent="claude", detail="issue #1"))
+        text = writer.render()
+        assert "claude" in text
+        assert "issue #1" in text
+
+    def test_render_covers_timestamps(self, writer):
+        writer.ingest(AgentEvent(kind=EventKind.DISPATCH, agent="a", detail="start"))
+        writer.ingest(AgentEvent(kind=EventKind.COMMIT, agent="a", detail="done"))
+        text = writer.render()
+        assert "chronicle covers" in text.lower()
+
+    def test_events_persisted_to_disk(self, writer, tmp_path):
+        writer.ingest(AgentEvent(kind=EventKind.COMMIT, agent="claude", detail="feat: x"))
+        lines = (tmp_path / "chronicle.jsonl").read_text().strip().splitlines()
+        assert len(lines) == 1
+        data = json.loads(lines[0])
+        assert data["kind"] == "commit"
+        assert data["agent"] == "claude"
+
+    def test_load_existing_on_init(self, tmp_path):
+        log = tmp_path / "chronicle.jsonl"
+        evt = AgentEvent(kind=EventKind.PUSH, agent="mimo", detail="pushed branch")
+        log.write_text(json.dumps(evt.to_dict()) + "\n")
+
+        writer2 = ChronicleWriter(log_path=log)
+        assert len(writer2._events) == 1
+        assert writer2._events[0].kind == EventKind.PUSH
+
+    def test_malformed_lines_are_skipped(self, tmp_path):
+        log = tmp_path / "chronicle.jsonl"
+        log.write_text("not-json\n{}\n")
+        # Should not raise
+        writer2 = ChronicleWriter(log_path=log)
+        assert writer2._events == []
+
+    def test_template_rotation(self, writer):
+        """Consecutive events of the same kind use different templates."""
+        sentences = set()
+        for _ in range(3):
+            writer.ingest(AgentEvent(kind=EventKind.HEARTBEAT, agent="claude"))
+        text = writer.render()
+        # At least one of the template variants should appear
+        assert "pulse" in text or "breathed" in text or "checked in" in text
+
+    def test_render_markdown(self, writer):
+        writer.ingest(AgentEvent(kind=EventKind.PR_OPEN, agent="claude", detail="PR #99"))
+        md = writer.render_markdown()
+        assert md.startswith("# Chronicle")
+        assert "PR #99" in md
+
+    def test_summary(self, writer):
+        writer.ingest(AgentEvent(kind=EventKind.DISPATCH, agent="claude", detail="x"))
+        writer.ingest(AgentEvent(kind=EventKind.COMMIT, agent="claude", detail="y"))
+        s = writer.summary()
+        assert s["total_events"] == 2
+        assert "claude" in s["agents"]
+        assert s["kind_counts"]["dispatch"] == 1
+        assert s["kind_counts"]["commit"] == 1
+
+    def test_max_events_limit(self, writer):
+        for i in range(10):
+            writer.ingest(AgentEvent(kind=EventKind.IDLE, agent="a", detail=str(i)))
+        text = writer.render(max_events=3)
+        # Only 3 events should appear in prose — check coverage header
+        assert "3 event(s)" in text
+
+
+# ---------------------------------------------------------------------------
+# Arc detection
+# ---------------------------------------------------------------------------
+
+class TestArcDetection:
+    @pytest.fixture
+    def writer(self, tmp_path):
+        return ChronicleWriter(log_path=tmp_path / "chronicle.jsonl")
+
+    def _ingest(self, writer, *kinds, agent="claude"):
+        for k in kinds:
+            writer.ingest(AgentEvent(kind=k, agent=agent, detail="x"))
+
+    def test_struggle_and_recovery_arc(self, writer):
+        self._ingest(writer, EventKind.DISPATCH, EventKind.ERROR, EventKind.RECOVERY)
+        text = writer.render()
+        assert "struggle" in text.lower() or "trouble" in text.lower()
+
+    def test_no_arc_when_no_pattern(self, writer):
+        self._ingest(writer, EventKind.IDLE)
+        text = writer.render()
+        # Should not include arc language (only 1 event, no pattern)
+        assert "converged" not in text
+        assert "struggle" not in text
+
+    def test_solo_sprint_arc(self, writer):
+        self._ingest(
+            writer,
+            EventKind.DISPATCH,
+            EventKind.COMMIT,
+            EventKind.PR_OPEN,
+            EventKind.PR_MERGE,
+        )
+        text = writer.render()
+        assert "solo" in text.lower() or "alone" in text.lower()
+
+    def test_fleet_convergence_arc(self, writer, tmp_path):
+        writer2 = ChronicleWriter(log_path=tmp_path / "chronicle.jsonl")
+        writer2.ingest(AgentEvent(kind=EventKind.DISPATCH, agent="claude", detail="x"))
+        writer2.ingest(AgentEvent(kind=EventKind.COLLABORATION, agent="mimo", detail="x"))
+        writer2.ingest(AgentEvent(kind=EventKind.COMMIT, agent="claude", detail="x"))
+        text = writer2.render()
+        assert "converged" in text.lower() or "fleet" in text.lower()
+
+    def test_silent_grind_arc(self, writer):
+        self._ingest(writer, EventKind.COMMIT, EventKind.COMMIT, EventKind.COMMIT)
+        text = writer.render()
+        assert "steady" in text.lower() or "quiet" in text.lower() or "grind" in text.lower()
+
+    def test_abandon_then_retry_arc(self, writer):
+        self._ingest(writer, EventKind.DISPATCH, EventKind.ABANDON, EventKind.DISPATCH)
+        text = writer.render()
+        assert "let go" in text.lower() or "abandon" in text.lower() or "called again" in text.lower()
+
+
+# ---------------------------------------------------------------------------
+# Convenience constructors
+# ---------------------------------------------------------------------------
+
+class TestConvenienceConstructors:
+    def test_event_from_gitea_issue(self):
+        payload = {"number": 42, "title": "feat: add narrative engine"}
+        evt = event_from_gitea_issue(payload, agent="claude")
+        assert evt.kind == EventKind.DISPATCH
+        assert "42" in evt.detail
+        assert evt.agent == "claude"
+
+    def test_event_from_heartbeat(self):
+        hb = {"model": "claude-sonnet", "status": "thinking", "cycle": 7}
+        evt = event_from_heartbeat(hb)
+        assert evt.kind == EventKind.HEARTBEAT
+        assert evt.agent == "claude-sonnet"
+        assert "7" in evt.detail
+
+    def test_event_from_commit(self):
+        commit = {"message": "feat: chronicle\n\nFixes #1607", "sha": "abc1234567"}
+        evt = event_from_commit(commit, agent="claude")
+        assert evt.kind == EventKind.COMMIT
+        assert evt.detail == "feat: chronicle"  # subject line only
+        assert evt.metadata["sha"] == "abc12345"