feat(ship): observe-a-run V-3 (part) — cost column on Home recent-runs

ship/src/lib/run-dir.test.ts

@@ -263,3 +263,59 @@ describe("issue #427 — scanRuns surfaces seconds_since_last_event", () => {
     expect(got?.seconds_since_last_event).toBeGreaterThan(STUCK_THRESHOLD_SECONDS);
   });
 });
+
+describe("issue #430 — scanRuns aggregates cost_usd from telemetry.json", () => {
+  function seedTelemetry(runId: string, rows: Array<{ stage: string; cost_usd: number }>): void {
+    const lines = rows.map((r) =>
+      JSON.stringify({
+        stage: r.stage,
+        cost_usd: r.cost_usd,
+        duration_ms: 1000,
+        prompt_tokens: 100,
+        output_tokens: 10,
+      }),
+    );
+    writeFileSync(join(runsRoot, runId, "telemetry.json"), `${lines.join("\n")}\n`);
+  }
+
+  it("sums per-stage cost_usd into RunSummary.cost_usd", () => {
+    const runId = "2026-01-01-000010-issue-430";
+    seedRun(makeProjectDir(), runId, { state: "complete" });
+    seedTelemetry(runId, [
+      { stage: "validate", cost_usd: 1.5 },
+      { stage: "impl", cost_usd: 6.25 },
+      { stage: "review", cost_usd: 0.8 },
+    ]);
+    const got = scanRuns().find((s) => s.run_id === runId);
+    expect(got).not.toBeUndefined();
+    expect(got?.cost_usd).toBeCloseTo(8.55, 5);
+  });
+
+  it("leaves cost_usd undefined when telemetry.json is absent", () => {
+    const runId = "2026-01-01-000011-issue-430";
+    seedRun(makeProjectDir(), runId, { state: "complete" });
+    const got = scanRuns().find((s) => s.run_id === runId);
+    expect(got).not.toBeUndefined();
+    expect(got?.cost_usd).toBeUndefined();
+  });
+
+  it("leaves cost_usd undefined when telemetry.json has no parseable rows", () => {
+    const runId = "2026-01-01-000012-issue-430";
+    seedRun(makeProjectDir(), runId, { state: "complete" });
+    writeFileSync(join(runsRoot, runId, "telemetry.json"), "\n   \nnot-json\n");
+    const got = scanRuns().find((s) => s.run_id === runId);
+    expect(got).not.toBeUndefined();
+    expect(got?.cost_usd).toBeUndefined();
+  });
+
+  it("ignores rows with non-numeric cost_usd values", () => {
+    const runId = "2026-01-01-000013-issue-430";
+    seedRun(makeProjectDir(), runId, { state: "complete" });
+    writeFileSync(
+      join(runsRoot, runId, "telemetry.json"),
+      `${JSON.stringify({ stage: "v", cost_usd: "nope" })}\n${JSON.stringify({ stage: "i", cost_usd: 2.5 })}\n`,
+    );
+    const got = scanRuns().find((s) => s.run_id === runId);
+    expect(got?.cost_usd).toBeCloseTo(2.5, 5);
+  });
+});

ship/src/lib/run-dir.ts

@@ -32,6 +32,10 @@ export interface RunSummary {
   /// for running runs (#427). Server-derived to avoid client clock skew;
   /// `> STUCK_THRESHOLD_SECONDS` is the NowBar anomaly signal.
   seconds_since_last_event?: number;
+  /// Aggregate cost across all phases (USD), summed from telemetry.json
+  /// per-stage `cost_usd` rows. Absent when telemetry.json is missing or
+  /// reports zero phases. Per V-3 (#430): the operator's primary kill signal.
+  cost_usd?: number;
 }
 
 export interface StageEntry {
@@ -236,6 +240,36 @@ export function computeSecondsSinceLastEvent(
   }
 }
 
+// Sum per-stage `cost_usd` across telemetry.json rows. Returns null when the
+// file is missing, empty, or contains no parseable rows with a numeric cost
+// — null is the "no signal" value, distinct from a real zero-cost run.
+function sumCostFromTelemetry(runDir: string): number | null {
+  const path = join(runDir, "telemetry.json");
+  if (!existsSync(path)) return null;
+  let text: string;
+  try {
+    text = readFileSync(path, "utf8");
+  } catch {
+    return null;
+  }
+  let total = 0;
+  let rows = 0;
+  for (const line of text.split("\n")) {
+    if (line.trim() === "") continue;
+    try {
+      const r = JSON.parse(line) as Record<string, unknown>;
+      const cost = r["cost_usd"];
+      if (typeof cost === "number" && Number.isFinite(cost)) {
+        total += cost;
+        rows++;
+      }
+    } catch {
+      // skip malformed
+    }
+  }
+  return rows > 0 ? total : null;
+}
+
 function latestJsonMtime(runDir: string): string | null {
   try {
     const entries = readdirSync(runDir);
@@ -371,6 +405,8 @@ export function scanRuns(opts?: BuildOpts): RunSummary[] {
       const seconds = computeSecondsSinceLastEvent(fullPath);
       if (seconds !== null) summary.seconds_since_last_event = seconds;
     }
+    const cost = sumCostFromTelemetry(fullPath);
+    if (cost !== null) summary.cost_usd = cost;
     out.push(summary);
   }
   // Newest first by run_id (which is timestamp-prefixed).

ship/src/web/pages/Home.tsx

@@ -48,6 +48,11 @@ function durationOf(startedAt: string): string {
   return `${Math.floor(ms / 60_000)}m ${Math.floor((ms % 60_000) / 1000)}s`;
 }
 
+function formatCost(cost: number | undefined): string {
+  if (cost === undefined || !Number.isFinite(cost)) return "—";
+  return `$${cost.toFixed(2)}`;
+}
+
 export function Home() {
   const navigate = useNavigate();
   const qc = useQueryClient();
@@ -220,6 +225,7 @@ function RunsTable({ runs }: { runs: RunSummary[] }) {
           <th>State</th>
           <th>Started</th>
           <th>Duration</th>
+          <th>Cost</th>
           <th>Run ID</th>
           <th></th>
           <th></th>
@@ -316,6 +322,9 @@ function RunGroupRows({
         </td>
         <td>{relativeTime(latest.started_at)}</td>
         <td className="mono">{durationOf(latest.started_at)}</td>
+        <td className="mono" data-testid="cost-cell">
+          {formatCost(latest.cost_usd)}
+        </td>
         <td className="mono" style={{ color: "var(--text-muted)", fontSize: "0.75rem" }}>
           {latest.run_id}
         </td>
@@ -358,7 +367,7 @@ function RunGroupRows({
       </tr>
       {conflict ? (
         <tr style={{ background: "var(--bg-muted)" }}>
-          <td colSpan={7} style={{ fontSize: "0.85rem" }}>
+          <td colSpan={8} style={{ fontSize: "0.85rem" }}>
             run already in flight:{" "}
             <Link
               to={`/runs/${conflict.runId}`}
@@ -372,7 +381,7 @@ function RunGroupRows({
       ) : null}
       {error ? (
         <tr style={{ background: "var(--bg-muted)" }}>
-          <td colSpan={7} style={{ fontSize: "0.85rem", color: "var(--danger, #c33)" }}>
+          <td colSpan={8} style={{ fontSize: "0.85rem", color: "var(--danger, #c33)" }}>
             rerun failed: {error}
           </td>
         </tr>
@@ -393,6 +402,7 @@ function RunGroupRows({
               </td>
               <td>{relativeTime(r.started_at)}</td>
               <td className="mono">{durationOf(r.started_at)}</td>
+              <td className="mono">{formatCost(r.cost_usd)}</td>
               <td className="mono" style={{ color: "var(--text-muted)", fontSize: "0.75rem" }}>
                 {r.run_id}
               </td>

ship/src/web/types.ts

@@ -21,6 +21,9 @@ export interface RunSummary {
   /// Drives NowBar's `no progress >5m` anomaly (compared against
   /// `STUCK_THRESHOLD_SECONDS`).
   seconds_since_last_event?: number;
+  /// Aggregate cost across all phases (USD), summed from telemetry.json
+  /// per-stage rows. Absent when no telemetry. Per V-3 (#430).
+  cost_usd?: number;
 }
 
 export interface StageEntry {