Roll call: a page that cannot resolve the target declines instead of claiming

Field-testing with two pages open showed the first-wins claim letting the
wrong page answer: a tab whose page lacks the element won the claim,
resolved the selector locally, and replied no_match while another page had
the element. The overlay now resolves the selector before any claim and,
when its page cannot resolve it, declines with reason no_match and the
resolution verdict; the same check runs on the busy-to-idle re-claim. The
server records that verdict on the report and, once every connected
overlay has declined, prefers a report that could serve later (a tab
mid-session or with an apply in flight, which answers busy so the agent
retries) over no_match, and returns the resolution verdict only when no
page can serve; the timeout uses the same precedence.

Also from the same field tests: a tab on another page of the app was
resuming this page's session from the per-origin localStorage cache after
a dev-server reload re-initialised it, then sat in GENERATING for a wrapper
it never renders and declined every later target. restoreSessionWithoutWrapper
now resumes a cached session only on the page that saved it, the check the
server-adoption branch beside it already applied.

Covered by two Rust integration cases, two protocol cases, and contract
assertions for the resolve-before-claim path and the page gate; the
cross-page scenario of the field harness passes on a two-page site.

AI-assisted: found by field tests and fixed with Claude Code under
maintainer direction.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/cli/tests/agent_target.rs

@@ -376,3 +376,45 @@ fn agent_target_roll_call_counts_overlays_not_connections() {
     assert!(started.elapsed() < Duration::from_millis(350), "the busy verdict did not wait for the timeout");
     let _ = &mut a2;
 }
+
+#[test]
+fn agent_target_answers_the_resolution_verdict_when_no_page_can_serve() {
+    let s = Server::start("no-match");
+    let mut a = Overlay::connect(s.port, &s.token, "tab-a");
+    let mut b = Overlay::connect(s.port, &s.token, "tab-b");
+    a.next(|m| m["type"] == "connected");
+    b.next(|m| m["type"] == "connected");
+    let started = Instant::now();
+    let held = s.hold(serde_json::json!({}));
+    let target_id = a.next(|m| m["type"] == "agent_target")["targetId"].as_str().unwrap().to_string();
+    // Both idle pages lack the element: each declines with its resolution
+    // verdict instead of claiming.
+    let decline = |cid: &str, raw: u64| serde_json::json!({ "token": s.token, "targetId": target_id, "clientId": cid, "eligible": false, "state": "IDLE", "reason": "no_match", "result": { "ok": false, "error": "no_match", "selector": "h1", "matchCount": 0, "rawMatchCount": raw } });
+    assert_eq!(post_json(s.port, "/agent-target-claim", decline("tab-a", 0)).1, serde_json::json!({ "ok": true, "granted": false }));
+    assert_eq!(post_json(s.port, "/agent-target-claim", decline("tab-b", 2)).1, serde_json::json!({ "ok": true, "granted": false }));
+    let (_, verdict) = held.join().unwrap();
+    assert_eq!(verdict["error"], serde_json::json!("no_match"), "{verdict}");
+    assert_eq!(verdict["ok"], serde_json::json!(false));
+    assert_eq!(verdict["targetId"], serde_json::json!(target_id));
+    assert!(started.elapsed() < Duration::from_millis(350), "answered by the roll call, not the timeout");
+    let _ = &mut b;
+}
+
+#[test]
+fn agent_target_prefers_busy_over_no_match_across_pages() {
+    let s = Server::start("busy-wins");
+    let mut a = Overlay::connect(s.port, &s.token, "tab-a");
+    let mut b = Overlay::connect(s.port, &s.token, "tab-b");
+    a.next(|m| m["type"] == "connected");
+    b.next(|m| m["type"] == "connected");
+    let held = s.hold(serde_json::json!({}));
+    let target_id = a.next(|m| m["type"] == "agent_target")["targetId"].as_str().unwrap().to_string();
+    // The page that has the element is mid-session; the other page lacks it.
+    // The agent should retry later, so busy outranks no_match.
+    post_json(s.port, "/agent-target-claim", serde_json::json!({ "token": s.token, "targetId": target_id, "clientId": "tab-b", "eligible": false, "state": "IDLE", "reason": "no_match", "result": { "ok": false, "error": "no_match", "matchCount": 0, "rawMatchCount": 0 } }));
+    assert_eq!(s.claim(&target_id, "tab-a", false), serde_json::json!({ "ok": true, "granted": false }));
+    let (_, verdict) = held.join().unwrap();
+    assert_eq!(verdict["error"], serde_json::json!("busy"), "{verdict}");
+    assert_eq!(verdict["reason"], serde_json::json!("session_active"));
+    let _ = &mut b;
+}

crates/live/src/live_server.rs

@@ -2797,7 +2797,8 @@ fn handle_agent_target_claim_post(
     let eligible = msg.get("eligible").and_then(Value::as_bool) == Some(true);
     let state = msg.get("state").cloned().unwrap_or(Value::Null);
     let reason = msg.get("reason").cloned().unwrap_or(Value::Null);
-    let body = lock(shared).claim_agent_target(&target_id, &client_id, eligible, state, reason);
+    let result = msg.get("result").filter(|r| r.is_object()).cloned();
+    let body = lock(shared).claim_agent_target(&target_id, &client_id, eligible, state, reason, result);
     respond(stream, cors, json_res(200, body));
 }
 

crates/live/src/server_state.rs

@@ -49,6 +49,9 @@ pub struct AgentTargetReport {
     pub client_id: String,
     pub state: Value,
     pub reason: Value,
+    /// The overlay's resolution verdict when it declined because its page
+    /// cannot resolve the target (`reason: no_match`).
+    pub result: Option<Value>,
 }
 
 /// A held-open `POST /agent-target` (the `generate` command): resolved by
@@ -780,7 +783,7 @@ impl ServerState {
                 let verdict = if pending.reports.is_empty() {
                     json!({ "ok": false, "error": "browser_timeout", "timeoutMs": timeout_ms })
                 } else {
-                    agent_target_busy_verdict(pending)
+                    agent_target_verdict_from_reports(pending)
                 };
                 st.resolve_agent_target(&id, verdict);
             }
@@ -815,7 +818,7 @@ impl ServerState {
                 if p.owner.is_some() || p.reports.is_empty() || p.reports.len() < connected {
                     None
                 } else {
-                    Some(agent_target_busy_verdict(p))
+                    Some(agent_target_verdict_from_reports(p))
                 }
             });
         if let Some(verdict) = verdict {
@@ -864,6 +867,7 @@ impl ServerState {
         eligible: bool,
         state: Value,
         reason: Value,
+        result: Option<Value>,
     ) -> Value {
         let lease_ms = self.agent_target_lease_ms();
         let now = now_i64();
@@ -880,6 +884,7 @@ impl ServerState {
                 client_id: client_id.to_string(),
                 state,
                 reason,
+                result,
             });
             // A holder that turned busy hands the lease back, so the roll
             // call can complete and an eligible tab's retry is granted at
@@ -1478,8 +1483,27 @@ fn env_positive_ms(env: &Env, key: &str) -> Option<u64> {
         .filter(|v| *v > 0)
 }
 
-/// The busy verdict for a held target: the first report's state and reason.
-pub fn agent_target_busy_verdict(pending: &AgentTargetPending) -> Value {
+/// The verdict for a held target once every connected overlay declined. A
+/// tab that could serve later (mid-session, an apply in flight) outranks a
+/// page that simply lacks the element, so the agent retries instead of
+/// giving up; only when no page can resolve the target does the resolution
+/// verdict (`no_match`, `invalid_selector`, ...) come back.
+pub fn agent_target_verdict_from_reports(pending: &AgentTargetPending) -> Value {
+    let busy = pending
+        .reports
+        .iter()
+        .find(|r| r.reason.as_str() != Some("no_match"))
+        .or_else(|| pending.reports.first());
+    if let Some(r) = busy.filter(|r| r.reason.as_str() != Some("no_match")) {
+        return json!({ "ok": false, "error": "busy", "state": r.state, "reason": r.reason });
+    }
+    if let Some(result) = pending.reports.iter().find_map(|r| r.result.as_ref()) {
+        let mut verdict = result.clone();
+        if let Some(obj) = verdict.as_object_mut() {
+            obj.insert("ok".into(), json!(false));
+        }
+        return verdict;
+    }
     let first = pending.reports.first();
     json!({
         "ok": false,

docs/CLI-CONTRACT.md

@@ -1481,7 +1481,7 @@ Binds `127.0.0.1:PORT`. CORS: if request has `Origin` and (origin is loopback ht
 | `POST /manual-edit` | | 410 `{"error":"/manual-edit is removed; use /manual-edit-stash and /manual-edit-commit for staged copy edits."}` |
 | `POST /agent-target` | body JSON `token` mismatch → 401 `{"error":"Unauthorized"}`; invalid JSON → 400 `{"error":"Invalid JSON"}` | Agent-initiated targeting (the `generate` command). Validation (400 `{"error":<msg>}`, messages verbatim): `agent_target: selector is required`, `agent_target: selector too long` (>1000 chars), `agent_target: invalid action (valid: <VISUAL_ACTIONS joined ', '>)`, `agent_target: count must be 1-8`, `agent_target: text must be a string of at most 500 chars`, `agent_target: index must be a positive integer (1-based)`, `agent_target: prompt must be a string of at most 2000 chars`, `agent_target: dryRun must be a boolean`. No SSE client → 200 `{ok:false, error:'no_browser_connected'}`. Otherwise mint an 8-hex `targetId`, broadcast `agent_target` (see 6.2), and **hold the response** until `/agent-target-result` resolves it, every connected overlay has declined (busy roll call, see `/agent-target-claim`), or `IMPECCABLE_AGENT_TARGET_TIMEOUT_MS` (default 15000) elapses: busy verdict `{ok:false, error:'busy', state, reason}` from the first report when any report exists, else `{ok:false, error:'browser_timeout', timeoutMs}`. The held reply is 200 `{targetId, ...result}`; shutdown resolves every held request with `{ok:false, error:'server_stopping'}`. |
 | `POST /agent-target-result` | 401 / 400 Invalid JSON | `targetId` (non-empty string) required else 400 `{"error":"agent_target_result: missing targetId"}`; the remaining body fields (minus `token`) resolve the held request; 200 `{ok:true, delivered:boolean}` (`delivered:false` when nothing awaits that id). |
-| `POST /agent-target-claim` | 401 / 400 Invalid JSON | `targetId` and `clientId` (non-empty strings) required else 400 `{"error":"agent_target_claim: missing targetId or clientId"}`. Roll call plus a first-wins lease, so exactly one overlay acts on a broadcast target. Unknown or resolved target → `{ok:true, granted:false, pending:false}` (ends a rescuer's retry loop). `eligible !== true` → record `{state, reason}` under `clientId` (replacing an earlier report), release the lease if this client holds it, answer `{ok:true, granted:false}`, then complete the roll call when no owner holds the lease and reports ≥ connected SSE clients (verdict from the first report). `eligible === true` → drop this client's earlier report; `granted` when no owner, the same owner (renew), or the lease lapsed (`IMPECCABLE_AGENT_TARGET_CLAIM_LEASE_MS`, default 3000); answer `{ok:true, granted, pending:true}`. |
+| `POST /agent-target-claim` | 401 / 400 Invalid JSON | `targetId` and `clientId` (non-empty strings) required else 400 `{"error":"agent_target_claim: missing targetId or clientId"}`. Roll call plus a first-wins lease, so exactly one overlay acts on a broadcast target. Unknown or resolved target → `{ok:true, granted:false, pending:false}` (ends a rescuer's retry loop). `eligible !== true` → record `{state, reason, result?}` under `clientId` (replacing an earlier report; `result` is the overlay's resolution verdict when `reason` is `no_match`, i.e. its page cannot resolve the selector), release the lease if this client holds it, answer `{ok:true, granted:false}`, then complete the roll call when no owner holds the lease and reports ≥ connected overlays. Verdict precedence: a report whose `reason` is not `no_match` (a tab that could serve later) → `{ok:false, error:'busy', state, reason}`; otherwise the first report's `result` (e.g. `no_match` with `rawMatchCount`, `invalid_selector`); the timeout uses the same precedence when any report exists. `eligible === true` → drop this client's earlier report; `granted` when no owner, the same owner (renew), or the lease lapsed (`IMPECCABLE_AGENT_TARGET_CLAIM_LEASE_MS`, default 3000); answer `{ok:true, granted, pending:true}`. |
 | anything else | | 404 `Not found` |
 
 Pending-event summary in `/status.pendingEvents[]`: `{id, type, leased:boolean, leaseUntil:number|null}` plus for `manual_edit_apply`: `pageUrl, chunk, repair, evidencePath, agentAction, manualApplySummary:{pageUrl, chunk, entryCount, opCount, files[]}`.

skill/scripts/live-browser.js

@@ -7263,6 +7263,7 @@
     if (agentTargetOverlayGone()) return;
     const busy = agentTargetBusyReason();
     if (busy) { declineAgentTargetBusy(msg, busy); return; }
+    if (declineAgentTargetUnresolvable(msg)) return;
     claimAgentTarget(msg.targetId, { eligible: true }).then((claim) => {
       if (claim.granted) { actOnAgentTarget(msg); return; }
       if (!claim.pending) return;
@@ -7284,6 +7285,19 @@
   // target, so a replay must not start a second claim or a second Go.
   const agentTargetsSeen = [];
 
+  // Only a page that can resolve the target claims it. A tab whose page
+  // lacks the element declines with its resolution verdict instead, so a
+  // first-wins claim never lets the wrong page answer for a target that
+  // another page has. The server prefers a busy report (a tab that could
+  // serve later) over these, and returns the resolution verdict only when
+  // no connected page can serve.
+  function declineAgentTargetUnresolvable(msg) {
+    const probe = resolveAgentTargetElement(msg);
+    if (!probe.error) return false;
+    claimAgentTarget(msg.targetId, { eligible: false, state, reason: 'no_match', result: probe.error });
+    return true;
+  }
+
   function handleAgentTarget(msg) {
     if (!msg || typeof msg.targetId !== 'string') return;
     if (agentTargetsSeen.includes(msg.targetId)) return;
@@ -7297,6 +7311,7 @@
       declineAgentTargetBusy(msg, busy);
       return;
     }
+    if (declineAgentTargetUnresolvable(msg)) return;
     // Eligible tabs race for the server's lease and only the holder acts. A
     // hidden tab yields a short head start so a visible one wins when both
     // exist, and still serves the request on its own: the user finds the
@@ -9376,7 +9391,12 @@ void main() {
   }
 
   function restoreSessionWithoutWrapper(reason, activeSessions) {
-    const cached = loadSession();
+    // The session cache is per origin, so a tab on another page of the same
+    // app sees this page's session too. Only the page that saved it may
+    // resume it: the server-adoption branch below already applies the same
+    // check, and a tab on another page has nothing to render for it.
+    const cachedRaw = loadSession();
+    const cached = cachedRaw?.id && !pageMatchesCurrent(cachedRaw.pageUrl) ? null : cachedRaw;
     // localStorage is a cache, not a gate. A cleared tab, a second browser
     // profile, or a teardown that dropped local state all leave the durable
     // server session as the only record of work in progress; adopt it instead

tests/live-agent-target.test.mjs

@@ -641,6 +641,63 @@ describe('POST /agent-target', { skip: ENGINE_BIN ? false : ENGINE_MISSING_MESSA
     }
   });
 
+  it('answers the resolution verdict when every idle page declined as unable to resolve', async () => {
+    // Two idle tabs on pages that lack the element decline with their
+    // resolution verdicts; the request resolves as no_match, not busy.
+    const tabA = await openSseClient(server, { clientId: 'tab-a' });
+    const tabB = await openSseClient(server, { clientId: 'tab-b' });
+    try {
+      await tabA.next((m) => m.type === 'connected');
+      await tabB.next((m) => m.type === 'connected');
+      const startedAt = Date.now();
+      const held = postJson(server, '/agent-target', {
+        token: server.token, selector: 'h1', action: 'bolder', count: 3,
+      });
+      const pushed = await tabA.next((m) => m.type === 'agent_target');
+      for (const [clientId, raw] of [['tab-a', 0], ['tab-b', 3]]) {
+        const report = await (await postJson(server, '/agent-target-claim', {
+          token: server.token, targetId: pushed.targetId, clientId, eligible: false, state: 'IDLE', reason: 'no_match',
+          result: { ok: false, error: 'no_match', selector: 'h1', matchCount: 0, rawMatchCount: raw },
+        })).json();
+        assert.deepEqual(report, { ok: true, granted: false });
+      }
+      const verdict = await (await held).json();
+      assert.equal(verdict.error, 'no_match');
+      assert.equal(verdict.ok, false);
+      assert.equal(verdict.targetId, pushed.targetId);
+      assert.ok(Date.now() - startedAt < 350, 'answered by the roll call, not the timeout');
+    } finally {
+      tabA.close();
+      tabB.close();
+    }
+  });
+
+  it('prefers busy over no_match, so the agent retries when the right page is mid-session', async () => {
+    const tabA = await openSseClient(server, { clientId: 'tab-a' });
+    const tabB = await openSseClient(server, { clientId: 'tab-b' });
+    try {
+      await tabA.next((m) => m.type === 'connected');
+      await tabB.next((m) => m.type === 'connected');
+      const held = postJson(server, '/agent-target', {
+        token: server.token, selector: 'h1', action: 'bolder', count: 3,
+      });
+      const pushed = await tabA.next((m) => m.type === 'agent_target');
+      await postJson(server, '/agent-target-claim', {
+        token: server.token, targetId: pushed.targetId, clientId: 'tab-b', eligible: false, state: 'IDLE', reason: 'no_match',
+        result: { ok: false, error: 'no_match', matchCount: 0, rawMatchCount: 0 },
+      });
+      await postJson(server, '/agent-target-claim', {
+        token: server.token, targetId: pushed.targetId, clientId: 'tab-a', eligible: false, state: 'CYCLING', reason: 'session_active',
+      });
+      const verdict = await (await held).json();
+      assert.equal(verdict.error, 'busy');
+      assert.equal(verdict.reason, 'session_active');
+    } finally {
+      tabA.close();
+      tabB.close();
+    }
+  });
+
   it('completes the roll call when the last silent overlay disconnects', async () => {
     // Tab A reported busy; tab B never answered and then left. Every overlay
     // still connected has declined, so the verdict is busy now, not at the

tests/live-browser-source.test.mjs

@@ -851,6 +851,32 @@ describe('live-browser source contracts', () => {
       /function handleAgentTarget\(msg\) \{[\s\S]{0,120}?if \(agentTargetsSeen\.includes\(msg\.targetId\)\) return;/,
       'a replayed target this page already handled must not start a second claim or Go',
     );
+    // A page that cannot resolve the target never claims it: a first-wins
+    // claim would otherwise let the wrong page answer no_match for a target
+    // another page has.
+    assert.match(
+      SOURCE,
+      /function handleAgentTarget\(msg\) \{[\s\S]{0,700}?if \(declineAgentTargetUnresolvable\(msg\)\) return;/,
+      'the first claim resolves the selector on this page first',
+    );
+    assert.match(
+      SOURCE,
+      /function claimAndActOnAgentTarget\(msg\) \{[\s\S]{0,300}?if \(declineAgentTargetUnresolvable\(msg\)\) return;/,
+      'the re-claim resolves the selector on this page first',
+    );
+    assert.match(
+      SOURCE,
+      /function declineAgentTargetUnresolvable\(msg\) \{[\s\S]{0,200}?resolveAgentTargetElement\(msg\)[\s\S]{0,200}?reason: 'no_match', result: probe\.error/,
+      'the decline carries the resolution verdict for the server to return when no page can serve',
+    );
+    // The per-origin session cache must not let a tab on another page of
+    // the app resume this page's session (it would sit in GENERATING for a
+    // wrapper it never renders, and decline every later agent target).
+    assert.match(
+      SOURCE,
+      /function restoreSessionWithoutWrapper\(reason, activeSessions\) \{[\s\S]{0,600}?const cached = cachedRaw\?\.id && !pageMatchesCurrent\(cachedRaw\.pageUrl\) \? null : cachedRaw;/,
+      'a cached session is resumed only by the page that saved it',
+    );
     assert.match(helper, /setTimeout\(\(\) => claimAndActOnAgentTarget\(msg\), AGENT_TARGET_RESCUE_RETRY_MS\);/, 'a denied claim on a live request retries until the lease lapses');
     assert.match(
       SOURCE,