diff --git a/apps/headless/Sources/HeadlessProtocol/AgentRuntime.swift b/apps/headless/Sources/HeadlessProtocol/AgentRuntime.swift
index da42728..6cdb9dd 100644
--- a/apps/headless/Sources/HeadlessProtocol/AgentRuntime.swift
+++ b/apps/headless/Sources/HeadlessProtocol/AgentRuntime.swift
@@ -7,6 +7,11 @@ if (!globalThis.__headlessAgent) {
     const regionRefs = new WeakMap();
     let current = new Map();
     let currentRegions = new Map();
+    // Every reference ever handed out, so a failed lookup can say whether the
+    // reference expired or was never issued at all.
+    const issuedRefs = new Set();
+    const issuedRegionRefs = new Set();
+    const maximumTrackedRegions = 256;
     let lastMutation = performance.now();
     new MutationObserver(() => { lastMutation = performance.now(); })
       .observe(document, {subtree: true, childList: true, attributes: true, characterData: true});
@@ -107,6 +112,7 @@ if (!globalThis.__headlessAgent) {
     const refFor = element => {
       let ref = refs.get(element);
       if (!ref) { ref = `@e${nextRef++}`; refs.set(element, ref); }
+      issuedRefs.add(ref);
       current.set(ref, element);
       return ref;
     };
@@ -211,15 +217,30 @@ if (!globalThis.__headlessAgent) {
     const regionRefFor = element => {
       let ref = regionRefs.get(element);
       if (!ref) { ref = `@r${nextRegionRef++}`; regionRefs.set(element, ref); }
+      issuedRegionRefs.add(ref);
       currentRegions.set(ref, element);
+      // Region references stay resolvable across inspections so a scoped
+      // `--within @rN` workflow keeps working, but this map holds elements
+      // strongly. Drop the oldest so a long-lived page cannot grow it without
+      // bound, and never drop the reference just issued.
+      while (currentRegions.size > maximumTrackedRegions) {
+        const oldest = currentRegions.keys().next().value;
+        if (oldest === undefined || oldest === ref) break;
+        currentRegions.delete(oldest);
+      }
       return ref;
     };
     const resolveRegion = reference => {
       if (!reference) return document;
       const element = currentRegions.get(reference);
-      if (!element || !element.isConnected || !visible(element)) {
+      if (!element) {
+        throw new Error(issuedRegionRefs.has(reference)
+          ? `REGION_NOT_FOUND:${reference} (expired: inspect again to refresh region references)`
+          : `REGION_NOT_FOUND:${reference} (unknown: no inspection has issued this reference)`);
+      }
+      if (!element.isConnected || !visible(element)) {
         currentRegions.delete(reference);
-        throw new Error(`REGION_NOT_FOUND:${reference}`);
+        throw new Error(`REGION_NOT_FOUND:${reference} (detached: the region is no longer visible on this page)`);
       }
       return element;
     };
@@ -423,7 +444,18 @@ if (!globalThis.__headlessAgent) {
     };
     const resolve = target => {
       const element = current.get(target);
-      if (!element || !element.isConnected) throw new Error(`ELEMENT_NOT_FOUND:${target}`);
+      // Element references describe the most recent inspection only. Saying so
+      // is the difference between an agent re-inspecting and an agent retrying
+      // the same dead reference.
+      if (!element) {
+        throw new Error(issuedRefs.has(target)
+          ? `ELEMENT_NOT_FOUND:${target} (expired: element references come from the most recent inspection — inspect again to refresh)`
+          : `ELEMENT_NOT_FOUND:${target} (unknown: no inspection has issued this reference)`);
+      }
+      if (!element.isConnected) {
+        current.delete(target);
+        throw new Error(`ELEMENT_NOT_FOUND:${target} (detached: the element is no longer in the page)`);
+      }
       return element;
     };
     const find = (wantedRole, wantedName) => {
diff --git a/apps/headless/Tests/agent-runtime.test.mjs b/apps/headless/Tests/agent-runtime.test.mjs
index d6dc8ae..efc67e1 100644
--- a/apps/headless/Tests/agent-runtime.test.mjs
+++ b/apps/headless/Tests/agent-runtime.test.mjs
@@ -104,6 +104,31 @@ assert.throws(
   /REGION_NOT_FOUND/,
 );
 
+// A region reference issued by an earlier inspection stays usable, which is
+// what makes the outline-then-scope workflow possible across calls.
+assert.equal(
+  agent.snapshot(false, false, {context: 'text', within: targetRegion.ref, limit: 2}).within,
+  targetRegion.ref,
+);
+assert.throws(
+  () => agent.snapshot(false, false, {context: 'text', within: '@r999999'}),
+  /REGION_NOT_FOUND.*unknown/,
+);
+
+// Element references describe the most recent inspection only. A stale one has
+// to say it expired, otherwise an agent cannot tell "re-inspect" from
+// "this element never existed" and retries the dead reference.
+const staleRef = full.elements[full.elements.length - 1].ref;
+assert.match(staleRef, /^@e\d+$/);
+agent.snapshot(false, false, {context: 'summary', limit: 8, budget: 700});
+assert.throws(() => agent.click({target: staleRef}), /ELEMENT_NOT_FOUND.*expired/);
+assert.throws(() => agent.click({target: '@e999999'}), /ELEMENT_NOT_FOUND.*unknown/);
+
+// A reference from the latest inspection still resolves.
+const fresh = agent.snapshot(false, false, {context: 'actions', limit: 5});
+assert(fresh.elements.length > 0, 'actions context should return executable controls');
+assert.equal(agent.click({target: fresh.elements[0].ref}).clicked, fresh.elements[0].ref);
+
 console.log(JSON.stringify({
   selectedRegion: targetRegion.ref,
   full: full.contextStats,
diff --git a/apps/headless/docs/P1.md b/apps/headless/docs/P1.md
index dac6a87..8a91662 100644
--- a/apps/headless/docs/P1.md
+++ b/apps/headless/docs/P1.md
@@ -69,6 +69,26 @@ focused response reports encoded bytes, estimated tokens, the applied budget,
 and omitted counts. Page-derived strings are marked as untrusted content.
 `--interactive` remains a legacy alias for the action-focused view.
 
+### Reference lifetime
+
+The two reference kinds deliberately differ, because they are used differently.
+
+- **Element references (`@e1`)** describe the **most recent inspection only**.
+  Every inspection reissues them, so a reference from an earlier call stops
+  resolving — including when a narrow context such as `summary` returns fewer
+  controls than the `full` call before it. Act on a reference from the
+  inspection you just ran, or target by role and name instead.
+- **Region references (`@r4`)** stay resolvable across inspections, so the
+  outline-then-scope workflow works: take `@r4` from an `outline`, then scope
+  repeated `text` and `actions` calls to it. They are bounded per page and drop
+  oldest-first.
+
+A reference that does not resolve says why, rather than failing anonymously:
+`expired` (issued earlier, superseded by a later inspection — inspect again),
+`unknown` (never issued — do not guess or invent references), or `detached`
+(the element or region has left the page). All three surface as
+`ELEMENT_NOT_FOUND` or `REGION_NOT_FOUND`.
+
 ## Recording
 
 The built-in recorder captures browser pixels and writes MP4, MOV, WebM, or GIF
diff --git a/docs/roadmap/improvements-backlog.md b/docs/roadmap/improvements-backlog.md
index 4850d3f..a4674e6 100644
--- a/docs/roadmap/improvements-backlog.md
+++ b/docs/roadmap/improvements-backlog.md
@@ -72,11 +72,19 @@ loop. Add backoff + a fatal threshold.
 map is reset on each `snapshot()` (`HP/AgentRuntime.swift:376`), so a
 `--context summary` (max 8 elements) invalidates all refs from a prior
 `full`; the agent later gets a bare `ELEMENT_NOT_FOUND`. Meanwhile
-`currentRegions` is *never* reset and grows for the page lifetime. Decide the
+`currentRegions` is *never* reset and grows for the page lifetime. ~~Decide the
 contract (likely: refs from the latest inspection only — already the skill's
 teaching), then (a) make the error say *why* ("ref expired; re-inspect"),
 (b) reset regions consistently on navigation, (c) document in P1.md. Test:
-inspect-full → inspect-summary → click stale `@eN` asserts the new error.
+inspect-full → inspect-summary → click stale `@eN` asserts the new error.~~
+**Done.** The contract is now explicit and asymmetric on purpose: `@eN` is
+latest-inspection-only, `@rN` stays resolvable so the outline-then-scope
+workflow survives across calls. Failures name the cause — `expired`, `unknown`,
+or `detached` — instead of an anonymous `ELEMENT_NOT_FOUND`. Region tracking is
+bounded at 256 oldest-first rather than growing for the page lifetime, which
+also releases the strong references it was holding to detached nodes.
+Documented in P1 under "Reference lifetime"; covered in
+`Tests/agent-runtime.test.mjs`.
 
 **A6. `--json`/`--session` stripped from anywhere in argv.** ([#17](https://github.com/LockInTime/headless/issues/17)) Global-option
 stripping (`HP/CLI.swift:46-49`) happens before subcommand parsing, so