diff --git a/wasm/dist-repl/repl.js b/wasm/dist-repl/repl.js
index 1ab7f7f..0c2de3c 100644
--- a/wasm/dist-repl/repl.js
+++ b/wasm/dist-repl/repl.js
@@ -264,7 +264,14 @@ async function autoPauseTab(tab) {
     }
 
     if (activeInput) {
-        tab.autoPause = { tier, blob, inputSrc: activeInput, savedAt: Date.now() };
+        // Asm tier has no SAB poll site, so we can't snapshot env mid-eval.
+        // Fall back to replay mode: every successful prior input gets
+        // re-eval'd on resume to rebuild the env, then the active input
+        // is sent fresh. Same pattern the manual asm portal-save uses.
+        const replayInputs = (tier === "asm")
+            ? tab.transcript.filter((e) => e.kind !== "error" && e.input !== activeInput).map((e) => e.input)
+            : null;
+        tab.autoPause = { tier, blob, replayInputs, inputSrc: activeInput, savedAt: Date.now() };
     }
 
     // Terminate the worker(s) so the heap is reclaimed while the tab
@@ -284,8 +291,21 @@ async function autoResumeTab(tab) {
     tab.tier = ap.tier;
     tierSelectEl.value = ap.tier;
 
-    if (ap.blob) {
-        rebootTier(tab.id, ap.tier);
+    rebootTier(tab.id, ap.tier);
+
+    if (ap.replayInputs && ap.replayInputs.length) {
+        // Asm tier replay path — re-eval every successful prior input
+        // in order so the env is reconstructed before sendInput fires
+        // the active one. Errors mid-replay are swallowed; restoring
+        // from a transcript that defined-on-error is the user's call.
+        for (const src of ap.replayInputs) {
+            try { await evalInTier(tab.id, ap.tier, src); } catch (e) { /* keep going */ }
+        }
+        tab.transcript.push({
+            input: `; resumed asm tier — replayed ${ap.replayInputs.length} prior inputs`,
+            results: [{ tier: ap.tier, output: "#t" }], kind: "ok",
+        });
+    } else if (ap.blob) {
         // Round-trip through the tier so portal-load! has the blob
         // to read. The bare 'init eval forces the tier to bootstrap
         // before we push the blob into MEMFS.
diff --git a/wasm/repl/repl.js b/wasm/repl/repl.js
index 1ab7f7f..0c2de3c 100644
--- a/wasm/repl/repl.js
+++ b/wasm/repl/repl.js
@@ -264,7 +264,14 @@ async function autoPauseTab(tab) {
     }
 
     if (activeInput) {
-        tab.autoPause = { tier, blob, inputSrc: activeInput, savedAt: Date.now() };
+        // Asm tier has no SAB poll site, so we can't snapshot env mid-eval.
+        // Fall back to replay mode: every successful prior input gets
+        // re-eval'd on resume to rebuild the env, then the active input
+        // is sent fresh. Same pattern the manual asm portal-save uses.
+        const replayInputs = (tier === "asm")
+            ? tab.transcript.filter((e) => e.kind !== "error" && e.input !== activeInput).map((e) => e.input)
+            : null;
+        tab.autoPause = { tier, blob, replayInputs, inputSrc: activeInput, savedAt: Date.now() };
     }
 
     // Terminate the worker(s) so the heap is reclaimed while the tab
@@ -284,8 +291,21 @@ async function autoResumeTab(tab) {
     tab.tier = ap.tier;
     tierSelectEl.value = ap.tier;
 
-    if (ap.blob) {
-        rebootTier(tab.id, ap.tier);
+    rebootTier(tab.id, ap.tier);
+
+    if (ap.replayInputs && ap.replayInputs.length) {
+        // Asm tier replay path — re-eval every successful prior input
+        // in order so the env is reconstructed before sendInput fires
+        // the active one. Errors mid-replay are swallowed; restoring
+        // from a transcript that defined-on-error is the user's call.
+        for (const src of ap.replayInputs) {
+            try { await evalInTier(tab.id, ap.tier, src); } catch (e) { /* keep going */ }
+        }
+        tab.transcript.push({
+            input: `; resumed asm tier — replayed ${ap.replayInputs.length} prior inputs`,
+            results: [{ tier: ap.tier, output: "#t" }], kind: "ok",
+        });
+    } else if (ap.blob) {
         // Round-trip through the tier so portal-load! has the blob
         // to read. The bare 'init eval forces the tier to bootstrap
         // before we push the blob into MEMFS.
diff --git a/www/repl/repl.js b/www/repl/repl.js
index 1ab7f7f..0c2de3c 100644
--- a/www/repl/repl.js
+++ b/www/repl/repl.js
@@ -264,7 +264,14 @@ async function autoPauseTab(tab) {
     }
 
     if (activeInput) {
-        tab.autoPause = { tier, blob, inputSrc: activeInput, savedAt: Date.now() };
+        // Asm tier has no SAB poll site, so we can't snapshot env mid-eval.
+        // Fall back to replay mode: every successful prior input gets
+        // re-eval'd on resume to rebuild the env, then the active input
+        // is sent fresh. Same pattern the manual asm portal-save uses.
+        const replayInputs = (tier === "asm")
+            ? tab.transcript.filter((e) => e.kind !== "error" && e.input !== activeInput).map((e) => e.input)
+            : null;
+        tab.autoPause = { tier, blob, replayInputs, inputSrc: activeInput, savedAt: Date.now() };
     }
 
     // Terminate the worker(s) so the heap is reclaimed while the tab
@@ -284,8 +291,21 @@ async function autoResumeTab(tab) {
     tab.tier = ap.tier;
     tierSelectEl.value = ap.tier;
 
-    if (ap.blob) {
-        rebootTier(tab.id, ap.tier);
+    rebootTier(tab.id, ap.tier);
+
+    if (ap.replayInputs && ap.replayInputs.length) {
+        // Asm tier replay path — re-eval every successful prior input
+        // in order so the env is reconstructed before sendInput fires
+        // the active one. Errors mid-replay are swallowed; restoring
+        // from a transcript that defined-on-error is the user's call.
+        for (const src of ap.replayInputs) {
+            try { await evalInTier(tab.id, ap.tier, src); } catch (e) { /* keep going */ }
+        }
+        tab.transcript.push({
+            input: `; resumed asm tier — replayed ${ap.replayInputs.length} prior inputs`,
+            results: [{ tier: ap.tier, output: "#t" }], kind: "ok",
+        });
+    } else if (ap.blob) {
         // Round-trip through the tier so portal-load! has the blob
         // to read. The bare 'init eval forces the tier to bootstrap
         // before we push the blob into MEMFS.