diff --git a/Dockerfile b/Dockerfile
index 965cb8b..19d40be 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -35,6 +35,10 @@ RUN npm run build
 FROM node:22-alpine
 WORKDIR /app
 
+# Runs Claude Code sessions inside a named tmux session per lane so both the
+# dashboard (via node-pty attach) and a real terminal can share one live pane.
+RUN apk add --no-cache tmux
+
 COPY --from=server-deps /app/node_modules ./node_modules/
 COPY package.json ./
 COPY server/ ./server/
diff --git a/client/package-lock.json b/client/package-lock.json
index 9a1b944..acef41a 100644
--- a/client/package-lock.json
+++ b/client/package-lock.json
@@ -10,6 +10,8 @@
       "dependencies": {
         "@fontsource/inter": "^5.2.8",
         "@fontsource/jetbrains-mono": "^5.2.8",
+        "@xterm/addon-fit": "^0.10.0",
+        "@xterm/xterm": "^5.5.0",
         "d3": "^7.9.0",
         "d3-sankey": "^0.12.3",
         "i18next": "^26.0.8",
@@ -2100,6 +2102,21 @@
         "url": "https://opencollective.com/vitest"
       }
     },
+    "node_modules/@xterm/addon-fit": {
+      "version": "0.10.0",
+      "resolved": "https://registry.npmjs.org/@xterm/addon-fit/-/addon-fit-0.10.0.tgz",
+      "integrity": "sha512-UFYkDm4HUahf2lnEyHvio51TNGiLK66mqP2JoATy7hRZeXaGMRDr00JiSF7m63vR5WKATF605yEggJKsw0JpMQ==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@xterm/xterm": "^5.0.0"
+      }
+    },
+    "node_modules/@xterm/xterm": {
+      "version": "5.5.0",
+      "resolved": "https://registry.npmjs.org/@xterm/xterm/-/xterm-5.5.0.tgz",
+      "integrity": "sha512-hqJHYaQb5OptNunnyAnkHyM8aCjZ1MEIDTQu1iIbbTD/xops91NB5yq1ZK/dC2JDbVWtF23zUtl9JE2NqwT87A==",
+      "license": "MIT"
+    },
     "node_modules/agent-base": {
       "version": "7.1.4",
       "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-7.1.4.tgz",
diff --git a/client/package.json b/client/package.json
index 62adb1d..82a30e3 100644
--- a/client/package.json
+++ b/client/package.json
@@ -13,6 +13,8 @@
   "dependencies": {
     "@fontsource/inter": "^5.2.8",
     "@fontsource/jetbrains-mono": "^5.2.8",
+    "@xterm/addon-fit": "^0.10.0",
+    "@xterm/xterm": "^5.5.0",
     "d3": "^7.9.0",
     "d3-sankey": "^0.12.3",
     "i18next": "^26.0.8",
diff --git a/package-lock.json b/package-lock.json
index 125d804..16bcd97 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -15,6 +15,7 @@
         "cross-spawn": "^7.0.6",
         "express": "^4.21.2",
         "multer": "^2.0.0",
+        "node-pty": "^1.1.0",
         "redoc": "^2.5.3",
         "swagger-ui-express": "^5.0.1",
         "tar": "^7.4.3",
@@ -1669,6 +1670,12 @@
         "node": ">=10"
       }
     },
+    "node_modules/node-addon-api": {
+      "version": "7.1.1",
+      "resolved": "https://registry.npmjs.org/node-addon-api/-/node-addon-api-7.1.1.tgz",
+      "integrity": "sha512-5m3bsyrjFWE1xf7nz7YXdN4udnVtXK6/Yfgn5qnahL6bCkf2yKt4k3nuTKAtT4r3IG8JNR2ncsIMdZuAzJjHQQ==",
+      "license": "MIT"
+    },
     "node_modules/node-fetch": {
       "version": "2.7.0",
       "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.7.0.tgz",
@@ -1701,6 +1708,16 @@
         "node": "4.x || >=6.0.0"
       }
     },
+    "node_modules/node-pty": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/node-pty/-/node-pty-1.1.0.tgz",
+      "integrity": "sha512-20JqtutY6JPXTUnL0ij1uad7Qe1baT46lyolh2sSENDd4sTzKZ4nmAFkeAARDKwmlLjPx6XKRlwRUxwjOy+lUg==",
+      "hasInstallScript": true,
+      "license": "MIT",
+      "dependencies": {
+        "node-addon-api": "^7.1.0"
+      }
+    },
     "node_modules/node-readfiles": {
       "version": "0.2.0",
       "resolved": "https://registry.npmjs.org/node-readfiles/-/node-readfiles-0.2.0.tgz",
diff --git a/package.json b/package.json
index f5d86e7..e1c6c3a 100644
--- a/package.json
+++ b/package.json
@@ -94,6 +94,7 @@
     "cross-spawn": "^7.0.6",
     "express": "^4.21.2",
     "multer": "^2.0.0",
+    "node-pty": "^1.1.0",
     "redoc": "^2.5.3",
     "swagger-ui-express": "^5.0.1",
     "tar": "^7.4.3",
diff --git a/server/db.js b/server/db.js
index a209222..b9b3f08 100644
--- a/server/db.js
+++ b/server/db.js
@@ -248,7 +248,7 @@ db.exec(`
   CREATE TABLE IF NOT EXISTS dashboard_runs (
     id TEXT PRIMARY KEY,
     session_id TEXT,
-    mode TEXT NOT NULL,
+    mode TEXT,
     cwd TEXT NOT NULL,
     model TEXT,
     permission_mode TEXT,
@@ -496,6 +496,15 @@ try {
 }
 db.prepare("CREATE INDEX IF NOT EXISTS idx_dashboard_runs_lane ON dashboard_runs(lane_id)").run();
 
+// Migrate: tmux session name backing this run (tmux+PTY terminal design,
+// 2026-08-11). Additive and nullable — historical rows spawned via the old
+// stream-json mode have no tmux session and are display-only history now.
+try {
+  db.prepare("SELECT tmux_session FROM dashboard_runs LIMIT 1").get();
+} catch {
+  db.prepare("ALTER TABLE dashboard_runs ADD COLUMN tmux_session TEXT").run();
+}
+
 // Migrate: add stage-detection columns to lanes. Inference is never evidence —
 // these are additive columns separate from `stage` (the declared stage), so
 // `stage`'s meaning is untouched and turning the feature off loses nothing.