feat(app): the harness switcher in the chat box (#1549)

packages/app-bundle/manifest.json

@@ -111,11 +111,14 @@
     "packages/app/src/components/dialog-select-directory-v2.css": "2e2f18abdca77f9fe85da157c40f288f3b1641ca92845208749e16455fd58637",
     "packages/app/src/components/dialog-select-file.tsx": "e6278ee35dd27d203e00ad73f70c709c44a6c06f81ffbd931edfaa0c986b9e03",
     "packages/app/src/components/external-link.tsx": "7130044026ad3ec417de4ba7389cc6059de46f21b370047046269c772aa7a4bb",
+    "packages/app/src/components/harness-switch-banner.tsx": "aba66bdbcdeb0e674f07e7f22827b509a66fae2a2e5fbc8eb12e1d54baa311a0",
+    "packages/app/src/components/harness-switch.test.ts": "db263ece42911e756fb8b6e88697a6bbbd0d1317decd1e63b027d9fe8c69b405",
+    "packages/app/src/components/harness-switch.ts": "b4cb2b2241d71c477be71285fe6041d4b0d604a26d74c30dc5239694211a1f90",
     "packages/app/src/components/help-button.tsx": "780d533f776a784660cfed072a131198bc6fcc8e8fe332e8e1a220d516c9684e",
     "packages/app/src/components/pane-bridge.tsx": "756b3306b51c963fac6778716f6c6c4626f0f3bf75c93b7cb4cab58ea0bf3d4e",
     "packages/app/src/components/profile-popover.tsx": "eff742e90544455f13234a9351bb1b82189663cba2cd3172bdcea1a8a37284e8",
     "packages/app/src/components/prompt-input-clipboard-structure.test.ts": "946b718c2164da394602f26e4d9919d752da0d0b9bee714f345ba16c274542da",
-    "packages/app/src/components/prompt-input-v2.tsx": "5ab46e41bda4fa11e99f06c37df76c1fd3cce061c6ba7a9f85bee369a965b98a",
+    "packages/app/src/components/prompt-input-v2.tsx": "7f3677740abfd76c0884c824523ab5f385bab9377b345477794f04276d618f40",
     "packages/app/src/components/prompt-input.tsx": "97a9bc55b46cf1f2d7c3e38110e736f7fa9db7f89121d3c013b9650a60d382d4",
     "packages/app/src/components/prompt-project-selector.tsx": "0157c954b938bce2b5aca9a82f4a72338e361f4c9027e55a7fd5a14a1654d294",
     "packages/app/src/components/report-bug-button.css": "909809b6241d53c386aa4c8ea34539ba162a8998fff755834c783025bc53a5fd",
@@ -210,7 +213,7 @@
     "packages/app/src/pages/home-session-archive.test.ts": "e8f1126287a3e9daa455efcc378e5d72aebdd092158bf8526f7779669b72e850",
     "packages/app/src/pages/home-session-archive.ts": "1b56c173f37f4a4dfd54088ef5fdb0dbcd3d9b62aeb08de4bfa0ed34f07d7ad5",
     "packages/app/src/pages/home.tsx": "06fb5c7718aacfd29b35e730e05d45076b39d6cd5d936d1270fb1bd9424c32fa",
-    "packages/app/src/pages/layout-new.tsx": "3ef477634cb6d7de0c32d3572c5ff699e07efff47e6e75458583456eb1ff8b27",
+    "packages/app/src/pages/layout-new.tsx": "8e1c643a47182db5c2bb7b0f6248196ca71e38394c5fe02dbe7f133beab32171",
     "packages/app/src/pages/layout.tsx": "eaf8bed869b5ec53582db732119fb903b223d749ebda354b1e388de3be02dc52",
     "packages/app/src/pages/new-session-landing.test.ts": "95e2780456a653a71e6f66b4302ae546e308a29e6b8ad9e84442938a3a226905",
     "packages/app/src/pages/new-session-landing.ts": "528d27cd5d441b521674328fb7812fb2acf77233e9e436d081c98ce611e8b268",
@@ -332,6 +335,7 @@
     "packages/opencode/test/server/amicode-credentials.test.ts": "ba77d064fd2be799930524510ce6e32c6f6a0d144d3cdf41673a8283dbe95bf6",
     "packages/opencode/test/server/amicode-dashboard.test.ts": "e25b284b9eb434da7f07dfa8b72b7919a0cd1ffaed275a6725d9cd44cd1298c0",
     "packages/opencode/test/server/amicode-file-resolve.test.ts": "39db84780125c8fd4551137e4f6a0ea6b0a9dce45b04e26ed15f649efe251311",
+    "packages/opencode/test/server/amicode-harness.test.ts": "96cc4f3e07b80624eb286a405839ab7469ee5244987a0a33235fbc063914b1a2",
     "packages/opencode/test/server/amicode-library.test.ts": "87b986c43390e1f94d6bcded0bb5d22be24beaab2c336773bb438ed1fc6a2d95",
     "packages/opencode/test/server/amicode-problems.test.ts": "4a8a9011f3796df4d6cde9999b86b507a8126fdc9138cc3ba305f930968c3392",
     "packages/opencode/test/server/amicode-profile.test.ts": "5e5dcfd2b3db5cb8d7aba2cf1f74ed2d76716af6e4f761f54b94e77174b314de",
@@ -617,6 +621,9 @@
     "packages/app/src/components/prompt-input/clipboard-bridge.test.ts": "15f76dca1a25d024128718e4099220b79ca029263410aab55502cf9caf9b2914",
     "packages/app/src/components/prompt-input/clipboard-bridge.ts": "4b5a1edf59d4c85268d6ff72aa9f9d66f82d4fdb887121fb978c09caf4c5be65",
     "packages/app/src/components/prompt-input/context-items.tsx": "027b02e394ccd14849052bf3fcacdae1e090c71d164fa8955addfe3f7abf1758",
+    "packages/app/src/components/prompt-input/harness-control.tsx": "c2fb0a672498fe4809cf88ddb3b52c1d04ddcc3d3b710cf40acb6a1dab212f9d",
+    "packages/app/src/components/prompt-input/harness.test.ts": "35739529b06829dd9fa169209c54ae668e0fc06d6968b00cfce638a221ce1361",
+    "packages/app/src/components/prompt-input/harness.ts": "8ae6a783c18a906383061cb1254101015f025080b39be3786c27be9bcd0ba9d1",
     "packages/app/src/components/prompt-input/image-attachments.tsx": "aa451ed6aa61a68ba0e8dacd8c45137f84c62566797a5242b75a89487ef0e9bf",
     "packages/app/src/components/prompt-input/placeholder.test.ts": "d3cee5e2c758faf5fda626e270adad81129622bbc2bf2c335c2bffe1544165c3",
     "packages/app/src/components/prompt-input/placeholder.ts": "6b2af23a0588e7970cd0dd059fc60c3671c907a76ba3db660483a932f1dce79d",
@@ -717,6 +724,7 @@
     "packages/opencode/src/server/amicode/credentials.ts": "f3a15c82496f9a3b6e8c1006a6a4ab419a02156e9a93a43c6c2319632c30063f",
     "packages/opencode/src/server/amicode/dashboard.ts": "031a4f40bfdc847984a1deecfefbe0fd27f42cbd1caf8823dc43c7eb5bcb9af0",
     "packages/opencode/src/server/amicode/file-resolve.ts": "3f0548fc97aad431d3f7707fd0b911e66fb4fd68ac4f643da71a2f00a73beffe",
+    "packages/opencode/src/server/amicode/harness.ts": "510d2373c377395d509b84795da65005532a32c816b1fa5f7b76fb413be5ed95",
     "packages/opencode/src/server/amicode/library.ts": "36013b19f7c57afaa1bab63e5ff34d79f09ec42640e2a8c4a40cb14c97c4b859",
     "packages/opencode/src/server/amicode/pasqal-secret.ts": "a0b53498bb7415c96e14b435367ffa93bd3d298fe12f7584cd401e649312fd69",
     "packages/opencode/src/server/amicode/problems.ts": "d56513cff90193ab436dcca379f065a4ce963eeb45c22178cf9a0151b49c9487",
@@ -847,8 +855,8 @@
     "packages/sdk/js/src/v2/gen/sdk.gen.ts": "6610638b4fb71bac498da98d232ef9adcd4b011b63e5e81a63fc6dc20d311b17",
     "packages/sdk/js/src/v2/gen/types.gen.ts": "0c23b262085d1e14b89bd03292a380c9ec8b52e66c4308304a05173362b79339",
     "packages/session-ui/src/v2/components/prompt-input/attachments.ts": "ff66078f2edc9a67a4df0d7dfd76a49be5eab27ac332b303f3412721ef7268ea",
-    "packages/session-ui/src/v2/components/prompt-input/index.tsx": "194b1c6d0c99000579df78b47c7ff72fe34f62a92ecd21b2a9377133d6d27bb9",
-    "packages/opencode/src/server/routes/instance/httpapi/server.ts": "85c200797fed41c0cd08e7aa699ce13aeb8a3d23aa2b9eddc4d72e72b8b5082c",
+    "packages/session-ui/src/v2/components/prompt-input/index.tsx": "811ebe3d4f6ba6318d3bf3efbac678d4d0484f83929b8f8ae1b7af1bc29911f4",
+    "packages/opencode/src/server/routes/instance/httpapi/server.ts": "8a8e47c2242bc61be078c2fb97ecaa37ebe45cb410b95819102731b52f2b3c31",
     "packages/opencode/src/server/routes/instance/httpapi/groups/experimental.ts": "944a0aee215a917e867fd9482f3c2bd40f49082bd3174c8a7d967ca40e34ec15",
     "packages/opencode/src/server/routes/instance/httpapi/groups/file.ts": "ed165131c62eeb29375db39edf89db8f87488e24ef99fc6f2cf19705ba35751a",
     "packages/opencode/src/server/routes/instance/httpapi/groups/mcp.ts": "048efa7b74d43c4ad4a75d0f8421c808760c8c0dcd593f0051a87044e40487d6",
@@ -873,10 +881,10 @@
     "packages/ui/src/v2/components/text-shimmer-v2.tsx"
   ],
   "exceptions": [],
-  "extracted_at": "2026-09-24T04:46:38.771Z",
+  "extracted_at": "2026-09-24T21:16:08.091Z",
   "per_package": {
     "packages/app": {
-      "A": 186,
+      "A": 192,
       "M": 157,
       "D": 0
     },
@@ -891,7 +899,7 @@
       "D": 0
     },
     "packages/opencode": {
-      "A": 69,
+      "A": 71,
       "M": 81,
       "D": 0
     },
@@ -922,7 +930,7 @@
     }
   },
   "counts": {
-    "overlay_total": 851,
+    "overlay_total": 859,
     "deletions": 7,
     "server_coupled": 0
   },
@@ -1030,6 +1038,9 @@
     "packages/app/src/components/dialog-select-directory-v2.css": "M",
     "packages/app/src/components/dialog-select-file.tsx": "M",
     "packages/app/src/components/external-link.tsx": "M",
+    "packages/app/src/components/harness-switch-banner.tsx": "A",
+    "packages/app/src/components/harness-switch.test.ts": "A",
+    "packages/app/src/components/harness-switch.ts": "A",
     "packages/app/src/components/help-button.tsx": "M",
     "packages/app/src/components/pane-bridge.tsx": "A",
     "packages/app/src/components/profile-popover.tsx": "A",
@@ -1251,6 +1262,7 @@
     "packages/opencode/test/server/amicode-credentials.test.ts": "A",
     "packages/opencode/test/server/amicode-dashboard.test.ts": "A",
     "packages/opencode/test/server/amicode-file-resolve.test.ts": "A",
+    "packages/opencode/test/server/amicode-harness.test.ts": "A",
     "packages/opencode/test/server/amicode-library.test.ts": "A",
     "packages/opencode/test/server/amicode-problems.test.ts": "A",
     "packages/opencode/test/server/amicode-profile.test.ts": "A",
@@ -1536,6 +1548,9 @@
     "packages/app/src/components/prompt-input/clipboard-bridge.test.ts": "A",
     "packages/app/src/components/prompt-input/clipboard-bridge.ts": "A",
     "packages/app/src/components/prompt-input/context-items.tsx": "M",
+    "packages/app/src/components/prompt-input/harness-control.tsx": "A",
+    "packages/app/src/components/prompt-input/harness.test.ts": "A",
+    "packages/app/src/components/prompt-input/harness.ts": "A",
     "packages/app/src/components/prompt-input/image-attachments.tsx": "M",
     "packages/app/src/components/prompt-input/placeholder.test.ts": "M",
     "packages/app/src/components/prompt-input/placeholder.ts": "M",
@@ -1636,6 +1651,7 @@
     "packages/opencode/src/server/amicode/credentials.ts": "A",
     "packages/opencode/src/server/amicode/dashboard.ts": "A",
     "packages/opencode/src/server/amicode/file-resolve.ts": "A",
+    "packages/opencode/src/server/amicode/harness.ts": "A",
     "packages/opencode/src/server/amicode/library.ts": "A",
     "packages/opencode/src/server/amicode/pasqal-secret.ts": "A",
     "packages/opencode/src/server/amicode/problems.ts": "A",

packages/app-bundle/overlay/packages/app/src/components/harness-switch-banner.tsx

@@ -0,0 +1,91 @@
+import { Show, createEffect, createSignal, onCleanup } from "solid-js"
+import {
+  harnessSwitchExpired,
+  harnessSwitchLabel,
+  harnessSwitchPhase,
+  type HarnessSwitchPhase,
+} from "@/components/harness-switch"
+import { useServerSDK } from "@/context/server-sdk"
+
+// Amicode: the visible half of a harness switch (amicode#1549) — the
+// solver-switch banner's twin for the composer's harness control. The switch
+// is real: the extension watcher persists the setting and restarts the server
+// underneath the webview; the SSE stream dies for those seconds and this
+// banner is the only narration. Scope mirrors the solver twin: it speaks ONLY
+// for a switch the app itself requested, so it cannot get stuck on a
+// transient blip.
+
+// Module-level: the call site (the composer's harness control) and the one
+// banner in the layout live in different component trees.
+const [target, setTarget] = createSignal<string | undefined>()
+const [startedAt, setStartedAt] = createSignal(0)
+
+/** Announce a switch the app just requested — `displayName` is the registry's
+ *  name for the picked harness, so the narration names what was picked. This
+ *  only mirrors the request; it never causes one. */
+export function beginHarnessSwitch(displayName: string) {
+  setTarget(displayName)
+  setStartedAt(Date.now())
+}
+
+function endHarnessSwitch() {
+  setTarget(undefined)
+  setStartedAt(0)
+}
+
+export function HarnessSwitchBanner() {
+  const sdk = useServerSDK()
+  const [sawDrop, setSawDrop] = createSignal(false)
+  const [elapsed, setElapsed] = createSignal(0)
+
+  // One clock, alive only while a switch is outstanding: it drives the expiry
+  // check, which has nothing else to react to.
+  createEffect(() => {
+    if (!target()) {
+      setSawDrop(false)
+      setElapsed(0)
+      return
+    }
+    const timer = setInterval(() => setElapsed(Date.now() - startedAt()), 500)
+    onCleanup(() => clearInterval(timer))
+  })
+
+  // Latch the drop: once the server has gone down, coming back up is the
+  // switch completing rather than the request still waiting to be picked up.
+  createEffect(() => {
+    if (target() && sdk().event.status() === "disconnected") setSawDrop(true)
+  })
+
+  const phase = (): HarnessSwitchPhase =>
+    harnessSwitchPhase({
+      target: target(),
+      connected: sdk().event.status() === "connected",
+      sawDrop: sawDrop(),
+    })
+
+  createEffect(() => {
+    const current = phase()
+    if (current === "idle") return
+    // Hold the completed chip briefly — the only confirmation the user gets
+    // inside the app; the extension's toast lands outside the webview.
+    if (current === "ready") {
+      const done = setTimeout(endHarnessSwitch, 3000)
+      onCleanup(() => clearTimeout(done))
+      return
+    }
+    if (harnessSwitchExpired(current, elapsed())) endHarnessSwitch()
+  })
+
+  const label = () => harnessSwitchLabel(phase(), target())
+
+  return (
+    <Show when={label()}>
+      {(text) => (
+        <div data-component="amicode-harness-switch" data-phase={phase()} role="status" aria-live="polite">
+          <i aria-hidden="true" />
+          <span>{text()}</span>
+        </div>
+      )}
+    </Show>
+  )
+}

packages/app-bundle/overlay/packages/app/src/components/harness-switch.test.ts

@@ -0,0 +1,44 @@
+import { describe, expect, test } from "bun:test"
+import {
+  harnessSwitchPhase,
+  harnessSwitchExpired,
+  harnessSwitchLabel,
+  HARNESS_SWITCH_STALL_MS,
+  HARNESS_SWITCH_MAX_MS,
+} from "./harness-switch"
+
+// amicode#1549 — the harness banner's decision layer, the solver-switch
+// twin's shape: pure helpers over two observable facts (a switch outstanding,
+// has the stream dropped), so the phase contract is testable without a DOM.
+
+describe("harnessSwitchPhase", () => {
+  test("no target → idle", () => {
+    expect(harnessSwitchPhase({ target: undefined, connected: true, sawDrop: false })).toBe("idle")
+  })
+
+  test("requested until the stream drops, restarting while down, ready on return", () => {
+    expect(harnessSwitchPhase({ target: "telaio", connected: true, sawDrop: false })).toBe("requested")
+    expect(harnessSwitchPhase({ target: "telaio", connected: false, sawDrop: false })).toBe("restarting")
+    expect(harnessSwitchPhase({ target: "telaio", connected: true, sawDrop: true })).toBe("ready")
+  })
+})
+
+describe("harnessSwitchExpired — never trap the user behind theater", () => {
+  test("requested stalls past the stall window; restarting past the ceiling", () => {
+    expect(harnessSwitchExpired("requested", HARNESS_SWITCH_STALL_MS + 1)).toBe(true)
+    expect(harnessSwitchExpired("requested", HARNESS_SWITCH_STALL_MS - 1)).toBe(false)
+    expect(harnessSwitchExpired("restarting", HARNESS_SWITCH_MAX_MS + 1)).toBe(true)
+    expect(harnessSwitchExpired("restarting", HARNESS_SWITCH_MAX_MS - 1)).toBe(false)
+    expect(harnessSwitchExpired("ready", Number.MAX_SAFE_INTEGER)).toBe(false)
+  })
+})
+
+describe("harnessSwitchLabel — honest narration, one name end to end", () => {
+  test("the labels narrate switching → restarting → ready", () => {
+    expect(harnessSwitchLabel("requested", "telaio (subscription)")).toBe("Switching to telaio (subscription)…")
+    expect(harnessSwitchLabel("restarting", "telaio (subscription)")).toBe("Restarting session server…")
+    expect(harnessSwitchLabel("ready", "telaio (subscription)")).toBe("telaio (subscription) ready")
+    expect(harnessSwitchLabel("idle", "telaio (subscription)")).toBeUndefined()
+    expect(harnessSwitchLabel("requested", undefined)).toBeUndefined()
+  })
+})

packages/app-bundle/overlay/packages/app/src/components/harness-switch.ts

@@ -0,0 +1,48 @@
+// amicode#1549 — the harness banner's decision layer, the solver-switch twin
+// (solver-switch.ts) in shape and discipline: a switch is not instant and it
+// is not quiet — the extension watcher sees {status:"switching"}, performs
+// the registry-gated setting persist, and RESTARTS the server underneath the
+// webview. For those seconds the SSE stream is simply gone; without a signal
+// that reads as an upgrade, the drop reads as a fault. Like the solver twin,
+// this speaks ONLY for a switch the app itself requested.
+//
+// Pure helpers so the phase contract is testable without a DOM.
+
+export type HarnessSwitchPhase = "idle" | "requested" | "restarting" | "ready"
+
+/** Phase from the two observable facts: is a switch outstanding, and has the
+ *  stream dropped yet. `sawDrop` is latched by the caller — once the server
+ *  has gone down, coming back up means "ready", not "still waiting to start". */
+export function harnessSwitchPhase(input: {
+  target: string | undefined
+  connected: boolean
+  sawDrop: boolean
+}): HarnessSwitchPhase {
+  if (!input.target) return "idle"
+  if (!input.connected) return "restarting"
+  return input.sawDrop ? "ready" : "requested"
+}
+
+/** The watcher polls harness.json every 1s, so a request that has not taken
+ *  the server down well inside this window is not going to — abandon quietly
+ *  rather than leave a permanent pill on screen (the solver twin's discipline). */
+export const HARNESS_SWITCH_STALL_MS = 12_000
+/** Total ceiling: never trap the user behind theater, however wedged the
+ *  restart is. */
+export const HARNESS_SWITCH_MAX_MS = 90_000
+
+export function harnessSwitchExpired(phase: HarnessSwitchPhase, elapsedMs: number): boolean {
+  if (phase === "requested") return elapsedMs > HARNESS_SWITCH_STALL_MS
+  if (phase === "restarting") return elapsedMs > HARNESS_SWITCH_MAX_MS
+  return false
+}
+
+/** One name end to end — the banner narrates the displayName the registry
+ *  published, so the banner and the select never disagree about what the user
+ *  just picked. */
+export function harnessSwitchLabel(phase: HarnessSwitchPhase, target: string | undefined): string | undefined {
+  if (!target || phase === "idle") return undefined
+  if (phase === "requested") return `Switching to ${target}…`
+  if (phase === "restarting") return "Restarting session server…"
+  return `${target} ready`
+}

packages/app-bundle/overlay/packages/app/src/components/prompt-input-v2.tsx

@@ -38,6 +38,8 @@ import {
   createPromptInputV2State,
   type PromptInputV2Interaction,
 } from "@opencode-ai/session-ui/v2/prompt-input/interaction"
+import { HarnessComposerControl } from "@/components/prompt-input/harness-control"
+import { harnessDegraded, liveHarnessState } from "@/components/prompt-input/harness"
 
 export type PromptInputV2ComposerProps = {
   class?: string
@@ -64,6 +66,13 @@ export function PromptInputV2Composer(props: PromptInputV2ComposerProps) {
         variantControlVisible={!props.controller.model.loading}
         attachKeybind={command.keybindParts("file.attach")}
         attachShortcut={command.keybind("file.attach")}
+        // amicode#1549: the harness switcher — a fourth select-slot riding the
+        // solver-mode trio. The control self-hides when no registry is
+        // published (stock-opencode behavior, unchanged); the degradation dim
+        // follows the serving harness's contract (telaio accepts no
+        // agent/model/variant).
+        harnessControl={<HarnessComposerControl />}
+        harnessDegraded={harnessDegraded(liveHarnessState())}
         // amicode/opencode#116: report-a-bug, right-anchored immediately left
         // of send. The boot-param gate lives HERE (not inside the button) so a
         // gated-off button passes `undefined` and the row's layout never shifts.