feat(agentos): liveChatCapable — hide chat-sandbox button for library agents

The chat-sandbox button + landing-chat input on the AgentOS SPA both
trigger `POST /agents/<name>/chat-sandbox`, which proxies to a remote
harness server at `${CA_BASE}/sandboxes`. For agents that run in
their host process (Python `ComputerAgent` harness, etc.) there's no
remote sandbox to proxy to — clicking the button gets a 502 (no
:8787) or a 400 (LIBRARY_AGENT_NO_LIVE_CHAT when source.type =
"library").

This patch adds UI-side gating so the button never renders for these
agents:

  routes/agents.ts
    - Import `hasResolvableSource`.
    - Add a derived `liveChatCapable: sCap && hasResolvableSource(source)`
      to each item in `GET /agents` so the SPA can decide without
      duplicating server-side logic.

  api.ts
    - Add `liveChatCapable?: boolean` to the `Agent` interface.
      Optional + defaults-true everywhere a value is missing — every
      legacy registry doc keeps rendering the button.

  App.tsx
    - Forward `liveChatCapable={agent.liveChatCapable !== false}` to
      `WorkspaceTab`.

  WorkspaceTab.tsx
    - New `liveChatCapable?: boolean` prop (default `true`).
    - Wrap both "New chat" buttons (collapsed + expanded sidebar) in
      `{liveChatCapable && (...)}`.

  HomePage.tsx
    - `resolveTarget()` returns `liveChatCapable` alongside
      `sandboxCapable`.
    - When the user submits a prompt for a sandbox-capable but
      non-live-chat-capable agent, show a friendly inline message
      ("library-mode agent — invoke from your code") instead of
      POSTing to `/chat-sandbox` and surfacing the 400.

Type-check: SPA + agentos-server both compile clean.

Author: abhi-bhat-lyzr

agentos/src/App.tsx

@@ -184,6 +184,7 @@ export default function App() {
                   key={agent.name}
                   agent={agent.name}
                   sandboxCapable={agent.sandboxCapable}
+                  liveChatCapable={agent.liveChatCapable !== false}
                   initialMessage={launchMessage}
                   onConsumedInitial={() => setLaunchMessage(null)}
                 />

agentos/src/api.ts

@@ -23,6 +23,11 @@ export interface Agent {
   sourceUrl: string | null;
   model: string | null;
   sandboxCapable: boolean;
+  /** True when the agent can actually spin up a live chat sandbox.
+   *  Equals `sandboxCapable && hasResolvableSource(source)`. Library-mode
+   *  agents (Python harness, etc.) have `false` so the UI hides the
+   *  "New chat" button instead of triggering a 400 on click. */
+  liveChatCapable?: boolean;
   sessionCount: number;
   activeSandboxes: number;
   lastActivity: string | null;

agentos/src/components/HomePage.tsx

@@ -94,10 +94,19 @@ export function HomePage({
 
   // Explicit framework → its mapped agent. sandboxCapable comes from the
   // registry when the agent is known, else inferred (deepagents run one-shot).
-  const resolveTarget = (): { name: string; sandboxCapable: boolean } => {
+  // liveChatCapable additionally checks the source can be resolved — library-
+  // mode agents (Python harness) have a non-resolvable source and so cannot
+  // start a live chat, even though their harness is sandboxable.
+  const resolveTarget = (): {
+    name: string;
+    sandboxCapable: boolean;
+    liveChatCapable: boolean;
+  } => {
     const name = selected.agent ?? agents[0]?.name ?? "gitagent";
     const found = agents.find((a) => a.name === name);
-    return { name, sandboxCapable: found ? found.sandboxCapable : selected.id !== "deep-agent" };
+    const sandboxCap = found ? found.sandboxCapable : selected.id !== "deep-agent";
+    const liveCap = found ? found.liveChatCapable !== false : sandboxCap;
+    return { name, sandboxCapable: sandboxCap, liveChatCapable: liveCap };
   };
 
   const submit = async () => {
@@ -140,6 +149,24 @@ export function HomePage({
       let streamUrl: string;
       let turnSession = sessionId;
 
+      if (!target.liveChatCapable && target.sandboxCapable) {
+        // Library-mode agent: sandbox-capable harness but source isn't
+        // resolvable into a workdir (Python harness, etc.). Surface a
+        // friendly explanation instead of POSTing to /chat-sandbox where
+        // the server would 400 with LIBRARY_AGENT_NO_LIVE_CHAT.
+        setMessages((cur) => [
+          ...cur,
+          {
+            role: "assistant",
+            text:
+              `${target.name} is a library-mode agent — it runs in its host ` +
+              `process (e.g. a Python SDK). AgentOS shows its telemetry but ` +
+              `can't start a new live chat from here. Invoke it from your code.`,
+          },
+        ]);
+        setBusy(false);
+        return;
+      }
       if (target.sandboxCapable) {
         let sb = sandboxId;
         if (!sb) {

agentos/src/components/WorkspaceTab.tsx

@@ -11,11 +11,17 @@ import { cn } from "../lib/cn.ts";
 export function WorkspaceTab({
   agent,
   sandboxCapable,
+  liveChatCapable = true,
   initialMessage,
   onConsumedInitial,
 }: {
   agent: string;
   sandboxCapable: boolean;
+  // True when the agent can spin up a live chat sandbox. False for
+  // library-mode agents (Python harness etc.) whose ``source`` doesn't
+  // resolve into something the server can clone. Defaults to true so
+  // existing callers and registry docs without the field keep working.
+  liveChatCapable?: boolean;
   initialMessage?: string | null;
   onConsumedInitial?: () => void;
 }) {
@@ -61,9 +67,11 @@ export function WorkspaceTab({
           >
             <PanelLeftClose className="h-4 w-4 rotate-180" />
           </Button>
-          <Button onClick={newChat} size="icon" title="New chat" className="h-8 w-8">
-            <Plus className="h-4 w-4" />
-          </Button>
+          {liveChatCapable && (
+            <Button onClick={newChat} size="icon" title="New chat" className="h-8 w-8">
+              <Plus className="h-4 w-4" />
+            </Button>
+          )}
           <div className="mt-1 text-[10px] text-muted-foreground [writing-mode:vertical-rl] rotate-180 tracking-wide">
             {sessions.length} sessions
           </div>
@@ -104,10 +112,12 @@ export function WorkspaceTab({
           <span className="text-xs text-muted-foreground truncate min-w-0">
             {sessions.length} session{sessions.length !== 1 ? "s" : ""}
           </span>
-          <Button variant="default" size="sm" onClick={newChat} className="ml-auto shrink-0 gap-1">
-            <Plus className="h-3 w-3" />
-            New
-          </Button>
+          {liveChatCapable && (
+            <Button variant="default" size="sm" onClick={newChat} className="ml-auto shrink-0 gap-1">
+              <Plus className="h-3 w-3" />
+              New
+            </Button>
+          )}
         </div>
         <div className="flex-1 overflow-y-auto min-w-0">
           {loading && (

packages/agentos-server/src/routes/agents.ts

@@ -16,7 +16,7 @@ import { registryColl, threadsColl, type RegistryDoc } from "../mongo.js";
 import { caBase } from "../upstream.js";
 import { caAuthHeader } from "../auth.js";
 import { agentLogStore } from "../stores/agent-log-store.js";
-import { normalizeSource, registryDocToAgentDef, sandboxCapable } from "../agent-defs.js";
+import { hasResolvableSource, normalizeSource, registryDocToAgentDef, sandboxCapable } from "../agent-defs.js";
 
 export const agentsRouter: IRouter = Router();
 
@@ -60,6 +60,7 @@ agentsRouter.get("/agents", async (_req, res, next) => {
         return t && (!acc || t > acc) ? t : acc;
       }, null);
       const { source, sourceUrl } = normalizeSource(r.source);
+      const sCap = sandboxCapable(agent.harness);
       out.push({
         name: agent.name,
         label: agent.label,
@@ -70,7 +71,14 @@ agentsRouter.get("/agents", async (_req, res, next) => {
         origin: "registry" as const,
         registeredBy: r.registeredBy ?? null,
         lastSeen: r.lastSeen ? r.lastSeen.toISOString() : null,
-        sandboxCapable: sandboxCapable(agent.harness),
+        sandboxCapable: sCap,
+        // True when this agent can actually spin up a live chat sandbox.
+        // ``sandboxCapable`` is true for everything except deepagents;
+        // adding the source-resolvability check hides the chat button for
+        // library-mode (Python harness) agents whose ``source.type`` is
+        // neither git/local nor inline-with-files. UI uses this to
+        // conditionally render the "New chat" button.
+        liveChatCapable: sCap && hasResolvableSource(agent.source),
         sessionCount: sessionIds.size,
         activeSandboxes: active,
         lastActivity: lastActivity ? lastActivity.toISOString() : null,