feat: inline prompt history area — scrollable session messages

The inline prompt now shows the current session's full message
history (user + assistant), scrollable, replacing the single-output
display from the previous commit. The user can scroll back through
prior exchanges in the same notebook's OpenCode session.

Server (opencode_bridge/):
  - New route: GET /opencode-bridge/session-messages?notebook=<path>
    - Resolves notebook to session via SessionManager.peek (no create).
    - If no session: {"messages": []} (no OpenCode call).
    - Else: GET /session/{id}/message on OpenCode Serve, project the
      raw {info, parts}[] into a frontend-friendly {role, content}[].
  - OpenCodeClient.list_session_messages(sid).
  - SessionManager.peek(notebook_path) -> Optional[str] (read without
    creating, to avoid spawning a session just to report emptiness).
  - Wired the new route in setup_route_handlers.

Client (src/):
  - types.ts: OpenCodeMessage { role, content } + OpenCodeMessagesResponse.
  - api/opencode_client.ts: callOpenCodeSessionMessages(notebook, serverSettings).
  - components/opencode_inline_prompt.ts:
    - Replaces the single .opencode-inline-output area with a
      scrollable .opencode-inline-history (max-height 320px, overflow-y
      auto, auto-scrolls to bottom on update).
    - setMessages(messages): renders user messages as plain text,
      assistant messages via marked.parse. No more setOutput/hideOutput.
  - components/opencode_cell_actions.ts:
    - _showPrompt now fires a _refreshHistory(notebookPath) which
      fetches and calls prompt.setMessages.
    - _handleResponse on success also calls _refreshHistory (the new
      assistant message appears as the last item in the history).
    - Cell source is still NOT replaced.
  - api/opencode_client module is mocked in the cell_actions test to
    avoid jsdom network calls.

style/base.css:
  - .opencode-inline-output* rules replaced with .opencode-inline-history
    (max-height 320px, overflow-y auto, border, padding) and
    .opencode-msg / .opencode-msg-user / .opencode-msg-assistant.
  - pre/code/p/h1-3 content styling scoped under .opencode-inline-history.

Tests:
  - pytest 37/37: FakeOpenCodeClient.list_session_messages + 3 new
    session_messages route tests (no session, projects messages, 400).
  - jest 29/29: setMessages renders user/assistant + history area tests.
  - FakeSessionManager.peek (returns None when session_id is falsy).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/__tests__/opencode_cell_actions.spec.ts

@@ -52,6 +52,15 @@ jest.mock('marked', () => ({
   marked: { parse: (md: string) => `<mock>${md}</mock>` }
 }));
 
+// Mock the network-touching API module so jsdom tests don't try to hit
+// a real notebook server (and to keep the refresh-history logic decoupled
+// from the network). The cell_actions tests focus on widget behavior.
+jest.mock('../api/opencode_client', () => ({
+  callOpenCodeEdit: jest.fn(),
+  callOpenCodeProviders: jest.fn(),
+  callOpenCodeSessionMessages: jest.fn().mockResolvedValue({ messages: [] })
+}));
+
 import {
   OpenCodeCellActions,
   setOpenCodeProviders,
@@ -330,17 +339,21 @@ describe('OpenCodeCellActions', () => {
     ).toBeNull();
   });
 
-  it('on a successful response, does NOT replace the cell source (renders to inline output instead)', () => {
+  it('on a successful response, does NOT replace the cell source and triggers a history refresh', () => {
     setOpenCodeProviders(null);
     const cell = makeFakeCell('x = 1');
     const actions = new OpenCodeCellActions(cell);
-    // Click once to create the inline prompt (so setOutput has a target).
+    // Click once to create the inline prompt (so the history refresh
+    // has a target and the cell source check has a baseline).
     Object.defineProperty(actions, 'parent', { value: cell, configurable: true });
     (actions as any).onAfterAttach({} as any);
     const btn = actions.node.querySelector('button') as HTMLButtonElement;
     btn.click();
 
-    // Simulate a successful response.
+    // The history refresh on show is async; spy on _refreshHistory to
+    // confirm it gets called (without depending on the network).
+    const refreshSpy = jest.spyOn(actions as any, '_refreshHistory');
+
     (actions as any)._handleResponse({
       ok: true,
       markdown: '# AI says hi\n\n```python\nprint("hi")\n```',
@@ -350,11 +363,8 @@ describe('OpenCodeCellActions', () => {
 
     // The cell source must remain unchanged.
     expect((cell as any).model.sharedModel.setSource).not.toHaveBeenCalled();
-    // The inline output area is now visible with the rendered markdown.
-    const output = cell.node.querySelector(
-      '.opencode-inline-prompt .opencode-inline-output'
-    ) as HTMLElement;
-    expect(output.style.display).toBe('block');
+    // A history refresh was triggered (to pick up the new assistant msg).
+    expect(refreshSpy).toHaveBeenCalledWith('foo.ipynb');
   });
 });
 
@@ -368,11 +378,12 @@ describe('OpenCodeInlinePrompt', () => {
       providers: null
     });
     expect(prompt.node.querySelector('textarea')).not.toBeNull();
-    // 3 buttons: 发送, 取消, and the output area close (✕).
-    expect(prompt.node.querySelectorAll('button').length).toBe(3);
+    // 2 buttons: 发送 and 取消 (no more output-area close button; the
+    // scrollable history area is the display).
+    expect(prompt.node.querySelectorAll('button').length).toBe(2);
   });
 
-  it('hides the output area by default; setOutput reveals it with rendered markdown', () => {
+  it('renders a history area; setMessages renders user text + assistant markdown and scrolls to bottom', () => {
     const cell = makeFakeCell('x = 1');
     const prompt = new OpenCodeInlinePrompt(cell, {
       onSubmit: jest.fn(),
@@ -380,22 +391,30 @@ describe('OpenCodeInlinePrompt', () => {
       disabled: false,
       providers: null
     });
-    const output = prompt.node.querySelector(
-      '.opencode-inline-prompt .opencode-inline-output'
+    const history = prompt.node.querySelector(
+      '.opencode-inline-prompt .opencode-inline-history'
     ) as HTMLElement;
-    expect(output).not.toBeNull();
-    expect(output.style.display).toBe('none');
+    expect(history).not.toBeNull();
+    // Initially empty (no messages yet).
+    expect(history.children.length).toBe(0);
 
-    prompt.setOutput('# Hello\n\n```python\nx = 1\n```');
-    expect(output.style.display).toBe('block');
-    const content = prompt.node.querySelector(
-      '.opencode-inline-prompt .opencode-inline-output-content'
-    ) as HTMLElement;
-    // marked is mocked to wrap the input in <mock>...</mock>.
-    expect(content.innerHTML).toContain('<mock>');
-    expect(content.innerHTML).toContain('# Hello');
-
-    prompt.hideOutput();
-    expect(output.style.display).toBe('none');
+    prompt.setMessages([
+      { role: 'user', content: 'fix the bug' },
+      {
+        role: 'assistant',
+        content: '# Here you go\n\n```python\nx = 1\n```'
+      }
+    ]);
+    expect(history.children.length).toBe(2);
+    const userMsg = history.querySelector('.opencode-msg-user') as HTMLElement;
+    const asstMsg = history.querySelector('.opencode-msg-assistant') as HTMLElement;
+    expect(userMsg).not.toBeNull();
+    // User messages are plain text (not rendered as HTML).
+    expect(userMsg.textContent).toBe('fix the bug');
+    expect(userMsg.innerHTML).not.toContain('<');
+    // Assistant messages are rendered as markdown via marked (mocked).
+    expect(asstMsg).not.toBeNull();
+    expect(asstMsg.innerHTML).toContain('<mock>');
+    expect(asstMsg.innerHTML).toContain('# Here you go');
   });
 });

src/api/opencode_client.ts

@@ -4,7 +4,7 @@
 import { URLExt } from '@jupyterlab/coreutils';
 import { ServerConnection } from '@jupyterlab/services';
 
-import type { OpenCodeProvidersResponse, OpenCodeRequest, OpenCodeResponse } from '../types';
+import type { OpenCodeProvidersResponse, OpenCodeRequest, OpenCodeResponse, OpenCodeMessagesResponse } from '../types';
 
 /**
  * Call POST /opencode-bridge/edit. Returns parsed response (success or failure).
@@ -54,6 +54,37 @@ export async function callOpenCodeEdit(
   return parsed as OpenCodeResponse;
 }
 
+/**
+ * Call GET /opencode-bridge/session-messages?notebook=<path>. Returns the
+ * current session's messages (projected to {role, content}[]) for the
+ * given notebook, or an empty list if no session exists yet.
+ */
+export async function callOpenCodeSessionMessages(
+  notebookPath: string,
+  serverSettings: ServerConnection.ISettings
+): Promise<OpenCodeMessagesResponse> {
+  const url =
+    URLExt.join(serverSettings.baseUrl, 'opencode-bridge', 'session-messages') +
+    '?notebook=' +
+    encodeURIComponent(notebookPath);
+
+  const init: RequestInit = { method: 'GET' };
+  let response: Response;
+  try {
+    response = await ServerConnection.makeRequest(url, init, serverSettings);
+  } catch (error) {
+    throw new Error(
+      `network error calling opencode-bridge/session-messages: ${(error as Error).message}`
+    );
+  }
+  if (!response.ok) {
+    throw new Error(
+      `opencode-bridge/session-messages failed: ${response.status} ${response.statusText}`
+    );
+  }
+  return (await response.json()) as OpenCodeMessagesResponse;
+}
+
 /**
  * Call GET /opencode-bridge/providers. Returns the parsed JSON response.
  * Throws on network error or non-2xx status.

src/components/opencode_cell_actions.ts

@@ -16,7 +16,7 @@ import type { NotebookPanel } from '@jupyterlab/notebook';
 import { ServerConnection } from '@jupyterlab/services';
 import { Widget } from '@lumino/widgets';
 
-import { callOpenCodeEdit } from '../api/opencode_client';
+import { callOpenCodeEdit, callOpenCodeSessionMessages } from '../api/opencode_client';
 import { extractCellContext } from '../context/cell_context';
 import type {
   CellContext,
@@ -123,6 +123,31 @@ export class OpenCodeCellActions extends Widget {
     });
     Widget.attach(prompt, this._cell.node);
     this._prompt = prompt;
+
+    // Fetch the current session's message history and render it into
+    // the prompt's scrollable history area. Empty list (no session yet)
+    // is a normal no-op render.
+    const notebookPath = this._context?.notebookPath;
+    if (notebookPath) {
+      void this._refreshHistory(notebookPath);
+    }
+  }
+
+  private async _refreshHistory(notebookPath: string): Promise<void> {
+    if (!_serverSettings || !this._prompt) {
+      return;
+    }
+    try {
+      const resp = await callOpenCodeSessionMessages(
+        notebookPath,
+        _serverSettings
+      );
+      this._prompt.setMessages(resp.messages);
+    } catch (e) {
+      // Non-fatal: the history is a convenience. The user can still
+      // send new prompts; just the scrollback won't update.
+      console.warn('opencode_bridge: failed to fetch session messages', e);
+    }
   }
 
   private _hidePrompt(): void {
@@ -172,11 +197,12 @@ export class OpenCodeCellActions extends Widget {
   private _handleResponse(resp: OpenCodeResponse): void {
     this._status = 'idle';
     if (resp.ok) {
-      // Display the AI response in the inline prompt's output area as
-      // rendered markdown. The cell source is NOT replaced — the user
-      // decides what to do with the output (close it, or resend).
-      if (this._prompt) {
-        this._prompt.setOutput(resp.markdown);
+      // Refetch the (now-updated) session history and render the new
+      // assistant message as the last item in the scrollable history.
+      // The cell source is NOT replaced.
+      const notebookPath = this._context?.notebookPath;
+      if (notebookPath) {
+        void this._refreshHistory(notebookPath);
       }
       Notification.info(
         `OpenCode 完成 (${resp.markdown.length} chars). Session: ${resp.sessionId.slice(0, 8)}…`

src/components/opencode_inline_prompt.ts

@@ -1,17 +1,19 @@
 /**
  * Inline prompt widget attached to a cell's DOM when the AI button is clicked.
- * Renders two <select> boxes (provider + model), a textarea, and send/cancel
- * buttons. The model select's default for the chosen provider is
- * `default[providerID]` (from the /config/providers response) when that
- * modelID is present in the provider's models; otherwise the first model.
+ * Renders two <select> boxes (provider + model), a textarea, send/cancel
+ * buttons, and a scrollable history area that shows the current session's
+ * messages (user + assistant). The model select's default for the chosen
+ * provider is `default[providerID]` from the /config/providers response.
  *
- * v3-final: no settings — picks come from the OpenCode Serve providers cache.
+ * v3-final: no settings — picks come from the OpenCode Serve providers
+ * cache; history comes from /session-messages; cell source is NOT replaced
+ * (the AI reply is rendered as markdown inside this history area).
  */
 import { CodeCell } from '@jupyterlab/cells';
 import { Widget } from '@lumino/widgets';
 import { marked } from 'marked';
 
-import type { OpenCodeProvidersResponse } from '../types';
+import type { OpenCodeMessage, OpenCodeProvidersResponse } from '../types';
 
 export interface IOpenCodeInlinePromptOptions {
   onSubmit: (text: string, providerId?: string, modelId?: string) => void;
@@ -70,8 +72,7 @@ export class OpenCodeInlinePrompt extends Widget {
   private _modelSelect: HTMLSelectElement | null = null;
   private _providerModels: FlatProvider[];
   private _defaultMap: { [pid: string]: string };
-  private _outputArea: HTMLDivElement;
-  private _outputContent: HTMLDivElement;
+  private _historyEl: HTMLDivElement;
 
   constructor(
     _cell: CodeCell,
@@ -154,33 +155,15 @@ export class OpenCodeInlinePrompt extends Widget {
       }
       this.node.appendChild(row);
     }
+
+    // Scrollable history of the current session's messages. Empty until
+    // setMessages() is called by the owning cell action.
+    this._historyEl = document.createElement('div');
+    this._historyEl.className = 'opencode-inline-history';
+    this.node.appendChild(this._historyEl);
+
     this.node.appendChild(this._textarea);
     this.node.appendChild(actions);
-
-    // Output area: hidden by default; revealed by setOutput() with the
-    // markdown-rendered AI response. The cell source is NOT replaced.
-    this._outputArea = document.createElement('div');
-    this._outputArea.className = 'opencode-inline-output';
-    this._outputArea.style.display = 'none';
-    const outputHeader = document.createElement('div');
-    outputHeader.className = 'opencode-inline-output-header';
-    const outputTitle = document.createElement('span');
-    outputTitle.textContent = '结果';
-    const outputCloseBtn = document.createElement('button');
-    outputCloseBtn.className = 'opencode-inline-output-close';
-    outputCloseBtn.type = 'button';
-    outputCloseBtn.textContent = '✕';
-    outputCloseBtn.title = '关闭输出';
-    outputCloseBtn.addEventListener('click', () => {
-      this.hideOutput();
-    });
-    outputHeader.appendChild(outputTitle);
-    outputHeader.appendChild(outputCloseBtn);
-    this._outputContent = document.createElement('div');
-    this._outputContent.className = 'opencode-inline-output-content';
-    this._outputArea.appendChild(outputHeader);
-    this._outputArea.appendChild(this._outputContent);
-    this.node.appendChild(this._outputArea);
   }
 
   private _rebuildModelSelect(providerId: string | undefined): void {
@@ -226,18 +209,23 @@ export class OpenCodeInlinePrompt extends Widget {
   }
 
   /**
-   * Render the AI response as markdown and show the output area in place
-   * of replacing the cell source. Safe for local-trusted content from the
-   * user's OpenCode Serve; do not feed untrusted markdown here without
-   * adding a sanitizer (e.g. DOMPurify).
+   * Render the current session's messages into the scrollable history
+   * area. User messages are plain text; assistant messages are rendered
+   * as markdown via marked. Auto-scrolls to the bottom so the most
+   * recent message is visible.
    */
-  setOutput(markdown: string): void {
-    this._outputContent.innerHTML = marked.parse(markdown) as string;
-    this._outputArea.style.display = 'block';
-  }
-
-  hideOutput(): void {
-    this._outputArea.style.display = 'none';
-    this._outputContent.textContent = '';
+  setMessages(messages: OpenCodeMessage[]): void {
+    this._historyEl.textContent = '';
+    for (const msg of messages) {
+      const wrap = document.createElement('div');
+      wrap.className = `opencode-msg opencode-msg-${msg.role}`;
+      if (msg.role === 'user') {
+        wrap.textContent = msg.content;
+      } else {
+        wrap.innerHTML = marked.parse(msg.content) as string;
+      }
+      this._historyEl.appendChild(wrap);
+    }
+    this._historyEl.scrollTop = this._historyEl.scrollHeight;
   }
 }

src/types.ts

@@ -49,13 +49,20 @@ export interface OpenCodeFailure {
 
 export type OpenCodeResponse = OpenCodeSuccess | OpenCodeFailure;
 
+/** Response from GET /opencode-bridge/session-messages?notebook=... .
+ *  Projected from OpenCode's {info, parts}[] by the server into a
+ *  frontend-friendly {role, content}[]. */
+export interface OpenCodeMessage {
+  role: "user" | "assistant";
+  content: string;
+}
+
+export interface OpenCodeMessagesResponse {
+  messages: OpenCodeMessage[];
+}
+
 /** Response from GET /opencode-bridge/providers (proxies OpenCode /config/providers).
- *
- * Per the OpenCode server docs, `/config/providers` returns
- * `{ providers: Provider[], default: { [providerID]: modelID } }`. Each
- * `Provider.models` is a Record keyed by modelID (NOT an array), so we
- * can reference a model by its string ID (also matching `default[providerID]`).
- */
+ *  Each Provider.models is a Record keyed by modelID (NOT an array). */
 export interface OpenCodeModel {
   id: string;
   name?: string;