feat: improve Gemini CLI timeline display by stripping ANSI colors and providing markdown fallback

src/cli/adapters/gemini-cli.ts

@@ -0,0 +1,128 @@
+import type { PlatformAdapter } from '../types.js';
+
+/**
+ * Gemini CLI Platform Adapter
+ *
+ * Normalizes Gemini CLI's hook JSON to NormalizedHookInput.
+ * Gemini CLI supports 11 lifecycle hooks; we register 8:
+ *
+ * Lifecycle:
+ *   SessionStart  → context     (inject memory context)
+ *   SessionEnd    → session-complete
+ *   PreCompress   → summarize
+ *   Notification  → observation (system events like ToolPermission)
+ *
+ * Agent:
+ *   BeforeAgent   → user-message (captures user prompt)
+ *   AfterAgent    → observation  (full agent response)
+ *
+ * Tool:
+ *   BeforeTool    → observation  (tool intent before execution)
+ *   AfterTool     → observation  (tool result after execution)
+ *
+ * Unmapped (not useful for memory):
+ *   BeforeModel, AfterModel, BeforeToolSelection — model-level events
+ *   that fire per-LLM-call, too chatty for observation capture.
+ *
+ * Base fields (all events): session_id, transcript_path, cwd, hook_event_name, timestamp
+ *
+ * Output format: { continue, stopReason, suppressOutput, systemMessage, decision, reason, hookSpecificOutput }
+ * Advisory hooks (SessionStart, SessionEnd, PreCompress, Notification) ignore flow-control fields.
+ */
+export const geminiCliAdapter: PlatformAdapter = {
+  normalizeInput(raw) {
+    const r = (raw ?? {}) as any;
+
+    // CWD resolution chain: JSON field → env vars → process.cwd()
+    const cwd = r.cwd
+      ?? process.env.GEMINI_CWD
+      ?? process.env.GEMINI_PROJECT_DIR
+      ?? process.env.CLAUDE_PROJECT_DIR
+      ?? process.cwd();
+
+    const sessionId = r.session_id
+      ?? process.env.GEMINI_SESSION_ID
+      ?? undefined;
+
+    const hookEventName: string | undefined = r.hook_event_name;
+
+    // Tool fields — present in BeforeTool, AfterTool
+    let toolName: string | undefined = r.tool_name;
+    let toolInput: unknown = r.tool_input;
+    let toolResponse: unknown = r.tool_response;
+
+    // AfterAgent: synthesize observation shape from the full agent response
+    if (hookEventName === 'AfterAgent' && r.prompt_response) {
+      toolName = toolName ?? 'GeminiAgent';
+      toolInput = toolInput ?? { prompt: r.prompt };
+      toolResponse = toolResponse ?? { response: r.prompt_response };
+    }
+
+    // BeforeTool: has tool_name and tool_input but no tool_response yet
+    // Synthesize a marker so observation handler knows this is pre-execution
+    if (hookEventName === 'BeforeTool' && toolName && !toolResponse) {
+      toolResponse = { _preExecution: true };
+    }
+
+    // Notification: capture as an observation with notification details
+    if (hookEventName === 'Notification') {
+      toolName = toolName ?? 'GeminiNotification';
+      toolInput = toolInput ?? {
+        notification_type: r.notification_type,
+        message: r.message,
+      };
+      toolResponse = toolResponse ?? { details: r.details };
+    }
+
+    // Collect platform-specific metadata
+    const metadata: Record<string, unknown> = {};
+    if (r.source) metadata.source = r.source;                     // SessionStart: startup|resume|clear
+    if (r.reason) metadata.reason = r.reason;                     // SessionEnd: exit|clear|logout|...
+    if (r.trigger) metadata.trigger = r.trigger;                  // PreCompress: auto|manual
+    if (r.mcp_context) metadata.mcp_context = r.mcp_context;     // Tool hooks: MCP server context
+    if (r.notification_type) metadata.notification_type = r.notification_type;
+    if (r.stop_hook_active !== undefined) metadata.stop_hook_active = r.stop_hook_active;
+    if (r.original_request_name) metadata.original_request_name = r.original_request_name;
+    if (hookEventName) metadata.hook_event_name = hookEventName;
+
+    return {
+      sessionId,
+      cwd,
+      prompt: r.prompt,
+      toolName,
+      toolInput,
+      toolResponse,
+      transcriptPath: r.transcript_path,
+      metadata: Object.keys(metadata).length > 0 ? metadata : undefined,
+    };
+  },
+
+  formatOutput(result) {
+    // Gemini CLI expects: { continue, stopReason, suppressOutput, systemMessage, decision, reason, hookSpecificOutput }
+    const output: Record<string, unknown> = {};
+
+    // Flow control — always include `continue` to prevent accidental agent termination
+    output.continue = result.continue ?? true;
+
+    if (result.suppressOutput !== undefined) {
+      output.suppressOutput = result.suppressOutput;
+    }
+
+    if (result.systemMessage) {
+      // Strip ANSI escape sequences: matches colors, text formatting, and terminal control codes
+      // Gemini CLI often has issues with ANSI escape sequences in tool output (showing them as raw text)
+      const ansiRegex = /[\u001b\u009b][[()#;?]*(?:[0-9]{1,4}(?:;[0-9]{0,4})*)?[0-9A-ORZcf-nqry=><]/g;
+      output.systemMessage = result.systemMessage.replace(ansiRegex, '');
+    }
+
+    // hookSpecificOutput is a first-class Gemini CLI field — pass through directly
+    // This includes additionalContext for context injection in SessionStart, BeforeAgent, AfterTool
+    if (result.hookSpecificOutput) {
+      output.hookSpecificOutput = {
+        additionalContext: result.hookSpecificOutput.additionalContext,
+      };
+    }
+
+    return output;
+  }
+};

src/cli/adapters/index.ts

@@ -1,16 +1,19 @@
 import type { PlatformAdapter } from '../types.js';
 import { claudeCodeAdapter } from './claude-code.js';
 import { cursorAdapter } from './cursor.js';
+import { geminiCliAdapter } from './gemini-cli.js';
 import { rawAdapter } from './raw.js';
 
 export function getPlatformAdapter(platform: string): PlatformAdapter {
   switch (platform) {
     case 'claude-code': return claudeCodeAdapter;
     case 'cursor': return cursorAdapter;
+    case 'gemini':
+    case 'gemini-cli': return geminiCliAdapter;
     case 'raw': return rawAdapter;
     // Codex CLI and other compatible platforms use the raw adapter (accepts both camelCase and snake_case fields)
     default: return rawAdapter;
   }
 }
 
-export { claudeCodeAdapter, cursorAdapter, rawAdapter };
+export { claudeCodeAdapter, cursorAdapter, geminiCliAdapter, rawAdapter };

src/cli/handlers/context.ts

@@ -66,9 +66,15 @@ export const contextHandler: EventHandler = {
 
       const additionalContext = contextResult.trim();
       const coloredTimeline = colorResult.trim();
+      const platform = input.platform;
 
-      const systemMessage = showTerminalOutput && coloredTimeline
-        ? `${coloredTimeline}\n\nView Observations Live @ http://localhost:${port}`
+      // Use colored timeline for display if available, otherwise fall back to 
+      // plain markdown context (especially useful for platforms like Gemini 
+      // where we want to ensure visibility even if colors aren't fetched).
+      const displayContent = coloredTimeline || (platform === 'gemini-cli' || platform === 'gemini' ? additionalContext : '');
+
+      const systemMessage = showTerminalOutput && displayContent
+        ? `${displayContent}\n\nView Observations Live @ http://localhost:${port}`
         : undefined;
 
       return {