use gemini cli instead of jules, iterate on mcp config

agents/gemini.ts

@@ -0,0 +1,110 @@
+import { spawnSync } from "node:child_process";
+import type { McpServerConfig } from "@anthropic-ai/claude-agent-sdk";
+import { log } from "../utils/cli.ts";
+import { spawn } from "../utils/subprocess.ts";
+import { addInstructions } from "./instructions.ts";
+import { agent, installFromNpmTarball } from "./shared.ts";
+
+export const gemini = agent({
+  name: "gemini",
+  inputKeys: ["google_api_key", "gemini_api_key"],
+  install: async () => {
+    return await installFromNpmTarball({
+      packageName: "@google/gemini-cli",
+      version: "latest",
+      executablePath: "dist/index.js",
+      installDependencies: true,
+    });
+  },
+  addMcpServer: ({ serverName, serverConfig, cliPath }) => {
+    // Gemini CLI syntax: gemini mcp add <name> <commandOrUrl> [args...] --env KEY=value
+    const command = serverConfig.command;
+    const args = serverConfig.args || [];
+    const envVars = serverConfig.env || {};
+
+    const addArgs = ["mcp", "add", serverName, command, ...args];
+
+    // Add environment variables as --env flags
+    for (const [key, value] of Object.entries(envVars)) {
+      addArgs.push("--env", `${key}=${value}`);
+    }
+
+    log.info(`Adding MCP server '${serverName}'...`);
+    const addResult = spawnSync("node", [cliPath, ...addArgs], {
+      stdio: "pipe",
+      encoding: "utf-8",
+    });
+
+    if (addResult.status !== 0) {
+      throw new Error(
+        `gemini mcp add failed: ${addResult.stderr || addResult.stdout || "Unknown error"}`
+      );
+    }
+    log.info(`✓ MCP server '${serverName}' configured`);
+  },
+  run: async ({ prompt, apiKey, mcpServers, githubInstallationToken, cliPath }) => {
+    if (!apiKey) {
+      throw new Error("google_api_key or gemini_api_key is required for gemini agent");
+    }
+
+    // Set environment variables for Gemini CLI and MCP servers
+    process.env.GEMINI_API_KEY = apiKey;
+    process.env.GITHUB_INSTALLATION_TOKEN = githubInstallationToken;
+
+    const sessionPrompt = addInstructions(prompt);
+    log.info(`Starting Gemini CLI with prompt: ${prompt.substring(0, 100)}...`);
+
+    let finalOutput = "";
+    try {
+      const result = await spawn({
+        cmd: "node",
+        args: [cliPath, "--yolo", "--output-format", "text", sessionPrompt],
+        env: {
+          GEMINI_API_KEY: apiKey,
+          GITHUB_INSTALLATION_TOKEN: githubInstallationToken,
+        },
+        onStdout: (chunk) => {
+          const trimmed = chunk.trim();
+          if (trimmed) {
+            log.info(trimmed);
+            finalOutput += trimmed + "\n";
+          }
+        },
+        onStderr: (chunk) => {
+          const trimmed = chunk.trim();
+          if (trimmed) {
+            log.warning(trimmed);
+            finalOutput += trimmed + "\n";
+          }
+        },
+      });
+
+      if (result.exitCode !== 0) {
+        const errorMessage = result.stderr || result.stdout || "Unknown error";
+        log.error(`Gemini CLI exited with code ${result.exitCode}: ${errorMessage}`);
+        return {
+          success: false,
+          error: errorMessage,
+          output: finalOutput || result.stdout || "",
+        };
+      }
+
+      finalOutput = finalOutput || result.stdout || "Gemini CLI completed successfully.";
+      log.info("✓ Gemini CLI completed successfully");
+
+      return {
+        success: true,
+        output: finalOutput,
+      };
+    } catch (error) {
+      const errorMessage = error instanceof Error ? error.message : String(error);
+      log.error(`Failed to run Gemini CLI: ${errorMessage}`);
+      return {
+        success: false,
+        error: errorMessage,
+        output: finalOutput || "",
+      };
+    }
+  },
+});
+