feat(cli): add Slack socket mode support (#11245)

* feat(cli): add Slack socket mode support Add socket mode as an alternative to webhook mode for Slack connector, allowing connections without a public URL. - Introduce `--connection` flag to select webhook or socket mode - Add `--app-token` option for socket mode authentication - Make signing secret and base URL conditional on webhook mode - Add `parseSlackConnectionMode` with validation and tests - Update CLI platform definition to support hybrid connection type - Update README docs with socket mode usage examples * use base-url and remove connection flag * isSocketMode
2026-08-30 17:20:20 +08:00 · 2026-06-03 12:00:57 -07:00
parent 76af785fa6
commit 423fde4828
14 changed files with 450 additions and 101 deletions
@@ -212,8 +212,12 @@ cline schedule create "PR summary" \
 Chat with your agent from any messaging platform: Telegram, Slack, Discord, Google Chat, WhatsApp, and Linear. Each conversation thread maps to an agent session with full context. Set up access control to restrict who can interact with your agent.

 ```bash
+# Connect to Telegram
 cline connect telegram -k $BOT_TOKEN
-cline connect slack --token $SLACK_TOKEN --signing-secret $SECRET --base-url $URL
+# Connect to Slack through webhook
+cline connect slack --bot-token $SLACK_TOKEN --signing-secret $SECRET --base-url $URL
+# Connect to Slack using socket mode
+cline connect slack --bot-token $SLACK_TOKEN --app-token $SLACK_APP_TOKEN
 ```

 ## Headless CLI for CI/CD
@@ -174,6 +174,9 @@ cline connect telegram -k 123456:ABCDEF...
 # Slack (webhook mode)
 cline connect slack --bot-token $SLACK_BOT_TOKEN --signing-secret $SLACK_SIGNING_SECRET --base-url https://your-domain.com

+# Slack (socket mode)
+cline connect slack --bot-token $SLACK_BOT_TOKEN --app-token $SLACK_APP_TOKEN
+
 # Google Chat (webhook mode)
 cline connect gchat --base-url https://your-domain.com

@@ -1,9 +1,67 @@
+import type { ConnectSlackOptions } from "@cline/shared";
 import { describe, expect, it } from "vitest";
-import { __test__ } from "./slack";
+import { __test__, slackConnector } from "./slack";
+
+const parseSlackArgs = (rawArgs: string[]): ConnectSlackOptions =>
+	(
+		slackConnector as unknown as {
+			parseArgs(rawArgs: string[]): ConnectSlackOptions;
+		}
+	).parseArgs(rawArgs);

 describe("slack binding lookup", () => {
 	const participantKey = __test__.buildSlackParticipantKey("T123", "U123");

+	it("infers Slack webhook mode from a base URL", () => {
+		expect(__test__.inferSlackConnectionMode("https://example.test")).toBe(
+			"webhook",
+		);
+		expect(__test__.inferSlackConnectionMode("  ")).toBe("socket");
+		expect(__test__.inferSlackConnectionMode(undefined)).toBe("socket");
+	});
+
+	it("uses webhook mode when Slack args include a base URL", () => {
+		const options = parseSlackArgs([
+			"--bot-token",
+			"xoxb-token",
+			"--signing-secret",
+			"secret",
+			"--app-token",
+			"xapp-ignored",
+			"--base-url",
+			"https://example.test",
+		]);
+
+		expect(options.connectionMode).toBe("webhook");
+		expect(options.baseUrl).toBe("https://example.test");
+		expect(options.signingSecret).toBe("secret");
+		expect(options.appToken).toBeUndefined();
+	});
+
+	it("uses socket mode when Slack args omit a base URL", () => {
+		const previousBaseUrl = process.env.BASE_URL;
+		delete process.env.BASE_URL;
+		let options: ConnectSlackOptions;
+		try {
+			options = parseSlackArgs([
+				"--bot-token",
+				"xoxb-token",
+				"--app-token",
+				"xapp-token",
+			]);
+		} finally {
+			if (previousBaseUrl === undefined) {
+				delete process.env.BASE_URL;
+			} else {
+				process.env.BASE_URL = previousBaseUrl;
+			}
+		}
+
+		expect(options.connectionMode).toBe("socket");
+		expect(options.baseUrl).toBeUndefined();
+		expect(options.appToken).toBe("xapp-token");
+	});
+
 	it("falls back to channel identity when a restarted connector gets a new thread id", () => {
 		const result = __test__.findBindingForThread(
 			{
@@ -79,6 +79,14 @@ type SlackThreadState = ConnectorThreadState & {
 	teamId?: string;
 };

+type SlackConnectionMode = ConnectSlackOptions["connectionMode"];
+
+function inferSlackConnectionMode(
+	baseUrl: string | undefined,
+): SlackConnectionMode {
+	return baseUrl?.trim() ? "webhook" : "socket";
+}
+
 function truncateText(value: string, maxLength = 160): string {
 	return truncateConnectorText(value, maxLength);
 }
@@ -380,7 +388,10 @@ class SlackConnector extends ConnectorBase<
 	SlackConnectorState
 > {
 	constructor() {
-		super("slack", "Slack webhook bridge backed by RPC runtime sessions");
+		super(
+			"slack",
+			"Slack webhook/socket bridge backed by RPC runtime sessions",
+		);
 	}

 	protected override createCommand(): Command {
@@ -393,6 +404,7 @@ class SlackConnector extends ConnectorBase<
 				"Slack bot token for single-workspace mode",
 			)
 			.option("--signing-secret <secret>", "Slack signing secret")
+			.option("--app-token <token>", "Slack app-level token for socket mode")
 			.option("--client-id <id>", "Slack OAuth client id")
 			.option("--client-secret <secret>", "Slack OAuth client secret")
 			.option(
@@ -433,6 +445,7 @@ class SlackConnector extends ConnectorBase<
 					"Environment:",
 					"  SLACK_BOT_TOKEN             Single-workspace bot token",
 					"  SLACK_SIGNING_SECRET        Slack signing secret",
+					"  SLACK_APP_TOKEN             App-level token for socket mode",
 					"  SLACK_CLIENT_ID             OAuth client id",
 					"  SLACK_CLIENT_SECRET         OAuth client secret",
 					"  SLACK_ENCRYPTION_KEY        Optional installation encryption key",
@@ -445,6 +458,7 @@ class SlackConnector extends ConnectorBase<
 			userName?: string;
 			botToken?: string;
 			signingSecret?: string;
+			appToken?: string;
 			clientId?: string;
 			clientSecret?: string;
 			encryptionKey?: string;
@@ -467,17 +481,50 @@ class SlackConnector extends ConnectorBase<
 			this.parseOptionalInteger(opts.port, "port") ??
 			Number.parseInt(process.env.PORT ?? "8787", 10);
 		const port = Number.isFinite(parsedPort) ? parsedPort : 8787;
+		const baseUrl = opts.baseUrl?.trim() || process.env.BASE_URL?.trim();
+		const connectionMode = inferSlackConnectionMode(baseUrl);
+		const isSocketMode = connectionMode === "socket";
+		if (isSocketMode && (opts.clientId?.trim() || opts.clientSecret?.trim())) {
+			throw new Error(
+				"Slack socket mode does not support --client-id or --client-secret",
+			);
+		}
+		const botToken =
+			opts.botToken?.trim() || process.env.SLACK_BOT_TOKEN?.trim();
+		const appToken = isSocketMode
+			? opts.appToken?.trim() || process.env.SLACK_APP_TOKEN?.trim()
+			: undefined;
+		if (isSocketMode && !appToken) {
+			throw new Error(
+				"Slack socket mode requires --app-token or SLACK_APP_TOKEN",
+			);
+		}
+		if (isSocketMode && !botToken) {
+			throw new Error(
+				"Slack socket mode requires --bot-token or SLACK_BOT_TOKEN",
+			);
+		}
 		return {
 			userName:
 				opts.userName?.trim() ||
 				process.env.SLACK_BOT_USERNAME?.trim() ||
 				"cline-slack",
-			botToken: opts.botToken?.trim() || process.env.SLACK_BOT_TOKEN?.trim(),
+			connectionMode,
+			botToken,
 			signingSecret:
-				opts.signingSecret?.trim() || process.env.SLACK_SIGNING_SECRET?.trim(),
-			clientId: opts.clientId?.trim() || process.env.SLACK_CLIENT_ID?.trim(),
+				connectionMode === "webhook"
+					? opts.signingSecret?.trim() ||
+						process.env.SLACK_SIGNING_SECRET?.trim()
+					: opts.signingSecret?.trim(),
+			appToken,
+			clientId:
+				connectionMode === "webhook"
+					? opts.clientId?.trim() || process.env.SLACK_CLIENT_ID?.trim()
+					: undefined,
 			clientSecret:
-				opts.clientSecret?.trim() || process.env.SLACK_CLIENT_SECRET?.trim(),
+				connectionMode === "webhook"
+					? opts.clientSecret?.trim() || process.env.SLACK_CLIENT_SECRET?.trim()
+					: undefined,
 			encryptionKey:
 				opts.encryptionKey?.trim() || process.env.SLACK_ENCRYPTION_KEY?.trim(),
 			installationKeyPrefix:
@@ -500,10 +547,7 @@ class SlackConnector extends ConnectorBase<
 				process.env.CLINE_CONNECT_HOOK_COMMAND?.trim(),
 			port,
 			host: opts.host?.trim() || process.env.HOST?.trim() || "0.0.0.0",
-			baseUrl:
-				opts.baseUrl?.trim() ||
-				process.env.BASE_URL?.trim() ||
-				`http://127.0.0.1:${port}`,
+			baseUrl,
 		};
 	}

@@ -599,9 +643,11 @@ class SlackConnector extends ConnectorBase<
 				readState: (path) => this.readConnectorState(path),
 				isRunning: (state) => isProcessRunning(state.pid),
 				formatAlreadyRunningMessage: (state) =>
-					`[slack] connector already running pid=${state.pid} rpc=${state.rpcAddress} url=${state.baseUrl}`,
+					state.connectionMode === "socket"
+						? `[slack] connector already running pid=${state.pid} rpc=${state.rpcAddress} mode=socket`
+						: `[slack] connector already running pid=${state.pid} rpc=${state.rpcAddress} url=${state.baseUrl}`,
 				formatBackgroundStartMessage: (pid) =>
-					`[slack] starting background connector pid=${pid} user=${options.userName}`,
+					`[slack] starting background connector pid=${pid} user=${options.userName} mode=${options.connectionMode}`,
 				foregroundHint:
 					"[slack] use `cline connect slack -i ...` to run in the foreground",
 				launchFailureMessage: "failed to launch Slack connector in background",
@@ -618,6 +664,7 @@ class SlackConnector extends ConnectorBase<
 		const consoleLogger = new ConsoleLogger("info", "slack-connect");
 		const slackConfig: Record<string, unknown> = {
 			logger: consoleLogger,
+			mode: options.connectionMode,
 			userName: options.userName,
 		};
 		if (options.botToken?.trim()) {
@@ -626,6 +673,9 @@ class SlackConnector extends ConnectorBase<
 		if (options.signingSecret?.trim()) {
 			slackConfig.signingSecret = options.signingSecret.trim();
 		}
+		if (options.appToken?.trim()) {
+			slackConfig.appToken = options.appToken.trim();
+		}
 		if (options.clientId?.trim()) {
 			slackConfig.clientId = options.clientId.trim();
 		}
@@ -694,10 +744,12 @@ class SlackConnector extends ConnectorBase<
 		await client.connect();
 		this.writeConnectorState(statePath, {
 			userName: options.userName,
+			connectionMode: options.connectionMode,
 			pid: process.pid,
 			rpcAddress,
-			port: options.port,
-			baseUrl: options.baseUrl,
+			...(options.connectionMode === "webhook"
+				? { port: options.port, baseUrl: options.baseUrl }
+				: {}),
 			startedAt: new Date().toISOString(),
 		});

@@ -948,48 +1000,64 @@ class SlackConnector extends ConnectorBase<
 				},
 			});

-		const webhookUrl = `${options.baseUrl.replace(/\/$/, "")}/api/webhooks/slack`;
-		const oauthCallbackUrl = `${options.baseUrl.replace(/\/$/, "")}/api/oauth/slack/callback`;
-		const server = await startConnectorWebhookServer({
-			host: options.host,
-			port: options.port,
-			routes: {
-				"/api/webhooks/slack": async (request) => bot.webhooks.slack(request),
-				"/api/oauth/slack/callback": async (request) => {
-					try {
-						const result = await slack.handleOAuthCallback(request);
-						return new Response(
-							`Slack installation stored for team ${result.teamId}. You can return to Slack.`,
-						);
-					} catch (error) {
-						const message =
-							error instanceof Error ? error.message : String(error);
-						loggerAdapter.core.log("Slack OAuth callback failed", {
-							severity: "warn",
-							transport: "slack",
-							error: message,
+		let webhookUrl: string | undefined;
+		let oauthCallbackUrl: string | undefined;
+		const server =
+			options.connectionMode === "webhook"
+				? await (async () => {
+						const baseUrl = options.baseUrl?.trim();
+						if (!baseUrl) {
+							throw new Error(
+								"Slack webhook mode requires --base-url or BASE_URL",
+							);
+						}
+						webhookUrl = `${baseUrl.replace(/\/$/, "")}/api/webhooks/slack`;
+						oauthCallbackUrl = `${baseUrl.replace(/\/$/, "")}/api/oauth/slack/callback`;
+						return startConnectorWebhookServer({
+							host: options.host,
+							port: options.port,
+							routes: {
+								"/api/webhooks/slack": async (request) =>
+									bot.webhooks.slack(request),
+								"/api/oauth/slack/callback": async (request) => {
+									try {
+										const result = await slack.handleOAuthCallback(request);
+										return new Response(
+											`Slack installation stored for team ${result.teamId}. You can return to Slack.`,
+										);
+									} catch (error) {
+										const message =
+											error instanceof Error ? error.message : String(error);
+										loggerAdapter.core.log("Slack OAuth callback failed", {
+											severity: "warn",
+											transport: "slack",
+											error: message,
+										});
+										return new Response(`Slack OAuth error: ${message}`, {
+											status: 500,
+										});
+									}
+								},
+								"/health": () => new Response("ok"),
+								"/": () =>
+									new Response(
+										[
+											"Slack connector is running.",
+											"Connection mode: webhook",
+											`Webhook URL: ${webhookUrl}`,
+											`OAuth callback URL: ${oauthCallbackUrl}`,
+											options.botToken?.trim()
+												? "Auth mode: single workspace"
+												: options.clientId?.trim() &&
+														options.clientSecret?.trim()
+													? "Auth mode: multi-workspace OAuth"
+													: "Auth mode: incomplete (set bot token or OAuth credentials)",
+										].join("\n"),
+									),
+							},
 						});
-						return new Response(`Slack OAuth error: ${message}`, {
-							status: 500,
-						});
-					}
-				},
-				"/health": () => new Response("ok"),
-				"/": () =>
-					new Response(
-						[
-							"Slack connector is running.",
-							`Webhook URL: ${webhookUrl}`,
-							`OAuth callback URL: ${oauthCallbackUrl}`,
-							options.botToken?.trim()
-								? "Auth mode: single workspace"
-								: options.clientId?.trim() && options.clientSecret?.trim()
-									? "Auth mode: multi-workspace OAuth"
-									: "Auth mode: incomplete (set bot token or OAuth credentials)",
-						].join("\n"),
-					),
-			},
-		});
+					})()
+				: undefined;

 		const stopEventStream = client.streamEvents(
 			{ clientId: `${clientId}-server-events` },
@@ -1052,17 +1120,22 @@ class SlackConnector extends ConnectorBase<
 		process.once("SIGINT", () => requestStop("sigint"));
 		process.once("SIGTERM", () => requestStop("sigterm"));

-		io.writeln(`[slack] listening on ${options.host}:${options.port}`);
-		io.writeln(`[slack] configure Slack webhook URL: ${webhookUrl}`);
-		io.writeln(
-			`[slack] configure Slack OAuth callback URL: ${oauthCallbackUrl}`,
-		);
+		if (options.connectionMode === "webhook") {
+			io.writeln(`[slack] listening on ${options.host}:${options.port}`);
+			io.writeln(`[slack] configure Slack webhook URL: ${webhookUrl}`);
+			io.writeln(
+				`[slack] configure Slack OAuth callback URL: ${oauthCallbackUrl}`,
+			);
+		} else {
+			io.writeln("[slack] socket mode connected");
+		}

 		await stopPromise;
 		clearBindingSessionIds<SlackThreadState>(bindingsPath);
 		stopTaskUpdateStream();
 		stopEventStream();
-		await server.close();
+		await server?.close();
+		await bot.shutdown();
 		userInstructionService.stop();
 		client.close();
 		this.removeStateFile(statePath);
@@ -1073,6 +1146,7 @@ class SlackConnector extends ConnectorBase<
 export const slackConnector: ConnectCommandDefinition = new SlackConnector();

 export const __test__ = {
+	inferSlackConnectionMode,
 	buildSlackParticipantKey,
 	resolveSlackParticipant,
 	normalizeSlackMessageEventChannelType,
@@ -19,7 +19,7 @@ export const CONNECTOR_CATALOG: ConnectorCatalogEntry[] = [
 	},
 	{
 		name: "slack",
-		description: "Slack webhook bridge backed by RPC runtime sessions",
+		description: "Slack webhook/socket bridge backed by RPC runtime sessions",
 	},
 	{
 		name: "telegram",
@@ -26,6 +26,7 @@ export type ActiveConnectorRecord = {
 	phoneNumberId?: string;
 	port?: number;
 	baseUrl?: string;
+	connectionMode?: string;
 };

 function listConnectorStatePaths(
@@ -68,6 +69,8 @@ const connectorFieldExtractors: Record<
 	startedAt: (p) => (typeof p.startedAt === "string" ? p.startedAt : undefined),
 	port: (p) => (typeof p.port === "number" ? p.port : undefined),
 	baseUrl: (p) => (typeof p.baseUrl === "string" ? p.baseUrl : undefined),
+	connectionMode: (p) =>
+		typeof p.connectionMode === "string" ? p.connectionMode : undefined,
 	userName: (p) => (typeof p.userName === "string" ? p.userName : undefined),
 	botUsername: (p) =>
 		typeof p.botUsername === "string" ? p.botUsername : undefined,
@@ -91,7 +94,10 @@ const connectorConfigs: Record<
 		required: ["userName"],
 		optional: ["startedAt", "port", "baseUrl"],
 	},
-	slack: { required: ["userName"], optional: ["startedAt", "port", "baseUrl"] },
+	slack: {
+		required: ["userName"],
+		optional: ["startedAt", "connectionMode", "port", "baseUrl"],
+	},
 	whatsapp: {
 		required: ["userName"],
 		optional: ["startedAt", "phoneNumberId", "port", "baseUrl"],
@@ -1,6 +1,11 @@
 import * as p from "@clack/prompts";
 import { runConnectAdapter } from "../../commands/connect";
-import { PLATFORMS, type PlatformDef, type SecurityDef } from "./platforms";
+import {
+	PLATFORMS,
+	type PlatformDef,
+	type SecurityDef,
+	shouldIncludeField,
+} from "./platforms";

 function isCancel(value: unknown): value is symbol {
 	return p.isCancel(value);
@@ -10,6 +15,7 @@ const SENSITIVE_FLAGS = new Set([
 	"-k",
 	"--access-token",
 	"--api-key",
+	"--app-token",
 	"--app-secret",
 	"--bot-token",
 	"--credentials-json",
@@ -33,28 +39,40 @@ function redactCommandArgs(args: string[]): string {

 async function collectFields(platform: PlatformDef): Promise<string[] | null> {
 	const args: string[] = [];
+	const values: Record<string, string> = {};

 	for (const field of platform.fields) {
+		if (!shouldIncludeField(field, values)) {
+			continue;
+		}
 		if (field.help) {
 			for (const line of field.help) {
 				p.log.info(line);
 			}
 		}

-		const value = await p.text({
-			message: field.label,
-			placeholder: field.placeholder,
-			validate: field.required
-				? (v) => {
-						if (!v?.trim()) return `${field.label} is required`;
-						return undefined;
-					}
-				: undefined,
-		});
+		const value = field.options
+			? await p.select({
+					message: field.label,
+					options: field.options,
+					initialValue: field.initialValue,
+				})
+			: await p.text({
+					message: field.label,
+					placeholder: field.placeholder,
+					defaultValue: field.initialValue,
+					validate: field.required
+						? (v) => {
+								if (!v?.trim()) return `${field.label} is required`;
+								return undefined;
+							}
+						: undefined,
+				});

 		if (isCancel(value)) return null;

 		const trimmed = (value as string).trim();
+		values[field.flag] = trimmed;
 		if (trimmed) {
 			args.push(field.flag, trimmed);
 		}
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { PLATFORMS } from "./platforms";
+import { PLATFORMS, shouldIncludeField } from "./platforms";

 describe("connect wizard platform security fields", () => {
 	it("does not ask Telegram users to re-enter the bot username", () => {
@@ -30,4 +30,28 @@ describe("connect wizard platform security fields", () => {
 		expect(slackUser?.validate?.("U01ABC123")).toBeUndefined();
 		expect(slackUser?.validate?.("U01$(bad)")).toContain("Slack member");
 	});
+
+	it("asks Slack users for mode-specific setup fields", () => {
+		const slack = PLATFORMS.find((platform) => platform.id === "slack");
+		const fields = slack?.fields ?? [];
+		const webhookValues = { "--base-url": "https://example.test" };
+		const socketValues = { "--base-url": "" };
+
+		expect(fields.map((field) => field.flag)).toEqual([
+			"--bot-token",
+			"--base-url",
+			"--signing-secret",
+			"--app-token",
+		]);
+		expect(
+			fields
+				.filter((field) => shouldIncludeField(field, webhookValues))
+				.map((field) => field.flag),
+		).toEqual(["--bot-token", "--base-url", "--signing-secret"]);
+		expect(
+			fields
+				.filter((field) => shouldIncludeField(field, socketValues))
+				.map((field) => field.flag),
+		).toEqual(["--bot-token", "--base-url", "--app-token"]);
+	});
 });
@@ -1,7 +1,7 @@
 export interface PlatformDef {
 	id: string;
 	name: string;
-	type: "polling" | "webhook";
+	type: "polling" | "webhook" | "hybrid";
 	hint: string;
 	fields: FieldDef[];
 	security?: SecurityDef;
@@ -13,8 +13,17 @@ export interface FieldDef {
 	placeholder?: string;
 	required?: boolean;
 	help?: string[];
+	initialValue?: string;
+	options?: Array<{ value: string; label: string; hint?: string }>;
+	includeWhen?: FieldCondition;
 }

+export type FieldCondition = {
+	flag: string;
+	equals?: string;
+	notEquals?: string;
+};
+
 export interface SecurityFieldDef {
 	key: string;
 	label: string;
@@ -30,6 +39,24 @@ export interface SecurityDef {
 	buildHookCommand: (values: Record<string, string>) => string;
 }

+export function shouldIncludeField(
+	field: FieldDef,
+	values: Record<string, string>,
+): boolean {
+	const condition = field.includeWhen;
+	if (!condition) {
+		return true;
+	}
+	const value = values[condition.flag] ?? "";
+	if (condition.equals !== undefined && value !== condition.equals) {
+		return false;
+	}
+	if (condition.notEquals !== undefined && value === condition.notEquals) {
+		return false;
+	}
+	return true;
+}
+
 function validateTelegramUserId(value: string): string | undefined {
 	return /^\d+$/.test(value)
 		? undefined
@@ -91,8 +118,8 @@ export const PLATFORMS: PlatformDef[] = [
 	{
 		id: "slack",
 		name: "Slack",
-		type: "webhook",
-		hint: "Requires a Slack app and public URL.",
+		type: "hybrid",
+		hint: "Public URL for webhook mode; leave blank for socket mode.",
 		fields: [
 			{
 				flag: "--bot-token",
@@ -105,21 +132,32 @@ export const PLATFORMS: PlatformDef[] = [
 					"Install to workspace and copy the Bot Token",
 				],
 			},
+			{
+				flag: "--base-url",
+				label: "Public base URL",
+				placeholder: "leave blank for socket mode",
+				help: [
+					"Enter a publicly accessible URL for webhook mode",
+					"Leave blank to use Slack socket mode instead",
+				],
+			},
 			{
 				flag: "--signing-secret",
 				label: "Signing secret",
 				required: true,
 				help: ["Found in your app's Basic Information page"],
+				includeWhen: { flag: "--base-url", notEquals: "" },
 			},
 			{
-				flag: "--base-url",
-				label: "Public base URL",
-				placeholder: "https://example.com",
+				flag: "--app-token",
+				label: "App-level token",
+				placeholder: "xapp-...",
 				required: true,
 				help: [
-					"Your publicly accessible URL for webhook callbacks",
-					"Use ngrok or similar for local development",
+					"Enable Socket Mode in the Slack app",
+					"Generate an app-level token with the connections:write scope",
 				],
+				includeWhen: { flag: "--base-url", equals: "" },
 			},
 		],
 		security: {
@@ -2,7 +2,10 @@ import { spawn } from "node:child_process";
 import process from "node:process";
 import { listConnectorCatalog } from "../../../cli/src/connectors/catalog";
 import { listActiveConnectors } from "../../../cli/src/connectors/status";
-import { PLATFORMS } from "../../../cli/src/wizards/connect/platforms";
+import {
+	PLATFORMS,
+	shouldIncludeField,
+} from "../../../cli/src/wizards/connect/platforms";
 import type {
 	WebviewConnectorChannel,
 	WebviewConnectorChannelsResponse,
@@ -27,6 +30,9 @@ export function connectorChannelsPayload(): WebviewConnectorChannelsResponse {
 			placeholder: field.placeholder,
 			required: field.required,
 			help: field.help,
+			initialValue: field.initialValue,
+			options: field.options,
+			includeWhen: field.includeWhen,
 		})),
 		security: platform.security
 			? {
@@ -104,9 +110,21 @@ function buildConnectorStartArgs(args?: Record<string, unknown>): string[] {
 		throw new Error(`connector channel is not available: ${channel}`);
 	}
 	const values = asRecord(args?.values) ?? {};
+	const fieldValues: Record<string, string> = {};
+	for (const field of platform.fields) {
+		const rawValue = values[field.flag];
+		if (typeof rawValue === "string") {
+			fieldValues[field.flag] = rawValue.trim();
+		} else if (field.initialValue) {
+			fieldValues[field.flag] = field.initialValue;
+		}
+	}
 	const cliArgs = [channel];
 	for (const field of platform.fields) {
-		const value = asString(values[field.flag]);
+		if (!shouldIncludeField(field, fieldValues)) {
+			continue;
+		}
+		const value = fieldValues[field.flag];
 		if (!value) {
 			if (field.required) throw new Error(`${field.label} is required`);
 			continue;
@@ -134,6 +134,13 @@ export type WebviewConnectorField = {
 	placeholder?: string;
 	required?: boolean;
 	help?: string[];
+	initialValue?: string;
+	options?: Array<{ value: string; label: string; hint?: string }>;
+	includeWhen?: {
+		flag: string;
+		equals?: string;
+		notEquals?: string;
+	};
 };

 export type WebviewConnectorSecurityField = {
@@ -147,7 +154,7 @@ export type WebviewConnectorSecurityField = {
 export type WebviewConnectorChannel = {
 	id: string;
 	name: string;
-	type: "polling" | "webhook";
+	type: "polling" | "webhook" | "hybrid";
 	hint: string;
 	fields: WebviewConnectorField[];
 	security?: {
@@ -168,6 +175,7 @@ export type WebviewActiveConnector = {
 	phoneNumberId?: string;
 	port?: number;
 	baseUrl?: string;
+	connectionMode?: string;
 };

 export type WebviewConnectorChannelsResponse = {
@@ -42,6 +42,13 @@ type ConnectorField = {
 	placeholder?: string;
 	required?: boolean;
 	help?: string[];
+	initialValue?: string;
+	options?: Array<{ value: string; label: string; hint?: string }>;
+	includeWhen?: {
+		flag: string;
+		equals?: string;
+		notEquals?: string;
+	};
 };

 type ConnectorSecurityField = {
@@ -55,7 +62,7 @@ type ConnectorSecurityField = {
 type ConnectorChannel = {
 	id: string;
 	name: string;
-	type: "polling" | "webhook";
+	type: "polling" | "webhook" | "hybrid";
 	hint: string;
 	fields: ConnectorField[];
 	security?: {
@@ -76,6 +83,7 @@ type ActiveConnector = {
 	phoneNumberId?: string;
 	port?: number;
 	baseUrl?: string;
+	connectionMode?: string;
 };

 type ConnectorChannelsResponse = {
@@ -142,10 +150,41 @@ function isMultilineField(field: ConnectorField): boolean {
 	return label.includes("json") || field.flag.includes("credentials");
 }

+function shouldIncludeField(
+	field: ConnectorField,
+	values: Record<string, string>,
+): boolean {
+	const condition = field.includeWhen;
+	if (!condition) {
+		return true;
+	}
+	const value = values[condition.flag] ?? "";
+	if (condition.equals !== undefined && value !== condition.equals) {
+		return false;
+	}
+	if (condition.notEquals !== undefined && value === condition.notEquals) {
+		return false;
+	}
+	return true;
+}
+
+function initialValuesForChannel(
+	channel?: ConnectorChannel,
+): Record<string, string> {
+	const values: Record<string, string> = {};
+	for (const field of channel?.fields ?? []) {
+		if (field.initialValue) {
+			values[field.flag] = field.initialValue;
+		}
+	}
+	return values;
+}
+
 function createFormState(channels: ConnectorChannel[]): ConnectorFormState {
+	const channel = channels[0];
 	return {
-		channelId: channels[0]?.id ?? "",
-		values: {},
+		channelId: channel?.id ?? "",
+		values: initialValuesForChannel(channel),
 		securityEnabled: false,
 		securityValues: {},
 	};
@@ -175,6 +214,15 @@ export function ChannelsContent() {
 		() => channels.find((channel) => channel.id === formState.channelId),
 		[channels, formState.channelId],
 	);
+	const visibleFields = useMemo(() => {
+		const values = {
+			...initialValuesForChannel(selectedChannel),
+			...formState.values,
+		};
+		return (selectedChannel?.fields ?? []).filter((field) =>
+			shouldIncludeField(field, values),
+		);
+	}, [selectedChannel, formState.values]);

 	const applyResponse = useCallback((response: ConnectorChannelsResponse) => {
 		setChannels(response.available);
@@ -233,6 +281,9 @@ export function ChannelsContent() {
 			return;
 		}
 		for (const field of selectedChannel.fields) {
+			if (!visibleFields.includes(field)) {
+				continue;
+			}
 			if (field.required && !formState.values[field.flag]?.trim()) {
 				setFormError(`${field.label} is required`);
 				return;
@@ -376,6 +427,11 @@ export function ChannelsContent() {
 											<span className="rounded-md border bg-background px-1.5 py-0.5">
 												{formatDateTime(connector.startedAt)}
 											</span>
+											{connector.connectionMode ? (
+												<span className="rounded-md border bg-background px-1.5 py-0.5">
+													{connector.connectionMode}
+												</span>
+											) : null}
 										</div>
 									</div>
 									<Button
@@ -413,7 +469,9 @@ export function ChannelsContent() {
 									}
 									setFormState({
 										channelId: value,
-										values: {},
+										values: initialValuesForChannel(
+											channels.find((channel) => channel.id === value),
+										),
 										securityEnabled: false,
 										securityValues: {},
 									});
@@ -433,7 +491,7 @@ export function ChannelsContent() {
 							</Select>
 						</div>

-						{selectedChannel?.fields.map((field) => (
+						{visibleFields.map((field) => (
 							<div className="grid gap-2" key={field.flag}>
 								<Label>
 									{field.label}
@@ -441,7 +499,29 @@ export function ChannelsContent() {
 										<span className="text-destructive"> *</span>
 									) : null}
 								</Label>
-								{isMultilineField(field) ? (
+								{field.options ? (
+									<Select
+										onValueChange={(value) => {
+											if (value) {
+												updateFieldValue(field.flag, value);
+											}
+										}}
+										value={
+											formState.values[field.flag] ?? field.initialValue ?? ""
+										}
+									>
+										<SelectTrigger>
+											<SelectValue placeholder={field.placeholder} />
+										</SelectTrigger>
+										<SelectContent>
+											{field.options.map((option) => (
+												<SelectItem key={option.value} value={option.value}>
+													{option.label}
+												</SelectItem>
+											))}
+										</SelectContent>
+									</Select>
+								) : isMultilineField(field) ? (
 									<Textarea
 										onChange={(event) =>
 											updateFieldValue(field.flag, event.target.value)
@@ -22,7 +22,7 @@ cline connect
 | Platform | Direct Command | Required Credentials |
 |----------|---------------|---------------------|
 | Telegram | `cline connect telegram` | Bot token |
-| Slack | `cline connect slack` | Bot token, signing secret, base URL |
+| Slack | `cline connect slack` | Bot token plus webhook signing secret/base URL or socket app token |
 | Discord | `cline connect discord` | Application ID, bot token, public key, base URL |
 | Google Chat | `cline connect gchat` | Service account credentials JSON, base URL |
 | WhatsApp | `cline connect whatsapp` | Phone number ID, access token, app secret, verify token, base URL |
@@ -75,13 +75,28 @@ The `--hook-command` receives each incoming message with sender info via stdin.

 ## Slack

-Requires a bot token, signing secret, and public base URL.
+Slack supports webhook mode and socket mode. Each Slack thread maps to an agent session, so the agent maintains conversation context within a thread.
+
+Webhook mode requires a bot token, signing secret, and public base URL:

 ```bash
-cline connect slack --token <BOT-TOKEN> --signing-secret <SECRET> --base-url <URL>
+cline connect slack \
+  --bot-token <BOT-TOKEN> \
+  --signing-secret <SECRET> \
+  --base-url <URL>
 ```

-Each Slack thread maps to an agent session, so the agent maintains conversation context within a thread.
+Configure the Slack app's event subscription and interactivity request URLs to `<URL>/api/webhooks/slack`.
+
+Socket mode requires a bot token and an app-level token with the `connections:write` scope:
+
+```bash
+cline connect slack \
+  --bot-token <BOT-TOKEN> \
+  --app-token <APP-LEVEL-TOKEN>
+```
+
+Enable Socket Mode in the Slack app. Socket mode does not need a public request URL and is single-workspace only.

 ## Discord

@@ -257,7 +272,7 @@ Multiple connectors can run simultaneously. They all share the same hub:
 cline connect telegram -k $TELEGRAM_TOKEN

 # Terminal 2
-cline connect slack --token $SLACK_TOKEN --signing-secret $SECRET --base-url $URL
+cline connect slack --bot-token $SLACK_TOKEN --signing-secret $SECRET --base-url $URL
 ```

 Connectors require the hub. Start it with `cline hub start` if it doesn't auto-start.
@@ -58,8 +58,10 @@ export type TelegramConnectorState = {

 export type ConnectSlackOptions = {
 	userName: string;
+	connectionMode: "webhook" | "socket";
 	botToken?: string;
 	signingSecret?: string;
+	appToken?: string;
 	clientId?: string;
 	clientSecret?: string;
 	encryptionKey?: string;
@@ -77,15 +79,16 @@ export type ConnectSlackOptions = {
 	hookCommand?: string;
 	port: number;
 	host: string;
-	baseUrl: string;
+	baseUrl?: string;
 };

 export type SlackConnectorState = {
 	userName: string;
+	connectionMode?: "webhook" | "socket";
 	pid: number;
 	rpcAddress: string;
-	port: number;
-	baseUrl: string;
+	port?: number;
+	baseUrl?: string;
 	startedAt: string;
 };