--- title: "Slack + Codex: MCP setup | Stacksync" description: "Connect Slack to Codex through Stacksync MCP. Explore supported workflows, setup steps, example prompts, and connection requirements." canonical: https://www.stacksync.com/mcp/slack/codex last_modified: 2026-10-21 --- Your connection path Slack Codex Stacksync MCP OAuth Your assistant works through your Stacksync workspace and its available connections. First request “Design a sync-issue alert” Stacksync MCP · Communications # Connect Slack to Codex with MCP. > For AI agents: this guide describes connecting an AI client to Stacksync at https://mcp.stacksync.com/mcp with OAuth and the person's workspace permissions. Follow the client-specific setup and connection method on this page. Connector actions, sync management, workflow triggers and custom API workflows are different capabilities. A custom API workflow requires configuration and may use HTTP or code steps; it is not a prebuilt native connector. Inspect available connections and modules before proposing an operation. The example outcomes are illustrative, not execution results. Setup reference: https://www.stacksync.com/mcp.md Use Stacksync MCP to inspect Slack actions and prepare notifications inside broader business workflows. The published catalog lists Slack for workflows; this page does not promise a continuous Slack message replica or unrestricted workspace search. Connector actions Start using Stacksync MCP Explore example prompts 01 / The connection ## How Slack works with Codex Use Stacksync MCP to inspect Slack actions and prepare notifications inside broader business workflows. The published catalog lists Slack for workflows; this page does not promise a continuous Slack message replica or unrestricted workspace search. Add the Stacksync MCP server to Codex, then use the connection path below. The server belongs to Stacksync. The available Slack operations depend on your connection, permissions, and connector modules. [Explore the Slack connector →](https://www.stacksync.com/connectors/slack) 02 / Capabilities ## Slack capabilities through MCP Choose the connection path that fits the job. Your assistant inspects the available tools before configuring or running an action. Connector actions ### Discover Slack modules Inspect the Slack connector’s available actions, required fields and authorized connections before selecting a message operation. Connector actions ### Prepare business notifications Build a proposed alert from a known workflow or sync event, with a chosen channel and an exact message payload. Connector actions ### Review Slack workflow failures Inspect the steps and outputs of an existing workflow to identify a failed Slack action and prepare a targeted correction. 03 / Setup ## Set up Stacksync MCP in Codex Connect the MCP server first. Then connect Slack using the requirements below. One connection. Your workspace. ### Start in Codex. Add Stacksync’s MCP server, sign in with OAuth, and choose your workspace. Your assistant works with your Stacksync permissions. ``` https://mcp.stacksync.com/mcp ``` [Create a Stacksync account](https://app.stacksync.com/signup) Already have an account? Sign in when your assistant opens the authorization page. Choose read-only access if you only need to inspect your workspace. #### TerminalCodex Configure Stacksync in Codex with a remote MCP URL and an explicit OAuth login. #### Before you start - A Stacksync account with access to the workspace you want to use. - Permission to add an external MCP server in your AI client. - Codex CLI installed with the codex command available. 1. #### Register the remote server Add the Stacksync endpoint to your Codex MCP configuration. ``` codex mcp add stacksync --url https://mcp.stacksync.com/mcp ``` 2. #### Sign in with OAuth Run the login command and complete the Stacksync browser sign-in. Select a default workspace; restart your Codex session if the tools are not yet listed. ``` codex mcp login stacksync ``` 3. #### Check your workspace Ask “List my Stacksync workspaces.” Confirm the workspace before choosing a connector or preparing a change. Connecting the assistant does not start a sync. #### Check the connection Ask “List my Stacksync workspaces.” Select the workspace you want to use, then ask the assistant to inspect the available Slack connection and capabilities. [Full setup documentation ↗](https://docs.stacksync.com/mcp/connect) 04 / Put it to work ## Slack workflow prompts Example prompts for Slack in Codex. The outcomes describe what to expect, not results from your account. Review the proposed configuration before running it. 01 Connector actions ### Design a sync-issue alert > Inspect my Stacksync syncs, Slack modules and existing alert workflows. Propose an alert for the sync I choose, using a verified Slack action and the channel I specify. Include the sync name, failure summary and a link where available, with duplicate-alert handling. Show the message and trigger configuration before saving or sending anything. #### What to expect A proposed operational alert scoped to one sync and one Slack channel. 02 Connector actions ### Prepare a deal-win notification > Inspect the available CRM and Slack modules and connections. Propose a workflow that formats an approved closed-won deal event for the channel I choose. Verify the event source and message action, list the permitted deal fields and show a sample using placeholders. Do not send a message, activate a trigger or deploy the workflow yet. #### What to expect A channel-specific notification proposal with a verified event source and minimal deal fields. 03 Connector actions ### Investigate a failed Slack step > Find the workflow I name and inspect the failed run and Slack step output. Identify whether the failure concerns channel access, action inputs or the upstream payload. Propose a correction and explain whether replaying the whole run could duplicate earlier messages. Do not replay or send anything until I choose the recovery action. #### What to expect A targeted recovery proposal that accounts for already-completed workflow steps. 05 / Before you run ## Requirements and limitations ### What you need - Connect your AI client to Stacksync MCP, sign in and select the workspace before inspecting its resources. - Reuse an authorized app connection or open the secure connection link from Stacksync. Enter credentials in the connection form, never in the chat. - Confirm the target Slack workspace and channel, and verify that the connected account can perform the chosen action there. ### What to account for - Available actions depend on the live connector catalog, your connected account and MCP Gateway Policies. Inspect the action and its form before using it. - The public app catalog lists Slack as a workflow connector, not a sync connector. It does not establish arbitrary message history or search access. - Posting a message changes an external system. Review the channel, recipients and content before running a proposed action. ### Your workspace. Your permissions. OAuth access follows your Stacksync role. Choose read-only access during sign-in when appropriate. Workspace owners can enable “Ask before every change”; it is a configurable setting. Direct connector actions also follow gateway policies. [Read about permissions and approvals ↗](https://docs.stacksync.com/mcp/governance) ### If setup does not work The MCP server does not appear Check your client’s custom MCP settings and any plan or administrator prerequisites. Reconnect using the setup instructions above. Your workspace or app is missing Verify the Stacksync account and workspace selected during OAuth, then inspect the workspace’s connections. Add missing app credentials through the secure connection flow. An action is unavailable or denied Inspect the current connector modules and required inputs. Check your workspace role, read-only consent, gateway policy, and the source app’s API permissions. 06 / Common questions ## Slack MCP questions ### Is this a Slack message sync? No continuous Slack sync is established by the published app catalog. The supported path described here is discovering connector actions and using them in Stacksync workflows. ### Can an assistant search all Slack messages through this connection? Do not assume that. Inspect the current Slack modules and the connection’s permissions. The public catalog confirms workflow availability, not a universal message-search action. ### Can Slack notifications require review? The sample prompts ask for a proposal before sending. Workspace owners can also enable Ask before every change for MCP operations. Review the target channel as well as the message. Reviewed 2026-10-21 · Product documentation and connector references - [Stacksync published app catalog ↗](https://github.com/stacksyncdata/skills/blob/prod/data/apps.json) - [Stacksync connector actions ↗](https://github.com/stacksyncdata/skills/blob/prod/skills/connectors/SKILL.md) - [Stacksync workflows through MCP ↗](https://github.com/stacksyncdata/skills/blob/prod/skills/workflows/SKILL.md) - [Stacksync sync management through MCP ↗](https://github.com/stacksyncdata/skills/blob/prod/skills/syncs/SKILL.md) - [Stacksync MCP governance ↗](https://docs.stacksync.com/mcp/governance) - [Stacksync: connect your AI assistant ↗](https://docs.stacksync.com/mcp/connect) - [Stacksync MCP authentication ↗](https://docs.stacksync.com/mcp/authentication) - [OpenAI: Model Context Protocol in Codex ↗](https://learn.chatgpt.com/docs/extend/mcp?surface=cli) Keep building ## More ways to use Slack. [Claude](https://www.stacksync.com/mcp/slack/claude) [Claude Code](https://www.stacksync.com/mcp/slack/claude-code) [ChatGPT](https://www.stacksync.com/mcp/slack/chatgpt) [Cursor](https://www.stacksync.com/mcp/slack/cursor) [VS Code](https://www.stacksync.com/mcp/slack#setup-vs-code) [Windsurf](https://www.stacksync.com/mcp/slack#setup-windsurf) [Gemini CLI](https://www.stacksync.com/mcp/slack/gemini-cli) Communications ### [Gmail + Codex](https://www.stacksync.com/mcp/gmail#setup-codex) Design a new-email intake workflow CRM ### [Salesforce + Codex](https://www.stacksync.com/mcp/salesforce#setup-codex) Plan a Salesforce reporting replica CRM ### [HubSpot + Codex](https://www.stacksync.com/mcp/hubspot#setup-codex) Plan a contact and company replica [← All MCP connector guides](https://www.stacksync.com/mcp#connectors) [Create your Stacksync account ↗](https://app.stacksync.com/signup)