Find a user by email

Find a user by email

Returns the workspace member registered with an email address, so a message can mention or reach them.

Needs the users:read.email scope; a deactivated user returns users_not_found. Over MCP, slack_search_users finds people by name, email or role.

Set up

Use the first option your agent supports.

MCP (official, remote)

Add this server to your agent's MCP settings, then sign in when asked.

{ "mcpServers": { "slack": { "url": "https://mcp.slack.com/mcp" } } }

Call the MCP tool slack_search_users.

Server URL: https://mcp.slack.com/mcp

CLI (official)

Install the command, then confirm it runs.

curl -fsSL https://downloads.slack-edge.com/slack-cli/install.sh | bash
slack --version

Run slack api users.lookupByEmail.

Set $SLACK_BOT_TOKEN in your environment first (get a key: https://api.slack.com/apps).

API (official)

• Base URL: https://slack.com/api
• Endpoint: GET /users.lookupByEmail
• Auth: send the header Authorization: Bearer $SLACK_BOT_TOKEN
• Get a key: https://api.slack.com/apps
• Docs: https://docs.slack.dev/apis/web-api/

Before doing anything else, make one read-only call to confirm access.

Rules

• Ask the user before anything that sends messages, costs money, or changes data.
• Never print API keys.