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.

Note: Needs the users:read.email scope; a deactivated user returns users_not_found.

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 anything else, confirm access with the cheapest read-only call, like a list or a search. Never send or change anything to test access.

Rules

• Ask the user before anything that sends messages, costs money, or changes data, and say how many records it touches. One approval covers a batch the user has seen.
• Never print API keys.