Create a cohort

Create a cohort

Creates a cohort of persons from property or behavioral filters, or a static cohort from a list of person IDs.

Note: Needs a personal API key with the cohort:write scope.

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": { "posthog": { "url": "https://mcp.posthog.com/mcp" } } }

Call the MCP tool cohorts-create.

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

CLI (official)

Install the command, then confirm it runs.

npm install -g @posthog/cli@latest
posthog-cli --version

Run posthog-cli api call cohorts-create.

Set $POSTHOG_CLI_API_KEY in your environment first (get a key: https://app.posthog.com/settings/user-api-keys?preset=mcp_server).

API (official)

• Base URL: https://us.posthog.com
• Endpoint: POST /api/projects/{project_id}/cohorts/
• Auth: send the header Authorization: Bearer $POSTHOG_PERSONAL_API_KEY
• Get a key: https://us.posthog.com/settings/user-api-keys
• Docs: https://posthog.com/docs/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.