posthog-summary

PostHog Summary

PostHog product-analytics reporting for chat delivery. Produce a per-metric pulse over a window — what moved, why it matters — not a raw dashboard export. Single source (PostHog MCP); finish here, then optionally suggest a multi-source follow-up.

Requires the PostHog MCP integration (posthog_mcp). The REST-only posthog integration cannot serve this skill.

1. Discover

list_posthog_tools once with name_filter: "insights dashboard sql events" to find the query surface. Then call read-data-schema (or the equivalent schema tool) BEFORE any aggregation query and only reference events and properties it confirms exist. Do not reference a property (e.g. properties.$mcp_error) without seeing it in the schema first — HogQL rejects queries against unknown properties. To pull metric data, use call_posthog_tool with tool_name: "execute-sql" and SQL as a top-level string:

{
  "tool_name": "execute-sql",
  "arguments": { "query": "SELECT count() FROM events WHERE event = '$pageview'" }
}

Never nest the SQL ({"query": {"query": "SELECT …"}}) — PostHog rejects that with parameter "query" must be of type string. Use insight/dashboard tools when the user names a specific dashboard.

2. Fetch metrics

Map user words to windows:

• 24h — "today", "overnight", morning report
• 7d — "this week", default weekly report
• 30d — "this month", monthly rollup

Run one small HogQL query per metric — do NOT combine multiple metrics into a single aggregated statement, and never cross-join events against synthetic "window" rows. That combined shape is the most common cause of PostHog's unknown error running this query. Return only aggregate numbers (two columns: current / previous) — never event-level rows. Compute the two windows with an explicit conditional aggregate over a single time filter, e.g.:

SELECT
  countIf(timestamp >= now() - INTERVAL 7 DAY) AS current,
  countIf(timestamp >= now() - INTERVAL 14 DAY
          AND timestamp < now() - INTERVAL 7 DAY) AS previous
FROM events
WHERE event = '$pageview'