Sample queries

A starter set of HogQL queries for the most common MCP analytics questions. All of them assume the SDK is installed and at least a few $mcp_tool_call events have landed. See the event reference for the full property list.

{/ TODO: ProductScreenshot of the SQL editor showing one of these queries running with real MCP data /}

Top tools per server

SQL
Run in PostHog
SELECT
  properties.$mcp_server_name AS server,
  properties.$mcp_tool_name   AS tool,
  count() AS calls
FROM events
WHERE event = '$mcp_tool_call'
  AND timestamp > now() - INTERVAL 7 DAY
GROUP BY server, tool
ORDER BY calls DESC
LIMIT 50

Error rate per tool

SQL
Run in PostHog
SELECT
  properties.$mcp_tool_name AS tool,
  countIf(properties.$mcp_is_error)        AS errors,
  count()                                  AS total,
  countIf(properties.$mcp_is_error) / count() AS error_rate
FROM events
WHERE event = '$mcp_tool_call'
  AND timestamp > now() - INTERVAL 7 DAY
GROUP BY tool
ORDER BY total DESC

P95 latency per tool

SQL
Run in PostHog
SELECT
  properties.$mcp_tool_name AS tool,
  quantile(0.95)(toFloat(properties.$mcp_duration_ms)) AS p95_ms
FROM events
WHERE event = '$mcp_tool_call'
  AND timestamp > now() - INTERVAL 7 DAY
GROUP BY tool
ORDER BY p95_ms DESC

Intent samples split by source

How much of your traffic is supplying explicit context vs falling back to your intentFallback callback?

SQL
Run in PostHog
SELECT
  properties.$mcp_intent_source AS source,
  properties.$mcp_tool_name     AS tool,
  any(properties.$mcp_intent)   AS sample_intent,
  count()                       AS calls
FROM events
WHERE event = '$mcp_tool_call'
  AND timestamp > now() - INTERVAL 24 HOUR
GROUP BY source, tool
ORDER BY calls DESC

Active sessions per client

SQL
Run in PostHog
SELECT
  properties.$mcp_client_name AS client,
  uniq(properties.$session_id) AS sessions
FROM events
WHERE event IN ('$mcp_initialize', '$mcp_tool_call')
  AND timestamp > now() - INTERVAL 7 DAY
GROUP BY client
ORDER BY sessions DESC

Advertised tools that never get called

Tools listed in tools/list responses but never invoked. Useful to find dead surface area.

SQL
Run in PostHog
WITH listed AS (
  SELECT DISTINCT arrayJoin(properties.$mcp_listed_tool_names) AS tool_name
  FROM events
  WHERE event = '$mcp_tools_list'
    AND timestamp > now() - INTERVAL 30 DAY
),
called AS (
  SELECT DISTINCT properties.$mcp_tool_name AS tool_name
  FROM events
  WHERE event = '$mcp_tool_call'
    AND timestamp > now() - INTERVAL 30 DAY
)
SELECT tool_name AS zombie_tool
FROM listed
WHERE tool_name NOT IN (SELECT tool_name FROM called)
ORDER BY tool_name

Unmet user requests (requires reportMissing: true)

What were users trying to do that your tools couldn't satisfy?

SQL
Run in PostHog
SELECT
  properties.$mcp_intent       AS unmet_request,
  properties.$mcp_client_name  AS client,
  count()                      AS times_asked
FROM events
WHERE event = '$mcp_missing_capability'
  AND timestamp > now() - INTERVAL 30 DAY
GROUP BY unmet_request, client
ORDER BY times_asked DESC
LIMIT 50

Tool call volume by client and tool, daily

Good as a baseline trend for a dashboard.

SQL
Run in PostHog
SELECT
  toDate(timestamp)               AS day,
  properties.$mcp_client_name     AS client,
  properties.$mcp_tool_name       AS tool,
  count()                         AS calls
FROM events
WHERE event = '$mcp_tool_call'
  AND timestamp > now() - INTERVAL 30 DAY
GROUP BY day, client, tool
ORDER BY day DESC, calls DESC

Community questions

Was this page useful?

Questions about this page? or post a community question.