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2 changes: 1 addition & 1 deletion .claude-plugin/plugin.json
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
{
"name": "posthog",
"description": "Access PostHog analytics, feature flags, experiments, error tracking, and insights directly from Claude Code",
"version": "1.0.2",
"version": "1.0.3",
"author": {
"name": "PostHog",
"email": "hey@posthog.com",
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7 changes: 5 additions & 2 deletions .codex-plugin/plugin.json
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@@ -1,6 +1,6 @@
{
"name": "posthog",
"version": "1.0.2",
"version": "1.0.3",
"description": "Access PostHog analytics, feature flags, experiments, error tracking, and insights directly from Codex",
"author": {
"name": "PostHog",
Expand Down Expand Up @@ -28,7 +28,10 @@
"longDescription": "Access PostHog analytics, feature flags, experiments, error tracking, and insights directly from Codex. Query your data, manage flags, run A/B tests, and debug errors without leaving your editor.",
"developerName": "PostHog",
"category": "Productivity",
"capabilities": ["Read", "Write"],
"capabilities": [
"Read",
"Write"
],
"websiteURL": "https://posthog.com",
"privacyPolicyURL": "https://posthog.com/privacy",
"termsOfServiceURL": "https://posthog.com/terms",
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2 changes: 1 addition & 1 deletion .cursor-plugin/plugin.json
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@@ -1,7 +1,7 @@
{
"name": "posthog",
"displayName": "PostHog",
"version": "1.0.2",
"version": "1.0.3",
"description": "Access PostHog analytics, feature flags, experiments, error tracking, and insights directly from Cursor",
"author": {
"name": "PostHog",
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2 changes: 1 addition & 1 deletion gemini-extension.json
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
{
"name": "posthog",
"version": "1.0.1",
"version": "1.0.2",
"description": "Access PostHog analytics, feature flags, experiments, error tracking, and insights directly from Gemini CLI",
"mcpServers": {
"posthog": {
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2 changes: 2 additions & 0 deletions skills/.sync-manifest
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@@ -1,6 +1,8 @@
analyzing-experiment-session-replays
auditing-experiments-flags
cleaning-up-stale-feature-flags
exploring-llm-clusters
exploring-llm-traces
instrument-error-tracking
instrument-feature-flags
instrument-integration
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229 changes: 229 additions & 0 deletions skills/exploring-llm-clusters/SKILL.md
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---
name: exploring-llm-clusters
description: 'Investigate LLM analytics clusters — understand usage patterns in AI/LLM traffic, compare cluster behavior, compute cost/latency metrics, and drill into individual traces within clusters.'
---

# Exploring LLM clusters

Use this skill when investigating LLM analytics clusters —
understanding what patterns exist in your AI/LLM traffic,
comparing cluster behavior, and drilling into individual clusters.

## Tools

| Tool | Purpose |
| ------------------------------------------------ | ----------------------------------------------- |
| `posthog:llm-analytics-clustering-jobs-list` | List clustering job configurations for the team |
| `posthog:llm-analytics-clustering-jobs-retrieve` | Get a specific clustering job by ID |
| `posthog:execute-sql` | Query cluster run events and compute metrics |
| `posthog:query-llm-traces-list` | Find traces belonging to a cluster |
| `posthog:query-llm-trace` | Inspect a specific trace in detail |

## How clustering works

PostHog clusters LLM traces (or individual generations) by embedding similarity.
A Temporal workflow runs periodically or on-demand, producing cluster events stored as
`$ai_trace_clusters` (trace-level) or `$ai_generation_clusters` (generation-level).

Each cluster event contains:

- `$ai_clustering_run_id` — unique run identifier (format: `<team_id>_<level>_<YYYYMMDD>_<HHMMSS>[_<job_id>]`)
- `$ai_clustering_level` — `"trace"` or `"generation"`
- `$ai_window_start` / `$ai_window_end` — time window analyzed
- `$ai_total_items_analyzed` — number of traces/generations processed
- `$ai_clusters` — JSON array of cluster objects
- `$ai_clustering_params` — algorithm parameters used

### Cluster object shape (inside `$ai_clusters`)

```json
{
"cluster_id": 0,
"size": 42,
"title": "User authentication flows",
"description": "Traces involving login, signup, and token refresh operations",
"traces": {
"<trace_or_generation_id>": {
"distance_to_centroid": 0.123,
"rank": 0,
"x": -2.34,
"y": 1.56,
"timestamp": "2026-03-28T10:00:00Z",
"trace_id": "abc-123",
"generation_id": "gen-456"
}
},
"centroid_x": -2.1,
"centroid_y": 1.4
}
```

- `cluster_id: -1` is the **noise/outlier** cluster (items that didn't fit any cluster)
- Items in `traces` are keyed by trace ID (trace-level) or generation event UUID (generation-level)
- `rank` orders items by proximity to centroid (0 = closest)
- `x`, `y` are 2D coordinates for visualization (UMAP/PCA/t-SNE reduced)

## Clustering jobs

Each team can have up to 5 clustering jobs. A job defines:

- **name** — human-readable label
- **analysis_level** — `"trace"` or `"generation"`
- **event_filters** — property filters scoping which traces are included
- **enabled** — whether the job runs on schedule

Default jobs named `"Default - trace"` and `"Default - generation"` are auto-created
and disabled when a custom job is created for the same level.

## Workflow: explore clusters

### Step 1 — List recent clustering runs

```sql
posthog:execute-sql
SELECT
JSONExtractString(properties, '$ai_clustering_run_id') as run_id,
JSONExtractString(properties, '$ai_clustering_level') as level,
JSONExtractString(properties, '$ai_window_start') as window_start,
JSONExtractString(properties, '$ai_window_end') as window_end,
JSONExtractInt(properties, '$ai_total_items_analyzed') as total_items,
timestamp
FROM events
WHERE event IN ('$ai_trace_clusters', '$ai_generation_clusters')
AND timestamp >= now() - INTERVAL 7 DAY
ORDER BY timestamp DESC
LIMIT 10
```

### Step 2 — Get clusters from a specific run

```sql
posthog:execute-sql
SELECT
JSONExtractString(properties, '$ai_clustering_run_id') as run_id,
JSONExtractString(properties, '$ai_clustering_level') as level,
JSONExtractString(properties, '$ai_clustering_job_id') as job_id,
JSONExtractString(properties, '$ai_clustering_job_name') as job_name,
JSONExtractString(properties, '$ai_window_start') as window_start,
JSONExtractString(properties, '$ai_window_end') as window_end,
JSONExtractInt(properties, '$ai_total_items_analyzed') as total_items,
JSONExtractRaw(properties, '$ai_clusters') as clusters,
JSONExtractRaw(properties, '$ai_clustering_params') as params
FROM events
WHERE event IN ('$ai_trace_clusters', '$ai_generation_clusters')
AND JSONExtractString(properties, '$ai_clustering_run_id') = '<run_id>'
LIMIT 1
```

The `clusters` field is a JSON array. Parse it to see cluster titles, sizes, and descriptions.

**Important:** The clusters JSON can be very large (thousands of trace IDs with coordinates).
When the result is too large for inline display, it auto-persists to a file.
Use `print_clusters.py` from [scripts/](./scripts/) to get a readable summary.

### Step 3 — Compute metrics for clusters

For trace-level clusters, compute cost/latency/token metrics:

```sql
posthog:execute-sql
SELECT
JSONExtractString(properties, '$ai_trace_id') as trace_id,
sum(toFloat(properties.$ai_total_cost_usd)) as total_cost,
max(toFloat(properties.$ai_latency)) as latency,
sum(toInt(properties.$ai_input_tokens)) as input_tokens,
sum(toInt(properties.$ai_output_tokens)) as output_tokens,
countIf(properties.$ai_is_error = 'true') as error_count
FROM events
WHERE event IN ('$ai_generation', '$ai_embedding', '$ai_span')
AND timestamp >= parseDateTimeBestEffort('<window_start>')
AND timestamp <= parseDateTimeBestEffort('<window_end>')
AND JSONExtractString(properties, '$ai_trace_id') IN ('<trace_id_1>', '<trace_id_2>', ...)
GROUP BY trace_id
```

For generation-level clusters, match by event UUID:

```sql
posthog:execute-sql
SELECT
toString(uuid) as generation_id,
toFloat(properties.$ai_total_cost_usd) as cost,
toFloat(properties.$ai_latency) as latency,
toInt(properties.$ai_input_tokens) as input_tokens,
toInt(properties.$ai_output_tokens) as output_tokens,
if(properties.$ai_is_error = 'true', 1, 0) as is_error
FROM events
WHERE event = '$ai_generation'
AND timestamp >= parseDateTimeBestEffort('<window_start>')
AND timestamp <= parseDateTimeBestEffort('<window_end>')
AND toString(uuid) IN ('<gen_uuid_1>', '<gen_uuid_2>', ...)
```

### Step 4 — Drill into specific traces

Once you've identified interesting clusters, use the trace tools to inspect individual traces:

```json
posthog:query-llm-trace
{
"traceId": "<trace_id_from_cluster>",
"dateRange": {"date_from": "<window_start>", "date_to": "<window_end>"}
}
```

## Investigation patterns

### "What kinds of LLM usage do we have?"

1. List recent clustering runs (Step 1)
2. Load the latest run's clusters (Step 2)
3. Review cluster titles and descriptions — each represents a distinct usage pattern
4. Compare cluster sizes to understand traffic distribution

### "Which cluster is most expensive / slowest?"

1. Load clusters from a run (Step 2)
2. Extract trace IDs from each cluster
3. Compute metrics per cluster (Step 3)
4. Aggregate: `avg(cost)`, `avg(latency)`, `sum(cost)` per cluster
5. Compare across clusters

### "What's in this cluster?"

1. Load the cluster's traces (from the `traces` field)
2. Sort by `rank` (closest to centroid = most representative)
3. Inspect the top 3-5 traces via `query-llm-trace` to understand the pattern
4. Check the cluster `title` and `description` for the AI-generated summary

### "Are there error-heavy clusters?"

1. Compute metrics (Step 3) with `error_count`
2. Calculate error rate per cluster: `items_with_errors / total_items`
3. Focus on clusters with high error rates
4. Drill into errored traces to find root causes

### "How do clusters compare across runs?"

1. List multiple runs (Step 1)
2. Load clusters from each run
3. Compare cluster titles — similar titles across runs indicate stable patterns
4. Track cluster size changes to detect shifts in traffic patterns

## Constructing UI links

- **Clusters overview**: `https://app.posthog.com/llm-analytics/clusters`
- **Specific run**: `https://app.posthog.com/llm-analytics/clusters/<url_encoded_run_id>`
- **Cluster detail**: `https://app.posthog.com/llm-analytics/clusters/<url_encoded_run_id>/<cluster_id>`

Always surface these links so the user can verify visually in the PostHog UI.

## Tips

- Always set a time range in SQL queries — cluster events without time bounds are slow
- Start with run listing to orient, then drill into specific clusters
- Cluster titles and descriptions are AI-generated summaries — verify by inspecting traces
- The noise cluster (`cluster_id: -1`) contains outliers that didn't fit any pattern
- Use `llm-analytics-clustering-jobs-list` to understand what clustering configs are active
- Trace IDs in clusters can be used directly with `query-llm-trace` for deep inspection
- For large clusters, inspect the top-ranked traces (closest to centroid) for representative examples
103 changes: 103 additions & 0 deletions skills/exploring-llm-clusters/scripts/print_clusters.py
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"""Print a summary of clusters from a clustering run result."""

import json
import sys


def load_result_file(path):
with open(path) as f:
raw = json.load(f)
if isinstance(raw, list) and raw and isinstance(raw[0], dict) and raw[0].get("type") == "text":
raw = json.loads(raw[0]["text"])
return raw


def parse_result(raw):
"""Extract clusters array and run metadata from various result shapes."""
meta: dict[str, str | int | float] = {}
clusters = []

# Direct clusters array
if isinstance(raw, list) and raw and isinstance(raw[0], dict) and "cluster_id" in raw[0]:
return raw, meta

# SQL result — look for clusters JSON and metadata columns
if isinstance(raw, dict) and "results" in raw:
columns = raw.get("columns", [])
for row in raw["results"]:
for i, cell in enumerate(row):
col_name = columns[i] if i < len(columns) else ""
# Extract run metadata from known columns
if isinstance(cell, str) and col_name in (
"run_id", "level", "job_id", "job_name",
"window_start", "window_end", "total_items",
):
meta[col_name] = cell
elif isinstance(cell, (int, float)) and col_name == "total_items":
meta[col_name] = cell
# Find the clusters JSON
if isinstance(cell, str) and cell.startswith("["):
try:
parsed = json.loads(cell)
if isinstance(parsed, list) and parsed and "cluster_id" in parsed[0]:
clusters = parsed
except (json.JSONDecodeError, TypeError):
continue
return clusters, meta


if __name__ == "__main__":
if len(sys.argv) < 2:
print("Usage: python print_clusters.py <result_file_path>")
sys.exit(1)

data = load_result_file(sys.argv[1])
clusters, meta = parse_result(data)

if not clusters:
print("No clusters found in file.")
sys.exit(1)

clusters.sort(key=lambda c: c.get("size", 0), reverse=True)

print(f"\n{'='*80}")
if meta:
if meta.get("job_name"):
print(f" Job: {meta['job_name']}")
if meta.get("level"):
print(f" Level: {meta['level']}")
if meta.get("run_id"):
print(f" Run: {meta['run_id']}")
if meta.get("job_id"):
print(f" Job ID: {meta['job_id']}")
if meta.get("window_start") or meta.get("window_end"):
print(f" Window: {meta.get('window_start', '?')} → {meta.get('window_end', '?')}")
if meta.get("total_items"):
print(f" Items analyzed: {meta['total_items']}")
print(f" ---")
print(f" {len(clusters)} clusters, {sum(c.get('size', 0) for c in clusters)} total items")
print(f"{'='*80}")

for c in clusters:
cid = c.get("cluster_id", "?")
label = "(NOISE/OUTLIERS)" if cid == -1 else ""
title = c.get("title", f"Cluster {cid}")
size = c.get("size", 0)
desc = c.get("description", "")

print(f"\n Cluster {cid} {label}")
print(f" Title: {title}")
print(f" Size: {size} items")
if desc:
print(f" Desc: {desc[:200]}{'...' if len(desc) > 200 else ''}")

# Show top 5 traces by rank
traces = c.get("traces", {})
ranked = sorted(traces.items(), key=lambda t: t[1].get("rank", 999))[:5]
if ranked:
print(f" Top traces (by centroid proximity):")
for tid, info in ranked:
dist = info.get("distance_to_centroid")
ts = info.get("timestamp", "?")
dist_str = f"{dist:.4f}" if isinstance(dist, (int, float)) else "?"
print(f" #{info.get('rank', '?'):>3} {tid} dist={dist_str} {ts}")
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