Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/null-shot/cloudflare-skills/analytics-enginenpx skills add null-shot/cloudflare-skills --skill analytics-enginegit clone --depth 1 https://github.com/null-shot/cloudflare-skillsWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00057 | $0.02341 |
| Opus 5 | $0.00028 | $0.01171 |
| Sonnet 5 | $0.00011 | $0.00468 |
| Haiku 4.5 | $0.00006 | $0.00234 |
Grade A, and why
analytics-engine scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
async fetch(req: Request, env: Env): Promise<Response> { How it starts
The opening of the file, as written. The whole thing — 332 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Analytics Engine
Write high-cardinality event data at scale and query it with SQL. Perfect for user events, billing metrics, per-tenant analytics, and custom telemetry.
FIRST: Create Dataset
wrangler analytics-engine create my-dataset
Add binding in wrangler.jsonc:
{
"analytics_engine_datasets": [
{
"binding": "USER_EVENTS",
"dataset": "my-dataset"
}
]
}
When to Use
| Use Case | Why Analytics Engine |
|---|---|
| User behavior tracking | High-cardinality data (userId, sessionId, etc.) |
| Billing/usage metrics | Per-tenant aggregation with doubles |
| Custom telemetry | Non-blocking writes, queryable with SQL |
| A/B test metrics | Index by experiment ID, query results |
| API usage tracking | Count requests per customer/endpoint |
Quick Reference
| Operation | API | Notes |
|---|---|---|
| Write event | env.DATASET.writeDataPoint({ ... }) |
Non-blocking, do NOT await |
| Metrics | doubles: [value1, value2] |
Up to 20 numeric values |
| Labels | blobs: [label1, label2] |
Up to 20 text values |
| Grouping | indexes: [userId] |
1 index per datapoint (max 96 bytes) |
| Query data | SQL API via REST | GraphQL also available |
Data Model
Analytics Engine stores datapoints with three types of fields:
| Field Type | Purpose | Limit | Example |
|---|---|---|---|
| doubles | Numeric metrics (counters, gauges, latency) | 20 per datapoint | [response_time, bytes_sent] |
| blobs | Text labels (URLs, names, IDs) | 20 per datapoint | [path, event_name] |
| indexes | Grouping key (userId, tenantId, etc.) | 1 per datapoint | [userId] |
Key concept: The index is the primary key that represents your app, customer, merchant, or tenant. Use it to group and filter data efficiently in SQL queries. For multiple dimensions, use blobs or create a composite index.
Write Events Example
interface Env {
USER_EVENTS: AnalyticsEngineDataset;
}
export default {
async fetch(req: Request, env: Env): Promise<Response> {
let url = new URL(req.url);
let path = url.pathname;
let userId = url.searchParams.get("userId");
// Write a datapoint for this visit, associating the data with
// the userId as our Analytics Engine 'index'
env.USER_EVENTS.writeDataPoint({
// Write metrics data: counters, gauges or latency statistics
doubles: [],
// Write text labels - URLs, app names, event_names, etc
blobs: [path],
// Provide an index that groups your data correctly.
indexes: [userId],
});
return Response.json({
hello: "world",
});
},
};
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 332 lines · 57 tokens per session scan A c82aaa50de6c
analytics-engine is a skill published in the GitHub repository null-shot/cloudflare-skills (0 stars, last pushed 7mo ago), licensed Apache-2.0. It adds 57 tokens to every session and 2,341 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It comes from a forked repository.
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