otel-metrics

Rules for creating OpenTelemetry measurements such as counters, histograms, and gauges. They focus on cardinality, meaning how many unique data series an attribute can create.

In plain words
What is it for?
Use it when adding or editing metrics and choosing safe attributes such as bounded states, booleans, controlled error codes, or limited shard numbers.
Why use it?
It prevents monitoring data from producing an unmanageable number of time series, which can waste storage and memory and make metrics harder to use.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/triggerdotdev/trigger.dev/otel-metrics
Clone the repo
git clone --depth 1 https://github.com/triggerdotdev/trigger.dev

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 599 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What 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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00599
Opus 5 $0.00000 $0.00300
Sonnet 5 $0.00000 $0.00120
Haiku 4.5 $0.00000 $0.00060

Measured yesterday against content hash 63c303d5bcda, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

otel-metrics scanned grade A with 0 findings 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 yesterday.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.cursor/rules/otel-metrics.mdc · 67 lines

How it starts

The opening of the file, as written. The whole thing — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OpenTelemetry Metrics Guidelines

When creating or editing OTEL metrics (counters, histograms, gauges), always ensure metric attributes have low cardinality.

What is Cardinality?

Cardinality refers to the number of unique values an attribute can have. Each unique combination of attribute values creates a new time series, which consumes memory and storage in your metrics backend.

Rules

DO use low-cardinality attributes:

  • Enums: environment_type (PRODUCTION, STAGING, DEVELOPMENT, PREVIEW)
  • Booleans: hasFailures, streaming, success
  • Bounded error codes: A finite, controlled set of error types
  • Shard IDs: When sharding is bounded (e.g., 0-15)

DO NOT use high-cardinality attributes:

  • UUIDs/IDs: envId, userId, runId, projectId, organizationId
  • Unbounded integers: itemCount, batchSize, retryCount
  • Timestamps: createdAt, startTime
  • Free-form strings: errorMessage, taskName, queueName

Example

// BAD - High cardinality
this.counter.add(1, {
  envId: options.environmentId,        // UUID - unbounded
  itemCount: options.runCount,         // Integer - unbounded
});

// GOOD - Low cardinality
this.counter.add(1, {
  environment_type: options.environmentType,  // Enum - 4 values
  streaming: true,                            // Boolean - 2 values
});

Prometheus Metric Naming

When metrics are exported via OTLP to Prometheus, the exporter automatically adds unit suffixes to metric names:

OTel Metric Name Unit Prometheus Name
my_duration_ms ms my_duration_ms_milliseconds
my_counter counter my_counter_total
items_inserted counter items_inserted_inserts_total
batch_size histogram batch_size_items_bucket

Keep this in mind when writing Grafana dashboards or Prometheus queries—the metric names in Prometheus will differ from the names defined in code.

Reference

Read the full file on GitHub · 67 lines

Changes

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.

  1. yesterday First seen · 67 lines · 0 tokens per session scan A 63c303d5bcda

Subscribe to this mod's changes

otel-metrics is a cursor rule published in the GitHub repository triggerdotdev/trigger.dev (16,165 stars, last pushed 2d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 599 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.