Otel Ottl

If you're writing or debugging OTTL expressions for OpenTelemetry Collector pipelines, this skill knows the syntax cold. It covers the full range of components that use OTTL, not just transform and filter processors but also connectors like routing and count, plus receivers like hostmetrics. The guidance on error modes is solid: it steers you toward error_mode: ignore for production, which is the right default most teams should use. You also get practical patterns for redaction, cardinality control, and performance optimization with where clauses. Made by dash0, who clearly use this stuff in production. Worth having around when you're configuring collector transforms and want to avoid the trial-and-error loop.

skills.sh installs: 631
GitHub stars: 99
last updated: Aug 21, 2026

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Install

$ npx -y skills add dash0hq/agent-skills --skill otel-ottl --agent claude-code

Installs into .claude/skills of the current project.

Files

OpenTelemetry Transformation Language (OTTL)

Components that use OTTL

OTTL is not limited to the transform and filter processors. Processors (transform, filter, tailsampling, logdedup) and connectors (routing, count, sum, signaltometrics) accept OTTL expressions. See components for the full list with use cases.

OTTL syntax

Path expressions

Navigate telemetry data using dot notation:

span.name
span.attributes["http.method"]
resource.attributes["service.name"]

Contexts (first path segment): resource, scope, span, spanevent, metric, datapoint, log.

Enumerations

Use int64 constants for enumeration fields:

span.status.code == STATUS_CODE_ERROR
span.kind == SPAN_KIND_SERVER

Operators

Assignment: = — Comparison: ==, !=, >, <, >=, <= — Logical: and, or, not

Functions

Converters (uppercase, return values):

ToUpperCase(span.attributes["http.request.method"])
Substring(log.body.string, 0, 1024)
Concat(["prefix", span.attributes["request.id"]], "-")
IsMatch(metric.name, "^k8s\\..*$")

Editors (lowercase, modify data in-place):

SKILL.md on GitHub