# Otel Declarative Config

> OpenTelemetry declarative YAML configuration for SDK setup. Use when configuring OpenTelemetry SDK providers (tracer, meter, logger), setting up OTLP exporters, defining sampling strategies, or writing otel config files. Triggers on "otel config", "OpenTelemetry YAML", "declarative configuration", "otelconf", "OTEL_CONFIG_FILE", "file_format", "configure tracing/metrics/logs export", or when the…

- **Type:** Skill
- **Install:** `agentstack add skill-ollygarden-opentelemetry-agent-skills-otel-declarative-config`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [ollygarden](https://agentstack.voostack.com/s/ollygarden)
- **Installs:** 0
- **Category:** [Data & Analytics](https://agentstack.voostack.com/c/data-and-analytics)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [ollygarden](https://github.com/ollygarden)
- **Source:** https://github.com/ollygarden/opentelemetry-agent-skills/tree/main/skills/otel-declarative-config

## Install

```sh
agentstack add skill-ollygarden-opentelemetry-agent-skills-otel-declarative-config
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# OpenTelemetry Declarative Configuration

Declarative configuration replaces scattered `OTEL_*` environment variables and language-specific
programmatic SDK setup with a single YAML file. One file configures all SDK components: tracer
provider, meter provider, logger provider, propagators, and resource.

For the current per-language SDK status, fetch the SDK compatibility matrix (see Sources of Truth).
Use it to understand implementation coverage, not as the only source for YAML literals.

## Sources of Truth

This skill teaches concepts. The schema itself, valid `file_format` strings, field names,
and SDK compatibility evolve per release — fetch from upstream rather than relying on
embedded copies. Cache results for the conversation; refetch only on schema-related errors.

| Fact | Fetch |
|---|---|
| Latest schema release tag | `gh release view --repo open-telemetry/opentelemetry-configuration --json tagName,publishedAt` |
| SDK ↔ schema compatibility matrix (coverage advisory, not authoritative for literal `file_format`) | `WebFetch https://raw.githubusercontent.com/open-telemetry/opentelemetry-configuration/main/language-support-status.md` |
| Field-by-field schema docs | `WebFetch https://raw.githubusercontent.com/open-telemetry/opentelemetry-configuration/main/schema-docs.md` |
| Compiled JSON Schema (validate generated YAML against this) | `WebFetch https://raw.githubusercontent.com/open-telemetry/opentelemetry-configuration/main/opentelemetry_configuration.json` |
| Canonical full example | `WebFetch https://raw.githubusercontent.com/open-telemetry/opentelemetry-configuration/main/examples/otel-sdk-config.yaml` |
| Migration template (every option, with comments) | `WebFetch https://raw.githubusercontent.com/open-telemetry/opentelemetry-configuration/main/examples/otel-sdk-migration-config.yaml` |
| Schema CHANGELOG (breaking-change history with migration steps) | `WebFetch https://raw.githubusercontent.com/open-telemetry/opentelemetry-configuration/main/CHANGELOG.md` |

**Workflow when generating YAML:**

1. Identify the exact runtime/package/agent version that will parse the file.
2. Fetch that runtime/package source, docs, or test fixtures and confirm the accepted
   `file_format` literal. If this conflicts with `language-support-status.md`, the
   runtime/package wins.
3. Fetch `examples/otel-sdk-config.yaml` → use as the structural template only after
   adapting the `file_format` and fields to the selected runtime/package.
4. Overlay the user's specific values (service name, endpoint, sampling, headers).
5. If validation matters, fetch `opentelemetry_configuration.json` and validate the result,
   then still verify against the selected runtime/package because SDK implementations may
   lag or differ from the schema repository.

The `latestSupportedFileFormat` values in `language-support-status.md` are schema/version
coverage metadata. Do not mechanically copy values like `1.0.0-rc.3` into YAML unless the
target SDK parser, agent docs, or package fixtures prove that exact literal is accepted.

Terminology trap: schema coverage identifiers and YAML `file_format` literals are related,
but not interchangeable. A matrix entry may use a semver-shaped value such as
`1.0.0-rc.3`, while an SDK parser may accept a config literal such as `1.0-rc.3` or
`1.0`. Generated YAML must use the parser-accepted literal.

For language-specific package versions and SDK API surface, see the Sources of Truth section
in each language's `otel-` skill (`otel-go`, `otel-java`, `otel-js`, `otel-python`).
`otel-dotnet` is listed in Cross-References below but does **not** support declarative YAML config yet — see the .NET note.

**Python note:** declarative config is supported via the experimental, private
`opentelemetry.sdk._configuration.file` module (install `opentelemetry-sdk[file-configuration]`).
Activation is programmatic — there is no `OTEL_CONFIG_FILE` CLI wiring like Go/JS; you must call
the loader in code at startup. See the `otel-python` skill and its `declarative-setup.md` reference.

**\.NET note:** declarative YAML config is **not yet implemented** in OpenTelemetry .NET
(tracked by [`open-telemetry/opentelemetry-dotnet#6380`](https://github.com/open-telemetry/opentelemetry-dotnet/issues/6380)).
.NET configures via the DI/builder API, `OTEL_*` env vars, and `IConfiguration`. Do **not**
use `OTEL_CONFIG_FILE` with .NET runtimes. See the `otel-dotnet` skill and its `setup.md` reference.

## Activation

The standard environment variable is `OTEL_CONFIG_FILE`:

```bash
export OTEL_CONFIG_FILE=/app/configs/otel.yaml
```

When set, the SDK reads this file at startup. All other `OTEL_*` env vars are ignored except
those referenced via `${env:VAR}` substitution inside the config file.

Language-specific activation varies — see the language `sdk-setup` skills for details.

## Environment Variable Substitution

| Syntax | Behavior |
|--------|----------|
| `${VAR}` | Substitute with value of `VAR` |
| `${env:VAR}` | Same as `${VAR}` (explicit prefix) |
| `${VAR:-default}` | Use `default` if `VAR` is unset or empty |
| `$$` | Escape sequence, resolves to literal `$` |

Rules:

- Substitution applies only to scalar values, not mapping keys
- Type coercion happens after substitution (`${BOOL}` where `BOOL=true` becomes boolean)
- No recursive substitution
- Invalid references produce a parse error

## Configuration Precedence

```
Programmatic API  >  Environment Variables  >  Configuration File
   (highest)                                      (lowest)
```

## Cross-References

- Language-specific setup: `otel-go`, `otel-java`, `otel-js`, `otel-python` (each loads its own `references/declarative-setup.md`); `otel-dotnet` (declarative YAML config not yet supported — see .NET note above).

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [ollygarden](https://github.com/ollygarden)
- **Source:** [ollygarden/opentelemetry-agent-skills](https://github.com/ollygarden/opentelemetry-agent-skills)
- **License:** Apache-2.0

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-ollygarden-opentelemetry-agent-skills-otel-declarative-config
- Seller: https://agentstack.voostack.com/s/ollygarden
- Browse the marketplace: https://agentstack.voostack.com/browse

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