Eppo Metrics Sync

A Python package for syncing metric definitions with Eppo's API. Manage your Eppo metrics as code using YAML files. Documentation is available in Eppo's documentation page.

Features

• Sync metrics and fact sources to Eppo
• Validate metric definitions locally
• Support for dbt models
• Dry-run capability for testing
• Prefix support for testing in shared workspaces

Installation

pip install eppo-metrics-sync

Usage

Basic usage

1. Set required environment variables:

export EPPO_API_KEY="your-api-key"

export EPPO_SYNC_TAG="your-sync-tag" # optional

export EPPO_REFERENCE_URL="your-reference-url" # optional

2. Create your metrics YAML files (see Documentation)

3. Run the sync:

python -m eppo_metrics_sync path/to/yaml/directory

CLI Options

python -m eppo_metrics_sync [OPTIONS] DIRECTORY

Options:

• --dryrun Validate files without syncing to Eppo
• --schema Schema type: eppo (default) or dbt-model
• --sync-prefix Prefix for fact/metric names (useful for testing)
• --dbt-model-prefix Warehouse/schema prefix for dbt models
• --allow-upgrades Allow existing non-certified metrics/fact sources to become certified

When to use --allow-upgrades

The --allow-upgrades flag is useful in the following scenarios:

• Promoting existing metrics to certified status: If you have existing metrics or fact sources in Eppo that are not currently certified, this flag allows them to be upgraded to certified status during the sync process.
• Migrating from manual to code-managed metrics: When transitioning from manually created metrics in the Eppo UI to managing them through YAML files, this flag enables the promotion of those metrics to certified status.
• Avoiding conflicts during migration: Without this flag, attempting to sync metrics that already exist in a non-certified state may result in conflicts or the sync process not upgrading their certification status.

Validation Rules & Constraints

The following validation rules are enforced when syncing metrics. Understanding these constraints upfront can help avoid validation errors during development:

Winsorization Constraints

Winsorization parameters (winsorization_lower_percentile, winsorization_upper_percentile) can only be used with these aggregation operations:

• ✅ sum
• ✅ count
• ✅ last_value
• ✅ first_value

Not supported for:

• ❌ count_distinct - Use different outlier handling approaches
• ❌ distinct_entity - Binary metrics don't need winsorization
• ❌ threshold - Threshold logic handles outliers differently
• ❌ retention - Binary retention metrics don't need winsorization
• ❌ conversion - Binary conversion metrics don't need winsorization

Advanced Aggregation Parameters

Each advanced aggregation type requires its specific parameter and cannot use others:

Threshold Metrics

• Required: threshold_metric_settings object with:
  • comparison_operator: "gt" or "gte"
  • aggregation_type: "sum" or "count" (not count_distinct)
  • breach_value: numeric threshold value
• Cannot use: retention_threshold_days, conversion_threshold_days

Retention Metrics

• Required: retention_threshold_days (numeric)
• Cannot use: threshold_metric_settings, conversion_threshold_days

Conversion Metrics

• Required: conversion_threshold_days (numeric)
• Cannot use: threshold_metric_settings, retention_threshold_days
• Cannot use: Timeframe parameters (aggregation_timeframe_start_value, aggregation_timeframe_end_value)

Timeframe Parameters

When using aggregation timeframe parameters:

• Required: aggregation_timeframe_unit must be specified if any timeframe parameters are used
• Supported units: "minutes", "hours", "days", "weeks", "calendar_days"
• Not supported for: conversion operations (use conversion_threshold_days instead)

Denominator Constraints

For ratio metrics, denominators can only use these operations:

• ✅ sum, count, count_distinct, distinct_entity, last_value, first_value
• ❌ Cannot use: threshold, retention, conversion

Guardrail Cutoff Signs

When using guardrail metrics (is_guardrail: true with guardrail_cutoff):

• If fact's desired_change: "increase" → guardrail_cutoff must be negative
• If fact's desired_change: "decrease" → guardrail_cutoff must be positive

Documentation

For detailed information about metric configuration, available options and constraints, see Eppo's documentation page.

Example YAML Configuration

fact_sources:
    - name: Revenue
      sql: |
          SELECT ts, user_id, amount
          FROM revenue_table
      timestamp_column: ts
      entities:
          - entity_name: User
            column: user_id
      facts:
          - name: Revenue
            column: amount

metrics:
    - name: Total Revenue
      description: Sum of Total Purchase Value in Purchases Fact Table
      entity: User
      numerator:
          fact_name: Revenue
          operation: sum

Development

Setup

Create a virtual environment

python -m venv .venv
source .venv/bin/activate

Install dependencies

pip install -r requirements.txt

Running the tests

pytest tests

Running the package

export EPPO_API_KEY="your-api-key"
export EPPO_SYNC_TAG="your-sync-tag"
export EPPO_REFERENCE_URL="your-reference-url"
python -m eppo_metrics_sync path/to/yaml/directory

Building and Publishing

For package maintainers:

1. Update version in pyproject.toml
2. Build the package:

python -m build

3. The package will be automatically published to PyPI when a new release is created on GitHub.