[Feature] Apply `tags` config to `metrics`

[dtaniwaki]

Is this a new bug in dbt-core?

• I believe this is a new bug in dbt-core
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

Tags specified for metrics are not reflected in parsed metric nodes in the following cases:

Case 1: +tags in dbt_project.yml

# dbt_project.yml
metrics:
  my_project:
    +tags:
      - project_tag

Case 2: tags in the metric's config: block (YAML)

# models/schema.yml
metrics:
  - name: my_metric
    label: "My Metric"
    type: simple
    type_params:
      measure: my_measure
    config:
      tags:
        - yaml_tag

After dbt parse, neither project_tag nor yaml_tag appears in the metric's tags field in manifest.json.

This affects both v1 and v2 metrics:

• v1 (UnparsedMetric): only inline tags: at the metric top level are used; config.tags (from YAML or dbt_project.yml) are ignored.
• v2 (UnparsedMetricV2): tags are always initialized to []; all tag sources are ignored.

Expected Behavior

Tags should be applied to metrics from all sources, consistent with models and other nodes:

• config.tags in the YAML definition
• +tags in dbt_project.yml
• These should be merged with any inline tags: specified on the metric.

Steps To Reproduce

1. Create a project with a metric.
2. Add config: tags: [yaml_tag] to the metric in schema.yml, or add +tags: [project_tag] to dbt_project.yml under metrics:.
3. Run dbt parse.
4. Check target/manifest.json — the metric's tags field is empty.

Relevant log output

N/A

Environment

- OS:
- Python:
- dbt:

Which database adapter are you using with dbt?

other (mention it in "Additional Context")

Additional Context

dbt-athena

Root cause is in core/dbt/parser/schema_yaml_readers.py (MetricParser): the resolved config dict (containing merged tags from all sources) is computed but its tags value is never merged into the metric's tag list.

[dbeatty10]

Thanks for reaching out about this @dtaniwaki !

We don't have metrics included as a supported node type in our documentation for tags. But I see what you are saying in the examples you provided.

I'm consulting with some other folks at dbt Labs to determine if we'd consider this a bug or a feature request. We'll let you know what we determine!

[dbeatty10]

@dtaniwaki after discussing with @QMalcolm, we believe that dbt never intentionally has supported tags for metrics or semantic models, which is why we don't see them in the documentation.

So I'm going to convert this to a feature request for further consideration.

Things to consider

Tags should be applied to metrics from all sources, consistent with models and other nodes:

• config.tags in the YAML definition
• +tags in dbt_project.yml
• These should be merged with any inline tags: specified on the metric.

The top-level tags specification on a node is the old/legacy way of specifying tags, which we are deprecating. Nodes originally had top-level tags attributes, but we converted tags to being nested under config. We combined the top-level tags and config.tags to support backwards compatibility. But given that metrics and semantic_models never truly supported the top-level tags property, we'd probably only implement it under config.

[dtaniwaki]

@dbeatty10
Thank you for your review. I implemented that feature in #12604. Would you review the PR?

[graciegoheen]

Thanks for opening! As discussed over here, I don't think we should add tags to semantic models.

Given that a) models already support tags and b) we're moving towards this new spec, I'm going to close this one out for now.

We'll be sticking with the top-level metrics: key in the new spec for the semantic layer, though, so I think it would be reasonable to support tags: as a config for metrics.

I'm going to edit this feature request accordingly.

[dtaniwaki]

@graciegoheen I removed the semantic model fix and updated the PR. Would you review it?