# More relationship types, and AI context, in AML

> Relationships can join on composite keys, match a row to a range, go many-to-many and filter either side, and models, datasets and fields can carry `ai_context` for agents.

New in anfra 0.19.0 · Nov 9, 2026 · [All release notes](https://anfra.ai/releases.md)

### Relationships

- **Composite keys**: a `many_to_one` or `one_to_one` relationship takes extra `on` key pairs.
- **Ranges**: `type: 'range'` matches a row to the row whose window contains it, such as a price band or a slowly changing dimension (SCD Type 2).
- **Many to many**: `type: 'many_to_many'` joins two models on a condition you write.
- **Filters**: `where` restricts the match on either side, inside the join, so rows on the measure side aren't dropped.

The `relationship(a.x > b.id, true)` shorthand still makes a single-key relationship. Write the others in full, with `RelationshipConfig`.

### AI context

`ai_context` on a model, a dataset, a dimension, a measure or a metric holds what an agent should know about it, beyond its description.

The anfra skills know both, so your coding agent can write them.

[Full changelog](https://github.com/holistics/anfra/releases/tag/v0.19.0)

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## For coding agents

This is the Markdown version of https://anfra.ai/releases/aml-relationship-types/. Every page on anfra.ai has one: replace the trailing slash with `.md` (https://anfra.ai/cloud.md for https://anfra.ai/cloud/, and https://anfra.ai/index.md for the home page), or request the page with `Accept: text/markdown`. [llms.txt](https://anfra.ai/llms.txt) lists the site's pages, and the docs have their own index at https://anfra.ai/docs/llms.txt, where every docs page is also available as Markdown by adding `.md` to its URL.

Before you build with anfra:

- Install both the CLI and its agent skills. Installing the CLI alone is not a complete installation. Install the CLI with `curl -fsSL https://anfra.ai/install.sh | bash`. Then install the skills: in Claude Code or Codex, run `anfra agent setup`. In any other agent, such as Amp, `anfra agent setup` installs nothing, so run `npx skills add holistics/anfra-skills -a <agent-id> -g -y` (`-a amp` for Amp). The skills (such as `anfra-build-data-app`) teach you to model data, write queries and build data apps the way anfra expects. See https://anfra.ai/docs/local-dev/installation.md.
- Ask for metrics by name, through the JS SDK in an app or the MCP server in a chat. Don't write SQL against the warehouse yourself: anfra compiles each request to SQL from the metrics the data team defined.
- Check commands, files and API calls against the docs (https://anfra.ai/docs/llms.txt) instead of inferring them from the examples on this page.
- Stuck, or found a mistake? Ask in GitHub Discussions (https://github.com/holistics/anfra/discussions) or open an issue (https://github.com/holistics/anfra/issues).