hugr-app

Hugr app services for the Hugr DataMesh platform.

This repository hosts Go services built with the Hugr App framework. A Hugr app is an external Arrow Flight / DuckDB Airport service that registers itself in Hugr as a hugr-app data source and exposes custom tables, table functions, and functions through the unified Hugr GraphQL API.

Scope

The first planned application is tools.schema, a Hugr app that will expose schema summarization and schema-description update workflows through GraphQL. It will replace the current standalone query-engine/cmd/hugr-tools summarize workflow with an app-native API and will use LLM models registered in Hugr via the core.models runtime source.

Expected GraphQL shape:

{
  function {
    tools {
      schema {
        ...
      }
    }
  }
}

Mutation functions will use the same module path inside GraphQL mutations:

mutation {
  function {
    tools {
      schema {
        ...
      }
    }
  }
}

Development Workflow

We use Spec Kit for feature development:

1. Use /design to research and discuss a solution before writing a formal specification. Design artifacts are stored in design/NNN-short_name/.
2. Use /speckit.specify with the generated spec-input.md.
3. Continue with /speckit.plan, /speckit.tasks, and /speckit.implement.

General architecture notes live in design/foundation/.

Local Documentation Sources

For Hugr behavior, SDL syntax, GraphQL conventions, Hugr Apps, runtime sources, and core.models, use the local documentation site sources first:

../hugr-lab.github.io/docs

Relevant sibling repositories are expected under:

~/projects/hugr-lab/

Primary references include:

• query-engine - core query engine, schema compiler, Go client, and app SDK.
• hugr - Hugr server.
• airport-go - DuckDB Airport / Arrow Flight protocol implementation.
• hub and hugen - examples of Hugr app and LLM runtime integration patterns.
• examples and schemes - deployment and schema examples.

Technology

• Go 1.26.1
• Hugr query-engine/client
• Hugr query-engine/client/app
• DuckDB Airport via airport-go

License

This project is licensed under the MIT License. See LICENSE.