Here is another library with some functionality that might be used as a reference point.

Pydantic models of many airflow structures:

Yaml-based dag system with support for dumping full rendered python files or instantiating in memory, based on hydra and omegaconf:




Tim Paine
tim.paine.nyc


On Oct 2, 2026, at 07:04, Tzu-ping Chung via dev <[email protected]> wrote:

Hi all,

With AIP-85, I've been working on a YAML Dag format, and would like some feedback on it. Shortest possible taste first:

   compatibility_date: "2026-10-30"
   dag_id: daily_sales
   schedule: "@daily"
   tasks:
     # A classical task using an operator.
     # There's no automatic template detection; {{ ds }} not wrapped in $t is a literal.
     - id: extract
       uses: airflow.providers.amazon.aws.transfers.s3_to_redshift.S3ToRedshiftOperator
       with:
         s3_bucket: retail-raw
         s3_key: {$t: "sales/{{ ds }}.csv"}
         schema: public
         table: sales
     # A taskflow-style task.
     # Things inside run: are arguments to the function.
     # $x means an XCom input.
     - id: notify
       run:
         channel: "#data"
         rows: {$x: extract}

## Why a new format

DagFactory is the direct inspiration and the feature-parity bar; longer term we'd like this to be the path that supersedes it.

The reason to start fresh rather than extending is that DagFactory is essentially Python transcribed into YAML; import paths, callables named by file+function, a default_args block shaped like a DAG() call. With recent AIP-108 (language SDKs), YAML can provide a more neutral foundation for declaring the dependency structure of tasks implemented in ANY language. We also want to better represent Airflow constructs such as XCom and assets.

== Design guidelines and decisions ==

- Language-neutral, not "Python in YAML". JSON is the data model, YAML just a skin: everything round-trips to JSON.
- Literal by default; templating is opt-in with {$t: ...} (inspired by AIP-80). This removes the implicit-Jinja surprises. Also, {$f: ...} is an explicit file template, removing the classic `cat {{ ds }}.sh` -> TemplateNotFound foot-gun. (There's also a $const to mark something as literal explicitly.)
- No default_args. Reusable `templates:` composed per task via `extends:`, and the merged task is validated against the real operator. An unaccepted argument is a parse error, not a silent drop.
- uses: a fully-qualified operator import path. run: the single code primitive for any language (Python/Go/Java written identically).
- compatibility_date (borrowed from Cloudflare Workers) pins the format semantics, so old files keep their meaning as the format evolves.
- It ships as an AIP-85 importer in the Task SDK, natively recognized by Airflow (enabled by a configuration).

== Deliberately left out of v1 (all additive, can land later) ==

- Task groups, dynamic task mapping, branching; AIP-104/111/113 (batching, loops, dynamic task groups).
- Assets / data-aware scheduling (inlets/outlets, asset expressions, watchers).
- Callbacks. They name a callable, so they wait on a declarative callable-reference grammar.
- Python run: execution. The format is settled; the @task_handler runtime that runs it is a separate work (Go/Java run: tasks already execute).
- Operator shorthand (e.g. amazon.S3ToRedshiftOperator) and cross-file shared config.

I've also created a draft PR that implements the parser. (Not the full AIP-85 importer yet.)
https://github.com/apache/airflow/pull/74084

Thanks,
TP


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