Thanks, TP. I like the general direction here.

I really like the language-neutral abstraction.

Vikram

On Mon, Oct 5, 2026 at 5:36 AM Kaxil Naik <[email protected]> wrote:

> Thanks TP, I am looking forward to this. The design is sensible to me, I
> added few comments on the PR around the code though, nothing major.
>
>
> On Mon, 5 Oct 2026 at 10:40, Pierre Jeambrun <[email protected]>
> wrote:
>
> > Thanks for opening the thread TP.
> >
> > This sounds like a nice plan forward, (proposed schema makes sense to me
> > and delaying some advanced features while we focus on the MVP seems
> > reasonable).
> >
> > I left a few small comments on the PR.
> >
> > Looking forward to hearing from other stakeholders.
> >
> > Pierre
> >
> > On Mon, Oct 5, 2026 at 8:00 AM Tzu-ping Chung via dev <
> > [email protected]> wrote:
> >
> > > I thought through the compatibility_date vs $schema differences and I
> > > think I tend to agree that using $schema would be easier for editors.
> > > compatibility_date has an edge on user ergonomics, but these days
> people
> > > are probably always doing copy-paste or just using an agent to generate
> > the
> > > skeleton anyway. I’ll switch to $schema and drop compatibility_date.
> > >
> > > The parser PR already contains a schema file, and we’ll publish it
> > similar
> > > to API specs under airflow.apache.org <http://airflow.apache.org/>.
> > >
> > > TP
> > >
> > >
> > > > On 3 Oct 2026, at 16:36, Shahar Epstein <[email protected]> wrote:
> > > >
> > > > Thanks for sharing it, TP!
> > > > I support the overall direction, specifically the language neutral
> > > format.
> > > > For the format to work well with editors and other tools, could we
> use
> > a
> > > > stable format identifier alongside/instead of compatibility_date, and
> > > > document the schema and semantics in a written spec? It would also
> help
> > > to
> > > > define metadata and typed params in the schema, reserve names for
> > > deferred
> > > > features such as assets and task groups, and clarify how run: tasks
> map
> > > to
> > > > code when the YAML is read independently.
> > > > I’d recommend looking at existing open workflow formats for
> > inspiration.
> > > > For example, the Open Workflow Specification
> > > > <https://open-workflow-specification.org/> is more data-centric than
> > > > task-centric, so it may not fit Airflow’s execution model, but its
> > schema
> > > > design could offer useful ideas.
> > > >
> > > >
> > > > Shahar
> > > >
> > > > On Fri, Oct 2, 2026 at 2:04 PM 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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> > > >>
> > > >>
> > >
> > >
> >
>

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