Add is_backfillable property to DAG API responses

[Dev-iL]

Context

Currently, when attempting to backfill a DAG that has an Asset schedule, after going to the backfill section in the trigger form and choosing dates we get an error saying: "No runs matching selected criteria." (on 2.11 it says "No run dates were found for the given dates and dag interval."). This is confusing UX-wise: instead of being shown right from the start (because it is tied to how the DAG is configured), it appears only after the user selects a date range. This sequence of events implies causality between the user's choice and the error — which is not true.

Additionally, DAGs that configure allowed_run_types to exclude BACKFILL_JOB had no upfront indication that backfilling is disabled.

Summary

• Adds a timetable_periodic boolean column to DagModel via Alembic migration (following the timetable_partitioned pattern), set from dag.timetable.periodic during DAG sync.
• Adds a computed is_backfillable field to DAG API responses that unifies both schedule compatibility (timetable_periodic) and run-type permissions (allowed_run_types) into a single source of truth.
• Replaces the backend's string-based timetable_summary == "None" check with a proper timetable.periodic check in both _do_dry_run and _create_backfill, catching all non-periodic schedules (@once, @continuous, asset-triggered, partitioned asset) — not just unscheduled DAGs.
• Adds allowed_run_types validation to _do_dry_run (previously only in _create_backfill), ensuring dry-run and create return consistent errors.
• Renames DagNoScheduleException to DagNonPeriodicScheduleException to reflect the broader validation.
• Updates the UI to use the new is_backfillable field instead of the hasSchedule heuristic, so the Backfill option is correctly disabled for all non-backfillable DAGs.

Changes

Migration:

• Migration 0111 adds timetable_periodic Boolean column to the dag table (server_default="0", nullable=False).
• dag_processing/collection.py sets dm.timetable_periodic = dag.timetable.periodic during DAG sync.

API / Models:

• DagModel declares timetable_periodic: Mapped[bool].
• DAGResponse.is_backfillable — computed field: True only when timetable_periodic is True AND BACKFILL_JOB is permitted by allowed_run_types.
• backfill.py — both _create_backfill and _do_dry_run check dag.timetable.periodic and allowed_run_types.
• Renamed DagNoScheduleException -> DagNonPeriodicScheduleException.
• dag_command.py — is_backfillable computed from both periodic and allowed_run_types.

UI:

• TriggerDAGModal.tsx uses is_backfillable to gate the Backfill radio option. hasSchedule is kept for TriggerDAGForm (controls data interval display — separate concern).
• Updated i18n strings (renamed backfill.tooltip to backfill.scheduleNotBackfillable in all 21 locales).

Tests:

• New TestIsBackfillable tests covering: non-periodic, periodic, allowed_run_types=None, backfill included/excluded, and the combined non-periodic+allowed case.
• New test_create_backfill_non_periodic_schedule_rejected and test_do_dry_run_non_periodic_schedule_rejected tests covering @once, @continuous, None, and asset schedules.
• Updated existing test_no_schedule_dag for new exception behavior.
• Updated test fixtures in DAG response tests, DagCard UI tests, and airflow-ctl tests.

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: Claude Opus 4.6 following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.

[Copilot]

Pull request overview

This PR improves backfill UX by exposing whether a DAG’s schedule supports backfilling via a new is_backfillable field in DAG API responses, enforcing non-periodic schedule rejection in backfill endpoints, and updating the UI to disable backfill when unsupported.

Changes:

• Add computed is_backfillable to DAG-related API response models and OpenAPI specs (public + UI).
• Validate backfills against dag.timetable.periodic (rejecting None, @once, @continuous, asset-triggered, partitioned asset schedules) and rename the related exception.
• Update Trigger DAG modal logic and i18n to use is_backfillable, plus add regression/unit tests.

Reviewed changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
uv.lock	Updates lockfile metadata/deps (includes OAuth/authlib-related changes).
airflow-ctl/src/airflowctl/api/datamodels/generated.py	Adds is_backfillable to generated CLI client DAG response models.
airflow-core/src/airflow/api_fastapi/core_api/datamodels/dags.py	Introduces computed is_backfillable on DAGResponse (and inheritors).
airflow-core/src/airflow/models/backfill.py	Renames schedule exception + switches backfill validation to timetable.periodic.
airflow-core/src/airflow/api_fastapi/core_api/routes/public/backfills.py	Updates route exception handling to the renamed exception.
airflow-core/src/airflow/api_fastapi/core_api/openapi/v2-rest-api-generated.yaml	Publishes is_backfillable in public OpenAPI schema for DAG responses.
airflow-core/src/airflow/api_fastapi/core_api/openapi/_private_ui.yaml	Publishes is_backfillable in private UI OpenAPI schema for DAG responses.
airflow-core/src/airflow/ui/openapi-gen/requests/types.gen.ts	Updates generated TS types to include is_backfillable.
airflow-core/src/airflow/ui/openapi-gen/requests/schemas.gen.ts	Updates generated TS schemas to include is_backfillable as required/readOnly.
airflow-core/src/airflow/ui/src/components/TriggerDag/TriggerDAGModal.tsx	Disables/gates Backfill option using dag.is_backfillable instead of hasSchedule.
airflow-core/src/airflow/ui/public/i18n/locales/en/components.json	Replaces tooltip string with scheduleNotBackfillable message.
airflow-core/tests/unit/models/test_backfill.py	Adds coverage for rejecting non-periodic schedules in create/dry-run helpers.
airflow-core/tests/unit/api_fastapi/core_api/routes/public/test_backfills.py	Updates validation expectations for non-periodic schedules.
airflow-core/tests/unit/api_fastapi/core_api/datamodels/test_dags.py	Adds unit tests for DAGResponse.is_backfillable computation.
airflow-core/tests/unit/api_fastapi/core_api/datamodels/__init__.py	Adds package init for new datamodel tests directory.

[pierrejeambrun]

A few suggestions, otherwise looking good to me

[Copilot]

Pull request overview

Copilot reviewed 44 out of 44 changed files in this pull request and generated 4 comments.

Comments suppressed due to low confidence (2)

airflow-core/tests/unit/api_fastapi/core_api/datamodels/test_dags.py:1

• DAGResponse.owners is typed as list[str] (and the OpenAPI/TS types reflect an array). Providing a bare string risks validation failure or unintended coercion (e.g., into a list of characters), making these tests flaky/incorrect. Change the default to a list such as ["airflow"].
  airflow-core/src/airflow/ui/public/i18n/locales/zh-CN/components.json:1
• Many non-English locale files introduce the new scheduleNotBackfillable message in English, which is a localization regression compared to the removed translated tooltip. Consider translating this new string per locale (or reusing the prior locale-specific tooltip phrasing adapted to the new meaning) so users don’t see English text in localized UIs.

[pierrejeambrun]

Looking good overall. Just a few nits and we should be good to merge.