flowfile-research-frontier

name

flowfile-research-frontier

description

The maintainer's three long-horizon research bets for Flowfile (AI-native flow building, visual↔code round-trip, decentralized execution on a centralized catalog) with the verified existing assets each builds on, PR-sized first steps, falsifiable milestones, and the research discipline that turns a hunch into a merged change. Use when scoping ambitious/exploratory work, writing a design doc or spike, proposing a "big idea," choosing what to prototype next, evaluating whether an experiment is worth shipping, or asked "what is Flowfile trying to become" / "where is this going" / "research direction" / "north star."

Flowfile Research Frontier

This is a map of unbuilt territory, not a description of shipped features. It names the maintainer's three standing research bets (as of 2026-07-03, v0.12.7), the concrete repo assets each one can stand on, and the discipline for taking a hunch to a merged change. Everything here labeled open or candidate is deliberately not built yet — do not describe it as if it ships.

Use this skill to scope and de-risk exploratory work. It tells you the falsifiable milestone to aim at and the first three PR-sized steps, so a spike produces a measurable result instead of a demo. It does not replace the how-to skills — it points at them.

When NOT to use this skill

• Actually shipping a new node → flowfile-node-development.
• Changing the AI agent/planner/providers → flowfile-ai-subsystem (owns all planner internals).
• Fixing a codegen ↔ graph-execution mismatch → flowfile-codegen-parity-campaign.
• The FlowFrame emission paths / stub pipeline → flowfile-frame-and-codegen.
• Env vars, feature flags, the MutableBool experiment-flag mechanism → flowfile-config-and-flags.
• How to prove a change is correct (test markers, isolation, the evidence bar) → flowfile-testing-and-validation.
• Getting a change merged (PRs, drift gates, review) → flowfile-change-control.
• Why a past idea was abandoned → flowfile-failure-archaeology.

If your task is to build one specific thing, you probably want a sibling above. Come here to decide what is worth building and how you will know it worked.

The three-word compass

The maintainer's frontier, verbatim intent:

• A — AI-native flow building. Agents that reliably build and edit pipelines, not demos.
• B — Visual ↔ code round-trip. Full two-way parity between visual flows, exported Python (raw Polars), and the FlowFrame API.
• C — Decentralized execution on a centralized catalog. Global components, catalog metadata in PostgreSQL, table data in S3 — and every local Flowfile instance brings its own compute, mixing local files and remote tables in complete harmony.

Each pillar below follows the same shape: why the state of the art fails → the specific asset Flowfile already has (verified) → three PR-sized first steps → a falsifiable milestone.

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Pillar A — AI-native flow building

Why current SOTA fails

AI flow-builders are demos. They generate a plausible pipeline once, on a clean canvas, and fall over on the second turn: they hallucinate column names, loop on tool-name mismatches, and mutate a live graph mid-run so a user's concurrent edit silently clobbers the model's work (or vice-versa). There is no staging, no drift detection, no atomic accept/reject — so "reliable editing of an existing pipeline" (the actual job) is unsolved.

Flowfile's specific existing asset (VERIFIED, as of 2026-07-03 v0.12.7)

Flowfile already has the machinery those demos lack — the diff-staged planner:

• A real multi-turn agent package: flowfile_core/flowfile_core/ai/agents/planner/ (loop.py, insertion.py, recovery.py, staged_schemas.py, …). Not a stub.
• Every LLM tool call goes through execute_tool_call(...) in flowfile_core/flowfile_core/ai/tools/executor/dispatch.py:37, which takes mode: ExecutionMode = "apply". The planner dispatches with mode="stage" so the live graph is never mutated mid-run — steps accumulate as staged entries.
• On completion the staged steps bundle into one reviewable GraphDiff via bundle_staged_results(...) at flowfile_core/flowfile_core/ai/diff.py:318, accepted/rejected atomically in the UI.
• Drift is handled: the session keeps a graph snapshot (sessions.capture_graph_snapshot, re-taken on every resume path in agents/planner/loop.py); a user canvas edit mid-run emits a drift_detected event and parks the session in paused_drift status until an explicit resume.
• Rejected steps are retried by feeding the executor's refusal_detail back as a role="tool" message (ai/tools/executor/refusals.py), and there is a per-session dry-run cache (ai/tools/dry_run.py).

So Flowfile is past the demo layer. The frontier is measured reliability on top of it. (Planner internals are owned by flowfile-ai-subsystem — read it before touching this code.)

First three concrete steps (each PR-sized)

1. Build a held-out benchmark harness. Add a fixture corpus of (natural_language_task, reference_flow) pairs under flowfile_core/tests/ai/, driving agents/planner/loop.py end-to-end against a recorded/replayed provider (the shared LiteLLMProvider seam makes every call interceptable — see flowfile-ai-subsystem). Assert: staged GraphDiff applies cleanly and the applied flow executes to a frame equal to the reference. Report success rate and retry count. This makes "reliable" a number before you touch the agent.
2. Instrument the refusal path. Emit structured refusal-reason counters from ai/tools/executor/refusals.py across the benchmark, so "the agent is flaky" becomes a ranked table of which tool calls fail and why. Failure is free — do not make refusals raise.
3. Add one executor-seam coercion for the top refusal reason, behind an experiment flag (see flowfile-config-and-flags for the MutableBool pattern). Doctrine: when the model consistently emits a recoverable wrong shape, normalize at the executor seam (mirror the existing _coerce_* handlers in ai/tools/executor/coercions.py) — do not keep tightening prompts. Measure the benchmark success delta the coercion buys.

Falsifiable milestone — you have a result when…

Over an N-task held-out benchmark, an agent given a task and a blank-or-partial graph produces a staged diff that (a) applies cleanly and (b) executes to a frame equal to the human reference (assert_frame_equal, order-insensitive), at a measured success rate ≥ your pre-registered threshold, with zero human tool-name corrections and a mean retry count below a pre-registered bound. If the harness cannot report those three numbers, you have a demo, not a result.

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Pillar B — visual ↔ code round-trip

Why current SOTA fails

Every visual ETL tool is a one-way street. It might export a script, but the export is a lossy, un-reimportable artifact — edit the code and you can never get back to the diagram; edit the diagram and the code silently drifts. There is no tool where the visual graph, hand-written code, and a fluent API are three renderings of one truth that survive a round-trip.

Flowfile's specific existing asset (VERIFIED, as of 2026-07-03 v0.12.7)

Flowfile has both directions of the bridge and one canonical DAG behind them:

• Graph → code: flowfile_core/flowfile_core/flowfile/code_generator/code_generator.py exposes export_flow_to_polars(flow_graph) (line 1602) and export_flow_to_flowframe(flow_graph) (line 1607), via FlowGraphToPolarsConverter / FlowGraphToFlowFrameConverter.
• Code → graph: flowfile_frame builds the same in-process FlowGraph as a side effect of every method call — native nodes where a schema exists, generated Polars-code nodes otherwise (FlowFrame._add_polars_code, flowfile_frame/flowfile_frame/flow_frame.py:588). The graph a frame builds is byte-identical in kind to what the Designer edits.
• Graph → visual editor: open_graph_in_editor(flow_graph) at flowfile/flowfile/api.py:399 saves the frame's graph and opens it in the running Designer.
• The parity discipline already exists: the Descending-sort codegen bug (#544) was root-caused by two executors carrying separate direction parsers; the fix centralized it into transform_schema.is_descending(...) (flowfile_core/flowfile_core/schemas/transform_schema.py:952), used by both the code generator and the execution engine. And there is a real equivalence test: flowfile_core/tests/flowfile/test_code_generator.py parametrizes over [export_flow_to_polars, export_flow_to_flowframe] and asserts the generated code, when executed, yields a frame equal to flow.get_node(N).get_resulting_data().data_frame.

So the pieces exist; what is open is full round-trip idempotence with zero lossy fallbacks. (Emission paths and the codegen bug family are owned by flowfile-frame-and-codegen and flowfile-codegen-parity-campaign — this pillar is the parity campaign's north star.)

The two lossy escape hatches that break round-trip (know your enemy)

1. UnsupportedNodeError in the code generator — a node with no codegen handler.
2. The base64-serialized-LazyFrame fallback in flow_frame.py _add_polars_code: when an expression is not convertible to source (e.g. an unresolvable lambda), the frame serializes a LazyFrame blob into the node and logs a warning ending "a breaking graph when using the the ui" (sic — the doubled "the" is in the source; grep breaking graph when using, flow_frame.py ~line 655). Such a node does not round-trip and the visual graph no longer matches the computation.

Any corpus flow that produces either is, by definition, not round-trippable.

First three concrete steps (each PR-sized)

1. Add a round-trip idempotence test. Extend flowfile_core/tests/flowfile/test_code_generator.py: for a flow corpus, assert export_flow_to_flowframe(g) → re-imported through flowfile_frame → re-exported is idempotent (graph-shape or normalized-string stable), and both executions frame-equal. This surfaces the exact nodes that don't survive the trip.
2. Fail the build on a lossy fallback. Add a test/lint that fails when a corpus flow yields a base64-serialized-LazyFrame node or raises UnsupportedNodeError — converting "sometimes lossy" into a hard, counted gate.
3. Add a native handler for the single most common UnsupportedNodeError node type (in the converter + code_generator/transform_handlers.py), following the one-shared-parser rule (the is_descending pattern) so graph-exec and codegen can never diverge. Ship it with an equivalence test. Cross-ref flowfile-codegen-parity-campaign for the full bug-family playbook.

Falsifiable milestone — you have a result when…

For every flow in a fixed corpus: export_flow_to_flowframe(g) re-imported rebuilds g' such that export_flow_to_flowframe(g') == export_flow_to_flowframe(g) (idempotent), both g and g' execute to assert_frame_equal results, and the corpus produces zero UnsupportedNodeError and zero base64-serialized-LazyFrame nodes. Measurable check: the extended parametrized test is green with those three counters at zero.

---

Pillar C — decentralized execution on a centralized catalog

Why current SOTA fails

Every catalog/lakehouse today assumes central compute: the catalog service owns the engine that reads and writes the data. "Decentralized" offerings still funnel queries through a shared cluster. Nobody offers: shared metadata + shared object-store data, where each participant brings their own local compute and treats a local Parquet file and a remote S3 Delta table as first-class peers in one pipeline, with credentials that never leak between participants.

Flowfile's specific existing assets (VERIFIED, as of 2026-07-03 v0.12.7)

Three seams are already in the right shape:

• Data can already live in object storage, per-catalog. Migration 028 (028_catalog_namespace_storage.py) added storage_uri + storage_connection_name to level-0 (catalog-root) namespaces. flowfile_core/flowfile_core/catalog/storage_backend.py resolve_for_namespace(...) (line 123) resolves a cloud CatalogStorageTarget when a URI is set, resolving the CloudStorageConnection as the catalog owner (owner_id = root.owner_id, line 107) — never the calling user. FLOWFILE_CATALOG_STORAGE_URI / _CONNECTION remain a creation-time default for new catalogs (catalog/services/namespaces.py:_env_default_storage, line 148); resolve_catalog_storage(_user_id, ...) (line 137) is now a shim that ignores its user_id. (Env-var mechanics are owned by flowfile-config-and-flags.)
• The worker reads cloud tables with its own compute. flowfile_worker/catalog_reader.py open_catalog_table(...) (line 29) does pl.scan_delta(validate_catalog_uri(...), storage_options=...) for cloud and local roots alike. Local compute reading remote data is already the code path.
• The catalog-DB seam is a single function. get_database_url() at shared/storage_config.py:402 is the one place every catalog-DB consumer resolves its URL (core database/connection.py, database/migration.py, alembic/env.py, the scheduler's engine.py, shared/run_completion.py). Today it only ever emits sqlite:///….
• Secrets are already instance-independent. A stored secret is $ffsec$1$<user_id>$<fernet_token> — the worker (and any peer) re-derives the per-user key from the shared master key with zero core round-trip (secret_manager.py ↔ flowfile_worker/secrets.py, byte-for-byte parallel). Sharing/decentralizing does not require re-encryption. (This contract is owned by flowfile-architecture-contract.)

What is open: get_database_url only speaks SQLite, and there is no two-instance harmony test. The metadata DB is deliberately always-local today; migration 028 is forward-only with no backfill. Also open: global components — user-defined components today are per-instance .py files under <user_data>/user_defined_nodes/ (shared/storage_config.py:109-114, loaded into CUSTOM_NODE_STORE); sharing them through the central catalog is a candidate follow-on to steps 1–3 below, with no design yet.

What PostgreSQL actually needs (probed empirically, 2026-07-03)

The full Alembic chain 001→028 was run against a disposable PostgreSQL 16 (monkeypatching shared.storage_config.get_database_url to a postgresql+psycopg2:// URL before importing flowfile_core, with FLOWFILE_DB_PATH pointed at a fresh scratch SQLite so the import side stays isolated — never set FLOWFILE_SKIP_STARTUP_MIGRATION for this). Results, so step 1 is honest:

• Migration 001 applies clean on Postgres. The chain's verified first failure is 002: ALTER TABLE catalog_tables ADD COLUMN is_optimized BOOLEAN DEFAULT 0 → psycopg2.errors.DatatypeMismatch: column "is_optimized" is of type boolean but default expression is of type integer (002_virtual_flow_tables.py:26, server_default=sa.text("0")).
• Exactly four migration files carry SQLite-isms; with those shimmed, the chain reaches 028 and init_db() even seeds the default user on Postgres (35 tables, alembic_version = 028):
  1. 002_virtual_flow_tables.py:26 — Boolean column with integer server_default=sa.text("0").
  2. 016_flow_api_endpoints.py:41,64 — same class, server_default=sa.text("1") on enabled.
  3. 026_project_uniqueness_and_uuid_not_null.py — three sites: the dedup SELECT/UPDATE using integer booleans (is_active = 1/0, lines 46–51), a hand-written SQLite CREATE TABLE _wp_new rebuild using DATETIME and BOOLEAN DEFAULT 0/1 (lines 81–97 — invisible to any type-level grep; Postgres fails with type "datetime" does not exist), and the partial index WHERE is_active = 1 (line 130).
  4. 020_user_groups_sharing.py:45-48 — SET is_public = 1 backfill. Dormant on a fresh DB (it only runs when a local_user row and a 'General' namespace already exist), so it never fires when bootstrapping Postgres from empty — fix it anyway for data-bearing paths.
• Everything else is already dialect-clean, verified by the same run: every op.batch_alter_table (degrades to plain ALTER off SQLite — do not rewrite them), render_as_batch=True in alembic/env.py:27,47 (harmless on Postgres — keep it), the raw backfills in 006/010/012/018/024, and all model column types. Every downstream engine creator already gates connect_args={"check_same_thread": False} on "sqlite" in url (flowfile_core/database/connection.py:25, flowfile_scheduler/flowfile_scheduler/engine.py:50-52, shared/run_completion.py:29-30,49-50), so consumers need no change.
• Seam changes beyond the migrations:
  • get_database_url() (shared/storage_config.py:402) wraps FLOWFILE_DB_PATH in sqlite:/// unconditionally — minimal change: pass values containing :// through as full URLs.
  • database/migration.py:_catalog_db_exists() (line 84) is a file-existence check that returns False for any non-SQLite URL, so every Postgres boot takes the fresh/legacy branch. Safe today only because get_legacy_database_path() returns None when FLOWFILE_DB_PATH is set; if the legacy branch ever fired on Postgres, migrate_data_from_legacy_db() executes PRAGMA foreign_keys = OFF/ON (lines 265, 280) → hard error. Make the existence check alembic_version-based for server URLs.
  • psycopg2-binary is dev-group only (pyproject.toml:112) — shipping Postgres support needs a runtime dependency (or an optional extra); today no driver ships.
• The hand-edit tension: flowfile_core doctrine forbids editing shipped migrations. A dialect-portability edit is the narrow exception, and only with proof SQLite behavior is unchanged — runnable check: run the chain on a fresh SQLite before and after the edit (FLOWFILE_DB_PATH=$(mktemp -d)/probe.db poetry run python -c "import flowfile_core") and diff the two sqlite3 <db> .schema dumps; they must be byte-identical.
• Test assets already provisioned: test_utils/postgres/ fixture with poetry scripts start_postgres / stop_postgres, and testcontainers ^4.10.0 in the dev group.

The one security wrinkle you must respect

Polars serializes storage_options (i.e. decrypted credentials) inline into a serialized LazyFrame blob. serialized_frame_uses_cloud(blob) (storage_backend.py:31) exists precisely to catch this: a cloud-scan blob must never be replayed — re-run the producer instead. A decentralized catalog makes this sharper: a replayed blob would ship one instance's credentials to another. Any cross-instance data path must route through resolve_for_namespace (owner-keyed credentials, worker re-derives), never through a shipped blob.

First three concrete steps (each PR-sized)

1. Generalize the metadata seam. The exact worklist is known (see the probe above): (a) teach get_database_url() (shared/storage_config.py:402) to pass ://-bearing values through as full URLs; (b) make _catalog_db_exists() (database/migration.py:84) alembic_version-based for server URLs; (c) fix the four migration files (002, 016, 026, 020) with SQLite-identical replacements (sa.false()/sa.true() for the defaults, TRUE/FALSE literals or boolean-typed bindparams for the raw SQL, portable types in 026's _wp_new DDL); (d) add a docker_integration-marked test that boots Postgres (testcontainers or test_utils/postgres/) and runs run_alembic_upgrade() against it. Expected observations: before the fixes the chain dies at 002 with psycopg2.errors.DatatypeMismatch on is_optimized; after, SELECT version_num FROM alembic_version returns 028 and the SQLite before/after .schema diff is empty. Keep render_as_batch=True — it is a no-op off SQLite. (Migration mechanics: flowfile-testing-and-validation + flowfile-change-control.)
2. Prove two-instance data sharing on the already-built cloud path. Add an integration test: two core processes sharing one catalog DB (via step 1's Postgres URL) and one MinIO bucket via a per-namespace storage_uri/storage_connection_name (migration 028). Assert instance B sees and reads a table instance A wrote, using instance B's own worker. (MinIO is already a test_utils/ fixture.)
3. Mixed local + cloud join, credential-blob guard hardened. Add a flow that joins a local Parquet file with a remote S3 Delta catalog table in one graph, and add an assertion that no cloud-backed catalog read is ever served from a replayed blob across instances (serialized_frame_uses_cloud must gate it). Cross-ref flowfile-architecture-contract for the worker-re-derives-secrets contract.

Falsifiable milestone — you have a result when…

Two independent local Flowfile instances (each with its own worker/compute), pointed at one PostgreSQL catalog and one S3 data root, can both list, read, and write catalog tables; a single flow joins a local file with a remote S3 table and produces a correct frame; and neither instance's worker ever holds the other's credentials in a replayable form. Measurable check: an integration test with two core processes sharing a Postgres get_database_url + one MinIO bucket, asserting cross-instance visibility, a mixed local+cloud join result, and zero cloud-blob replays.

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Research methodology — hunch → merged change (or documented retirement)

The frontier is speculative; the discipline is not. A change earns its way in here the same way every merged change does. Follow this or your spike stays a spike.

1. Predict numbers before you run

State the hypothesis as a quantity with a direction and a threshold, written down before the experiment: "the executor coercion in Pillar A/step 3 lifts benchmark success from X% to ≥Y%," or "the native handler in Pillar B/step 3 drops corpus UnsupportedNodeError count from N to 0." A hypothesis that can only be evaluated after seeing the output is not a hypothesis. Each pillar's milestone above is already written this way — copy that shape. Worked example: Pillar C's Postgres probe predicted (from a static grep) that the chain's first failure would be migration 002's boolean default; the live run against Postgres 16 confirmed exactly that failure, then surfaced 026's hand-written DDL that no grep predicted — the prediction earned trust, the surprise got recorded.

2. One mechanism must explain ALL observations — including the negatives

A result is not "it got better on the cases I hoped for." The mechanism you propose must account for the regressions and the no-ops too. If your coercion helps 8 tasks and breaks 2, the same causal story must explain the 2 — otherwise you have two mechanisms and understand neither. Flowfile history rewards this: the VizSessionRegistry 504s were only truly fixed once one mechanism (response-queue theft between two parents sharing a key) explained every symptom, not just the common one.

3. Survive an assigned adversarial-refutation pass

Before proposing the change, have someone (or yourself, in a separate pass) try to kill it: find the input that breaks the number, the confound that explains the delta without your mechanism, the negative case you didn't run. This repo has a documented failure mode for skipping this — Windows E2E tests that were green while testing nothing (OR-instead-of-AND on startup signals, test.skip() on launch failure, error-swallowing .catch(() => false)). A result that hasn't survived an attempt to refute it is that green-but-empty test.

4. The idea lifecycle (where the gates live)

hunch
  └─► experiment flag        (MutableBool / env gate — see flowfile-config-and-flags)
        default OFF; ship the plumbing dark so it can't regress the default path
  └─► validation             (the evidence bar — see flowfile-testing-and-validation)
        real integration tests over mocks; the pre-registered number must clear its threshold;
        survives the adversarial pass
  └─► EITHER  adopted change  (through flowfile-change-control: PR, drift gates, review)
      OR       documented retirement (write it up in flowfile-failure-archaeology so the next
               person doesn't re-run the dead experiment)

A retired idea is a deliverable, not a failure — the repo's abandoned directions (Airbyte connector, in-house fuzzy matching extracted to an external package, the walked-back FastAPI upgrade, the whole Electron toolchain) are load-bearing knowledge. Retire loudly.

5. Where good ideas have actually come from here

Not from greenfield brainstorming — from user pain and production bugs. The entire Alembic migration system was born from a production incident: a run-type mismatch between local and Docker databases (fixed by migration 006_normalize_run_type.py) forced the maintainer to "implement a mechanism to downgrade the db," which became versioned migrations. The uuid columns (flow_uuid, viz/dashboard uuids) trace to a concrete SQLite rowid-reuse bug pulling one flow's runs into another's history. The DST-correct cron cursor traces to a real double-fire risk. The best frontier work starts from an observed failure, then generalizes — when scoping a pillar, look first for the smallest real pain it removes, and make that your first PR.

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Provenance and maintenance

Re-verify volatile facts before relying on them (all commands read-only, run from repo root). Facts are stamped as of 2026-07-03 (v0.12.7).

Claim	One-line re-verification
Planner package + mode="stage" staging exists	ls flowfile_core/flowfile_core/ai/agents/planner/ && grep -n 'mode: ExecutionMode' flowfile_core/flowfile_core/ai/tools/executor/dispatch.py
bundle_staged_results → GraphDiff	grep -n 'def bundle_staged_results' flowfile_core/flowfile_core/ai/diff.py
Executor coercion + refusal seams	ls flowfile_core/flowfile_core/ai/tools/executor/ (expect coercions.py, refusals.py, dispatch.py)
Graph→code exporters	grep -n 'def export_flow_to_polars|def export_flow_to_flowframe' flowfile_core/flowfile_core/flowfile/code_generator/code_generator.py
Code→graph frame bridge	grep -n 'def _add_polars_code' flowfile_frame/flowfile_frame/flow_frame.py
Graph→editor entry point	grep -n 'def open_graph_in_editor' flowfile/flowfile/api.py
One shared sort-direction parser (parity discipline)	grep -n 'def is_descending' flowfile_core/flowfile_core/schemas/transform_schema.py
Codegen equivalence test parametrized over both exporters	grep -n 'export_flow_to_polars, export_flow_to_flowframe' flowfile_core/tests/flowfile/test_code_generator.py
Per-catalog object storage (migration 028)	`ls flowfile_core/flowfile_core/alembic/versions/
resolve_for_namespace / owner-keyed creds / resolve_catalog_storage shim	grep -n 'def resolve_for_namespace|owner_id = root.owner_id|def resolve_catalog_storage' flowfile_core/flowfile_core/catalog/storage_backend.py
Env vars are creation-time default only	grep -n 'FLOWFILE_CATALOG_STORAGE_URI|FLOWFILE_CATALOG_STORAGE_CONNECTION' flowfile_core/flowfile_core/configs/settings.py
Worker reads cloud catalog tables with its own compute	grep -n 'def open_catalog_table' flowfile_worker/flowfile_worker/catalog_reader.py
get_database_url is the single catalog-DB seam (SQLite-only today; wraps FLOWFILE_DB_PATH in sqlite:///)	sed -n '402,420p' shared/storage_config.py
The four Postgres-blocking migrations (002/016/026/020)	grep -n 'server_default=sa.text' flowfile_core/flowfile_core/alembic/versions/0{02,16}_*.py; grep -n 'DATETIME|is_active = 1' flowfile_core/flowfile_core/alembic/versions/026_*.py; grep -n 'is_public = 1' flowfile_core/flowfile_core/alembic/versions/020_*.py
_catalog_db_exists is file-based; legacy copy uses PRAGMAs	grep -n 'def _catalog_db_exists|PRAGMA foreign_keys' flowfile_core/flowfile_core/database/migration.py
Engine creators already dialect-gate check_same_thread	grep -rn 'check_same_thread' flowfile_core/flowfile_core/database/connection.py flowfile_scheduler/flowfile_scheduler/engine.py shared/run_completion.py
Postgres driver is dev-group only; test fixture exists	grep -n 'psycopg2-binary|start_postgres' pyproject.toml && ls test_utils/postgres/
Components are per-instance files (global components open)	grep -n 'def user_defined_nodes_directory' shared/storage_config.py
Secrets worker-re-derivable format	grep -n 'SECRET_FORMAT_PREFIX|KEY_DERIVATION_VERSION' flowfile_core/flowfile_core/secret_manager/secret_manager.py flowfile_worker/flowfile_worker/secrets.py
Cloud-blob replay guard	grep -n 'def serialized_frame_uses_cloud' flowfile_core/flowfile_core/catalog/storage_backend.py
Migration born from a production bug (methodology §5)	head -20 flowfile_core/flowfile_core/alembic/versions/006_normalize_run_type.py

Candidate / pending direction (do not treat as current truth): an unmerged architecture branch introduces an ExecutionBackend seam (local vs worker compute), a WorkerTransport owner of worker URLs, and a NodeSpec registry with a declarative _add_from_spec node path. As of 2026-07-03 these names return nothing on main (grep -rl 'class ExecutionBackend\|class WorkerTransport\|class NodeSpec' flowfile_core/flowfile_core is empty); re-run that grep before citing them, and check whether the branch has merged — if it has, it reshapes how nodes and execution are added and Pillars A/C should be re-scoped against it.

When the frontier moves: if a pillar ships, demote it out of this skill into the owning sibling (A→flowfile-ai-subsystem, B→flowfile-codegen-parity-campaign, C→flowfile-architecture-contract) and replace it here with the next open problem. Keep this skill about what is unbuilt.