Cyclone

A self-hosted EDI claims management suite for a single billing office. Parses 837P professional claims and 835 ERA remittances (X12 005010X222A1 and 005010X221A1), with a local-only FastAPI backend and a React UI for browsing, filtering, and inspecting the parsed data.

Local-only on purpose: binds to 127.0.0.1, no auth, no internet exposure. Built for one operator, one machine, one trading partner (Colorado Medicaid, currently).

Install

# Backend (Python 3.11+)
cd backend
python -m venv .venv
.venv/bin/pip install -e '.[dev]'

# Frontend (Node 20+)
cd ..
npm install

Dev

Two terminals:

# Terminal 1 — backend
cd backend
.venv/bin/python -m cyclone serve
# (defaults to 127.0.0.1:8000; override with CYCLONE_PORT=...; reload with CYCLONE_RELOAD=1)

# Terminal 2 — frontend
npm run dev
# (Vite on http://localhost:5173)

Then open http://localhost:5173. Drop an .txt 837P or 835 file on the Upload page; navigate to Claims, Remittances, Providers, or Activity to see the parsed data.

The frontend reads its backend URL from VITE_API_BASE_URL (default empty). Create a .env.local at the repo root with:

VITE_API_BASE_URL=http://127.0.0.1:8000

Without that, the UI falls back to its in-memory sample store via the existing data adapter (parses are disabled).

Test

# Backend
cd backend && .venv/bin/pytest

# Frontend type-check + build
npm run typecheck
npm run build

# Frontend unit tests
npm test

Live updates

The Claims, Remittances, and Activity pages stay current without manual refresh. The backend publishes an internal event on every store write, the page opens a streaming HTTP connection to the matching /api/<resource>/stream endpoint, and new rows are appended to the table the moment they hit the database.

Wire format

Each stream endpoint emits newline-delimited JSON. The first batch is the snapshot of currently-known rows; after that comes snapshot_end with the count, then the live events.

{"type":"item","data":{"id":"CLM-1", "...":"..."}}
{"type":"item","data":{"id":"CLM-2", "...":"..."}}
{"type":"snapshot_end","data":{"count":2}}
{"type":"item","data":{"id":"CLM-3", "...":"..."}}   ← live
{"type":"heartbeat","data":{"ts":"2026-06-20T23:17:09Z"}}   ← idle keep-alive

Lines are {"type": ..., "data": ...}; known types are item, snapshot_end, heartbeat, and (rare) item_dropped / error. Heartbeats keep the connection alive when nothing is happening — clients flip to stalled after 30s of total silence (heartbeat or otherwise) and surface a ↻ Reconnect button.

Endpoints

Method	Path	Subscribes to	Default sort
GET	/api/claims/stream	claim_written	-submission_date
GET	/api/remittances/stream	remittance_written	-received_date
GET	/api/activity/stream	activity_recorded	-timestamp (limit 50)

All three accept the same query params as their non-streaming counterparts (status, payer, date_from, …) so a frontend can swap a one-shot fetch for a tail with no URL surgery. Responses are Content-Type: application/x-ndjson.

Status pill

The pill in each toolbar reflects the current connection state:

Status	Badge variant	What it means
live	success	snapshot received, listening for new events
connecting	warning	opening the stream (initial mount)
reconnecting	warning	previous attempt failed, backing off before retry
stalled	destructive	no event (including heartbeat) for 30s — click ↻ Reconnect
error	destructive	stream errored — click ↻ Reconnect
closed	destructive	page unmounted

The reconnect button is only shown on stalled and error. The backoff schedule on error is 1s → 2s → 4s → 8s → 16s → 30s capped.

Knobs

Env var	Default	Effect
CYCLONE_TAIL_HEARTBEAT_S	15	Idle heartbeat interval (seconds). Lower it for tests.

Persistence

Parsed batches, claims, remittances, matches, and activity events are stored in a SQLite file at ~/.local/share/cyclone/cyclone.db by default. The directory is auto-created on first run.

To use a different location, set CYCLONE_DB_URL:

export CYCLONE_DB_URL=sqlite:///path/to/cyclone.db
# or
export CYCLONE_DB_URL=postgresql://user:pass@host:5432/cyclone

Backup

sqlite3 ~/.local/share/cyclone/cyclone.db ".backup /path/to/backup.db"

This is safe to run while the backend is running (uses SQLite's online backup API).

Project layout

.
├── backend/
│   ├── src/cyclone/
│   │   ├── api.py             # FastAPI app, GET + parse routes, /api/{resource}/stream
│   │   ├── pubsub.py          # in-process EventBus (drop-oldest, per-kind fan-out)
│   │   ├── store.py           # InMemoryStore, mappers, publish-on-write
│   │   ├── __main__.py        # `python -m cyclone serve`
│   │   ├── cli.py             # click CLI
│   │   └── parsers/           # X12 tokenizer, models, validator, writers
│   └── tests/
│       ├── fixtures/          # co_medicaid_*.txt, minimal_*.txt
│       ├── test_api.py        # parse-837/835 round-trip
│       ├── test_api_gets.py   # 6 GET endpoints
│       ├── test_store.py      # store + mappers + iterators
│       ├── test_api_streaming.py
│       ├── test_api_stream_live.py  # 3 live-tail endpoints + disconnect cleanup
│       ├── test_pubsub.py     # EventBus + subscribe/unsubscribe
│       └── test_api_parse_persists.py
├── src/                       # React + Vite + TypeScript UI
│   ├── components/
│   │   ├── ui/                # Skeleton, EmptyState, ErrorState, FilterChips, Pagination, …
│   │   └── TailStatusPill.tsx # live-tail status badge + reconnect button
│   ├── pages/                 # Claims, Remittances, Providers, Activity, Upload
│   ├── hooks/                 # useBatches, useClaims, useRemittances, useProviders, useActivity, useParse
│   │                          # + useTailStream, useMergedTail (live tail)
│   ├── lib/                   # api.ts (6 GET + parse837/parse835/health), format.ts, utils.ts
│   │                          # + tail-stream.ts (NDJSON parser)
│   ├── store/                 # zustand sample-data + parsed-batches store
│   │                          # + tail-store.ts (FIFO-capped live tail slices)
│   └── types/                 # shared TS types
├── docs/
│   ├── reference/             # condensed 837P/835/X12/CO Medicaid notes
│   └── superpowers/plans/     # implementation plan
├── tailwind.config.js         # shimmer, scan, row-flash keyframes
└── package.json

Roadmap

Sub-projects 2, 3, 4, and 5 are shipped. Next up:

• Sub-project 3 (shipped) — More 837P/835 features.
  • 837P validation rules: R034 enforces REF*G1 on frequency-code 7/8 claims; R035 enforces BHT06 transaction-type-code is in the allowed set per payer config.
  • 835 CAS deep-parsing: every CAS adjustment now surfaces with its CARC reason code + label (e.g. CO-29: The time limit for filing has expired), surfaced via GET /api/remittances/{id} and rendered as an expansion row on the Remittances page.
  • 999 ACK transaction set: full inbound parser + outbound serializer. Auto-generated on 837 ingest when ?ack=true is passed to POST /api/parse-837. Persisted to the acks table, browsable on a new /acks page, and downloadable as the regenerated raw 999 text.
  • 270/271 eligibility (API-only): POST /api/eligibility/request builds a 270 from a JSON payload (subscriber, provider, payer, service type); POST /api/eligibility/parse-271 ingests the response and returns structured coverage_benefits.
• Sub-project 4 (partially shipped) — Frontend features.
  • Per-claim detail drawer (shipped): click any row on the Claims page to open a side-panel drawer with the full claim context — state + amount header, validation panel, service lines, diagnoses, parties (billing provider, subscriber, payer), raw X12 segments, matched remittance summary, and a vertical state-history timeline. URL is synced (?claim=...) so links and back-button restore the drawer. Keyboard nav: j/k move between claims, esc closes, ? opens the cheatsheet overlay. Skeleton + error + not-found (404) states are all distinct. Powered by a new backend endpoint GET /api/claims/{claim_id} that returns the full drawer payload in a single round-trip.
  • Remaining SP4: batch diff view, advanced filters (date range, multi-status, saved filter sets).
• Sub-project 5 (shipped) — Live updates.
  • The Claims, Remittances, and Activity pages stream new rows in real time over Server-Sent Events encoded as newline-delimited JSON. The backend publishes a claim_written / remittance_written / activity_recorded event on every store write; the frontend opens an HTTP stream and dispatches each event into a per-resource Zustand store that the page reads on top of its base query results.
  • A small status pill in each toolbar surfaces the connection state — live / connecting / reconnecting / stalled / error / closed — and offers a manual ↻ Reconnect button on stalled or error. Stale connections (no event for 30s, heartbeat included) flip to stalled automatically; the back-off ladder on errors is 1s → 2s → 4s → 8s → 16s → 30s capped. See the "Live updates" section below for details.

SP3 endpoints

• POST /api/parse-837?ack=true — existing 837 parse, plus optional auto-generated 999 ACK persisted alongside the batch.
• POST /api/parse-999 — parse an inbound 999 ACK and persist it.
• GET /api/acks — list ACKs.
• GET /api/acks/{id} — ACK detail, including the regenerated raw_999_text.
• POST /api/eligibility/request — build a 270 from JSON.
• POST /api/eligibility/parse-271 — ingest a 271 and return parsed coverage benefits.

The UI gains a new Acks page (sidebar entry) that lists persisted ACKs and lets you download the regenerated 999 text.

SP4 endpoints (claim drawer)

• GET /api/claims/{claim_id} — full claim context for the drawer payload: header fields, diagnoses, service lines, parties (billing provider / subscriber / payer), validation result, raw X12 segments, matched remittance summary (or null), and the claim's state history (ordered newest-first). 404 with a structured { "error": "Not found", "detail": "Claim {id} not found" } body when the claim doesn't exist — distinct from a transient fetch failure so the UI can render a dedicated not-found state.

SP5 endpoints (live updates)

• GET /api/claims/stream — NDJSON stream of claim events. Emits a snapshot (filtered by the same query params as GET /api/claims), then snapshot_end, then live claim_written events as they arrive, with a 15s idle heartbeat.
• GET /api/remittances/stream — same shape for remittances (subscribes to remittance_written, default sort -received_date).
• GET /api/activity/stream — same shape for activity events (subscribes to activity_recorded, default limit=50).

License

No license file yet; this is internal-use software. Add a LICENSE file when one is decided.