HTTP API

dccd ui (UI only) and dccd start (full daemon) serve a JSON HTTP API built with FastAPI. The Web UI is a pure client of this API, so anything the UI does, you can script.

Base URL defaults to http://127.0.0.1:8080 (settings.ui_host / ui_port). Interactive OpenAPI docs are available at /docs.

Authentication

If settings.ui_auth_token is set, every /api/* route requires a bearer token (/health and the UI pages stay open):

curl -H "Authorization: Bearer $TOKEN" http://127.0.0.1:8080/api/inventory

Server-Sent Events cannot send headers, so /api/events also accepts the token as a query parameter: /api/events?token=$TOKEN. CORS is same-origin by default (configurable via settings.ui_allow_origins).

Endpoints

Inventory & data

Method	Path	Description
GET	/api/inventory	All stored datasets (exchange, pair, type, span, rows, time range, on-disk bytes, file count; OHLC also gets expected_rows / missing_rows for gap detection).
POST	/api/read	Read stored rows for a dataset; body {exchange, symbol, data_type, span, start_ns, end_ns} (returns up to 1 000 rows).

Backfill

Method	Path	Description
POST	/api/backfill	Launch a backfill; body {exchange, symbol, data_type, span?, start}. Returns {run_id}.
GET	/api/backfill/{run_id}	Poll a run: state, rows_written, progress (time-based), log_tail.
DELETE	/api/backfill/{run_id}	Cancel a running backfill (cooperative — stops at the next page, keeps collected rows).

# start, then poll
RID=$(curl -s -XPOST localhost:8080/api/backfill \
  -H 'Content-Type: application/json' \
  -d '{"exchange":"binance","symbol":"BTC/USDT","data_type":"ohlc","span":3600,"start":"2024-01-01"}' \
  | jq -r .run_id)
curl -s localhost:8080/api/backfill/$RID | jq '{state, rows_written, progress}'

Streams

Method	Path	Description
GET	/api/streams	Configured stream jobs and their running state.
POST	/api/streams/start	Start a stream; body {spec_id}.
POST	/api/streams/stop	Stop a stream; body {spec_id}.

Jobs

Method	Path	Description
GET	/api/jobs	All configured job specs + state (incl. start, every, snapshot_interval, depth).
POST	/api/jobs/create	Add a job; body {operation, exchange, symbol, data_type, span?, start?, trigger_kind?, every?, snapshot_interval?, depth?}. Returns {job_id}.
POST	/api/jobs/update	Change a job’s start (first date); body {job_id, start}.
POST	/api/jobs/delete	Remove a job (stored data is kept); body {job_id}.
POST	/api/jobs/run	Trigger one configured backfill job; body {job_id}.
POST	/api/jobs/run-all	Trigger every enabled backfill job.

All three mutating routes persist to config.yml and reconcile stream workers (a deleted stream’s worker is stopped and dropped).

Config, events & storage

Method	Path	Description
GET / PUT	/api/config	Read / replace the configuration (validated; persisted to config.yml).
GET	/api/events	SSE stream of live log / progress / status / sample events (sample carries a stream’s last value or bid/ask for liveness). Fans out to multiple concurrent consumers.
GET	/api/operations	List registered operations.
GET	/health	Liveness probe (always open).

The application factory is create_app.