HTTP API

Every reference endpoint is served as a GET /v3/... route on http://127.0.0.1:25503. The machine-readable contract is the bundled OpenAPI file; the human-readable contract is each reference page's HTTP tab.

# Stock EOD across a date range
curl 'http://127.0.0.1:25503/v3/stock/history/eod?symbol=AAPL&start_date=2025-03-03&end_date=2025-03-06'

# Option quote snapshot for one contract
curl 'http://127.0.0.1:25503/v3/option/snapshot/quote?symbol=SPY&expiration=2025-03-21&strike=570&right=C'

# Intraday OHLC bars across a range (same route as single-date; supply start_date/end_date instead of date)
curl 'http://127.0.0.1:25503/v3/stock/history/ohlc?symbol=AAPL&start_date=2025-03-03&end_date=2025-03-06&interval=1m'

# Trading calendar
curl 'http://127.0.0.1:25503/v3/calendar/open_today'

Parameters

Query parameters use the registry names shown on each reference page — symbol, expiration, strike, right, interval, start_date, end_date, … Date parameters accept both YYYYMMDD and ISO YYYY-MM-DD. Strikes are dollars (570, 17.5); rights accept C / P / call / put.

Response formats

Add format= to any route:

format	Content type	Shape
json (default)	application/json	The envelope below.
csv	text/csv	RFC 4180 with a header row.
ndjson / jsonl	application/x-ndjson	One JSON object per row, newline-delimited.
html	text/html	A browser-viewable <table>, served inline.

The JSON envelope:

{
    "header": { "format": "json", "error_type": "null" },
    "response": [ ... ]
}

Failures use one envelope shape across every route — see the error codes table.

Flat files

Whole-universe daily archives stream through dedicated routes with chunked bodies (bounded server memory at any download size):

curl 'http://127.0.0.1:25503/v3/option/flat_file/trade_quote?date=20250303&format=csv' -o trade_quotes.csv

See Flat Files for sizing guidance.

Terminal system routes

Mirrored 1:1 from the JVM terminal — unauthenticated GET, bare text/plain bodies.

Method	Route	Description
GET	/v3/terminal/shutdown	Kills the server process; returns the plain text OK.
GET	/v3/terminal/fpss/status	Streaming-channel health: CONNECTED / DISCONNECTED.
GET	/v3/terminal/mdds/status	Market-data-channel health: CONNECTED / DISCONNECTED.

Concurrency behavior

Bursts queue, they don't fail. The HTTP edge admits up to 256 simultaneous requests; beyond that they queue and are served in order, and a client that disconnects or times out frees its place immediately. Genuine upstream exhaustion surfaces as 503 with Retry-After.