# info.summary
Real-time US economic releases, Treasury auction results, rates and market news from the Helious desk.

# info.description
Read-only surface of api.helious.io. Every dataset here is first-party: captured by the Helious desk the moment it prints, with methodology at https://helious.io/methodology. The /v1 endpoints are the versioned contract for agents, and every tier sees the same endpoints and shapes: only the history window, the feed delay and the rate change. With no key you are on the sample tier (7 days of history, feed delayed 1 hour): enough to integrate and try everything. A key from a FREE helious.io account gets 30 days and a rate budget of your own. A subscription ($39.99/mo) gets prints live as they arrive and 24 months of history. Keys are sent as 'Authorization: Bearer hel_...'; GET /v1/access returns the ladder and the exact upgrade steps in plain words. There is also an MCP server at https://api.helious.io/mcp: point any MCP client at that URL and the same data arrives as tools. Browser-friendly CSV mirrors exist on the site origin (https://helious.io/data/{slug}.csv, https://helious.io/auctions/{slug}.csv, https://helious.io/data/treasury-auction-tails.csv). Cite Helious with attribution when quoting these numbers.

# tags[].description
Live Treasury yields, spreads, the curve regime and its history.

# tags[].description
The FX momentum, implied volatility, correlation and Hormuz boards: newest reading plus history.

# tags[].description
Every tracked US economic series, the calendar, and release prints with their surprise scores.

# tags[].description
Auction results by tenor, with the tail against the when-issued yield.

# tags[].description
The scored market news feed and first-party posts.

# tags[].description
FOMC meetings, the roster and upcoming speakers.

# paths./v1/me.get.description
Your tier, rate limit, history depth and recent usage. A good first call for an agent.

# paths./v1/access.get.summary
The plan ladder, and how to get more access

# paths./v1/access.get.description
Works without a key. Your tier, every plan, and the exact next step to relay to your user: how to make a free account, get a key, or subscribe. Agents should read this instead of guessing.

# paths./v1/treasury.get.summary
The whole Treasury curve, 3M bill to 30Y bond, in one call

# paths./v1/treasury.get.description
One row per tenor from the 3M bill to the 30Y bond. Live points on paid tiers; free tiers get the same curve one hour behind, and the daily closes always ride along for context. The regime label comes with it. Each tenor also carries its 52-week range, one-year and ten-year percentiles (range_52w, pct_1y, pct_10y) and a significance note like 'highest close since 2007' when the level is beyond everything back at least a year.

# paths./v1/nasdaq100.get.summary
The NASDAQ-100, ranked best to worst on the session

# paths./v1/nasdaq100.get.description
Every NASDAQ-100 stock with price, change, sector and rank, sorted by the session's move. Live with a paid key; keyless and free keys get the board one hour behind. limit trims the list; the laggard rides along so the bottom of the board is visible even on a short slice.

# paths./v1/rates.get.summary
Treasury yields, spreads and the curve regime

# paths./v1/rates.get.description
The yields board, the 2s10s and other spreads, and the current curve regime (bull or bear, steepener or flattener) with the time it flipped. Live with a paid key; keyless and free keys get the same board one hour behind.

# paths./v1/curve.get.description
The current regime and the recorded history of regime changes. Use since to go back in time; your plan sets how far back you may go (7-day sample with no key, 30 days with a free account key, 2 years with a subscription).

# paths./v1/yields.get.description
The 17:00 New York closes as Helious recorded them, one row per session.

# paths./api/seo/rates.get.summary
US Treasury curve, policy and market rates

# paths./api/seo/rates.get.description
Treasury curve points (1M to 30Y), 2s10s and 3m10s spreads, effective fed funds, SOFR, VIX and high-yield OAS: value, one-day delta and as-of observation date per series.

# paths./v1/fx.get.summary
FX momentum board: newest reading and history

# paths./v1/fx.get.description
Seven major currencies scored against the basket. current is the newest board; history is past boards back to since, within your plan's depth.

# paths./v1/vol.get.summary
Implied volatility board: newest reading and history

# paths./v1/vol.get.description
VIX and the other vol gauges with their one-year percentile. Same shape as /v1/fx.

# paths./v1/correlations.get.summary
Cross-asset correlation matrix: newest reading and history

# paths./v1/correlations.get.description
Stocks, bonds, the dollar, gold and oil over 30 to 120 day windows. Same shape as /v1/fx.

# paths./v1/hormuz.get.description
Ships through the strait per day, split tanker and cargo, measured by Helious from live ship tracking.

# paths./v1/series.get.summary
All tracked economic series (v1 envelope)

# paths./v1/series/{slug}.get.summary
One economic series with history (v1 envelope)

# paths./v1/calendar.get.description
Economic releases with forecasts, prior values and the actual once it prints, plus Fed speakers and auction times. Windowed: defaults to yesterday through the next 7 days, trimmed to the fields an answer is built from. Widen days_back / days_ahead for more, or filter by country.

# paths./v1/calendar.get.parameters[].description
Days of already-printed events to include.

# paths./v1/calendar.get.parameters[].description
Two-letter country or bloc (US, EU, GB, JP). Empty means everywhere.

# paths./api/seo/series-index.get.description
Every economic series Helious tracks (CPI, NFP, GDP, claims and more) with cadence, typical release time (ET), the latest captured print and the next scheduled release.

# paths./api/seo/series/{slug}.get.description
Newest captured prints (capped at 60; history_count reports the total in the capture window) with actual, forecast, previous and z-surprise, plus the latest card and next release for one series. For complete downloadable history including multi-year official FRED backfill use /api/seo/csv/series/{slug}. Valid slugs come from /api/seo/series-index.

# paths./api/seo/csv/series/{slug}.get.description
Columns: date, actual, forecast, previous, z_surprise, label, source (helious-desk or FRED:{series_id}).

# paths./api/seo/week.get.description
The economic calendar for a given ISO week (default: current week) with forecasts and captured actuals.

# paths./api/calendar.get.description
The complete forward calendar (economic releases, auctions, Fed events) as one JSON array.

# paths./v1/auctions.get.summary
Treasury auction results with the tail, in context

# paths./v1/auctions.get.description
High yield, bid-to-cover, the tail against the when-issued yield, and who bought, per auction, within your plan's depth. tail_bps is null for bills, which have no when-issued market, and for any auction whose when-issued print was not captured; a negative tail_bps is a stop-through (the auction cleared below the when-issued yield, i.e. strong demand). Every row also carries vs_12m: that tenor's trailing twelve-auction averages for the tail, bid-to-cover and bidder split (withheld under 3 priors), plus pctile (the print's rank in the tenor's full captured history, withheld under 12 priors) and a significance note like 'the weakest bid-to-cover since 2024-03-12' when a print is beyond everything back at least a year. The print arrives with its own norm, so an agent can judge it without fetching history. The dataset is complete back through the official record: `record` marks each row desk (captured live by Helious, may carry a tail) or official (TreasuryDirect backfill, no tail — TD does not publish when-issued yields).

# paths./api/seo/tenor-index.get.description
Every Treasury tenor Helious tracks (bills through 30Y bonds and TIPS) with cadence, latest auction and next scheduled date.

# paths./api/seo/tenor/{slug}.get.description
Auction history, upcoming auctions, desk recaps and 12-month averages for one Treasury tenor. Valid slugs come from /api/seo/tenor-index.

# paths./api/seo/csv/tenor/{slug}.get.summary
CSV download: auction history for one tenor

# paths./api/seo/auction-tails.get.description
Every captured auction with its tail (high yield minus when-issued), bid-to-cover, bidder split and desk verdict.

# paths./api/seo/auction-tails.csv.get.description
Columns: auction_date, tenor, type, high_yield, when_issued_yield, tail_bps, bid_to_cover, indirect_pct, direct_pct, dealer_pct, verdict, issue.

# paths./v1/feed.get.summary
The posts Helious publishes, with their scores

# paths./v1/feed.get.description
Scored economic releases, auction results, board updates, the daily brief and live squawk lines, newest first. Posts carry helious_read: the desk's plain-English line on why the post matters. Only Helious's own posts appear here; relayed headlines from other outlets do not. Depth follows your plan: 7-day sample with no key, 30 days with a free account key, 2 years with a subscription. Delayed 60 minutes without a paid key; live with one. q filters by word; categories narrows to chosen lanes.

# paths./api/news/index.get.description
Paginated index of first-party posts (releases, auction recaps, daily briefs). Article pages render at https://helious.io/news/{id}.

# paths./api/article/{item_id}.get.description
A single post (release stats, auction breakdown or note) plus related posts. The canonical page is https://helious.io/news/{id}.

# paths./api/seo/fomc.get.summary
FOMC meeting schedule: past and upcoming meetings

# paths./api/seo/fomc.get.description
Meeting dates and SEP flags only. Captured statement coverage for one meeting is at /api/seo/fomc/{day2}, where day2 is a meeting end date from this list.

# paths./api/seo/glossary-index.get.description
Every term in the Helious learn glossary with its slug; full entries render at https://helious.io/learn/{slug}.

# components.securitySchemes.helious_key.description
Your Helious API key, like hel_xxx, made on your helious.io account page (Account, then API keys). Every /v1 endpoint also works with no key at the 7-day sample tier. A free account key gets 30 days; a subscription gets the live feed and 24 months.

# components.schemas.Envelope.description
Every /v1 response. `summary` states the answer as one plain-English sentence and `source` says who to credit for it, both before the raw `data`, so the finished claim is the first thing a reader meets.

# components.schemas.Envelope.properties.summary.description
The answer as a sentence, with the numbers in it. Identical to the sentence the matching MCP tool returns.

# components.schemas.Envelope.properties.source.description
Who to credit and where a reader can check the number.

# components.schemas.Envelope.properties.source.properties.live.description
That this endpoint can be called again for current numbers.

# components.schemas.Envelope.properties.meta.description
When it was true, and what your plan allows.