> ## Documentation Index
> Fetch the complete documentation index at: https://docs.skylit.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Tool Catalog
> Every Skylit MCP tool, grouped by purpose, with its credit cost.
Limited beta — the Skylit API is in limited beta. Create and manage keys in the Developer tab of the Skylit app.
The server exposes **38 tools**. Each call costs the same credits as the
equivalent REST endpoint; the cost is shown per tool below and your remaining
balance is returned in each result's `meta`.
Tools that take a single option contract expect an **OPRA symbol** in URL-safe
form: `{ticker}__{YYMMDD}{C|P}{strike×1000, 8 digits}` — e.g.
`AAPL__260117C00250000`. Discover tickers with `flow_search` and expirations with
`expirations` first.
## Discovery
Find valid symbols and the active universe before calling analytics tools.
| Tool | Returns | Credits |
| ------------------------- | ------------------------------------------------------------------ | ------: |
| `flow_search` | Search underlyings by ticker fragment | 1 |
| `list_active_underlyings` | Every underlying that traded options on a date, ranked by premium | 1 |
| `expirations` | Available expiration dates for an underlying, with contract counts | 1 |
## Scores & trades
Scored options flow for a ticker or a single trade.
| Tool | Returns | Credits |
| ----------------- | --------------------------------------------------------------------- | ------: |
| `flow_feed` | Recent scored trades (Flow Score, FlowBonus) + VWF/SDF/FIR aggregates | 1 |
| `trade_score` | Full scoring + context for one trade id (from a `flow_feed` row) | 1 |
| `aggregate_score` | Composite + VWF/SDF/FIR across one or more trailing timeframes | 3 |
| `flow_aggregate` | Server-side rollup over an arbitrary `[start_time, end_time]` window | 3 |
## Sweeps & momentum
| Tool | Returns | Credits |
| --------------- | ----------------------------------------------------------------------- | ------: |
| `sweeps` | Aggregated multi-exchange sweeps with venues, premium, moneyness, score | 3 |
| `flow_momentum` | Live 5m/30m/1h flow vs trailing baseline, with z-scores + trend label | 3 |
| `flow_baseline` | Trailing per-time-of-day baseline `flow_momentum` compares against | 3 |
## Strike & tide concentration
| Tool | Returns | Credits |
| -------------- | -------------------------------------------------------------------- | ------: |
| `flow_strikes` | Top-N strikes by net/total premium with bull/bear split + OI context | 3 |
| `flow_tide` | Bucketed bullish vs bearish premium with cumulative net premium | 3 |
| `by_strike` | Strike-level distribution of a day's flow, optionally by DTE band | 3 |
## Screeners
Single-day and weekly top lists, plus unusual-activity scanners.
| Tool | Returns | Credits |
| ------------------------ | ----------------------------------------------------------------------- | ------: |
| `top_underlyings_daily` | Top underlyings by single-day flow (call/put split, net premium, ratio) | 1 |
| `top_underlyings_weekly` | Same, over the trailing week | 1 |
| `top_contracts_daily` | Single-day top-contract screener (premium / volume / OI / sweeps) | 1 |
| `top_contracts_weekly` | Same, over the trailing week | 1 |
| `unusual_volume` | Contracts with anomalous volume vs an `avg_period` baseline (RVOL) | 3 |
| `unusual_oi` | Contracts with significant open-interest changes (opening vs closing) | 3 |
## Bull/bear & pressure ratios
| Tool | Returns | Credits |
| -------------------- | ---------------------------------------------------------------------- | ------: |
| `chain_bull_bear` | Chain-level bull/bear/neutral % with call- and put-only breakdowns | 3 |
| `contract_bull_bear` | Bull/bear/neutral % for a single OPRA contract | 1 |
| `chain_ratio` | Chain-level ask/bid/mid + aggression ratios with a bias interpretation | 1 |
| `contract_ratio` | Same bid/ask/mid pressure for a single OPRA contract | 1 |
## Stats, Vol/OI & moneyness
| Tool | Returns | Credits |
| ------------------ | ------------------------------------------------------------------------ | ------: |
| `underlying_stats` | Daily aggregate stats for an underlying (premium, volume, net, OI) | 1 |
| `contract_stats` | Daily aggregate stats for a contract (volume, OI, premium, IV) | 1 |
| `vol_oi` | Vol/OI accumulation analysis; distinguishes new positioning from closing | 1 |
| `moneyness` | Premium/sentiment split across deep\_itm…deep\_otm + detected patterns | 1 |
## Chains, charts & RVOL
| Tool | Returns | Credits |
| ------------------ | ------------------------------------------------------------------------ | ------: |
| `option_chain` | Full chain at an expiration (per-strike call/put volume, OI, premium) | 3 |
| `underlying_chart` | Intraday OHLC-style bars for an underlying | 3 |
| `contract_chart` | Intraday OHLC-style bars for a single contract | 3 |
| `underlying_rvol` | Relative-volume bars for an underlying (`format=summary` for stats only) | 1 |
| `contract_rvol` | Relative-volume bars for a single contract | 1 |
## Market-wide & sector
| Tool | Returns | Credits |
| ----------------- | ------------------------------------------------------------- | ------: |
| `market_overview` | Market-wide flow for the day + top tickers by premium | 3 |
| `market_tide` | Bucketed net call/put premium time series with an SPY overlay | 3 |
| `market_breadth` | SPY/QQQ/IWM sentiment, advance/decline, per-sector rotation | 3 |
| `sector_flow` | Sector/industry flow aggregation with top-contributor tickers | 3 |
## Heatseeker — gamma/vanna heatmaps
| Tool | Returns | Credits |
| ------------------------- | --------------------------------------------------------------------- | ------: |
| `heat_heatmap` | Current per-strike gamma/vanna heatmap + live velocity (multi-symbol) | 1 |
| `heat_historical_heatmap` | Replay the heatmap at a past instant (up to 365 days back) | 5 |
`heat_heatmap` accepts comma-separated `symbols` (e.g. `SPY,SPX,QQQ`) for a single
cross-asset call — handy for finding gamma/vanna walls across correlated names at once.