Undertow — market liquidity map MCP Server

How concentrated the BTC depth backbone is today: which venue holds the largest share of ±1% aggregate depth, the HHI, the effective venue count (1/HHI), and per-venue depth in USD. Low effective venue count means an exit depends on one venue staying open. The subscriber exit_desk_full adds ETH and the venue-failure withdrawal scenario (what your exit costs if the top venue goes dark).

What the price IS when venues disagree: the cross-venue consensus mark for BTC and ETH, weighted by resting depth over squared half-spread (NOT a median of last prices), with the BLINDNESS GAP — how far the deepest venue sits from consensus, i.e. how wrong you would be pricing off the venue you would naturally trust — plus depth concentration (CR1/HHI) and the names of any dislocated venues. Use for 'what is BTC/ETH actually worth right now', 'is an exchange dislocated', or before trusting any single venue's price. Experimental until its accrual gates pass; the payload says so. Not investment advice.

Where this caller stands: whether the bearer token verified, the entitlement tier behind it (checked fresh, never trusted from the token), today's tool-call meter, and how to get full access. Call this first when a subscriber tool is missing from tools/list or a call is refused.

Realized depth-collapse episodes in BTC ±1% aggregate depth: onset, trough, drawdown fraction and recovery time for each episode that crossed the pre-registered threshold. Detection rules were declared before any episode accrued. Use when asked whether crypto liquidity has actually broken lately, as opposed to how it looks right now. The subscriber exit_desk_full carries the ETH desk beside BTC.

What selling a position of a given USD size costs RIGHT NOW, venue by venue, from live public order books (BTC, six venues). Returns the per-venue cost in basis points at the nearest published size rung, the cheapest and dearest venue with approximate dollar cost, and the venue spread. Estimates interpolated from published quote depth — never a book walk, refreshed roughly hourly. Not investment advice.

The Undertow board's TIER ROW: one liquidity tier per market segment (UST, IG, HY, EQUITY, ETF, FX, CN, CRYPTO, BSTOCK) plus the funding-stress overlay regime. PARTIAL means insufficient scoring history, reported honestly instead of guessed. Use for 'how liquid are markets today' at one glance, then drill into crypto with the other tools; the FULL board (every measure with its stress percentile and analyst note) is the subscriber board_full tool.

Undertow's own sealed forward-calls record: every call hash-chained and signed BEFORE its outcome, scored against the immutable point-in-time board for its horizon date, with misses kept published. Returns the full record with outcomes and the ledger root. Use when asked whether Undertow's judgements can be trusted, and quote the misses as prominently as the hits.

Can a watched fund's book actually leave the building? Unwind stress for the watched 13F filers (incl. the Situational Awareness LP replay): effective position count, whole-book days-to-exit at 10% of a median day's volume (bracketed as-if median large / median small-mid name, and each count published as a band that contains it rather than as a point, because the exact count returns the basket's median dollar volume by one division), and the leverage x shock x maintenance margin grid with its three honest states (NO_CALL / CALL / EQUITY_EXHAUSTED). Default is the per-filer headline; pass cik for one filer's full free row. Display-only measure on frozen grids; 13F sees no shorts or options, so every number is a floor. Use when asked whether a fund's book could exit, or what the Aschenbrenner failure mode looks like in a current filing. Not investment advice.