C4C: Mortgage Industry Regulations

Returns one playbook's full workflow instructions, its stages, the stage reference names and the rule-kit version: the Fannie Mae AI lender letter (LL-2026-04) P&P review, or FHA, VA or USDA loan-file QC. Input: the playbook `id`; an unknown id returns `unknown_playbook` with `valid_ids`. Playbook tools accept only ids and reference names, no document text; the user's P&Ps and loan files stay in their own chat.

Checks whether a passage appears in a regulator's source document; accepts text from any source. Inputs: `text` (up to 5,000 words); optional `register_id` (without it, up to 3 candidate documents are located by search). `outcome` is one of: exact (contiguous in the source, quote marks and dashes as the source writes them; a line break counts as a space); normalized (matches after folding quote and dash typography, `typography_folded`; ignoring page footers or running heads, `furniture_ignored`; spacing where the stored source splits or joins words, `spacing_ignored`; or added list markers, `list_markers_ignored`); composed (every word is in the source, in source order, but from non-contiguous pieces, as with an overview or an ellipsis; `omissions` lists the short source phrases skipped between pieces); not_found (no source support; `unsupported` lists the unsupported spans, and on a near miss `differences` gives the closest source text, the source words the text lacks and the words it adds); not_checked (over 5,000 words). `coverage` is the share of words found. `checked_against` names the documents checked (document, edition, retrieval date; ids in `checked_snapshot_ids`); `matched_against` names the one matched, `matched_register_id` / `matched_obligation_id` the stored text containing the passage. `matched_version` is current; superseded (the text is a prior version of the rule; `superseded_by` is the current register); or update-18-optional (HUD's Update 18 revision of an FHA 4000.1 section, optional until `mandatory_date`; `in_force_obligation_id` is the text in force by default). `obligation_currency` lists currency signals on the obligation holding the text (e.g. superseded-in-part). `rescinded: true` (with `rescinded_by`) means the passage is text a later issuance removed or replaced.

Returns only the verbatim paragraphs of one obligation (section) that contain the given terms. Inputs: `obligation_id`; `terms`, 1-6 short words or phrases ("cash-out", "credit score", "LTV"; abbreviations are expanded; numbers match as words or digits, so "five years" finds "five (5) years"); optional `max_passages`. Each passage has `verbatim` (the regulator's exact text), `offset` (its position in the section's text), `canonical_citation` (the pinpoint cite, where derivable) and `heading_path` (every heading above it, e.g. "vi. No Cash-Out Refinances > (A) Rate and Term > (i) Standard"). A match inside a table returns the whole table (`table: true`; `table_layout: "flattened"` when the source lost its layout and cells may not line up). A passage ending in a colon includes the list it introduces (`list_included: true`). `truncated` means more passages matched than were returned. No passages means no paragraph contains the terms as given; it is not a statement about the rule. `currency` is null or a version/status signal (dual-version, pending, revision-pending, superseded, expired...). On an FHA section HUD's Update 18 revises, `version` ("in-force" or "update-18-optional") says which text this is and `other_version` identifies the other.

Returns one obligation's (section's) verbatim regulator text with provenance. Inputs: `obligation_id`; optional `offset`, `limit`, `compare_versions`. `verbatim` holds the text between <<<BEGIN VERBATIM>>> and <<<END VERBATIM>>>. `canonical_citation` is the section's citation in the regulator's style (e.g. "4000.1 II.A.5.d", "B3-3.3-07", "38 U.S.C. 3709(b)"), or null. Paging: at most 24,000 chars per response; `chars_offset` + `chars_returned` is the position within `chars_total`; `next_offset` is the offset of the next page, or null when the section ends in this response; `truncated` means more text follows; `started_mid_section` means text before `chars_offset` is not included; `paging` gives page N of M. `currency` is null or a version/status signal (dual-version, pending, revision-pending, superseded, expired...) with a one-line `headline`. An FHA 4000.1 section HUD's Update 18 revises has two obligations, the in-force text and the revision (`<id>::update-18`); `version` says which this is and `other_version` identifies the other. `compare_versions: true` adds `version_changes`, the sentences Update 18 deletes and adds. `figures` is a best-effort extraction of figures in the text; an empty or incomplete list is not evidence that the text states no figure. `canonical_id`, when set, is the register this one is a same-text copy of.

Returns a playbook's rule kit. FNMA AI lender letter: the verbatim LL-2026-04, InfoSec Supplement and ECOA/Reg B/FCRA/AVM rows with citations, paginated; `next_offset` is the next page's offset, or null when the kit is complete. FHA/VA/USDA QC: the corpus registers each check area is grounded in. The kit block's fingerprint and dates identify its version. Playbook tools accept only ids and reference names, no document text; the user's P&Ps and loan files stay in their own chat.

Returns one stage reference document of a playbook (e.g. the FNMA playbook's DISCOVERY, RECONCILE, SYNTHESIS, PP-UPDATE, CHANGELOG or UPDATING stage). Inputs: `id`, `name` (one of the playbook's `references`). Playbook tools accept only ids and reference names, no document text; the user's P&Ps and loan files stay in their own chat.

Returns a manifest of one register (source document): its provenance, `currency` (null or a version/status signal: dual-version, pending revision, superseded, expired...) and its obligations (sections), each with `obligation_id`, section, `canonical_citation`, `chars_total` and `will_truncate` (true when the section exceeds one 24,000-char page). The manifest contains no regulator text. A dual-version section lists both obligations, each with `version` ("in-force" or "update-18-optional") and `other_version`.

Lists the guided compliance playbooks this server provides: the Fannie Mae AI lender letter (LL-2026-04) P&P review (AI inventory, AI governance policy, risk assessment, P&P updates, change log) and FHA, VA and USDA loan-file QC against the verbatim handbooks. Returns each playbook's id, what it does, when it applies and what the user provides. Playbook tools accept only ids and reference names, no document text; the user's P&Ps and loan files stay in their own chat.

Resolves a regulatory citation (e.g. '4000.1 II.A.8.d', 'B3-4.3-04', 'Freddie Mac Guide 5306.1', '38 U.S.C. 3737', 'M26-7 Chapter 4 Topic 9', 'SBA Notice 5000-872764', 'SOP 50 10 8 B.Ch1.A.2', 'HB-1-3555 11.3') to a `register_id`. Errors: `not_found` (the cite parses but is not in the corpus; `parsed` shows the parse), `ambiguous` (it could mean several registers, listed in `candidates`; no guess is made), `unparsed` (not recognizable as a citation). Near matches are not suggested. A handbook section resolves to the handbook's own register; documents that cite or amend it (e.g. Mortgagee Letters) are listed in `related` and are not the section's text. Identical copies of a section resolve to one register and are listed in `also_at`. A whole-handbook name returns `handbook`, an outline of its parts. A section the regulator renumbered returns `kind` "renumbered": `register_id` is the section under its new number, `renumbered_from` the old register, and no text is given under the old number.

Full-text search of US mortgage regulator text (Fannie Mae, Freddie Mac, FHA, VA, USDA, Ginnie Mae, SBA, CFPB). Inputs: `query`; optional `family` (one agency), `limit` (1-25), `currency_kind` (only sections carrying that currency signal; "any" = any signal). Common abbreviations (DTI, LTV, IRRRL, W-2, VOE, PITI, BK...) are expanded to the regulator's terms. Each result is one section: title, `obligation_id`, `canonical_citation` (the citation in the regulator's style, or null) and `excerpt`, a verbatim fragment near the match, not the whole rule. `match` is "all_terms" or "partial"; a partial result lists the query words it lacks in `missing_terms`. Order: `rank_score`, highest first = text score (title-weighted) x term coverage x title fit, with superseded, pending, incorporated or expired text x0.2, a special program's section (`special_program`: Home Possible, HomeReady, 203(k), HECM...) x0.5 unless the query names the program, and `obligation_type` "note" (source-credit notes) or "index" (a chapter heading) x0.2 unless the query asks for them. `section_status` "deleted" marks a deleted-section stub, ranked last. A query that is a citation returns the cited section first and sets `cited`; a bare handbook name ("HUD 4000.1") adds `handbook`, an outline of its parts. `currency` is null or a version/status signal whose kinds include dual-version, pending, revision-pending, superseded, superseded-in-part (a Mortgagee Letter replaced some provisions, named in `headline`), modified-by (a later issuance changes it, optional until its mandatory date) and expired. `version` "in-force" or "update-18-optional" marks the two texts of an FHA section HUD's Update 18 revises (`mandatory_date` for the revision); `other_version` is the other text's obligation_id. Empty results carry `reason` (empty_query, no_match, no_match_above_threshold) and may carry `guidance` naming shorthand in the query.