Skill Library Summary
For Sydney Bocik (Chief of Staff) + David Kawata | v1.0 | March 2026 | CONFIDENTIAL
How to use this document: each skill card shows exactly what the skill does, what data it needs, what it produces, the most important rule it enforces, and a worked example headline. Read left-to-right: Foundation → Intelligence → Routing → Qualification → Scoring → Recommendation → Compliance → Output.
S01 — Math | L0 — Foundation
S01 Math L0 — Foundation Purpose The shared function library for all mortgage math. Every other skill calls Math functions internally. 21 functions covering payment calculation, amortization, NPER, DSCR ratio, LTV, prepaid interest, and more. Inputs loan_amount, annual_rate, term_months, property_value, gross_rent Outputs pmt (monthly payment), nper (term), cash_available, dscr_ratio, ltv, prepaid_interest Key Rule PMT formula: r = annual_rate / 12. Factor = (r×(1+r)^n)/((1+r)^n-1). NEVER use annual rate directly in the formula. Example $434,137.50 VA loan at 6.50% → P&I = $2,744.04/month. Confirmed via pmt_factor.
S02 — VA Module | L1 — Borrower Intelligence
S02 VA Module L1 — Borrower Intelligence Purpose Determines VA loan eligibility, computes entitlement, calculates the required funding fee, validates residual income thresholds, and confirms Certificate of Eligibility requirements. Inputs veteran_status, service_type, service_months, entitlement_history, property_value, loan_amount Outputs va_eligible, entitlement_available, funding_fee_rate, funding_fee_amount, residual_income_threshold, coe_required Key Rule Funding fee first use (no down payment): 2.15%. Financed into the loan. Residual income is a hard PASS/FAIL — not a ratio. No PMI ever on VA loans. Example $425,000 purchase, first use, no down: funding fee = $9,137.50, financed. Total VA loan = $434,137.50.
S03 — Borrower Profile | L1 — Borrower Intelligence
S03 Borrower Profile L1 — Borrower Intelligence Purpose Normalizes all raw borrower input data into the canonical BorrowerProfile object — the single source of truth consumed by every downstream skill. Handles income averaging, credit score selection, asset verification, property type, and occupancy. Inputs Income documents (pay stubs, W-2, tax returns), credit report, bank statements, property address, purchase price Outputs BorrowerProfile: gmi_qualifying, qualifying_credit_score, verified_assets, ltv_primary, property_type, occupancy_type Key Rule Qualifying credit score = LOWEST middle score across all borrowers. For co-borrower files, this is the limiting factor. Income for variable earners = 2-year average. Example 3 credit scores pulled: 712/698/688. Qualifying score = 698 (middle of 3). If co-borrower: take lower of the two middles.
S04 — Program Router | L2 — Routing
S04 Program Router L2 — Routing Purpose Applies 5 sequential gates to determine which loan programs are eligible for full qualification. Programs failing any gate are eliminated — no further processing for that program. Eliminates wasted computation and prevents incorrect qualification attempts. Inputs BorrowerProfile (all fields) Outputs ProgramQueue: ordered list of programs passing all 5 gates, plus preliminary calculations (LTV, preliminary payment, prelim DTI) for each Key Rule 5 gates: occupancy type, property type, loan limits, credit score minimums, basic eligibility. Programs failing any gate are INELIGIBLE_ROUTER — not processed by L3 skills. Example Investment property: DSCR eligible, Conventional eligible, VA/FHA eliminated at Gate 1 (occupancy). DSCR scores first.
S05 — Constraint Detection | L2 — Routing
S05 Constraint Detection L2 — Routing Purpose Scans the BorrowerProfile and ProgramQueue for 25 types of binding and advisory constraints. BLOCKING constraints must be resolved for the program to qualify. ADVISORY constraints are flagged for underwriter attention. Feeds Scenario Generation. Inputs BorrowerProfile, ProgramQueue Outputs ConstraintSet: up to 25 constraint types, each tagged BLOCKING or ADVISORY, with the constraint value, threshold, gap, and resolution path Key Rule BLOCKING = hard stop on that program. ADVISORY = note only, does not block. Both must be surfaced. BLOCKING constraints directly drive Scenario Generation action types. Example DTI = 54.88% vs 45% Conventional limit: BLOCKING (gap = 9.88 ppts). Residual income above threshold: ADVISORY (pass, no action needed).
S06 — VA Qualification | L3 — Program Qualification
S06 VA Qualification L3 — Program Qualification Purpose Full 14-stage VA loan qualification. Computes PITIA, verifies all DTI ratios, validates residual income by household size and region, checks cash to close, verifies property eligibility, and produces the VA QualResult with complete decision lineage. Inputs BorrowerProfile, ProgramQueue[VA], VA_Module eligibility objects Outputs QualResult_VA: qualification_status, pitia, back_end_dti, residual_income_result, cash_to_close, funding_fee, LineageTrace_VA Key Rule VA = no down payment required. No PMI. Residual income is the critical VA-specific gate. Funding fee is financed — P&I computed on total loan including funding fee. Example Webb family: VA loan $434,137.50 at 6.50%, P&I=$2,744.04, PITI=$3,363.83, CTC=$12,750. QUALIFIED. Residual income $1,602.67 > $1,000 threshold.
S07 — Conventional | L3 — Program Qualification
S07 Conventional L3 — Program Qualification Purpose Full 17-stage Conventional loan qualification per Fannie Mae Selling Guide (Dec 2025). Computes LLPA grid adjustments, PMI rate, PITIA with PMI, all DTI calculations, and produces the Conventional QualResult with complete decision lineage. Inputs BorrowerProfile, ProgramQueue[CONV] Outputs QualResult_CONV: qualification_status, pitia_with_pmi, back_end_dti, llpa_adjustment, pmi_monthly, pmi_cancel_month, cash_to_close, LineageTrace_CONV Key Rule Max DTI: 36% manual / 45% DU standard / 50% DU with conditions. LLPA grid: LTV × credit score = rate adjustment. PMI cancels at 80% LTV (auto-cancel at 78%). Example Webb family: score 698, LTV 97%, back DTI 54.89% → INELIGIBLE_DTI (exceeds 50% DU max by 4.89 ppts). Proximity score = 43.37.
S08 — FHA Qualification | L3 — Program Qualification
S08 FHA Qualification L3 — Program Qualification Purpose Full 17-stage FHA loan qualification per HUD 4000.1. Computes UFMIP, monthly MIP, PITIM (payment including MIP), all DTI ratios, and produces the FHA QualResult with complete decision lineage. Includes TOTAL Scorecard AUS logic. Inputs BorrowerProfile, ProgramQueue[FHA] Outputs QualResult_FHA: qualification_status, pitim, back_end_dti, ufmip_amount, mip_monthly, lifetime_mip, cash_to_close, aus_recommendation, LineageTrace_FHA Key Rule UFMIP = base_loan × 1.75%, financed. P&I always on fha_total_loan (base + UFMIP). MIP = 0.55% annual if LTV > 90%, life of loan. TOTAL Scorecard max DTI = 57%. Example Webb family: FHA base $410,125, UFMIP $7,177.19, total $417,302.19, P&I=$2,637.54, MIP=$187.97/mo, PITIM=$3,456.85. QUALIFIED_TOTAL_ACCEPT.
S09 — DSCR Qualification | L3 — Program Qualification
S09 DSCR Qualification L3 — Program Qualification Purpose Full 14-stage DSCR loan qualification for investment properties. Qualification is based entirely on property income — no borrower income used. Computes DSCR ratio, max loan at 1x and 1.25x coverage, monthly cashflow, cap rate, and reserve requirements. Inputs BorrowerProfile, ProgramQueue[DSCR], gross_rent_monthly Outputs QualResult_DSCR: dscr_ratio, qualification_status, net_monthly_cashflow, max_loan_1x, max_loan_1.25x, cap_rate, required_reserves, cash_to_close, LineageTrace_DSCR Key Rule DSCR = gross_rent / PITIA. GROSS rent — not net, not after vacancy, not after expenses. No MI in DSCR denominator. ≥1.00 = eligible. ≥1.25 = preferred/strong. Example $380K property, 20% down, rent=$2,800, PITIA=$2,690.61 → DSCR=1.0407. Eligible. Net cashflow=$109.39/mo. Max loan at 1.25x = $319,644.
S10 — Optimization | L4 — Scoring
S10 Optimization L4 — Scoring Purpose Scores every evaluated program across 6 dimensions using absolute benchmarks. Produces composite scores (0–100) for ranking. Detects the Always-Approved state (is the borrower approved today?). Runs rate sensitivity analysis. Inputs All QualResults (VA, CONV, FHA, DSCR), BorrowerProfile.borrower_goal Outputs OptimizationResult: composite_score per program, dimension_scores (pay/MI/CTC/cert), quality_bonus, always_approved_state, rate_sensitivity Key Rule Absolute benchmarks: payment floor=$2,000, ceil=$5,000. MI divisor=700 (with 1.30 penalty for non-cancellable). CTC ceiling=property_value×25%. INELIGIBLE programs get proximity_score only. Example Webb family: VA composite=87.08 (pay=54.54, mi=86.95, ctc=88.00, cert=90.00 + qb=15). FHA composite=50.09. CONV proximity=43.37.
S11 — Scenario Generation | L4 — Scoring
S11 Scenario Generation L4 — Scoring Purpose Generates up to 5 concrete, actionable scenarios showing how the borrower can resolve binding constraints and reach program eligibility. 8 scenario types. Scored by effort-to-impact. PROGRAM_SWITCH always included if applicable. Inputs OptimizationResult, ConstraintSet, BorrowerProfile Outputs ScenarioSet: up to 5 scenarios, each with action_type, specific dollar amounts, timeline, effort_impact_score, programs_unlocked Key Rule effort_impact_score = effort×0.40 + impact×0.60. PROGRAM_SWITCH = take the better program now, immediately. Always highest priority if applicable. Tier 2 trigger: best scenario score ≥ 50. Example Webb CONV ineligible: S1=PROGRAM_SWITCH→VA (ei=95, take now). S2=CO_BORROWER (ei=58, need $2,014.36/mo income). S3=DEBT_PAYOFF (ei=44, eliminate $906.46/mo obligations).
S12 — Ranking | L5 — Recommendation
S12 Ranking L5 — Recommendation Purpose Sorts eligible programs by composite score. Applies 5 tiebreaker rules when programs are within 5 composite points of each other. Computes confidence scores with adjustments for CTC surplus, reserves, DTI comfort, credit strength, and risk layering. Inputs OptimizationResult, ScenarioSet Outputs RankedProgramList: programs in rank order, confidence_score per program, tiebreaker_log, risk_to_monitor per program Key Rule 5 tiebreakers: MI cancelability → approval certainty → CTC → payment → program mainstream. Confidence clamped 0.40–0.99. DSCR always ranked last vs standard programs. Example Webb: VA (87.08, conf=0.98) → FHA (50.09, conf=0.91). Gap=36.99 ppts — no tiebreaker needed. VA rank 1.
S13 — Overlay | L5 — Recommendation
S13 Overlay L5 — Recommendation Purpose Applies lender-specific credit and DTI overlays, waiting period checks, and state-specific rules to adjust confidence scores. Surfaces lender guidance for advisor. Adds compliance flags (HMDA, anti-steering). Inputs RankedProgramList, BorrowerProfile.property_state, BorrowerProfile.qualifying_credit_score Outputs OverlayAdjustedResult: overlay_adjusted_confidence per program, overlay_flags, lender_guidance, state_cost_estimate Key Rule Confidence adjustments: −0.03 to −0.20 depending on overlay type. WAITING_PERIOD_ACTIVE = −1.00 (blocks program). CA community property = −0.03. All results include HMDA_REPORTABLE flag. Example Webb in CA: VA conf 0.98 − 0.03 (CA community property) = 0.95. FHA conf 0.91 − 0.05 (DTI overlay) − 0.03 (CA) = 0.83. VA still rank 1.
S14 — Audit Trace | L6 — Compliance
S14 Audit Trace L6 — Compliance Purpose Consolidates all LineageTrace objects into the canonical decision record for a Clarity Engine run. Assigns trace IDs to every decision node. Detects deviations. Generates ECOA adverse action export if required. Builds HMDA fields and ML training record. Inputs All LineageTraces (from L3 skills), All QualResults, OverlayAdjustedResult, RankedProgramList Outputs AuditTrace: trace_ids (L0-L8), deviation_map, ECOA_adverse_action_export, HMDA_fields, ML_training_record, AuditSummary (BRIEF/STANDARD/FULL) Key Rule trace_id format: [Layer].[SkillCode].[Seq].[Outcome]. ECOA export required when ANY program is INELIGIBLE. ML training record includes data_quality_score. 'denied' never appears in BRIEF tier output. Example Webb: 87 decision nodes. DEV-001: CONV INELIGIBLE_DTI. ECOA reason: 'Debt obligations too high in relation to income.' BRIEF: 'We evaluated three programs. VA is your best fit.'
S15 — Always Approved | L7 — Output
S15 Always Approved L7 — Output Purpose The capstone Purlend skill. Produces the Always-Approved statement for every borrower — the definitive answer to 'what is my approved path?' 4 tiers cover every possible situation from approved-today to approved-in-time. Required closing: 'This path is clear.' Inputs RankedProgramList, OverlayAdjustedResult, ScenarioSet, AuditTrace Outputs AlwaysApprovedStatement: tier, status_line, best_path_detail, action_required, confidence_close ('This path is clear.'). Plus: PriorityActionPlan (up to 5 steps), TimeToApproval. Key Rule 4 tiers: T1=approved now (confidence≥0.70). T2=one action (best scenario ei≥50). T3=multiple actions (2+ changes). T4=time (waiting period only). 'denied' never appears. Max 5 action items. Example Webb T1: 'VA loan — you're approved today.' VA at 6.50%, $3,364/month, $12,750 to close, no down payment. '$58,531 less lifetime MI than FHA.' 'This path is clear — proceed with confidence.'
CONFIDENTIAL — PreFi, Inc. / Purpose Technology, Inc. d/b/a Purlend | Clarity Engine Skill Library Summary v1.0