FastMSR is an open-source Mortgage Servicing Rights (MSR) management system built with FastHTML — a server-side, HTMX-driven cockpit for valuing, trading and transferring mortgage servicing, with a simulated Freddie Mac Cash-Released XChange (CRX) bidding exchange at its core. Python-first, no JavaScript framework. Part of Predictive Labs' Fast* family of reference FastHTML apps.
Value the strip, win the bid, board the transfer. Runs on port 5008.
Synthetic data only — no PII. Everything ships and runs on deterministic, fully synthetic data generated by
seed.py. There are no real loans, borrowers or servicers anywhere in this repository.The Freddie Mac CRX integration is a SIMULATOR. There is no connection to Freddie Mac, Loan Selling Advisor or any external pricing service. Competitive servicer bids are produced by a local pricing model for demonstration only.
A click-through of the key module screens (regenerate any time with
bash scripts/build_demo_gif.sh while the app is running):
# 1. Virtualenv + dependencies
python -m venv .venv
.venv/bin/python -m pip install -r requirements.txt
# 2. (optional) configure — the app self-seeds and runs with zero config
cp .env.sample .env
# 3. Run (builds the synthetic SQLite DB on first boot)
.venv/bin/python web_app.py # http://localhost:5008Login: admin@fastmsr.example / FastMSR2026$ (override via FASTMSR_ADMIN_*
in .env). Rebuild the demo data any time with .venv/bin/python seed.py.
docker compose up --build # http://localhost:5008Dockerfile (python:3.12-slim, port 5008) seeds the database on first boot.
docker-compose.yml mounts a fastmsr-data volume at /data so the SQLite
database lives outside the image and survives rebuilds.
Switch role from the Acting as dropdown in the top bar. Write actions are permission-checked and every attempt — allowed or denied — is written to the Audit Trail. Modeled roles:
| Role | Can |
|---|---|
| Admin | everything |
| Seller/Transferor | import tapes, value, create/run/award CRX, advance transfers |
| Transferee/Buyer | advance transfers, set documents |
| Portfolio Manager | import tapes, value, create/run CRX |
| Compliance Officer | sign off compliance items |
| Read-Only/Investor | read only (try to award a bid → denied, logged) |
- Dashboard (
/) — aggregate UPB, MSR fair value (bps), active transfers and open alerts; a 6-month mark-to-market trend, live CRX bids by servicer, transfer status and a geographic-concentration risk read (inline SVG, no chart libs). - Portfolios (
/portfolios) — three seeded loan tapes. Each portfolio page gives FICO / note-rate / geographic stratifications, data-validation QC flags against eligibility rules, and the full loan tape. CSV import appends loans and re-runs QC. Loan pages (/loans/{id}) show a real monthly cash-flow DCF schedule. - Valuation & Analytics (
/valuation) — a real DCF of the servicing-fee strip. Tune CPR, default rate, discount rate and servicing cost, then recompute. Rate-shock scenarios (±100/±200 bps), effective duration & convexity from a ±25 bps discount bump, a retain-vs-release signal vs. the best live CRX bid, mark-to-market history, and CSV export. - CRX Exchange (
/crx) — simulated Freddie Mac Cash-Released XChange. Create an execution, select loans, exclude servicers, and run a competitive SRP auction across a simulated pool (Rocket, Freedom, Newrez, Chase, Mr. Cooper, PennyMac, Lakeview, Carrington). Highest SRP wins; award it to see automated net funding, the bifurcation note (seller retains sale reps, servicer assumes servicing) and the Imaged/Final document checklist referencing Exhibit 28A. A CRX award can initiate a concurrent servicing transfer. - Servicing Transfers (
/transfers) — concurrent (CRX) or standalone. Workflow status tracking, versioned document checklist, exception handling for data discrepancies, in-app borrower/investor notifications (CFPB 15-day rule) in the event log, and a MERS batch reference. - Compliance & Risk (
/compliance) — Freddie Guide and CFPB checklist items, live risk flags (concentration, prepayment, credit), and a hedging suggestion sized to the book's MSR duration / DV01. - Audit Trail (
/audit) — every permissioned action with acting role and outcome. Alerts (/alerts) surface bid wins, transfer deadlines and risk triggers.
valuation.py runs a monthly discounted-cash-flow of the servicing right: each
month the servicer earns the servicing-fee strip (plus a little ancillary income)
on the outstanding balance, less a per-loan cost; the balance amortises on the
note's own schedule plus a CPR prepayment and a small default rate; the net
strip is discounted at the chosen rate. Value ÷ annual servicing fee gives the
familiar MSR multiple. Because faster prepayment kills the fee strip sooner,
MSR is a negative-duration asset — its value rises when rates rise, which the
scenario table shows directly. Everything is pure arithmetic: deterministic and
zero-config.
web_app.py FastHTML routes, session auth, RBAC guards (entrypoint, :5008)
db.py SQLite schema + read/write helpers, RBAC + audit + alerts
valuation.py monthly MSR DCF, rate-shock scenarios, duration/convexity
crx.py MOCK Freddie Mac CRX competitive-bidding engine + Exhibit 28A
seed.py deterministic synthetic portfolios, loans, bids, transfers
web/layout.py dark slate + amber shell (top bar, nav, page chrome), CSS
web/views.py per-module server-rendered pages + inline SVG charts
static/ favicon + committed walkthrough GIF
scripts/ Playwright walkthrough → animated README GIF
Data layer is plain sqlite3 via a thin wrapper (no ORM); interactivity is HTMX +
a little inline JS. Consistent with the sibling apps (FastCRM, FastClinic).
| Area | Status |
|---|---|
| MSR DCF valuation, scenarios, duration/convexity | Real arithmetic model |
| Portfolio / loan CRUD, QC rules, stratification | Real |
| Servicing-transfer workflow, docs, exceptions, audit, RBAC | Real (in-app) |
| CSV import & valuation export | Real |
| Freddie Mac CRX bidding, SRP pricing, net funding | Simulated — local model, no external API |
| Servicer pool (Rocket, Chase, …) | Fictionalized appetite/pricing profiles |
| Borrower/investor notifications | In-app log only — no email/SMS is sent |
This is a reference implementation — single FastHTML process + SQLite, seeded demo data. A production MSR platform would typically add:
- Postgres / Snowflake for loan-level data at portfolio scale; a real prepayment model (e.g. Andrew Davidson / Yield Book / BlackRock) rather than a single CPR; nightly mark-to-market with rate-surface inputs.
- Real Freddie Mac integrations — Cash-Released XChange, Loan Selling Advisor
and Servicing Gateway APIs — replacing
crx.py. - Document management (imaging, e-vault, Exhibit 28A packaging) and MERS eRegistry integration for real transfers.
- SSO / SAML, granular RBAC, encryption at rest, and SOC 2 controls; immutable audit storage; real borrower/investor notification delivery on the CFPB / RESPA §6 timelines.
MIT © 2026 Predictive Labs Ltd. Built as an open-source reference for the Predictive Labs Fast* family of FastHTML applications.