Define durable v0.4.0 project intent

PROJECT.md

@@ -1,38 +1,79 @@
-# PROJECT.md
+# quant-pricer-cpp project intent
 
-## Project Profile
-- Name: quant-pricer-cpp
-- One-liner: (what is this repo, in one sentence?)
-- Type: (research | trading | infra | library | web | mixed)
-- Risk tier: (low | medium | high)
-- Primary languages: (e.g. Rust/C++/Python/TS)
-- External dependencies / services: (Kalshi, AWS, Postgres, etc.)
+## Project profile
 
-## Goals (what “done” looks like)
-- (bullet list)
+- **Purpose:** a C++20 and Python derivatives-pricing library with reproducible,
+  artifact-bound numerical evidence.
+- **Product type:** open-source library and research-validation system.
+- **Risk tier:** medium. The library computes prices and conditional risk
+  measures, but it is not a trading or live-risk system.
+- **Primary languages:** C++20, Python, CMake, and shell.
+- **External services:** GitHub Actions, GitHub Releases, and GitHub Pages.
 
-## Non-goals (explicitly out of scope)
-- (bullet list)
+## Goals
 
-## Current state
-- What works:
-- What’s missing:
-- What’s broken:
-- Biggest risks:
+- Make deterministic Black–Scholes portfolio valuation and exact user-supplied
+  stress scenarios a production-shaped, first-class C++/Python surface.
+- Preserve the broader analytic, Monte Carlo/QMC, PDE, Heston, SSVI, exotic,
+  VaR/ES, and reproducibility capabilities without inflating their claims.
+- Ship supported Python wheels and a build-complete source distribution through
+  a green cross-platform release workflow.
+- Bind accuracy, determinism, performance, and package claims to inspectable
+  tests, receipts, manifests, and frozen artifacts.
 
-## Quickstart (how to run)
-- (commands to install deps, run, test)
+## Non-goals
 
-## Architecture (high-level)
-- Modules:
-- Data flow:
-- Key invariants:
+- Trading alpha, return forecasts, order execution, or live P&L.
+- Probabilistic market-risk validation or claims that user-supplied stress
+  scenarios represent future market distributions.
+- Unqualified benchmark claims across hardware, compilers, or workloads.
+- PyPI or TestPyPI availability unless the corresponding provider state has
+  been separately verified.
 
-## Constraints / preferences
-- Performance constraints:
-- Safety constraints:
-- Style constraints:
+## Current product state
+
+- **v0.4.0 lead surface:** `bs_portfolio_risk` and
+  `bs_portfolio_scenarios` for mixed European call/put portfolios.
+- **Risk output:** position price/value/Greeks plus quantity-weighted portfolio
+  value, delta, gamma, vega, theta, and rho.
+- **Stress output:** exact five-factor repricing for spot, volatility, rate,
+  dividend, and elapsed-time shocks, with aggregate or position detail.
+- **Evidence:** independent QuantLib parity, exact zero-shock identity,
+  concurrent deterministic replay, sanitizers, package validation, and frozen
+  hardware-bound benchmark receipts.
+- **Distribution:** source builds and GitHub release assets are authoritative;
+  the project does not claim a PyPI package.
+
+## Quickstart
+
+```bash
+cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DQUANT_ENABLE_PYBIND=ON
+cmake --build build --parallel
+ctest --test-dir build --output-on-failure
+python python/examples/quickstart.py
+python python/examples/portfolio_risk.py
+```
+
+For an installed Python package, use a wheel matching the running Python and
+platform from the GitHub release, then run
+`python python/scripts/cibw_test_suite.py`.
+
+## Architecture and invariants
+
+- `include/quant/` and `src/` contain the native pricing and risk engines.
+- `python/pybind_module.cpp` exposes the supported Python API.
+- `tests/` owns native, Python, package, documentation, and release gates.
+- `docs/artifacts/` contains frozen evidence; `docs/product/` explains the
+  product contract and claim boundaries.
+- `.github/workflows/` owns CI, Pages, validation-pack, wheel, sdist, manifest,
+  and GitHub release automation.
+- Public claims must remain reproducible or artifact-bound, and public package
+  availability must be proven by provider evidence.
 
 ## Links
-- Docs:
-- Issues:
+
+- [README and quickstart](README.md)
+- [v0.4.0 product and evidence hub](docs/product/DERIVATIVES_SYSTEM_HUB.md)
+- [v0.4.0 release notes](docs/releases/v0.4.0.md)
+- [Generated documentation](https://mateobodon.github.io/quant-pricer-cpp/)
+- [GitHub releases](https://github.com/MateoBodon/quant-pricer-cpp/releases)