Architecture

Seven Rust crates, one TypeScript wallet adapter, a Vite SPA, and an agent skill.

Layers

Consumer layer
  Claude / Cursor / Cline / Continue  -> agent skill (SKILL.md)
  Browser dapp / Node CLI              -> wallet-adapter (TypeScript)
  Hosted playground                    -> frontend (Vite + React)
  Direct user                          -> oz-policy-cli

                  |  MCP, STDIO or Streamable HTTP, bearer auth
                  v

oz-policy-mcp
  9 tools, 5 resource URI families, 3 prompt templates, /healthz, on-disk snapshots

                  |
                  v

oz-policy-recorder    oz-policy-core      oz-policy-codegen   oz-policy-simhost   oz-policy-installer
RPC + XDR decoder     PolicySpec IR       askama templates     soroban-env-host    install envelope
                      decision tree       + sandbox            + proptest deny     + preflight gates

Rust workspace

Seven crates. Pinned dependencies, overflow-checks = true in both release and dev profiles.

Crate	Responsibility
`oz-policy-core`	`PolicySpec` IR, decision tree, SEP-41 detection, `ArgValue` (22 variants covering every `ScVal` shape, i128 serialized as JSON string), `Recording` IR, canonical `Error` enum
`oz-policy-recorder`	Soroban RPC client and XDR decoder, 30-second timeout on every RPC await, network passphrase cross-check
`oz-policy-codegen`	Seven askama constraint templates plus base skeleton, sandbox `cargo build --target wasm32-unknown-unknown`, `stellar contract optimize`, five-rule audit-lint pre-compile gate
`oz-policy-simhost`	In-process `soroban-env-host` harness, vendored minimal smart-account WASM, proptest deny-vector generator, deterministic for a fixed seed
`oz-policy-installer`	Builds the wallet-signable install envelope XDR, preflight gates for smart-account vintage, StrKey shape, network match. Does not submit.
`oz-policy-mcp`	rmcp Model Context Protocol server, STDIO and Streamable HTTP, nine tool handlers, on-chain `verify_install` readback, in-memory store plus on-disk snapshot store, bearer-token auth
`oz-policy-cli`	Thin CLI wrapping the above

TypeScript packages

Package	Responsibility
`wallet-adapter/`	SEP-43 types, Freighter adapter, headless or passkey-kit adapter, `installPolicy` (sign, submit, poll, extract `context_rule_id`), `verifyInstall` (spawns the MCP subprocess), OZ smart-account `AuthPayload` encoder with two-stage SHA-256 digest, V4-meta fallback for Protocol-23 result-meta
`frontend/`	Vite 8, React 19, react-router-dom 7, Monaco. Landing page plus `/playground` route plus `/playground/s/:snapshotId` share-URL route. Four playground tabs, three controller hooks, client-side preflight that mirrors the backend's regex set, URL sync, JSZip bundle export.

skills/oz-policy-builder/SKILL.md is an Anthropic Agent Skills package. It declares five MCP tools (the original Phase 5 surface) and ships three YAML evals (Blend, subscription, Soroswap). A flat-file twin in skills/oz-policy-builder/flat/ exposes prompt.md and tools.json for non-Claude frameworks.

Hosting

Caddy 2 reverse proxy, Let's Encrypt automatic TLS, HTTP/2 and HTTP/3.
policy.erentopal.xyz serves the Vite build via Caddy's file_server.
mcp.erentopal.xyz reverse-proxies to a systemd-managed oz-policy-mcp --http daemon. Hardened unit (StateDirectory, ProtectSystem=strict, ProtectHome=read-only). Codegen invocations from the daemon run under bwrap --unshare-net --ro-bind /.
docs.policy.erentopal.xyz serves this docs site via Caddy's file_server.

License

Apache-2.0. See LICENSE-APACHE in the repo.