01 // what
Replace a system with no code and no documentation with a deterministic, byte-for-byte replica, against cases we don't know.
system design · architecture
Architecture
Production on Cloudflare Workers with a Durable Object (single global state). The same engine (src/engine.mjs) runs on a local Node server. Integrity with ISO 7064 Mod 97-10.
Public entrypoint: https://caja-negra-reemplazo.parsec-ai-labs.workers.dev
EVALUATOR person · 100 hidden tests | | HTTPS + Bearer · JSON · 5s v +------------- WORKER (Cloudflare) -------------+ | GET /health -> 200 {"ok":true} | | POST /__reset -> 200 {"ok":true} | | POST /msg -> auth -> engine -> X-Req | | /* -> 404 E404 | +----------------------+------------------------+ | known route + auth v DURABLE OBJECT global-caja-negra · single state | v ENGINE ISO 7064 checksum · accounts · operations
C4 · level 1 — context
flowchart TD
Judge["Evaluator / Judge"]:::person
subgraph SYS["Autonomous replacement"]
EP["Worker HTTP /health /__reset /msg"]:::system
end
Oracle["Original service"]:::external
Judge -->|"HTTPS + Bearer, JSON in 5s"| SYS
SYS -.->|"offline comparison"| Oracle
classDef person fill:#102016,stroke:#39ff14,color:#d7f5c8;
classDef system fill:#0c1610,stroke:#7ee7ff,color:#d7f5c8;
classDef external fill:#141008,stroke:#ffb000,color:#ffe7b8;
synchronousdevelopment only
C4 · level 2 — containers
flowchart TB
subgraph PROD["WORKER + DURABLE OBJECT"]
Router["Worker fetch
CORS routing timing-safe auth"] Health["GET /health"] Reset["POST /__reset"] DO[("Durable Object
global-caja-negra")] Engine["BankingEngine
engine.mjs"] Check["checksum.mjs
ISO 7064 Mod 97-10"] Sec["security.mjs
8 KiB sanitize token"] Router --> Health Router --> Reset Router -->|"POST /msg"| DO Sec -.-> Router DO --> Engine Engine --> Check end subgraph LOCAL["Local Node server (tests)"] SNode["server.mjs node:http"] SNode --> Engine end subgraph DISC["Offline harness"] Fuzzer["Prober"] Oracle2["Oracle"] Comparator["Comparator"] SpecLog["experimentos.jsonl + SPEC.md"] Fuzzer --> Oracle2 Oracle2 --> Comparator Engine -.-> Comparator Comparator --> SpecLog end Judge2["Evaluator"]:::person Judge2 -->|"Bearer"| Router classDef person fill:#102016,stroke:#39ff14,color:#d7f5c8;
CORS routing timing-safe auth"] Health["GET /health"] Reset["POST /__reset"] DO[("Durable Object
global-caja-negra")] Engine["BankingEngine
engine.mjs"] Check["checksum.mjs
ISO 7064 Mod 97-10"] Sec["security.mjs
8 KiB sanitize token"] Router --> Health Router --> Reset Router -->|"POST /msg"| DO Sec -.-> Router DO --> Engine Engine --> Check end subgraph LOCAL["Local Node server (tests)"] SNode["server.mjs node:http"] SNode --> Engine end subgraph DISC["Offline harness"] Fuzzer["Prober"] Oracle2["Oracle"] Comparator["Comparator"] SpecLog["experimentos.jsonl + SPEC.md"] Fuzzer --> Oracle2 Oracle2 --> Comparator Engine -.-> Comparator Comparator --> SpecLog end Judge2["Evaluator"]:::person Judge2 -->|"Bearer"| Router classDef person fill:#102016,stroke:#39ff14,color:#d7f5c8;
Worker
Production entrypoint: CORS, routing, timing-safe auth and an 8 KiB body limit (E101). Unknown routes → 404 E404.
Durable Object
Single instance global-caja-negra: guarantees one state across requests, isolated by POST /__reset.
Engine + checksum
Deterministic state machine. Control with ISO 7064 Mod 97-10; error precedence and ANULA reversal.
Runtime of one test
POST /__reset → state 0 → POST /msg (1 to 12 requests) → validation → transition → exact body. More than 5 s is a failure.
Deployment
Worker + Durable Object on Cloudflare's edge. A single logical state; verified live (20/20 examples).