First PCD Circuit: A Minimal Walkthrough

Your First PCD Circuit — In Five Minutes

PCD — Printed Circuit Description — is a programming language where every program is a verifiable circuit. Other languages describe instructions. PCD describes connections between BRIK64 monomers — just like a PCB describes physical connections between components. Every PCD program can be measured, verified, and review-scoped before it ever runs.

In the next five minutes, you will write your first PCD circuit, run it, compile it to JavaScript and Python, and verify its certification. No setup wizards. No dependency hell. One binary, one command.

Step 1: Install BRIK64 CLI

The BRIK64 compiler is a single binary. One command. No package managers, no dependencies, no configuration files:

curl -L https://brik64.dev/install | sh

That installs BRIK64 CLI to ~/.brik/bin and adds it to your PATH. Verify it works:

BRIK64 CLI --version

Step 2: Create hello.pcd Create a file called hello.pcd. This is a factorial circuit — the kind of thing other languages need 10 lines and a prayer for:

// A factorial circuit
// Takes input n (8-bit unsigned), computes factorial
// Outputs result as 16-bit value
// Every operation is a verified BRIK64 monomer

This circuit takes an 8-bit unsigned integer n, computes its factorial, and outputs a 16-bit result. Every single operation in that pipeline is one of BRIK64's 128 review-scoped monomers. Not a library call. Not a runtime function. A verified atomic operation.

Step 3: Run It

Execute the circuit. No build step. No compilation wait. Just run:

BRIK64 CLI run hello.pcd # Input: n = 6 # Output: 720

The default input is n = 6, and 6! = 720. The circuit produces the correct result. But here is the difference from every other language: BRIK64 CLI automatically verifies the computation during execution. It does not just run your code — it records bounded evidence for it.

Step 4: Compile to JavaScript

Here is where it gets interesting. PCD circuits compile to 14 different target languages. Start with JavaScript:

BRIK64 CLI build hello.pcd -t javascript

This generates output/hello.js. Run it with Node:

node output/hello.js
# Output: 720

Same input, same output. Not approximately the same. Exactly the same. The compiled JavaScript preserves every verification guarantee from the original PCD circuit.

Step 5: Compile to Python

Want Python instead? Same command, different flag:

BRIK64 CLI build hello.pcd -t python

This generates output/hello.py. Same verified result. Same guarantees. one blueprint, supported targets. That is 14 targets from a single source of truth — Rust, JavaScript, TypeScript, Python, C, C++, Go, COBOL, PHP, Java, Swift, WebAssembly, BIR bytecode, and native x86-64.

Step 6: Check Certification

Now for the part that Few public tools in this category can do — verify the circuit's mathematical certification:

BRIK64 CLI check hello.pcd Circuit: factorial Monomers: 3 operations Composition: sequential TCE: 7 metrics evaluated ───────────────────────── closure check recorded

What Does closure check passed Mean? closure check passed means the circuit is closed — every input maps deterministically to an output, with zero information leakage. Not for some inputs. within the declared input domain. Your first circuit is not just tested. It is review-scoped. Go build something.