Install

Byspec needs Node.js 22 or later.

npm#

npm install -g @byspec-dev/cli
byspec --version

Single file#

The same self-contained bundle the cloud sandbox runs, for machines without npm access or for pinning an exact build:

curl -fsSLo byspec.mjs https://github.com/adamchensley/byspec/releases/download/v0.1.0/byspec.mjs
node byspec.mjs --version

Download: byspec.mjs (v0.1.0).

First run#

byspec init            # byspec.config.yaml, specs/README.md, an example spec
byspec lint specs/     # is every criterion testable?
byspec verify          # gather evidence, judge the residue, record the ledger

byspec init --agents also installs instruction blocks, a Claude Code Stop hook and MCP configuration for coding agents. See the CLI reference and the coding agents guide.

The judge#

Deterministic checks need nothing. Criteria with a judge entry need a model: Amazon Bedrock through the default AWS credential chain (the default), or the Anthropic API with ANTHROPIC_API_KEY. --no-judge skips the model and marks those criteria UNVERIFIABLE; --provider mock is for tests.