Getting started

1. Install

npm (macOS, Linux, Windows)

npm i -g @muthuishere/jevx

macOS / Linux

curl -fsSL https://muthuishere.github.io/jevx/install.sh | sh

Windows

curl -fsSLo install.cmd https://muthuishere.github.io/jevx/install.cmd && install.cmd

Each one puts the jevx binary on your PATH, copies the agent skill into ~/.claude/skills, ~/.agents/skills and ~/.codex/skills (if that folder exists), and adds the Claude Code hook entries, which stay disabled. JEVX_NO_HOOK=1 installs the skills only. Details in Install.

2. Set your key

jevx talks to hosted Jev out of the box. There is nothing to configure: put your key in the environment and you are done.

~/.zshrc or ~/.bashrc

export TYPESAFE_API_KEY=...        # your key from typesafe.ai

jevx reads the variable when a request is sent and never writes it anywhere. Without it, every call stops with a clear message and exit code 4 (never a fake “no”):

$ echo "Prod is down" | jevx is "Is this urgent?"
jevx: set your Jev API key: export TYPESAFE_API_KEY=... (from typesafe.ai). Or use another endpoint: jevx profile add NAME URL --model M --header 'Authorization: Bearer $YOUR_VAR' && jevx profile use NAME

Optional: your own endpoint

Only if you run a different System One endpoint (a self-hosted model, a personal model on your machine, another provider), add a profile: a URL, a model and headers. $VAR in any of them is expanded at request time, so keys stay out of the config file.

Terminal

jevx profile add local http://127.0.0.1:21131/v1/systemone --model myjev        # a local model: no key needed
jevx profile add acme https://jev.acme.dev/v1/systemone --model jev-latest --header "Authorization: Bearer $ACME_KEY"

$ jevx profile list
* jev        https://api.typesafe.ai/v1/systemone  model=jev-latest  Authorization: Bearer $TYPESAFE_API_KEY  (built in)
  local      http://127.0.0.1:21131/v1/systemone  model=myjev
(* = default; change with: jevx profile use NAME)

The built-in jev stays the default. Use a custom one for a single call with --profile local, or make it the default with jevx profile use local.

3. Ask something

$ echo "Prod is down" | jevx is "Is this urgent?"; echo "exit $?"
yes 0.92
exit 0

The word is the verdict, the number is P(yes). Exit 0 means yes, 1 no, 3 unsure, 4 an error. See Ask for every form.

4. Let the agent use it

Nothing more to do. The skill is installed, and Claude Code or Codex loads it when a task matches its description (classify, triage, filter, rank, “is this X”, “which of these”). Using it from an agent shows what the agent is told.

Where to go next

• Shortcuts: is, pick, filter, rank.
• Saved questions: write a question once, reuse it by name.
• Context: tell the model whose decision it is.
• CLI reference: every command on one page.