Hermes Jev Skills

Hermes Jev Skills is an open-source Python project published on GitHub under the owner handle kerpopule. It wires TypeSafe's Jev decision model into agents such as Hermes, Claude Code and Codex, covering model routing, memory, compaction, skill selection, search, triage, and computer and browser use. The latest release listed is v0.22.0, published 2026-09-29.

What It Is

The README describes Jev as TypeSafe's decision model, which never writes text. It takes a state and typed questions (pick one, score this, yes or no) and returns an answer with a calibrated confidence. This repository supplies the glue: a stdlib-only library and jev command, eleven agent-agnostic SKILL.md skills, a Hermes plugin, a model routing dashboard, and an installer. The README says the project is independent of TypeSafe AI, which makes Jev and TypeSafe.

What Jev Decides

The README lists measured decisions per skill:

• Model routing: which model is good enough for a turn, at about 0.4 s per turn.
• Search: which fetched results to open, whether the evidence is sufficient, and which candidate query to run.
• Memory: which retrieved passages are worth reading and which contain hidden instructions.
• Web screening on Hermes: withholding web results that carry instructions aimed at the agent.
• Skill selection, triage, mailbox sorting, choosing transcript turns, and computer and browser use.

The README reports that a handoff built from Jev's digest recalled less than one built from the plain transcript, so handoffs ship without Jev by default.

Setup Path

Installation is a git clone followed by python3 install.py, which needs Python 3.9 or newer and no dependencies. The installer detects Hermes, Claude Code and Codex and installs for each one it finds. --check previews changes and --uninstall reverses them. jev setup-key opens a one-time local page so the TypeSafe API key goes into the OS secret store without the agent seeing it. The README recommends starting with /jev routing shadow, which decides and logs without switching models.

Hermes Integration

The hermes-jev plugin uses only public plugin seams (pre_llm_call, transform_tool_result, the llm_request middleware, tools and a slash command), so the README says hermes update does not break it. Slash commands toggle routing, skills, notices and web screening. The agent gets five tools: jev_memory_filter, jev_compact_select, jev_choose_action, jev_supervise and jev_escalate. Model catalog data comes from models.dev, filtered to providers the machine holds keys or logins for. For Claude Code, the installer adds four lane subagents and a delimited block in ~/.claude/CLAUDE.md.

Privacy and Failure Behavior

The README states plainly that Jev is a cloud API and itemizes what leaves the machine per skill, with redaction, character caps and local screening. Profiles listed in private_profiles send only coarse features. Logs hold decisions only. The README says everything fails open: with no key, a timeout or low confidence, routing keeps the current model and other skills return the original data. Risk words never route to the cheapest tier.

Current Status

The repository was created 2026-09-18, was last pushed 2026-09-29, and is MIT licensed. Tests are offline with every Jev reply faked, and the docs folder includes guides on shadow mode, fleets and lanes.