jev-hermes

What jev-hermes does

jev-hermes hands cheap, typed decisions to Jev through OpenRouter's Decisions API, so the main model runs only when needed. Jev does not chat or write code. It answers typed questions about a state, with answer types such as noul, choice and score, and returns calibrated probabilities. The plugin adds a jev toolset with jev_decide and jev_mail_triage, plus a bundled reference skill named jev:jev.

A pre_tool_call hook checks every terminal command that Hermes' own patterns do not already flag. If Jev's escalate probability reaches 0.7, Hermes shows its normal approval prompt, and Jev never approves anything itself. An opt-in context engine swaps one step of Hermes' compressor so older tool outputs the assistant no longer needs become one-line stubs, with all messages kept. Mail triage returns counts and message ids without putting mail bodies into the agent context.

Key features

• jev_decide tool for typed decisions with intent, approval and mail triage presets
• jev_mail_triage tool that returns ids and counts, not mail bodies
• Automatic risky-command gate through a pre_tool_call hook
• Opt-in context engine that stubs unneeded old tool output
• Bundled skill available as jev:jev
• Settings for gate threshold, mode, timeout and fail-closed behavior in config.yaml

When to use it

• Catching commands such as kubectl delete namespace prod that fixed patterns miss
• Triaging Gmail without loading message bodies into the agent
• Shrinking long sessions by compacting old tool output

Who it is for: Hermes Agent users who want inexpensive guardrails and routing decisions in front of a more costly model.

How it fits with Hermes Agent

Built for Hermes Agent as a plugin with an optional skill form. It adds tools, a pre_tool_call approval gate and a context engine that builds on Hermes' own compressor.

How to install jev-hermes

These commands are copied from the project's README. Check the repository for the latest steps before you run them.

hermes plugins install de-niji/jev-hermes --enable

Requirements: An OpenRouter API key (OPENROUTER_API_KEY in the environment or in $HERMES_HOME/.env); the tools only appear when a key is found

Note: Per-turn routing still depends on the agent following the skill, and hooking it into Hermes directly with pre_llm_call is described as the next step.

FAQ