Open source for Hermes Agent
Hermes plugins and skills by MadeByBrain
Tools that grew out of working with Hermes every day. Each one solves a specific problem, is open on GitHub and installs with one command. Nous Research, the team behind Hermes, reviewed our plugins and accepted them into the official catalog.
- Free, MIT license
- Source code open on GitHub
- Official Hermes interfaces only
Reviewed and accepted into the official Hermes catalog: writing-guard ↗de-law ↗chat-length ↗
In short
Hermes Agent is an open source AI agent by Nous Research. Plugins extend it through official interfaces without touching the core. Skills are instructions that Hermes loads by itself when a task calls for them.
All plugins and skills at a glance
The collection grows with every tool that proves itself in our daily work.
New Plugin · v1.0.1 · Free
writing-guard
No em dashes, no AI phrases, one form of address.
In the official plugin catalog
Hermes checks each of its answers before you read it: em and en dashes, stock AI phrases in German and English, and a switch between du and Sie in German. By default one short line appears under the answer; if you want, the plugin replaces the dashes itself.
Details and installation ↓
Plugin · v1.0.0 · Free
de-law
German and EU law, word for word, with the source.
In the official plugin catalog
Ask Hermes about § 203 StGB or Art. 6 GDPR and it reads the provision in the official database before it answers. You get the wording, the version status of the law, the gazette reference and a ready-made source line instead of a quote from memory.
Details and installation ↓
Plugin · v1.1.0 · Free
chat-length
Knows when a fresh chat is the better move.
In the official plugin catalog
When a chat gets too long, Hermes adds a short notice below its answer. It contains a ready-made opener for a new chat. In the new chat, Hermes pulls the rest from the old conversation on its own.
Details and installation ↓ Installation
$ hermes plugins install writing-guard --enableRequires: Hermes Agent v0.22.2+
writing-guard
No em dashes, no AI phrases, one form of address.
In the official plugin catalog since November 2, 2026 ↗
Hermes checks each of its answers before you read it: em and en dashes, stock AI phrases in German and English, and a switch between du and Sie in German. By default one short line appears under the answer; if you want, the plugin replaces the dashes itself.
What it does
- Finds dashes outside code, links and quotes and can replace them by rule: ranges and list bullets become hyphens, a dash between words becomes a comma.
- Reports stock AI phrases such as "It's important to note", "I hope this helps" or "delve". You can add your own.
- du and Sie: reports both forms in one paragraph, a switch against the previous answer, or the wrong form when you set one.
Who it is for
For anyone who writes texts with Hermes that get sent or published: posts, newsletters, client mails, web pages. For agencies and editors a starting point: it checks surface rules, not tone, facts or your own style guide.
How it works
Report or fix
Mode report appends one line when there is a finding. Mode fix replaces the dashes. Phrases and the form of address are never rewritten automatically, because a rule does not know the meaning.
A tool for drafts
With writing_guard_check Hermes checks a draft itself before it hands you a mail or a post. A bundled skill reminds the model to do so.
Rules, not AI
No model call, no network, a few milliseconds per answer. The same result on every run.
Data and privacy
No network, no model calls. Per chat it stores only the last form of address used (du or Sie) with a timestamp, deleted after 30 days. The last report stays in memory only.
Test status
Live-tested with the Hermes CLI on v0.22.2 with Gemini 3.7 Flash, GPT-4o and Claude Haiku 4.5. Plus 57 offline tests and a run over 1,000 of our own answers: 133 contained dashes, although our rule bans them. We have not live-tested Desktop, TUI or gateways yet.
View in the catalog ↗ Installation
$ hermes plugins install de-law --enableRequires: Hermes Agent v0.22.2+
de-law
German and EU law, word for word, with the source.
In the official plugin catalog since October 25, 2026 ↗
Ask Hermes about § 203 StGB or Art. 6 GDPR and it reads the provision in the official database before it answers. You get the wording, the version status of the law, the gazette reference and a ready-made source line instead of a quote from memory.
What it does
- German federal law from Gesetze im Internet (about 6,100 laws and ordinances) and EU law such as the GDPR, AI Act, NIS2 or DORA from the Publications Office of the EU.
- Decisions of BVerfG, BGH, BVerwG, BFH, BAG, BSG and BPatG: search by file number, court and date, read the headnote, operative part or reasons.
- Every answer with version status, gazette reference, link and source line. If a provision does not exist, the plugin says so instead of guessing a nearby number.
Who it is for
For anyone who asks Hermes about German or EU law and wants the real wording with a source: founders, data protection and compliance officers, HR teams, consultants, journalists. For law firms a good starting point, not a complete legal research system.
How it works
Five tools
de_law_get, de_law_search, de_law_toc, de_case_search and de_case_get. A small bundled skill makes Hermes use them before a web search.
Official sources, no key
Gesetze im Internet and Rechtsprechung im Internet (German Federal Ministry of Justice, edited by the Federal Office of Justice) and CELLAR, the data behind EUR-Lex. No API key, no account.
Legal texts, not legal advice
The plugin returns statute and court texts and does not interpret them. They are the consolidated versions from the databases. Only the Bundesgesetzblatt and the Official Journal of the EU are binding.
Data and privacy
Section numbers and search words never leave your machine: the plugin downloads the whole law and searches it locally. The cache holds public legal texts only (up to 200 MB by default), no questions and no chat data. Requests go over HTTPS to the three official sources only, at most one per second.
Test status
Live-tested with the Hermes CLI on v0.22.2: § 203 StGB, § 312g BGB, § 43e BRAO, § 823 BGB, Art. 6 GDPR, Art. 50 AI Act in English and BVerfG 2 BvE 5/26. Plus 35 offline tests. We have not live-tested WebUI, Desktop, gateways or other models yet.
View in the catalog ↗ Installation
$ hermes plugins install chat-length --enable$ hermes gateway restartRequires: Hermes Agent v0.21.6+
chat-length
Knows when a fresh chat is the better move.
In the official plugin catalog since October 23, 2026 ↗
When a chat gets too long, Hermes adds a short notice below its answer. It contains a ready-made opener for a new chat. In the new chat, Hermes pulls the rest from the old conversation on its own.
What it does
- Measures how full the chat is from the real token counts your AI provider reports back. No guessing.
- Speaks up at 70 and at 90 percent (configurable), each level only once per chat.
- Hands you an opener with title, session ID, two or three status bullets and the open items. In the new chat, Hermes finds the history itself via
session_search.
Who it is for
For anyone who runs long working chats in Hermes Agent and is done writing handover documents.
How it works
Measured against compaction
Hermes compacts long chats automatically. By default chat-length therefore measures against that point, not against the full context window. Set basis: window to use the full window instead.
Prompt caching stays intact
The notice reaches the user message only on the turn that triggers it, never the system prompt. Verified with request dumps: every earlier message stays byte-identical.
Configurable
Thresholds, basis and language (auto, English or German) in config.yaml or in Hermes Desktop under Settings, Plugins. Background jobs such as cron, subagents and Kanban never get a notice.
Data and privacy
No network calls, no chat content stored. One small entry per chat with token counts, model and the level that fired, removed after 30 days.
Test status
Live-tested with the Hermes CLI on v0.21.6 and v0.22.2, plus 22 offline tests. The plugin runs server-side, so it is built for WebUI, Desktop and Telegram too. We have not live-tested it there yet.
View in the catalog ↗Why we build plugins
We run Hermes every day, as our own system and for clients. When something is missing, we build it so it helps others too, and we publish it. The bigger picture behind it is B.R.A.I.N., our personal AI system for business owners.
Frequently asked questions about the Hermes plugins
What is a Hermes plugin?
What is the difference between a plugin and a skill?
How do I install the plugins?
Are the plugins in the official Hermes plugin catalog?
Does de-law replace legal advice?
What data do the plugins send and store?
What do the plugins and skills cost?
Do the plugins work in WebUI, Desktop and Telegram?
Do you build custom plugins?
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