# Usage Guard: Hermes Agent plugin

> Keeps an agent inside its subscription allowance: refuses a provider dispatch once a subscription usage window is exhausted, so an account that allows paid extra usage stops at the wall instead of spending overage.

Canonical: https://hermeswatcher.com/plugins/usage-guard  
Tier: Community  
Official page (Nous Research): https://hermes-agent.nousresearch.com/docs/plugins/usage-guard  
Last updated in catalog: 2026-10-24

Keeps an agent inside its subscription allowance: refuses a provider dispatch once a subscription usage window is exhausted, so an account that allows paid extra usage stops at the wall instead of spending overage. Reads the usage Hermes already displays, holds no credentials, and never touches account or billing settings.

## Good to know before installing

Refuses main-loop provider calls (including MoA turns) for the providers in `provider_keys` (Anthropic and OpenAI Codex by default) when a subscription usage window reaches `threshold_percent`, and by default (`fail_open: false`) also refuses when usage data is missing, stale, unreadable, or the guard's own config is malformed; usage is read through Hermes's own account-usage fetcher (no credentials held, at most one read per source every 180 seconds by default) and cached in $HERMES_HOME/plugin-data/usage-guard/usage.json; a `pre_llm_call` hook adds a short usage note to the next turn's context at 80% and 90% used by default, and an opt-in (off by default) `llm_request` middleware lowers an existing output-token budget near the usage limit; both read only the cache, never the network; auxiliary calls (compression, vision, titles, MoA advisors) are not gated.

From the plugin's catalog listing.

## How to install

1. Install it. Hermes asks for any API keys it needs, then asks whether to turn it on.

```bash
hermes plugins install usage-guard
```

2. Said no? Turn it on later:

```bash
hermes plugins enable usage-guard
```

3. Restart Hermes so it loads the plugin.

Some plugins also need a sign-in or settings: see the official page. Memory plugins ask whether to become your memory provider instead. Steps follow the official plugins guide: https://hermes-agent.nousresearch.com/docs/user-guide/features/plugins

## Facts

- Category: AI models & providers, Automation & multi-agent
- Maintained by: mister-ideas (Community)
- Needs: No API keys declared
- Requires Hermes: `>=0.21.6`
- Version: 0.4.1
- In the catalog since: 2026-10-17, updated 2026-10-24

## Links

- [Full setup and settings (official page)](https://hermes-agent.nousresearch.com/docs/plugins/usage-guard)
- [Source code](https://github.com/mister-ideas/usage-guard)
- [All plugins](https://hermeswatcher.com/plugins.md)

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HermesWatcher is an independent guide. It is not affiliated with or endorsed by Nous Research. The [official Hermes Agent documentation](https://hermes-agent.nousresearch.com/docs) and [repository](https://github.com/NousResearch/hermes-agent) from Nous Research are the authority; each page here lists the official sources it was written from. If this site and the official docs disagree, trust the official docs. Index for agents: https://hermeswatcher.com/llms.txt