Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add AtlasOmnia/donna-starter --skill hermes-plugin-developmentgit clone --depth 1 https://github.com/AtlasOmnia/donna-starterWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/atlasomnia/donna-starter/hermes-plugin-development)<a href="https://agentmods.dev/skills/atlasomnia/donna-starter/hermes-plugin-development"><img src="https://agentmods.dev/badge/skills/atlasomnia/donna-starter/hermes-plugin-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/atlasomnia/donna-starter/hermes-plugin-development"><img src="https://agentmods.dev/badge/skills/atlasomnia/donna-starter/hermes-plugin-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Privilege Escalation · line 253 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- medium Rogue Agent · line 340 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00031 | $0.07002 |
| Opus 5.5 | $0.00012 | $0.02801 |
| Sonnet 5.5 | $0.00006 | $0.01400 |
| Haiku 4.5 | $0.00003 | $0.00700 |
Grade A, and why
hermes-plugin-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- hermes-plugin-development — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 389 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hermes Plugin Development
Use when: creating, debugging, or integrating Hermes Agent plugins, including Python backend plugins (tools, hooks, routers, middleware) and JavaScript Hermes Desktop runtime plugins.
Core patterns
- Choose the extension surface first:
- Backend plugins live under
~/.hermes/plugins/<name>/and add tools, hooks, commands, providers, or middleware. - Desktop runtime plugins live under
$HERMES_HOME/desktop-plugins/<name>/plugin.jsand add native UI contributions through@hermes/plugin-sdk. For model-picker specifics, including a Desktop-local/switchcommand plus backend command-inventory bridge, usereferences/desktop-model-picker-plugin.md. - Resolve the requested interaction surface before building anything. “TUI,” “terminal,” “over SSH,” or “from Windows over SSH” means the prompt_toolkit CLI, not Hermes Desktop. Never substitute a Desktop popover or a backend text-response command.
- Backend plugin slash handlers return text; they cannot open a prompt_toolkit modal. For a TUI command that opens an existing picker, prefer a central command alias or an update-safe
quick_commandsalias. If the user requires an explicit Session/Global step, aliasing to bare/modelis insufficient because the standard picker follows its persistence default; extend the TUI picker state with a scope stage and verify that scope reaches the final switch call. For live verification, use a fresh CLI under tmux, synchronize on the visible composer, capture each modal stage, then repeat through the user's real SSH path; do not mistake raw PTY repaint fragments for a product failure. Seereferences/tui-model-picker-slash-command.md. - Desktop-only slash-like UI commands may use a two-surface integration: composer middleware opens/cancels locally, while an enabled Python backend plugin registers inventory/autocomplete and a non-Desktop fallback. Middleware receives a
{ text, attachments }draft object—never test it with raw strings. This pattern does not satisfy TUI/SSH requests. - Backend plugins use:
__init__.py: Python code + hook implementationsplugin.yaml: metadata + hook declarations- Optional
config.yaml: per-profile settings (e.g., router_model, floor_toolsets)
What ships with it
18 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/api-server-live-plugin-contract.md 5.0 KB
- references/cross-platform-prefetch-publication.md 4.7 KB
- references/desktop-model-picker-plugin.md 7.0 KB
- references/external-model-gateway-affinity.md 3.4 KB
- references/fail-closed-policy-plugin-deployment.md 5.7 KB
- references/gmail-oauth-handoff.md 2.2 KB
- references/hook-contextvar-lifecycle.md 2.4 KB
- references/least-privilege-workspace-oauth.md 2.7 KB
- references/long-goal-public-prep-handoff.md 2.1 KB
- references/modelx-branch-drift-triage.md 1.8 KB
- references/multiplex-profile-guarded-prefetch.md 3.7 KB
- references/public-plugin-distribution-checklist.md 4.2 KB
- references/public-plugin-repo-replacement.md 3.0 KB
- references/router-model-latency.md 2.2 KB
- references/runtime-hook-composition-regression.md 2.5 KB
- references/self-gated-policy-plugin-deployment.md 5.4 KB
- references/tool-router-production-hardening.md 7.0 KB
- references/tui-model-picker-slash-command.md 6.0 KB
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 389 lines · 31 tokens per session scan A d2c6c397994e
hermes-plugin-development is a skill published in the GitHub repository AtlasOmnia/donna-starter (131 stars, last pushed 8d ago), licensed MIT. It adds 31 tokens to every session and 7,002 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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adhoc-verification
Produce fresh, focused, local verification evidence for a code change without relying on the full test suite. Use when a system reminder (or the user) demands ad-hoc verification after an edit, or when you want to prove one behavior in isolation. Covers the correct way to write a throwaway supertest/harness script…
grill-with-docs
Cross-examine codebase architecture against official library documentation and API specs. Identifies deprecations, anti-patterns, and suboptimal library usage.
frontend-visual-verification
Confirm a CSS/HTML/template change actually rendered in a running browser — without being fooled by stale browser cache. Use whenever you edited frontend code (CSS, EJS/HTML, components) and must verify the visual result, especially when a vision screenshot seems to contradict the DOM or the served asset.
inspecting-hermes-desktop-dom
When you are developing apps/desktop and the user is running that same app (hgui / npm run dev), you can read the live rendered DOM of the window they are looking at — computed styles, geometry, which CSS rule actually won, console output — instead of inferring it from .tsx and being wrong.
nextjs-app-router-dev
A skill for developing and troubleshooting Next.js applications that use the App Router, including Edge middleware, SQLite, and session-based authentication.