hermes-agent/website/docs/user-guide/features/built-in-plugins.md
Teknium 249534e472
plugins: add security-guidance — pattern-matched warnings on dangerous code writes (#33131)
New opt-in plugin that scans the content passed to write_file / patch /
skill_manage for 25 known-dangerous code patterns — pickle.load,
yaml.load, eval(, os.system, subprocess(shell=True), child_process.exec,
dangerouslySetInnerHTML, innerHTML/outerHTML/document.write/
insertAdjacentHTML, crypto.createCipher (no IV), AES ECB,
TLS verification disabled, XXE-prone xml.etree/minidom parsers,
<script src=//...> without SRI, torch.load without weights_only=True,
GitHub Actions ${{ github.event.* }} injection — and appends a
"Security guidance" warning block to the tool result via the
transform_tool_result hook.

Default behaviour is non-blocking: the file is written and the warning
rides back to the model in the next turn so it can self-correct or
document why the construct is safe. SECURITY_GUIDANCE_BLOCK=1 upgrades
to refusing the write entirely; SECURITY_GUIDANCE_DISABLE=1 is the
kill switch.

Pattern data (patterns.py) is a verbatim Apache-2.0 fork of
Anthropic's claude-plugins-official/plugins/security-guidance/hooks/
patterns.py at commit 0bde168 (2026-05-26). LICENSE and NOTICE
preserve attribution. The Hermes-side plugin glue (__init__.py,
plugin.yaml, README.md, tests) is original work.

Plugin is opt-in like all bundled plugins:
  hermes plugins enable security-guidance

Inspired by https://x.com/ClaudeDevs/status/1927108527247... — Anthropic
shipped this as their security-guidance plugin for Claude Code on
2026-05-26 with a measured 30-40% reduction in security-related PR
comments on internal rollout.

What's NOT ported (deferred):
  * Layer 2 (LLM diff review on turn end) — would route through main
    model by default on Hermes, real money on reasoning models. A
    follow-up can wire it to a cheap aux model with explicit opt-in.
  * Layer 3 (agentic commit-time review) — agent can run this on
    demand via delegate_task today.
  * .hermes/security-guidance.md project-rules file — only used by
    layers 2/3 upstream.
2026-05-27 02:07:21 -07:00

18 KiB
Raw Blame History

sidebar_position sidebar_label title description
12 Built-in Plugins Built-in Plugins Plugins shipped with Hermes Agent that run automatically via lifecycle hooks — disk-cleanup and friends

Built-in Plugins

Hermes ships a small set of plugins bundled with the repository. They live under <repo>/plugins/<name>/ and load automatically alongside user-installed plugins in ~/.hermes/plugins/. They use the same plugin surface as third-party plugins — hooks, tools, slash commands — just maintained in-tree.

See the Plugins page for the general plugin system, and Build a Hermes Plugin to write your own.

How discovery works

The PluginManager scans four sources, in order:

  1. Bundled<repo>/plugins/<name>/ (what this page documents)
  2. User~/.hermes/plugins/<name>/
  3. Project./.hermes/plugins/<name>/ (requires HERMES_ENABLE_PROJECT_PLUGINS=1)
  4. Pip entry pointshermes_agent.plugins

On name collision, later sources win — a user plugin named disk-cleanup would replace the bundled one.

plugins/memory/ and plugins/context_engine/ are deliberately excluded from bundled scanning. Those directories use their own discovery paths because memory providers and context engines are single-select providers configured through hermes memory setup / context.engine in config.

Bundled plugins are opt-in

Bundled plugins ship disabled. Discovery finds them (they appear in hermes plugins list and the interactive hermes plugins UI), but none load until you explicitly enable them:

hermes plugins enable disk-cleanup

Or via ~/.hermes/config.yaml:

plugins:
  enabled:
    - disk-cleanup

This is the same mechanism user-installed plugins use. Bundled plugins are never auto-enabled — not on fresh install, not for existing users upgrading to a newer Hermes. You always opt in explicitly.

To turn a bundled plugin off again:

hermes plugins disable disk-cleanup
# or: remove it from plugins.enabled in config.yaml

Currently shipped

The repo ships these bundled plugins under plugins/. All are opt-in — enable them via hermes plugins enable <name>.

Plugin Kind Purpose
disk-cleanup hooks + slash command Auto-track ephemeral files and clean them on session end
security-guidance hooks Pattern-match dangerous code on write_file/patch and append a security warning (or block) — 25 rules (Apache-2.0 fork of Anthropic's claude-plugins-official patterns)
observability/langfuse hooks Trace turns / LLM calls / tools to Langfuse
spotify backend (7 tools) Native Spotify playback, queue, search, playlists, albums, library
google_meet standalone Join Meet calls, live-caption transcription, optional realtime duplex audio
image_gen/openai image backend OpenAI gpt-image-2 image generation backend (alternative to FAL)
image_gen/openai-codex image backend OpenAI image generation via Codex OAuth
image_gen/xai image backend xAI grok-2-image backend
hermes-achievements dashboard tab Steam-style collectible badges generated from your real Hermes session history
kanban/dashboard dashboard tab Kanban board UI for the multi-agent dispatcher — tasks, comments, fan-out, board switching. See Kanban Multi-Agent.

Memory providers (plugins/memory/*) and context engines (plugins/context_engine/*) are listed separately on Memory Providers — they're managed through hermes memory and hermes plugins respectively. The full per-plugin detail for the two long-running hooks-based plugins follows.

disk-cleanup

Auto-tracks and removes ephemeral files created during sessions — test scripts, temp outputs, cron logs, stale chrome profiles — without requiring the agent to remember to call a tool.

How it works:

Hook Behaviour
post_tool_call When write_file / terminal / patch creates a file matching test_*, tmp_*, or *.test.* inside HERMES_HOME or /tmp/hermes-*, track it silently as test / temp / cron-output.
on_session_end If any test files were auto-tracked during the turn, run the safe quick cleanup and log a one-line summary. Stays silent otherwise.

Deletion rules:

Category Threshold Confirmation
test every session end Never
temp >7 days since tracked Never
cron-output >14 days since tracked Never
empty dirs under HERMES_HOME always Never
research >30 days, beyond 10 newest Always (deep only)
chrome-profile >14 days since tracked Always (deep only)
files >500 MB never auto Always (deep only)

Slash command/disk-cleanup available in both CLI and gateway sessions:

/disk-cleanup status                     # breakdown + top-10 largest
/disk-cleanup dry-run                    # preview without deleting
/disk-cleanup quick                      # run safe cleanup now
/disk-cleanup deep                       # quick + list items needing confirmation
/disk-cleanup track <path> <category>    # manual tracking
/disk-cleanup forget <path>              # stop tracking (does not delete)

State — everything lives at $HERMES_HOME/disk-cleanup/:

File Contents
tracked.json Tracked paths with category, size, and timestamp
tracked.json.bak Atomic-write backup of the above
cleanup.log Append-only audit trail of every track / skip / reject / delete

Safety — cleanup only ever touches paths under HERMES_HOME or /tmp/hermes-*. Windows mounts (/mnt/c/...) are rejected. Well-known top-level state dirs (logs/, memories/, sessions/, cron/, cache/, skills/, plugins/, disk-cleanup/ itself) are never removed even when empty — a fresh install does not get gutted on first session end.

Enabling: hermes plugins enable disk-cleanup (or check the box in hermes plugins).

Disabling again: hermes plugins disable disk-cleanup.

security-guidance

Fast pattern-matched security warnings on file writes. When the agent's write_file / patch / skill_manage calls carry content matching a known-dangerous code pattern — pickle.load, yaml.load without SafeLoader, eval(, os.system, subprocess(..., shell=True), JS child_process.exec, React dangerouslySetInnerHTML, raw .innerHTML = / .outerHTML = / document.write, Node crypto.createCipher, AES ECB mode, TLS verification disabled, XXE-prone xml.etree / minidom parsers, <script src="//..." > without SRI, torch.load without weights_only=True, GitHub Actions ${{ github.event.* }} injection — the plugin appends a ⚠️ Security guidance block to the tool's result.

The file is still written. The model reads the warning in the next turn's tool message and can either fix the code or document why the construct is safe in this context. Pattern matching has a non-trivial false-positive rate, which is why warn (not block) is the default.

Coverage: 25 rules total, covering unsafe deserialization, command injection, XSS sinks, crypto footguns, XXE, supply-chain (SRI), and CI/CD workflow injection. The pattern data is a verbatim Apache-2.0 fork of Anthropic's claude-plugins-official — see the plugin's LICENSE and NOTICE files for attribution.

Modes:

Env var Effect
(unset) warn mode (default) — file is written, warning appended to result
SECURITY_GUIDANCE_BLOCK=1 block mode — write refused, warning returned as the block reason
SECURITY_GUIDANCE_DISABLE=1 kill switch — plugin loads but does nothing

Enabling: hermes plugins enable security-guidance (or check the box in hermes plugins).

Disabling again: hermes plugins disable security-guidance.

What it does not do (yet): the upstream Anthropic plugin has two more layers — an LLM diff review on each agent turn that touched files, and an agentic commit-time review that traces data flow across files. Neither is ported. The agent can already run those reviews on demand via delegate_task.

observability/langfuse

Traces Hermes turns, LLM calls, and tool invocations to Langfuse — an open-source LLM observability platform. One span per turn, one generation per API call, one tool observation per tool call. Usage totals, per-type token counts, and cost estimates come out of Hermes' canonical agent.usage_pricing numbers, so the Langfuse dashboard sees the same breakdown (input / output / cache_read_input_tokens / cache_creation_input_tokens / reasoning_tokens) that appears in hermes logs.

The plugin is fail-open: no SDK installed, no credentials, or a transient Langfuse error — all turn into a silent no-op in the hook. The agent loop is never impacted.

Setup:

pip install langfuse
hermes plugins enable observability/langfuse

Or check the box in the interactive hermes plugins UI. Then put the credentials in ~/.hermes/.env:

HERMES_LANGFUSE_PUBLIC_KEY=pk-lf-...
HERMES_LANGFUSE_SECRET_KEY=sk-lf-...
HERMES_LANGFUSE_BASE_URL=https://cloud.langfuse.com   # or your self-hosted URL

How it works:

Hook Behaviour
pre_api_request / pre_llm_call Open (or reuse) a per-turn root span "Hermes turn". Start a generation child observation for this API call with serialized recent messages as input.
post_api_request / post_llm_call Close the generation, attach usage_details, cost_details, finish_reason, assistant output + tool calls. If no tool calls and non-empty content, close the turn.
pre_tool_call Start a tool child observation with sanitized args.
post_tool_call Close the tool observation with sanitized result. read_file payloads get summarized (head + tail + omitted-line count) so a huge file read stays under HERMES_LANGFUSE_MAX_CHARS.

Session grouping keys off the Hermes session ID (or task ID for sub-agents) via langfuse.propagate_attributes, so everything in a single hermes chat session lives under one Langfuse session.

Verify:

hermes plugins list                 # observability/langfuse should show "enabled"
hermes chat -q "hello"              # check the Langfuse UI for a "Hermes turn" trace

Optional tuning (in .env):

Variable Default Purpose
HERMES_LANGFUSE_ENV Environment tag on traces (production, staging, …)
HERMES_LANGFUSE_RELEASE Release/version tag
HERMES_LANGFUSE_SAMPLE_RATE 1.0 Sampling rate passed to the SDK (0.01.0)
HERMES_LANGFUSE_MAX_CHARS 12000 Per-field truncation for message content / tool args / tool results
HERMES_LANGFUSE_DEBUG false Verbose plugin logging to agent.log

Hermes-prefixed and standard SDK env vars (LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY, LANGFUSE_BASE_URL) are both accepted — Hermes-prefixed wins when both are set.

Performance: the Langfuse client is cached after the first hook call. If credentials or SDK are missing, that decision is also cached — subsequent hooks fast-return without re-checking env vars or reloading config.

Disabling: hermes plugins disable observability/langfuse. The plugin module is still discovered, but no module code runs until you re-enable.

google_meet

Lets the agent join, transcribe, and participate in Google Meet calls — take notes on a meeting, summarize the back-and-forth after, follow up on specific points, and (optionally) speak replies back into the call via TTS.

What it adds:

  • A headless virtual participant that joins a Meet URL using browser automation
  • Live transcription of the meeting audio via the configured STT provider
  • A meet_summarize / meet_speak / meet_followup toolset the agent invokes to act on what it heard
  • Post-meeting artifacts (transcript, speaker-attributed notes, action items) saved under ~/.hermes/cache/google_meet/<meeting_id>/

Setup:

hermes plugins enable google_meet
# Prompts you to sign in via the plugin's OAuth flow on first use —
# needs a Google account with Meet access. Host approval may be required
# if the meeting enforces "only invited participants can join".

Usage from chat:

"Join meet.google.com/abc-defg-hij and take notes. After the call, send me a summary with action items."

The agent kicks off the meeting join, streams the transcription back into its context as the call proceeds, and produces a structured summary when the meeting ends (or when you tell it to stop).

When to use it: recurring standups where you want a bot to transcribe + summarize for async attendees; deposition-style interviews where you want structured notes; any case where you'd otherwise need Fireflies / Otter / Grain. When you'd rather not have an AI listening in — don't enable it.

Disabling: hermes plugins disable google_meet. Any cached transcripts and recordings stay in ~/.hermes/cache/google_meet/ until you remove them.

hermes-achievements

Adds a Steam-style achievements tab to the dashboard — 60+ collectible, tiered badges generated from your real Hermes session history. Tool-chain feats, debugging patterns, vibe-coding streaks, skill/memory usage, model/provider variety, lifestyle quirks (weekend and night sessions). Originally authored by @PCinkusz as an external plugin; brought in-tree so it stays in lockstep with Hermes feature changes.

How it works:

  • Scans your entire ~/.hermes/state.db session history on the dashboard backend
  • Per-session stats are cached by (started_at, last_active) fingerprint, so only new or changed sessions re-analyze on subsequent scans
  • First-ever scan runs in a background thread — the dashboard never blocks waiting for it, even on databases with thousands of sessions
  • Unlock state is persisted to $HERMES_HOME/plugins/hermes-achievements/state.json

Tier progression: Copper → Silver → Gold → Diamond → Olympian. Each card exposes a "What counts" section listing the exact metric being tracked.

Achievement states:

State Meaning
Unlocked At least one tier achieved
Discovered Known achievement, progress visible, not yet earned
Secret Hidden until Hermes detects the first related signal in your history

API — routes mount under /api/plugins/hermes-achievements/:

Endpoint Purpose
GET /achievements Full catalog with per-badge unlock state (returns a pending placeholder while the first cold scan is running)
GET /scan-status State of the background scanner: idle / running / failed, last duration, run count
GET /recent-unlocks Twenty most recently unlocked badges, newest first
GET /sessions/{id}/badges Badges earned primarily in one specific session
POST /rescan Manual synchronous rescan (blocks; use when the user clicks the rescan button)
POST /reset-state Clear unlock history and cached snapshot

State files — live under $HERMES_HOME/plugins/hermes-achievements/:

File Contents
state.json Unlock history: which badges you've earned and when. Stable across Hermes updates.
scan_snapshot.json Last completed scan payload (served immediately on dashboard load)
scan_checkpoint.json Per-session stats cache keyed by fingerprint (makes warm rescans fast)

Performance notes:

  • Cold scan on ~8,000 sessions takes a few minutes. It runs in a background thread on first dashboard request; the UI sees a pending placeholder and polls /scan-status.
  • Incremental results during a cold scan — the scanner publishes a partial snapshot every ~250 sessions so each dashboard refresh shows more badges unlocked as the scan progresses. No minute-long stare at zeros.
  • Warm rescan reuses per-session stats for every session whose started_at + last_active fingerprint matches the checkpoint — completes in seconds even on large histories.
  • The in-memory snapshot TTL is 120s; stale requests serve the old snapshot immediately and kick a background refresh. You never wait on a spinner just because TTL expired.

Enabling: Nothing to enable — hermes-achievements is a dashboard-only plugin (no lifecycle hooks, no model-visible tools). It auto-registers as a tab in hermes dashboard on first launch. The plugins.enabled config only gates lifecycle/tool plugins; dashboard plugins are discovered purely via their dashboard/manifest.json.

Opting out: Delete or rename plugins/hermes-achievements/dashboard/manifest.json, or override it with a user plugin of the same name in ~/.hermes/plugins/hermes-achievements/ that ships no dashboard. The plugin's state files under $HERMES_HOME/plugins/hermes-achievements/ survive — reinstalling preserves your unlock history.

Adding a bundled plugin

Bundled plugins are written exactly like any other Hermes plugin — see Build a Hermes Plugin. The only differences are:

  • Directory lives at <repo>/plugins/<name>/ instead of ~/.hermes/plugins/<name>/
  • Manifest source is reported as bundled in hermes plugins list
  • User plugins with the same name override the bundled version

A plugin is a good candidate for bundling when:

  • It has no optional dependencies (or they're already pip install .[all] deps)
  • The behaviour benefits most users and is opt-out rather than opt-in
  • The logic ties into lifecycle hooks that the agent would otherwise have to remember to invoke
  • It complements a core capability without expanding the model-visible tool surface

Counter-examples — things that should stay as user-installable plugins, not bundled: third-party integrations with API keys, niche workflows, large dependency trees, anything that would meaningfully change agent behaviour by default.