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local-system-one-hermes

❖ Communityv0.5.2

Automation · by NMTZ-z · added

Local System One / Laya Typed Decisions control plane for Hermes Agent. Sends task text to a loopback sidecar for reversible OFF/Shadow/Canary routing decisions, with explicit Canary acknowledgement and fail-open behavior.

Open in Hermes Desktop
hermes plugins install local-system-one-hermes
Repository ↗Reviewed source @ 823aff5 ↗Documentation ↗

What it adds

Hooks 1

pre_llm_call

Middleware 1

llm_request

README

From the reviewed commit 823aff5 ↗; it updates when the author re-pins.

Local System One for Hermes

A reversible System One / Laya Typed Decisions control layer for Hermes Agent.

Use it when you want Hermes to make small, frequent routing decisions locally before the main LLM call, without replacing Hermes' normal provider or turning a small model into an all-powerful router.

Typical decisions include:

  • whether a task needs public/current Web information;
  • whether a bounded task is eligible for a lower reasoning tier;
  • which decisions should remain observation-only until enough evidence exists.

The plugin talks to a separate Local System One service over loopback HTTP. It is deliberately conservative: first install is OFF, Shadow changes nothing, Canary requires explicit acknowledgement, and any Local System One failure leaves the original Hermes request unchanged.

Before you install

You need:

  • Hermes Agent >=0.21.4;
  • macOS / Apple Silicon for the validated Local System One runtime;
  • a running Local System One service, normally at http://127.0.0.1:8787.

The Local System One runtime lives in the same public repository:

git clone https://github.com/NMTZ-z/system-one-benchmark-lab.git
cd system-one-benchmark-lab

python3.12 -m venv .venv
. .venv/bin/activate
python -m pip install -e .
local-system-one --host 127.0.0.1 --port 8787

Check it before enabling the plugin:

curl http://127.0.0.1:8787/health

For the optional Apple Neural Engine backend, see the repository root README.

Install

Hermes Plugin Catalog

Once this plugin is listed in the official Hermes Plugin Catalog:

hermes plugins install local-system-one-hermes

Catalog installs are pinned to the exact commit reviewed by Hermes maintainers.

Direct Git install

Before catalog admission, or when deliberately installing a custom revision:

hermes plugins install \
  NMTZ-z/system-one-benchmark-lab/integrations/hermes/local-system-one-hermes

Hermes treats direct Git installs as custom/unreviewed sources. For reproducibility, pin a full commit SHA with --ref.

The repository also contains helper scripts for profile-aware installation and rollback:

scripts/install_hermes_system_one_plugin.sh systemoneeval
scripts/hermes_system_one_status.sh systemoneeval

Recommended first run: Shadow

Start with a disposable or evaluation profile:

scripts/set_hermes_system_one_mode.sh systemoneeval shadow

Shadow mode:

  • calls the enabled Local System One gates;
  • records privacy-safe operational metadata;
  • does not rewrite the Hermes provider request.

This is the recommended way to evaluate the plugin before allowing any request mutation.

Modes

Mode Local System One calls Changes Hermes provider request? Recommended use
off No No Default / fully inert
shadow Yes No Evaluation and calibration
canary Yes Only narrow audited rules Explicit experiments

Off

No Local System One HTTP calls and no Hermes request changes.

scripts/set_hermes_system_one_mode.sh systemoneeval off

Shadow

Observe recommendations without changing the provider request.

scripts/set_hermes_system_one_mode.sh systemoneeval shadow

Canary

Canary can mutate a provider request, so entering it requires explicit acknowledgement:

scripts/set_hermes_system_one_mode.sh systemoneeval canary --ack-canary

Leaving Canary for shadow or off automatically revokes the acknowledgement.

If mode=canary is set without acknowledgement, the plugin degrades to Shadow behavior instead of mutating requests.

What Canary is allowed to do

Canary only acts on audited deterministic rules. Model-probability recommendations remain observation-only.

Public-Web filter

For audited hard no-Web rules, acknowledged Canary may hide only the directly advertised Hermes tools:

  • web_search
  • web_extract

It does not disable terminal access, browser tooling, MCP/connectors, local files, or indirect network paths. It is not a network sandbox.

Reasoning downgrade

Disabled by default.

If you explicitly enable canary_reasoning_downgrade_enabled, audited hard-fast rules may change one first provider request from:

reasoning_effort=high -> reasoning_effort=low

for gemini-3.8-flash-tiered.

This remains experimental. A 32-pair Hermes benchmark preserved measured task quality but did not establish a reliable latency improvement, so the public plugin does not enable or advertise this as a guaranteed optimization.

Safe defaults

Setting Default
mode off
search_gate_enabled true
model_tier_gate_enabled true
canary_acknowledged false
canary_web_filter_enabled true
canary_reasoning_downgrade_enabled false
timeout_ms 500

Hermes exposes these settings through the plugin settings UI.

Fail-open behavior

Local System One is advisory infrastructure, not a dependency Hermes must survive.

If the sidecar is unavailable, times out, or returns an incomplete recommendation:

  • the plugin does not apply Canary mutations;
  • Hermes keeps its original provider request;
  • the main Hermes turn continues.

This behavior has been tested with deliberate dead-service fault injection.

Privacy

Raw task text is not written into plugin state.

Shadow/Canary state stores only operational metadata such as:

  • request IDs;
  • decision source / route reason;
  • probabilities or scores;
  • backend and latency;
  • names of tools changed by Canary.

The Local System One service also avoids persisting raw request payloads by default.

Rollback / uninstall

Return to Shadow or OFF at any time:

scripts/set_hermes_system_one_mode.sh systemoneeval shadow
scripts/set_hermes_system_one_mode.sh systemoneeval off

Full removal:

scripts/uninstall_hermes_system_one_plugin.sh systemoneeval

Uninstall removes this plugin's configuration and state while leaving Hermes, other plugins, models, sessions and agent files alone.

Verification

From the repository root:

python -m pytest -q \
  tests/test_hermes_system_one_plugin.py \
  tests/test_hermes_system_one_scripts.py

hermes plugins validate integrations/hermes/local-system-one-hermes
hermes plugins doctor integrations/hermes/local-system-one-hermes --ci

A disposable live lifecycle smoke test is also included:

scripts/smoke_hermes_system_one_live.sh systemoneeval

It exercises OFF, Shadow, acknowledged Canary, fail-open behavior and restoration.

Current release posture

  • OFF: safe default and fully inert
  • Shadow: recommended evaluation mode
  • hard no-Web Canary: narrow, evidence-backed experiment
  • reasoning downgrade Canary: experimental and disabled by default
  • model-probability Active routing: not supported

For architecture, benchmark evidence and the Laya/ANE runtime, see the main project:

https://github.com/NMTZ-z/system-one-benchmark-lab

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