Hermes Agent Plugin Development — Build Custom Extensions
Extend Hermes Agent with custom plugins, skills, and tools tailored to your workflows. Build integrations with your internal systems, create domain-specific automation, and package reusable capabilities that your agents can invoke on demand.
Plugin Architecture
Plugins live in ~/.hermes/plugins/ and register tools, hooks, and CLI commands. The PluginManager discovers them at startup — no core changes needed.
Tool Registration
Each plugin can register as many tools as needed via ctx.register_tool(...). Tools get full schema support, availability gating via check_fn, and error wrapping.
Lifecycle Hooks
Hook into pre_tool_call, post_tool_call, pre_llm_call, post_llm_call, on_session_start, and on_session_end to build observability, validation, and stateful plugins.
Skills System
Skills are markdown-driven capability packs with SKILL.md frontmatter, scripts, templates, and references. They inject domain knowledge and procedures into the agent's context on demand.
What We Build
- ✓Custom integrations: connect Hermes to your internal APIs, databases, CRMs, ticketing systems, and proprietary tools
- ✓Domain-specific skills: packaged knowledge and procedures for your industry — legal, healthcare, fintech, manufacturing
- ✓Automation workflows: multi-step agent procedures that combine tools, memory, and delegation into repeatable pipelines
- ✓Model provider plugins: connect Hermes to any LLM backend — custom endpoints, on-premise models, specialized providers
- ✓Memory backends: pluggable persistence layers — vector DBs, graph stores, document archives, custom schemas
- ✓Platform adapters: connect Hermes to new messaging platforms, channels, or custom webhook receivers
Plugin Categories We Support
General Plugins
Tools, hooks, CLI commands. The most flexible category — anything that doesn't fit elsewhere goes here.
Memory Providers
Pluggable memory backends implementing the MemoryProvider ABC. Honcho, mem0, supermemory, and custom implementations.
Model Providers
Inference backends — OpenAI, Anthropic, Gemini, OpenRouter, custom endpoints. Register via ProviderProfile.
Context Engines
Custom context assembly and retrieval strategies. Plug into the agent's context pipeline for domain-specific enrichment.
Image Generation
Providers for DALL-E, Stable Diffusion, ComfyUI, and other image generation backends — tools agents can call to create visuals.
Kanban & Dispatch
Multi-agent work queues with SQLite-backed boards, assignees, reviews, and auto-dispatch. Workers spawned per-task with isolated contexts.
Development Approach
- 1Requirements gathering: what integrations, tools, or workflows does the client need? What existing systems must Hermes connect to?
- 2Architecture: choose plugin category, define tool schemas, design hook integration points, plan skill structure
- 3Implementation: write the plugin in Python, register tools and hooks, package skills with scripts and references, test with real Hermes startup
- 4Integration testing: verify the plugin loads correctly, tools appear in the agent's schema, hooks fire at the right times, skills inject properly
- 5Delivery & documentation: install the plugin, document its tools and usage, hand over maintenance guidance
Ideal For
- Companies that want Hermes to connect to proprietary internal systems
- Teams that need domain-specific AI knowledge packaged as reusable skills
- Organizations building custom automation workflows on top of Hermes Agent
- Developers who want to extend Hermes with new platforms, providers, or tools