Plugins

Overview

Plugins add route-local behavior after a decision matches. They can rewrite a request, retrieve context, short-circuit generation, inspect a response, or control what operational data is retained.

Shared services and stores belong under global:; the decision plugin only enables and tunes that behavior for one route.

Key Advantages

• Keeps behavior attached to the route that needs it.
• Reuses shared stores and services without duplicating their configuration.
• Makes request mutation, retrieval, and response inspection auditable.

What Problem Does It Solve?

Routes often need different behavior even when they share the same Router. Plugins keep those differences next to the decision instead of hiding them in application middleware or enabling them globally.

When to Use

Use a plugin when behavior should apply only after a specific route matches. Use global: instead when every route shares the same service or backing store. Plugin entries live under routing.decisions[].plugins.

Configuration

routing:
  decisions:
    - name: cached-support
      description: Reuse cached responses for support requests.
      priority: 100
      rules:
        operator: AND
        conditions: []
      modelRefs:
        - model: support-model
      plugins:
        - type: response_cache
          configuration:
            enabled: true
            ttl_seconds: 3600

Plugin Inventory

Type	Goal	Shared dependency	Guide
fast_response	Return a configured response without calling a model	None	Fast Response
system_prompt	Insert, replace, or append route-specific instructions	None	System Prompt
header_mutation	Add, update, or delete downstream headers	None	Header Mutation
request_params	Enforce request parameter limits	None	Request Parameters
tools	Allow, block, filter, or remove tools and tool history	Optional global tool catalog	Tools
tool_selection	Add tools from a catalog or filter caller tools semantically	Embedding runtime; tool database for add mode	Tool Selection
context_compression	Reduce large provider-bound tool output or history	Optional embedding runtime and recovery store	Context Compression
response_cache	Reuse compatible prior responses	global.stores.response_cache	Response Cache
memory	Retrieve and optionally store conversational memory	global.stores.memory	Memory
rag	Retrieve documents before generation	Configured RAG/vector backend	RAG
router_replay	Override replay capture for one route	global.services.router_replay	Router Replay
hallucination	Inspect factual support in a response	Hallucination/NLI modules as configured	Hallucination
response_jailbreak	Screen a generated response for jailbreak content	Prompt-guard runtime	Response Jailbreak
image_gen	Send a matched route to an image-generation backend	Configured image backend	Image Generation

Content Safety bundles three supported plugins, not an additional plugin type.

Operational Boundaries

• Plugins can interact when more than one mutates the provider-bound request or response. The Router pipeline fixes their execution order; reordering entries in YAML does not change it.
• Retrieval, memory, cache, and replay may persist request-derived content. Configure retention, tenant/user scope, authentication, and encryption for the selected backend.
• Header and prompt mutation can cross trust boundaries. Do not copy untrusted caller metadata into privileged headers or system instructions.
• Validate the complete recipe before deployment so unsupported plugin names or incompatible settings fail before traffic reaches the Router.