Policy packs

A pack turns one guardrails: entry in aegis.yaml into pipeline nodes. First-party packs use exactly the same entry-point contract as third-party ones — an import-linter rule in CI stops them from reaching into Aegis internals — so anything they do, your plugin can do too.

All five ship with pip install aegis-gateway. LLM Guard's model library is opt-in — see LLM Guard.

Pack	pack:	Adds	Kind	Options
PII masking	aegis.pii	ingress mask + egress unmask, or ingress detect	node / guard	mode, entities, threshold, allow_list
Residency	aegis.residency	ingress guard	guard	region, jurisdiction, allowed_regions, require_approval
Classification	aegis.classification	ingress node	node	—
Budgets	aegis.budgets	ingress guard + egress recorder	guard / node	default_cap
LLM Guard	aegis.llm_guard	ingress guard	guard	scanners, threshold

How a pack plugs in

guardrails:
  pii:                 # your name for this instance — referenced below
    pack: aegis.pii    # which pack builds it (an aegis.packs entry point)
    mode: mask         # anything else is passed to the pack's factory

pipeline:
  ingress: [pii]       # the pack decides which node goes in which stage;
  egress: [pii]        # listing the name in a stage places that stage's nodes

At startup build_executor() looks up each pack: in the aegis.packs entry-point group and calls its from_config(name, cfg) factory, which returns {"ingress": [...], "egress": [...]}. Each route then collects, in the order you listed them, the nodes each named guardrail contributes to each stage.

Run aegis plugin list --group aegis.packs to see what's installed, and aegis policy lint to catch a pack: that isn't.

Combining packs

Packs never import each other; they cooperate through RunState. The classification pack writes labels["classification"], which any later node can read. Order matters — list the producer before the consumer:

guardrails:
  classify:
    pack: aegis.classification
  pii:
    pack: aegis.pii
    mode: mask
  budget:
    pack: aegis.budgets
    default_cap: 50.0

pipeline:
  ingress: [budget, classify, pii]
  egress: [pii, budget]

Want a pack that doesn't exist? Write one — it is a normal Python package.