routing-policy-change

name	routing-policy-change
category	primary
description	Modifies routing policy after signal extraction, including matched-decision logic, candidate-model selection, and downstream looper behavior. Use when changing decision predicates, thresholds, priorities, model ranking, cost or latency routing, or other post-signal routing policy.

Routing Policy Change

Trigger

• Change boolean decision logic after signal extraction
• Change candidate-model selection, ranking, cost routing, or latency routing
• Change looper behavior that belongs to matched-decision policy instead of signal extraction or plugin hooks

Workflow

1. Read change surfaces, module boundaries, and the Go router playbook for routing-policy context
2. Modify decision predicates, downstream model selection, or matched-decision looper behavior
3. Run make agent-report ENV=cpu CHANGED_FILES="..." to identify impacted surfaces
4. Run make agent-ci-gate CHANGED_FILES="..." to validate all affected constraints
5. Verify routing-policy behavior is covered by targeted tests and affected E2E expectations

Gotchas

• Keep signal extraction upstream; do not smuggle classifier changes into this primary unless the signal contract itself is changing.
• Keep plugin hooks separate; looper changes that only support matched-decision policy belong here, but request or response body plugins still belong to the plugin flow.
• Decision predicates and candidate-model ranking can change user-visible routing even when the patch looks small, so they are not refactors by default.

Must Read

• docs/agent/change-surfaces.md
• docs/agent/module-boundaries.md
• docs/agent/playbooks/go-router.md

Standard Commands

• make agent-report ENV=cpu CHANGED_FILES="..."
• make agent-ci-gate CHANGED_FILES="..."
• make agent-feature-gate ENV=cpu CHANGED_FILES="..."

Acceptance

• Decision predicates and downstream candidate-model selection stay aligned with the same routing-policy intent
• Targeted tests and affected E2E coverage are updated when routing-policy behavior changes
• Routing-policy logic stays downstream of signal extraction and separate from plugin-only processing