feat(routing): routing_rules schema + types — M4-001/002/003 (#315)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/src/agent/routing/routing.types.ts

@@ -0,0 +1,118 @@
+/**
+ * Routing engine types — M4-002 (condition types) and M4-003 (action types).
+ *
+ * These types are re-exported from `@mosaic/types` for shared use across packages.
+ */
+
+// ─── Classification primitives ───────────────────────────────────────────────
+
+/** Category of work the agent is being asked to perform */
+export type TaskType =
+  | 'coding'
+  | 'research'
+  | 'summarization'
+  | 'conversation'
+  | 'analysis'
+  | 'creative';
+
+/** Estimated complexity of the task, used to bias toward cheaper or more capable models */
+export type Complexity = 'simple' | 'moderate' | 'complex';
+
+/** Primary knowledge domain of the task */
+export type Domain = 'frontend' | 'backend' | 'devops' | 'docs' | 'general';
+
+/**
+ * Cost tier for model selection.
+ * Extends the existing `CostTier` in `@mosaic/types` with `local` for self-hosted models.
+ */
+export type CostTier = 'cheap' | 'standard' | 'premium' | 'local';
+
+/** Special model capability required by the task */
+export type Capability = 'tools' | 'vision' | 'long-context' | 'reasoning' | 'embedding';
+
+// ─── Condition types ─────────────────────────────────────────────────────────
+
+/**
+ * A single predicate that must be satisfied for a routing rule to match.
+ *
+ * - `eq`       — scalar equality: `field === value`
+ * - `in`       — set membership: `value` contains `field`
+ * - `includes` — array containment: `field` (array) includes `value`
+ */
+export interface RoutingCondition {
+  /** The task-classification field to test */
+  field: 'taskType' | 'complexity' | 'domain' | 'costTier' | 'requiredCapabilities';
+  /** Comparison operator */
+  operator: 'eq' | 'in' | 'includes';
+  /** Expected value or set of values */
+  value: string | string[];
+}
+
+// ─── Action types ────────────────────────────────────────────────────────────
+
+/**
+ * The routing action to execute when all conditions in a rule are satisfied.
+ */
+export interface RoutingAction {
+  /** LLM provider identifier, e.g. `'anthropic'`, `'openai'`, `'ollama'` */
+  provider: string;
+  /** Model identifier, e.g. `'claude-opus-4-6'`, `'gpt-4o'` */
+  model: string;
+  /** Optional: use a specific pre-configured agent config from the agent registry */
+  agentConfigId?: string;
+  /** Optional: override the agent's default system prompt for this route */
+  systemPromptOverride?: string;
+  /** Optional: restrict the tool set available to the agent for this route */
+  toolAllowlist?: string[];
+}
+
+// ─── Rule and decision types ─────────────────────────────────────────────────
+
+/**
+ * Full routing rule as stored in the database and used at runtime.
+ */
+export interface RoutingRule {
+  /** UUID primary key */
+  id: string;
+  /** Human-readable rule name */
+  name: string;
+  /** Lower number = evaluated first; unique per scope */
+  priority: number;
+  /** `'system'` rules apply globally; `'user'` rules override for a specific user */
+  scope: 'system' | 'user';
+  /** Present only for `'user'`-scoped rules */
+  userId?: string;
+  /** All conditions must match for the rule to fire */
+  conditions: RoutingCondition[];
+  /** Action to take when all conditions are met */
+  action: RoutingAction;
+  /** Whether this rule is active */
+  enabled: boolean;
+}
+
+/**
+ * Structured representation of what an agent has been asked to do,
+ * produced by the task classifier and consumed by the routing engine.
+ */
+export interface TaskClassification {
+  taskType: TaskType;
+  complexity: Complexity;
+  domain: Domain;
+  requiredCapabilities: Capability[];
+}
+
+/**
+ * Output of the routing engine — which model to use and why.
+ */
+export interface RoutingDecision {
+  /** LLM provider identifier */
+  provider: string;
+  /** Model identifier */
+  model: string;
+  /** Optional agent config to apply */
+  agentConfigId?: string;
+  /** Name of the rule that matched, for observability */
+  ruleName: string;
+  /** Human-readable explanation of why this rule was selected */
+  reason: string;
+}