refactor(shared): deduplicate model resolution utility functions

Extract normalizeModel() (3 identical copies) and normalizeModelID()
(2 identical copies) into canonical src/shared/model-normalization.ts.
Delete dead-end duplicate model-name-matcher.ts. Update all consumers.

src/hooks/anthropic-effort/hook.ts

@@ -1,11 +1,7 @@
-import { log } from "../../shared"
+import { log, normalizeModelID } from "../../shared"
 
 const OPUS_4_6_PATTERN = /claude-opus-4[-.]6/i
 
-function normalizeModelID(modelID: string): string {
-  return modelID.replace(/\.(\d+)/g, "-$1")
-}
-
 function isClaudeProvider(providerID: string, modelID: string): boolean {
   if (["anthropic", "google-vertex-anthropic", "opencode"].includes(providerID)) return true
   if (providerID === "github-copilot" && modelID.toLowerCase().includes("claude")) return true

src/hooks/think-mode/switcher.ts

@@ -16,6 +16,8 @@
  * inconsistencies defensively while maintaining backwards compatibility.
  */
 
+import { normalizeModelID } from "../../shared"
+
 /**
  * Extracts provider-specific prefix from model ID (if present).
  * Custom providers may use prefixes for routing (e.g., vertex_ai/, openai/).
@@ -36,24 +38,6 @@ function extractModelPrefix(modelID: string): { prefix: string; base: string } {
   }
 }
 
-/**
- * Normalizes model IDs to use consistent hyphen formatting.
- * GitHub Copilot may use dots (claude-opus-4.6) but our maps use hyphens (claude-opus-4-6).
- * This ensures lookups work regardless of format.
- *
- * @example
- * normalizeModelID("claude-opus-4.6") // "claude-opus-4-6"
- * normalizeModelID("gemini-3.5-pro") // "gemini-3-5-pro"
- * normalizeModelID("gpt-5.2") // "gpt-5-2"
- * normalizeModelID("vertex_ai/claude-opus-4.6") // "vertex_ai/claude-opus-4-6"
- */
-function normalizeModelID(modelID: string): string {
-  // Replace dots with hyphens when followed by a digit
-  // This handles version numbers like 4.5 → 4-5, 5.2 → 5-2
-  return modelID.replace(/\.(\d+)/g, "-$1")
-}
-
-
 
 // Maps model IDs to their "high reasoning" variant (internal convention)
 // For OpenAI models, this signals that reasoning_effort should be set to "high"

src/shared/AGENTS.md

@@ -33,7 +33,7 @@ resolveModel(input)
   4. System default: Ultimate fallback
 ```
 
-Key files: `model-resolver.ts` (entry), `model-resolution-pipeline.ts` (orchestration), `model-requirements.ts` (fallback chains), `model-name-matcher.ts` (fuzzy matching).
+Key files: `model-resolver.ts` (entry), `model-resolution-pipeline.ts` (orchestration), `model-requirements.ts` (fallback chains), `model-availability.ts` (fuzzy matching).
 
 ## MIGRATION SYSTEM
 

src/shared/fallback-model-availability.ts

@@ -1,6 +1,6 @@
 import { readConnectedProvidersCache } from "./connected-providers-cache"
 import { log } from "./logger"
-import { fuzzyMatchModel } from "./model-name-matcher"
+import { fuzzyMatchModel } from "./model-availability"
 
 type FallbackEntry = { providers: string[]; model: string }
 

src/shared/index.ts

@@ -34,6 +34,7 @@ export * from "./system-directive"
 export * from "./agent-tool-restrictions"
 export * from "./model-requirements"
 export * from "./model-resolver"
+export { normalizeModel, normalizeModelID } from "./model-normalization"
 export { normalizeFallbackModels } from "./model-resolver"
 export { resolveModelPipeline } from "./model-resolution-pipeline"
 export type {

src/shared/model-name-matcher.ts

@@ -1,83 +0,0 @@
-import { log } from "./logger"
-
-function normalizeModelName(name: string): string {
-	return name
-		.toLowerCase()
-		.replace(/claude-(opus|sonnet|haiku)-(\d+)[.-](\d+)/g, "claude-$1-$2.$3")
-}
-
-export function fuzzyMatchModel(
-	target: string,
-	available: Set<string>,
-	providers?: string[],
-): string | null {
-	log("[fuzzyMatchModel] called", { target, availableCount: available.size, providers })
-
-	if (available.size === 0) {
-		log("[fuzzyMatchModel] empty available set")
-		return null
-	}
-
-	const targetNormalized = normalizeModelName(target)
-
-	let candidates = Array.from(available)
-	if (providers && providers.length > 0) {
-		const providerSet = new Set(providers)
-		candidates = candidates.filter((model) => {
-			const [provider] = model.split("/")
-			return providerSet.has(provider)
-		})
-		log("[fuzzyMatchModel] filtered by providers", {
-			candidateCount: candidates.length,
-			candidates: candidates.slice(0, 10),
-		})
-	}
-
-	if (candidates.length === 0) {
-		log("[fuzzyMatchModel] no candidates after filter")
-		return null
-	}
-
-	const matches = candidates.filter((model) =>
-		normalizeModelName(model).includes(targetNormalized),
-	)
-
-	log("[fuzzyMatchModel] substring matches", {
-		targetNormalized,
-		matchCount: matches.length,
-		matches,
-	})
-
-	if (matches.length === 0) {
-		return null
-	}
-
-	const exactMatch = matches.find(
-		(model) => normalizeModelName(model) === targetNormalized,
-	)
-	if (exactMatch) {
-		log("[fuzzyMatchModel] exact match found", { exactMatch })
-		return exactMatch
-	}
-
-	const exactModelIdMatches = matches.filter((model) => {
-		const modelId = model.split("/").slice(1).join("/")
-		return normalizeModelName(modelId) === targetNormalized
-	})
-	if (exactModelIdMatches.length > 0) {
-		const result = exactModelIdMatches.reduce((shortest, current) =>
-			current.length < shortest.length ? current : shortest,
-		)
-		log("[fuzzyMatchModel] exact model ID match found", {
-			result,
-			candidateCount: exactModelIdMatches.length,
-		})
-		return result
-	}
-
-	const result = matches.reduce((shortest, current) =>
-		current.length < shortest.length ? current : shortest,
-	)
-	log("[fuzzyMatchModel] shortest match", { result })
-	return result
-}

src/shared/model-normalization.test.ts

@@ -0,0 +1,123 @@
+import { describe, expect, test } from "bun:test"
+import { normalizeModel, normalizeModelID } from "./model-normalization"
+
+describe("normalizeModel", () => {
+	describe("#given undefined input", () => {
+		test("#when normalizeModel is called with undefined #then returns undefined", () => {
+			// given
+			const input = undefined
+
+			// when
+			const result = normalizeModel(input)
+
+			// then
+			expect(result).toBeUndefined()
+		})
+	})
+
+	describe("#given empty string", () => {
+		test("#when normalizeModel is called with empty string #then returns undefined", () => {
+			// given
+			const input = ""
+
+			// when
+			const result = normalizeModel(input)
+
+			// then
+			expect(result).toBeUndefined()
+		})
+	})
+
+	describe("#given whitespace-only string", () => {
+		test("#when normalizeModel is called with whitespace-only string #then returns undefined", () => {
+			// given
+			const input = "   "
+
+			// when
+			const result = normalizeModel(input)
+
+			// then
+			expect(result).toBeUndefined()
+		})
+	})
+
+	describe("#given valid model string", () => {
+		test("#when normalizeModel is called with valid model string #then returns same string", () => {
+			// given
+			const input = "claude-3-opus"
+
+			// when
+			const result = normalizeModel(input)
+
+			// then
+			expect(result).toBe("claude-3-opus")
+		})
+	})
+
+	describe("#given string with leading and trailing spaces", () => {
+		test("#when normalizeModel is called with spaces #then returns trimmed string", () => {
+			// given
+			const input = "  claude-3-opus  "
+
+			// when
+			const result = normalizeModel(input)
+
+			// then
+			expect(result).toBe("claude-3-opus")
+		})
+	})
+
+	describe("#given string with only spaces", () => {
+		test("#when normalizeModel is called with only spaces #then returns undefined", () => {
+			// given
+			const input = "     "
+
+			// when
+			const result = normalizeModel(input)
+
+			// then
+			expect(result).toBeUndefined()
+		})
+	})
+})
+
+describe("normalizeModelID", () => {
+	describe("#given model with dots in version numbers", () => {
+		test("#when normalizeModelID is called with claude-3.5-sonnet #then returns claude-3-5-sonnet", () => {
+			// given
+			const input = "claude-3.5-sonnet"
+
+			// when
+			const result = normalizeModelID(input)
+
+			// then
+			expect(result).toBe("claude-3-5-sonnet")
+		})
+	})
+
+	describe("#given model without dots", () => {
+		test("#when normalizeModelID is called with claude-opus #then returns unchanged", () => {
+			// given
+			const input = "claude-opus"
+
+			// when
+			const result = normalizeModelID(input)
+
+			// then
+			expect(result).toBe("claude-opus")
+		})
+	})
+
+	describe("#given model with multiple dot-numbers", () => {
+		test("#when normalizeModelID is called with model.1.2 #then returns model-1-2", () => {
+			// given
+			const input = "model.1.2"
+
+			// when
+			const result = normalizeModelID(input)
+
+			// then
+			expect(result).toBe("model-1-2")
+		})
+	})
+})

src/shared/model-normalization.ts

@@ -0,0 +1,8 @@
+export function normalizeModel(model?: string): string | undefined {
+	const trimmed = model?.trim()
+	return trimmed || undefined
+}
+
+export function normalizeModelID(modelID: string): string {
+	return modelID.replace(/\.(\d+)/g, "-$1")
+}

src/shared/model-resolution-pipeline.ts

@@ -3,6 +3,7 @@ import * as connectedProvidersCache from "./connected-providers-cache"
 import { fuzzyMatchModel } from "./model-availability"
 import type { FallbackEntry } from "./model-requirements"
 import { transformModelForProvider } from "./provider-model-id-transform"
+import { normalizeModel } from "./model-normalization"
 
 export type ModelResolutionRequest = {
   intent?: {
@@ -35,10 +36,6 @@ export type ModelResolutionResult = {
   reason?: string
 }
 
-function normalizeModel(model?: string): string | undefined {
-  const trimmed = model?.trim()
-  return trimmed || undefined
-}
 
 export function resolveModelPipeline(
   request: ModelResolutionRequest,

src/shared/model-resolver.ts

@@ -1,4 +1,5 @@
 import type { FallbackEntry } from "./model-requirements"
+import { normalizeModel } from "./model-normalization"
 import { resolveModelPipeline } from "./model-resolution-pipeline"
 
 export type ModelResolutionInput = {
@@ -29,10 +30,6 @@ export type ExtendedModelResolutionInput = {
 	systemDefaultModel?: string
 }
 
-function normalizeModel(model?: string): string | undefined {
-	const trimmed = model?.trim()
-	return trimmed || undefined
-}
 
 export function resolveModel(input: ModelResolutionInput): string | undefined {
 	return (

src/tools/delegate-task/model-selection.ts

@@ -1,11 +1,8 @@
 import type { FallbackEntry } from "../../shared/model-requirements"
+import { normalizeModel } from "../../shared/model-normalization"
 import { fuzzyMatchModel } from "../../shared/model-availability"
 import { transformModelForProvider } from "../../shared/provider-model-id-transform"
 
-function normalizeModel(model?: string): string | undefined {
-  const trimmed = model?.trim()
-  return trimmed || undefined
-}
 
 export function resolveModelForDelegateTask(input: {
   userModel?: string