Merge remote-tracking branch 'origin/dev' into refactor/modular-code-enforcement

# Conflicts:
#	src/features/background-agent/manager.ts
#	src/features/background-agent/spawner.ts
#	src/features/tmux-subagent/manager.ts
#	src/shared/model-availability.test.ts
#	src/shared/model-availability.ts
#	src/shared/model-resolution-pipeline.ts
#	src/tools/delegate-task/executor.ts

src/shared/git-worktree/collect-git-diff-stats.test.ts

@@ -0,0 +1,66 @@
+/// <reference types="bun-types" />
+
+import { describe, expect, mock, test } from "bun:test"
+
+const execSyncMock = mock(() => {
+  throw new Error("execSync should not be called")
+})
+
+const execFileSyncMock = mock((file: string, args: string[], _opts: { cwd?: string }) => {
+  if (file !== "git") throw new Error(`unexpected file: ${file}`)
+  const subcommand = args[0]
+
+  if (subcommand === "diff") {
+    return "1\t2\tfile.ts\n"
+  }
+
+  if (subcommand === "status") {
+    return " M file.ts\n"
+  }
+
+  throw new Error(`unexpected args: ${args.join(" ")}`)
+})
+
+mock.module("node:child_process", () => ({
+  execSync: execSyncMock,
+  execFileSync: execFileSyncMock,
+}))
+
+const { collectGitDiffStats } = await import("./collect-git-diff-stats")
+
+describe("collectGitDiffStats", () => {
+  test("uses execFileSync with arg arrays (no shell injection)", () => {
+    //#given
+    const directory = "/tmp/safe-repo;touch /tmp/pwn"
+
+    //#when
+    const result = collectGitDiffStats(directory)
+
+    //#then
+    expect(execSyncMock).not.toHaveBeenCalled()
+    expect(execFileSyncMock).toHaveBeenCalledTimes(2)
+
+    const [firstCallFile, firstCallArgs, firstCallOpts] = execFileSyncMock.mock
+      .calls[0]! as unknown as [string, string[], { cwd?: string }]
+    expect(firstCallFile).toBe("git")
+    expect(firstCallArgs).toEqual(["diff", "--numstat", "HEAD"])
+    expect(firstCallOpts.cwd).toBe(directory)
+    expect(firstCallArgs.join(" ")).not.toContain(directory)
+
+    const [secondCallFile, secondCallArgs, secondCallOpts] = execFileSyncMock.mock
+      .calls[1]! as unknown as [string, string[], { cwd?: string }]
+    expect(secondCallFile).toBe("git")
+    expect(secondCallArgs).toEqual(["status", "--porcelain"])
+    expect(secondCallOpts.cwd).toBe(directory)
+    expect(secondCallArgs.join(" ")).not.toContain(directory)
+
+    expect(result).toEqual([
+      {
+        path: "file.ts",
+        added: 1,
+        removed: 2,
+        status: "modified",
+      },
+    ])
+  })
+})

src/shared/migration/config-migration.ts

@@ -8,30 +8,32 @@ export function migrateConfigFile(
   configPath: string,
   rawConfig: Record<string, unknown>
 ): boolean {
+  // Work on a deep copy — only apply changes to rawConfig if file write succeeds
+  const copy = structuredClone(rawConfig)
   let needsWrite = false
 
   // Load previously applied migrations
-  const existingMigrations = Array.isArray(rawConfig._migrations)
-    ? new Set(rawConfig._migrations as string[])
+  const existingMigrations = Array.isArray(copy._migrations)
+    ? new Set(copy._migrations as string[])
     : new Set<string>()
   const allNewMigrations: string[] = []
 
-  if (rawConfig.agents && typeof rawConfig.agents === "object") {
-    const { migrated, changed } = migrateAgentNames(rawConfig.agents as Record<string, unknown>)
+  if (copy.agents && typeof copy.agents === "object") {
+    const { migrated, changed } = migrateAgentNames(copy.agents as Record<string, unknown>)
     if (changed) {
-      rawConfig.agents = migrated
+      copy.agents = migrated
       needsWrite = true
     }
   }
 
   // Migrate model versions in agents (skip already-applied migrations)
-  if (rawConfig.agents && typeof rawConfig.agents === "object") {
+  if (copy.agents && typeof copy.agents === "object") {
     const { migrated, changed, newMigrations } = migrateModelVersions(
-      rawConfig.agents as Record<string, unknown>,
+      copy.agents as Record<string, unknown>,
       existingMigrations
     )
     if (changed) {
-      rawConfig.agents = migrated
+      copy.agents = migrated
       needsWrite = true
       log("Migrated model versions in agents config")
     }
@@ -39,13 +41,13 @@ export function migrateConfigFile(
   }
 
   // Migrate model versions in categories (skip already-applied migrations)
-  if (rawConfig.categories && typeof rawConfig.categories === "object") {
+  if (copy.categories && typeof copy.categories === "object") {
     const { migrated, changed, newMigrations } = migrateModelVersions(
-      rawConfig.categories as Record<string, unknown>,
+      copy.categories as Record<string, unknown>,
       existingMigrations
     )
     if (changed) {
-      rawConfig.categories = migrated
+      copy.categories = migrated
       needsWrite = true
       log("Migrated model versions in categories config")
     }
@@ -56,20 +58,20 @@ export function migrateConfigFile(
   if (allNewMigrations.length > 0) {
     const updatedMigrations = Array.from(existingMigrations)
     updatedMigrations.push(...allNewMigrations)
-    rawConfig._migrations = updatedMigrations
+    copy._migrations = updatedMigrations
     needsWrite = true
   }
 
-  if (rawConfig.omo_agent) {
-    rawConfig.sisyphus_agent = rawConfig.omo_agent
-    delete rawConfig.omo_agent
+  if (copy.omo_agent) {
+    copy.sisyphus_agent = copy.omo_agent
+    delete copy.omo_agent
     needsWrite = true
   }
 
-  if (rawConfig.disabled_agents && Array.isArray(rawConfig.disabled_agents)) {
+  if (copy.disabled_agents && Array.isArray(copy.disabled_agents)) {
     const migrated: string[] = []
     let changed = false
-    for (const agent of rawConfig.disabled_agents as string[]) {
+    for (const agent of copy.disabled_agents as string[]) {
       const newAgent = AGENT_NAME_MAP[agent.toLowerCase()] ?? AGENT_NAME_MAP[agent] ?? agent
       if (newAgent !== agent) {
         changed = true
@@ -77,15 +79,15 @@ export function migrateConfigFile(
       migrated.push(newAgent)
     }
     if (changed) {
-      rawConfig.disabled_agents = migrated
+      copy.disabled_agents = migrated
       needsWrite = true
     }
   }
 
-  if (rawConfig.disabled_hooks && Array.isArray(rawConfig.disabled_hooks)) {
-    const { migrated, changed, removed } = migrateHookNames(rawConfig.disabled_hooks as string[])
+  if (copy.disabled_hooks && Array.isArray(copy.disabled_hooks)) {
+    const { migrated, changed, removed } = migrateHookNames(copy.disabled_hooks as string[])
     if (changed) {
-      rawConfig.disabled_hooks = migrated
+      copy.disabled_hooks = migrated
       needsWrite = true
     }
     if (removed.length > 0) {
@@ -99,13 +101,25 @@ export function migrateConfigFile(
     try {
       const timestamp = new Date().toISOString().replace(/[:.]/g, "-")
       const backupPath = `${configPath}.bak.${timestamp}`
-      fs.copyFileSync(configPath, backupPath)
+      try {
+        fs.copyFileSync(configPath, backupPath)
+      } catch {
+        // Original file may not exist yet — skip backup
+      }
 
-      fs.writeFileSync(configPath, JSON.stringify(rawConfig, null, 2) + "\n", "utf-8")
+      fs.writeFileSync(configPath, JSON.stringify(copy, null, 2) + "\n", "utf-8")
       log(`Migrated config file: ${configPath} (backup: ${backupPath})`)
     } catch (err) {
       log(`Failed to write migrated config to ${configPath}:`, err)
+      // File write failed — rawConfig is untouched, preserving user's original values
+      return false
     }
+
+    // File write succeeded — apply changes to the original rawConfig
+    for (const key of Object.keys(rawConfig)) {
+      delete rawConfig[key]
+    }
+    Object.assign(rawConfig, copy)
   }
 
   return needsWrite

src/shared/model-availability.test.ts

@@ -5,198 +5,174 @@ import { tmpdir } from "os"
 import { join } from "path"
 
 let __resetModelCache: () => void
-let fetchAvailableModels: (
-	client?: unknown,
-	options?: { connectedProviders?: string[] | null },
-) => Promise<Set<string>>
+let fetchAvailableModels: (client?: unknown, options?: { connectedProviders?: string[] | null }) => Promise<Set<string>>
 let fuzzyMatchModel: (target: string, available: Set<string>, providers?: string[]) => string | null
 let isModelAvailable: (targetModel: string, availableModels: Set<string>) => boolean
 let getConnectedProviders: (client: unknown) => Promise<string[]>
 
 beforeAll(async () => {
-	;({
-		__resetModelCache,
-		fetchAvailableModels,
-		fuzzyMatchModel,
-		isModelAvailable,
-		getConnectedProviders,
-	} = await import("./model-availability"))
+  ;({
+    __resetModelCache,
+    fetchAvailableModels,
+    fuzzyMatchModel,
+    isModelAvailable,
+    getConnectedProviders,
+  } = await import("./model-availability"))
 })
 
 describe("fetchAvailableModels", () => {
-	let tempDir: string
+  let tempDir: string
 	let originalXdgCache: string | undefined
 
-	beforeEach(() => {
-		__resetModelCache()
-		tempDir = mkdtempSync(join(tmpdir(), "opencode-test-"))
+
+  beforeEach(() => {
+    __resetModelCache()
+    tempDir = mkdtempSync(join(tmpdir(), "opencode-test-"))
 		originalXdgCache = process.env.XDG_CACHE_HOME
 		process.env.XDG_CACHE_HOME = tempDir
-	})
+  })
 
-	afterEach(() => {
-		if (originalXdgCache !== undefined) {
+  afterEach(() => {
+    if (originalXdgCache !== undefined) {
 			process.env.XDG_CACHE_HOME = originalXdgCache
 		} else {
 			delete process.env.XDG_CACHE_HOME
 		}
-		rmSync(tempDir, { recursive: true, force: true })
-	})
+    rmSync(tempDir, { recursive: true, force: true })
+  })
 
-	function writeModelsCache(data: Record<string, any>) {
-		const cacheDir = join(tempDir, "opencode")
-		require("fs").mkdirSync(cacheDir, { recursive: true })
-		writeFileSync(join(cacheDir, "models.json"), JSON.stringify(data))
-	}
+  function writeModelsCache(data: Record<string, any>) {
+    const cacheDir = join(tempDir, "opencode")
+    require("fs").mkdirSync(cacheDir, { recursive: true })
+    writeFileSync(join(cacheDir, "models.json"), JSON.stringify(data))
+  }
 
-	it("#given cache file with models #when fetchAvailableModels called with connectedProviders #then returns Set of model IDs", async () => {
-		writeModelsCache({
-			openai: { id: "openai", models: { "gpt-5.2": { id: "gpt-5.2" } } },
-			anthropic: {
-				id: "anthropic",
-				models: { "claude-opus-4-6": { id: "claude-opus-4-6" } },
-			},
-			google: { id: "google", models: { "gemini-3-pro": { id: "gemini-3-pro" } } },
-		})
+  it("#given cache file with models #when fetchAvailableModels called with connectedProviders #then returns Set of model IDs", async () => {
+    writeModelsCache({
+      openai: { id: "openai", models: { "gpt-5.2": { id: "gpt-5.2" } } },
+      anthropic: { id: "anthropic", models: { "claude-opus-4-6": { id: "claude-opus-4-6" } } },
+      google: { id: "google", models: { "gemini-3-pro": { id: "gemini-3-pro" } } },
+    })
 
-		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai", "anthropic", "google"],
-		})
+    const result = await fetchAvailableModels(undefined, {
+      connectedProviders: ["openai", "anthropic", "google"]
+    })
 
-		expect(result).toBeInstanceOf(Set)
-		expect(result.size).toBe(3)
-		expect(result.has("openai/gpt-5.2")).toBe(true)
-		expect(result.has("anthropic/claude-opus-4-6")).toBe(true)
-		expect(result.has("google/gemini-3-pro")).toBe(true)
-	})
+    expect(result).toBeInstanceOf(Set)
+    expect(result.size).toBe(3)
+    expect(result.has("openai/gpt-5.2")).toBe(true)
+    expect(result.has("anthropic/claude-opus-4-6")).toBe(true)
+    expect(result.has("google/gemini-3-pro")).toBe(true)
+  })
 
-	it("#given connectedProviders unknown #when fetchAvailableModels called without options #then returns empty Set", async () => {
-		writeModelsCache({
-			openai: { id: "openai", models: { "gpt-5.2": { id: "gpt-5.2" } } },
-		})
+  it("#given connectedProviders unknown #when fetchAvailableModels called without options #then returns empty Set", async () => {
+    writeModelsCache({
+      openai: { id: "openai", models: { "gpt-5.2": { id: "gpt-5.2" } } },
+    })
 
-		const result = await fetchAvailableModels()
+    const result = await fetchAvailableModels()
 
-		expect(result).toBeInstanceOf(Set)
-		expect(result.size).toBe(0)
-	})
+    expect(result).toBeInstanceOf(Set)
+    expect(result.size).toBe(0)
+  })
 
-	it("#given connectedProviders unknown but client can list #when fetchAvailableModels called with client #then returns models from API filtered by connected providers", async () => {
-		const client = {
-			provider: {
-				list: async () => ({ data: { connected: ["openai"] } }),
-			},
-			model: {
-				list: async () => ({
-					data: [
-						{ id: "gpt-5.3-codex", provider: "openai" },
-						{ id: "gemini-3-pro", provider: "google" },
-					],
-				}),
-			},
-		}
+  it("#given connectedProviders unknown but client can list #when fetchAvailableModels called with client #then returns models from API filtered by connected providers", async () => {
+    const client = {
+      provider: {
+        list: async () => ({ data: { connected: ["openai"] } }),
+      },
+      model: {
+        list: async () => ({
+          data: [
+            { id: "gpt-5.3-codex", provider: "openai" },
+            { id: "gemini-3-pro", provider: "google" },
+          ],
+        }),
+      },
+    }
 
-		const result = await fetchAvailableModels(client)
+    const result = await fetchAvailableModels(client)
 
-		expect(result).toBeInstanceOf(Set)
-		expect(result.has("openai/gpt-5.3-codex")).toBe(true)
-		expect(result.has("google/gemini-3-pro")).toBe(false)
-	})
+    expect(result).toBeInstanceOf(Set)
+    expect(result.has("openai/gpt-5.3-codex")).toBe(true)
+    expect(result.has("google/gemini-3-pro")).toBe(false)
+  })
 
-	it("#given cache file not found #when fetchAvailableModels called with connectedProviders #then returns empty Set", async () => {
-		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai"],
-		})
+  it("#given cache file not found #when fetchAvailableModels called with connectedProviders #then returns empty Set", async () => {
+    const result = await fetchAvailableModels(undefined, { connectedProviders: ["openai"] })
 
-		expect(result).toBeInstanceOf(Set)
-		expect(result.size).toBe(0)
-	})
+    expect(result).toBeInstanceOf(Set)
+    expect(result.size).toBe(0)
+  })
 
-	it("#given cache missing but client can list #when fetchAvailableModels called with connectedProviders #then returns models from API", async () => {
-		const client = {
-			provider: {
-				list: async () => ({ data: { connected: ["openai", "google"] } }),
-			},
-			model: {
-				list: async () => ({
-					data: [
-						{ id: "gpt-5.3-codex", provider: "openai" },
-						{ id: "gemini-3-pro", provider: "google" },
-					],
-				}),
-			},
-		}
+  it("#given cache missing but client can list #when fetchAvailableModels called with connectedProviders #then returns models from API", async () => {
+    const client = {
+      provider: {
+        list: async () => ({ data: { connected: ["openai", "google"] } }),
+      },
+      model: {
+        list: async () => ({
+          data: [
+            { id: "gpt-5.3-codex", provider: "openai" },
+            { id: "gemini-3-pro", provider: "google" },
+          ],
+        }),
+      },
+    }
 
-		const result = await fetchAvailableModels(client, {
-			connectedProviders: ["openai", "google"],
-		})
+    const result = await fetchAvailableModels(client, { connectedProviders: ["openai", "google"] })
 
-		expect(result).toBeInstanceOf(Set)
-		expect(result.has("openai/gpt-5.3-codex")).toBe(true)
-		expect(result.has("google/gemini-3-pro")).toBe(true)
-	})
+    expect(result).toBeInstanceOf(Set)
+    expect(result.has("openai/gpt-5.3-codex")).toBe(true)
+    expect(result.has("google/gemini-3-pro")).toBe(true)
+  })
 
-	it("#given cache read twice #when second call made with same providers #then reads fresh each time", async () => {
-		writeModelsCache({
-			openai: { id: "openai", models: { "gpt-5.2": { id: "gpt-5.2" } } },
-			anthropic: {
-				id: "anthropic",
-				models: { "claude-opus-4-6": { id: "claude-opus-4-6" } },
-			},
-		})
+  it("#given cache read twice #when second call made with same providers #then reads fresh each time", async () => {
+    writeModelsCache({
+      openai: { id: "openai", models: { "gpt-5.2": { id: "gpt-5.2" } } },
+      anthropic: { id: "anthropic", models: { "claude-opus-4-6": { id: "claude-opus-4-6" } } },
+    })
 
-		const result1 = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai"],
-		})
-		const result2 = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai"],
-		})
+    const result1 = await fetchAvailableModels(undefined, { connectedProviders: ["openai"] })
+    const result2 = await fetchAvailableModels(undefined, { connectedProviders: ["openai"] })
 
-		expect(result1.size).toBe(result2.size)
-		expect(result1.has("openai/gpt-5.2")).toBe(true)
-	})
+    expect(result1.size).toBe(result2.size)
+    expect(result1.has("openai/gpt-5.2")).toBe(true)
+  })
 
-	it("#given empty providers in cache #when fetchAvailableModels called with connectedProviders #then returns empty Set", async () => {
-		writeModelsCache({})
+  it("#given empty providers in cache #when fetchAvailableModels called with connectedProviders #then returns empty Set", async () => {
+    writeModelsCache({})
 
-		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai"],
-		})
+    const result = await fetchAvailableModels(undefined, { connectedProviders: ["openai"] })
 
-		expect(result).toBeInstanceOf(Set)
-		expect(result.size).toBe(0)
-	})
+    expect(result).toBeInstanceOf(Set)
+    expect(result.size).toBe(0)
+  })
 
-	it("#given cache file with various providers #when fetchAvailableModels called with all providers #then extracts all IDs correctly", async () => {
-		writeModelsCache({
-			openai: {
-				id: "openai",
-				models: { "gpt-5.3-codex": { id: "gpt-5.3-codex" } },
-			},
-			anthropic: {
-				id: "anthropic",
-				models: { "claude-sonnet-4-5": { id: "claude-sonnet-4-5" } },
-			},
-			google: {
-				id: "google",
-				models: { "gemini-3-flash": { id: "gemini-3-flash" } },
-			},
-			opencode: { id: "opencode", models: { "gpt-5-nano": { id: "gpt-5-nano" } } },
-		})
+  it("#given cache file with various providers #when fetchAvailableModels called with all providers #then extracts all IDs correctly", async () => {
+    writeModelsCache({
+      openai: { id: "openai", models: { "gpt-5.3-codex": { id: "gpt-5.3-codex" } } },
+      anthropic: { id: "anthropic", models: { "claude-sonnet-4-5": { id: "claude-sonnet-4-5" } } },
+      google: { id: "google", models: { "gemini-3-flash": { id: "gemini-3-flash" } } },
+      opencode: { id: "opencode", models: { "gpt-5-nano": { id: "gpt-5-nano" } } },
+    })
 
-		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai", "anthropic", "google", "opencode"],
-		})
+    const result = await fetchAvailableModels(undefined, {
+      connectedProviders: ["openai", "anthropic", "google", "opencode"]
+    })
 
-		expect(result.size).toBe(4)
-		expect(result.has("openai/gpt-5.3-codex")).toBe(true)
-		expect(result.has("anthropic/claude-sonnet-4-5")).toBe(true)
-		expect(result.has("google/gemini-3-flash")).toBe(true)
-		expect(result.has("opencode/gpt-5-nano")).toBe(true)
-	})
+    expect(result.size).toBe(4)
+    expect(result.has("openai/gpt-5.3-codex")).toBe(true)
+    expect(result.has("anthropic/claude-sonnet-4-5")).toBe(true)
+    expect(result.has("google/gemini-3-flash")).toBe(true)
+    expect(result.has("opencode/gpt-5-nano")).toBe(true)
+  })
 })
 
 describe("fuzzyMatchModel", () => {
+	// given available models from multiple providers
+	// when searching for a substring match
+	// then return the matching model
 	it("should match substring in model name", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -207,6 +183,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given available model with preview suffix
+	// when searching with provider-prefixed base model
+	// then return preview model
 	it("should match preview suffix for gemini-3-flash", () => {
 		const available = new Set(["google/gemini-3-flash-preview"])
 		const result = fuzzyMatchModel(
@@ -217,6 +196,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("google/gemini-3-flash-preview")
 	})
 
+	// given available models with partial matches
+	// when searching for a substring
+	// then return exact match if it exists
 	it("should prefer exact match over substring match", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -227,6 +209,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given available models with multiple substring matches
+	// when searching for a substring
+	// then return the shorter model name (more specific)
 	it("should prefer shorter model name when multiple matches exist", () => {
 		const available = new Set([
 			"openai/gpt-5.2-ultra",
@@ -236,6 +221,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("openai/gpt-5.2-ultra")
 	})
 
+	// given available models with claude variants
+	// when searching for claude-opus
+	// then return matching claude-opus model
 	it("should match claude-opus to claude-opus-4-6", () => {
 		const available = new Set([
 			"anthropic/claude-opus-4-6",
@@ -245,6 +233,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("anthropic/claude-opus-4-6")
 	})
 
+	// given available models from multiple providers
+	// when providers filter is specified
+	// then only search models from specified providers
 	it("should filter by provider when providers array is given", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -255,6 +246,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given available models from multiple providers
+	// when providers filter excludes matching models
+	// then return null
 	it("should return null when provider filter excludes all matches", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -264,6 +258,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBeNull()
 	})
 
+	// given available models
+	// when no substring match exists
+	// then return null
 	it("should return null when no match found", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -273,6 +270,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBeNull()
 	})
 
+	// given available models with different cases
+	// when searching with different case
+	// then match case-insensitively
 	it("should match case-insensitively", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -282,6 +282,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given available models with exact match and longer variants
+	// when searching for exact match
+	// then return exact match first
 	it("should prioritize exact match over longer variants", () => {
 		const available = new Set([
 			"anthropic/claude-opus-4-6",
@@ -291,6 +294,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("anthropic/claude-opus-4-6")
 	})
 
+	// given available models with similar model IDs (e.g., glm-4.7 and glm-4.7-free)
+	// when searching for the longer variant (glm-4.7-free)
+	// then return exact model ID match, not the shorter one
 	it("should prefer exact model ID match over shorter substring match", () => {
 		const available = new Set([
 			"zai-coding-plan/glm-4.7",
@@ -300,6 +306,9 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("zai-coding-plan/glm-4.7-free")
 	})
 
+	// given available models with similar model IDs
+	// when searching for the shorter variant
+	// then return the shorter match (existing behavior preserved)
 	it("should still prefer shorter match when searching for shorter variant", () => {
 		const available = new Set([
 			"zai-coding-plan/glm-4.7",
@@ -309,12 +318,21 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("zai-coding-plan/glm-4.7")
 	})
 
+	// given same model ID from multiple providers
+	// when searching for exact model ID
+	// then return shortest full string (preserves tie-break behavior)
 	it("should use shortest tie-break when multiple providers have same model ID", () => {
-		const available = new Set(["opencode/gpt-5.2", "openai/gpt-5.2"])
+		const available = new Set([
+			"opencode/gpt-5.2",
+			"openai/gpt-5.2",
+		])
 		const result = fuzzyMatchModel("gpt-5.2", available)
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given available models with multiple providers
+	// when multiple providers are specified
+	// then search all specified providers
 	it("should search all specified providers", () => {
 		const available = new Set([
 			"openai/gpt-5.2",
@@ -325,12 +343,21 @@ describe("fuzzyMatchModel", () => {
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given available models with provider prefix
+	// when searching with provider filter
+	// then only match models with correct provider prefix
 	it("should only match models with correct provider prefix", () => {
-		const available = new Set(["openai/gpt-5.2", "anthropic/gpt-something"])
+		const available = new Set([
+			"openai/gpt-5.2",
+			"anthropic/gpt-something",
+		])
 		const result = fuzzyMatchModel("gpt", available, ["openai"])
 		expect(result).toBe("openai/gpt-5.2")
 	})
 
+	// given empty available set
+	// when searching
+	// then return null
 	it("should return null for empty available set", () => {
 		const available = new Set<string>()
 		const result = fuzzyMatchModel("gpt", available)
@@ -339,13 +366,16 @@ describe("fuzzyMatchModel", () => {
 })
 
 describe("getConnectedProviders", () => {
+	// given SDK client with connected providers
+	// when provider.list returns data
+	// then returns connected array
 	it("should return connected providers from SDK", async () => {
 		const mockClient = {
 			provider: {
 				list: async () => ({
-					data: { connected: ["anthropic", "opencode", "google"] },
-				}),
-			},
+					data: { connected: ["anthropic", "opencode", "google"] }
+				})
+			}
 		}
 
 		const result = await getConnectedProviders(mockClient)
@@ -353,13 +383,14 @@ describe("getConnectedProviders", () => {
 		expect(result).toEqual(["anthropic", "opencode", "google"])
 	})
 
+	// given SDK client
+	// when provider.list throws error
+	// then returns empty array
 	it("should return empty array on SDK error", async () => {
 		const mockClient = {
 			provider: {
-				list: async () => {
-					throw new Error("Network error")
-				},
-			},
+				list: async () => { throw new Error("Network error") }
+			}
 		}
 
 		const result = await getConnectedProviders(mockClient)
@@ -367,11 +398,14 @@ describe("getConnectedProviders", () => {
 		expect(result).toEqual([])
 	})
 
+	// given SDK client with empty connected array
+	// when provider.list returns empty
+	// then returns empty array
 	it("should return empty array when no providers connected", async () => {
 		const mockClient = {
 			provider: {
-				list: async () => ({ data: { connected: [] } }),
-			},
+				list: async () => ({ data: { connected: [] } })
+			}
 		}
 
 		const result = await getConnectedProviders(mockClient)
@@ -379,6 +413,9 @@ describe("getConnectedProviders", () => {
 		expect(result).toEqual([])
 	})
 
+	// given SDK client without provider.list method
+	// when getConnectedProviders called
+	// then returns empty array
 	it("should return empty array when client.provider.list not available", async () => {
 		const mockClient = {}
 
@@ -387,17 +424,23 @@ describe("getConnectedProviders", () => {
 		expect(result).toEqual([])
 	})
 
+	// given null client
+	// when getConnectedProviders called
+	// then returns empty array
 	it("should return empty array for null client", async () => {
 		const result = await getConnectedProviders(null)
 
 		expect(result).toEqual([])
 	})
 
+	// given SDK client with missing data.connected
+	// when provider.list returns without connected field
+	// then returns empty array
 	it("should return empty array when data.connected is undefined", async () => {
 		const mockClient = {
 			provider: {
-				list: async () => ({ data: {} }),
-			},
+				list: async () => ({ data: {} })
+			}
 		}
 
 		const result = await getConnectedProviders(mockClient)
@@ -432,6 +475,9 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		writeFileSync(join(cacheDir, "models.json"), JSON.stringify(data))
 	}
 
+	// given cache with multiple providers
+	// when connectedProviders specifies one provider
+	// then only returns models from that provider
 	it("should filter models by connected providers", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
@@ -440,7 +486,7 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["anthropic"],
+			connectedProviders: ["anthropic"]
 		})
 
 		expect(result.size).toBe(1)
@@ -449,6 +495,9 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		expect(result.has("google/gemini-3-pro")).toBe(false)
 	})
 
+	// given cache with multiple providers
+	// when connectedProviders specifies multiple providers
+	// then returns models from all specified providers
 	it("should filter models by multiple connected providers", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
@@ -457,7 +506,7 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["anthropic", "google"],
+			connectedProviders: ["anthropic", "google"]
 		})
 
 		expect(result.size).toBe(2)
@@ -466,6 +515,9 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		expect(result.has("openai/gpt-5.2")).toBe(false)
 	})
 
+	// given cache with models
+	// when connectedProviders is empty array
+	// then returns empty set
 	it("should return empty set when connectedProviders is empty", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
@@ -473,12 +525,15 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: [],
+			connectedProviders: []
 		})
 
 		expect(result.size).toBe(0)
 	})
 
+	// given cache with models
+	// when connectedProviders is undefined (no options)
+	// then returns empty set (triggers fallback in resolver)
 	it("should return empty set when connectedProviders not specified", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
@@ -490,18 +545,24 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		expect(result.size).toBe(0)
 	})
 
+	// given cache with models
+	// when connectedProviders contains provider not in cache
+	// then returns empty set for that provider
 	it("should handle provider not in cache gracefully", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["azure"],
+			connectedProviders: ["azure"]
 		})
 
 		expect(result.size).toBe(0)
 	})
 
+	// given cache with models and mixed connected providers
+	// when some providers exist in cache and some don't
+	// then returns models only from matching providers
 	it("should return models from providers that exist in both cache and connected list", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
@@ -509,31 +570,39 @@ describe("fetchAvailableModels with connected providers filtering", () => {
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["anthropic", "azure", "unknown"],
+			connectedProviders: ["anthropic", "azure", "unknown"]
 		})
 
 		expect(result.size).toBe(1)
 		expect(result.has("anthropic/claude-opus-4-6")).toBe(true)
 	})
 
+	// given filtered fetch
+	// when called twice with different filters
+	// then does NOT use cache (dynamic per-session)
 	it("should not cache filtered results", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
 			anthropic: { models: { "claude-opus-4-6": { id: "claude-opus-4-6" } } },
 		})
 
+		// First call with anthropic
 		const result1 = await fetchAvailableModels(undefined, {
-			connectedProviders: ["anthropic"],
+			connectedProviders: ["anthropic"]
 		})
 		expect(result1.size).toBe(1)
 
+		// Second call with openai - should work, not cached
 		const result2 = await fetchAvailableModels(undefined, {
-			connectedProviders: ["openai"],
+			connectedProviders: ["openai"]
 		})
 		expect(result2.size).toBe(1)
 		expect(result2.has("openai/gpt-5.2")).toBe(true)
 	})
 
+	// given connectedProviders unknown
+	// when called twice without connectedProviders
+	// then always returns empty set (triggers fallback)
 	it("should return empty set when connectedProviders unknown", async () => {
 		writeModelsCache({
 			openai: { models: { "gpt-5.2": { id: "gpt-5.2" } } },
@@ -567,19 +636,13 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 		rmSync(tempDir, { recursive: true, force: true })
 	})
 
-	function writeProviderModelsCache(data: {
-		models: Record<string, string[] | any[]>
-		connected: string[]
-	}) {
+	function writeProviderModelsCache(data: { models: Record<string, string[] | any[]>; connected: string[] }) {
 		const cacheDir = join(tempDir, "oh-my-opencode")
 		require("fs").mkdirSync(cacheDir, { recursive: true })
-		writeFileSync(
-			join(cacheDir, "provider-models.json"),
-			JSON.stringify({
-				...data,
-				updatedAt: new Date().toISOString(),
-			}),
-		)
+		writeFileSync(join(cacheDir, "provider-models.json"), JSON.stringify({
+			...data,
+			updatedAt: new Date().toISOString()
+		}))
 	}
 
 	function writeModelsCache(data: Record<string, any>) {
@@ -588,21 +651,24 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 		writeFileSync(join(cacheDir, "models.json"), JSON.stringify(data))
 	}
 
+	// given provider-models cache exists (whitelist-filtered)
+	// when fetchAvailableModels called
+	// then uses provider-models cache instead of models.json
 	it("should prefer provider-models cache over models.json", async () => {
 		writeProviderModelsCache({
 			models: {
 				opencode: ["glm-4.7-free", "gpt-5-nano"],
-				anthropic: ["claude-opus-4-6"],
+				anthropic: ["claude-opus-4-6"]
 			},
-			connected: ["opencode", "anthropic"],
+			connected: ["opencode", "anthropic"]
 		})
 		writeModelsCache({
 			opencode: { models: { "glm-4.7-free": {}, "gpt-5-nano": {}, "gpt-5.2": {} } },
-			anthropic: { models: { "claude-opus-4-6": {}, "claude-sonnet-4-5": {} } },
+			anthropic: { models: { "claude-opus-4-6": {}, "claude-sonnet-4-5": {} } }
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["opencode", "anthropic"],
+			connectedProviders: ["opencode", "anthropic"]
 		})
 
 		expect(result.size).toBe(3)
@@ -613,9 +679,13 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 		expect(result.has("anthropic/claude-sonnet-4-5")).toBe(false)
 	})
 
+	// given provider-models cache exists but has no models (API failure)
+	// when fetchAvailableModels called
+	// then falls back to models.json so fuzzy matching can still work
 	it("should fall back to models.json when provider-models cache is empty", async () => {
 		writeProviderModelsCache({
-			models: {},
+			models: {
+			},
 			connected: ["google"],
 		})
 		writeModelsCache({
@@ -625,22 +695,21 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 		const availableModels = await fetchAvailableModels(undefined, {
 			connectedProviders: ["google"],
 		})
-		const match = fuzzyMatchModel(
-			"google/gemini-3-flash",
-			availableModels,
-			["google"],
-		)
+		const match = fuzzyMatchModel("google/gemini-3-flash", availableModels, ["google"])
 
 		expect(match).toBe("google/gemini-3-flash-preview")
 	})
 
+	// given only models.json exists (no provider-models cache)
+	// when fetchAvailableModels called
+	// then falls back to models.json (no whitelist filtering)
 	it("should fallback to models.json when provider-models cache not found", async () => {
 		writeModelsCache({
 			opencode: { models: { "glm-4.7-free": {}, "gpt-5-nano": {}, "gpt-5.2": {} } },
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["opencode"],
+			connectedProviders: ["opencode"]
 		})
 
 		expect(result.size).toBe(3)
@@ -649,18 +718,21 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 		expect(result.has("opencode/gpt-5.2")).toBe(true)
 	})
 
+	// given provider-models cache with whitelist
+	// when connectedProviders filters to subset
+	// then only returns models from connected providers
 	it("should filter by connectedProviders even with provider-models cache", async () => {
 		writeProviderModelsCache({
 			models: {
 				opencode: ["glm-4.7-free"],
 				anthropic: ["claude-opus-4-6"],
-				google: ["gemini-3-pro"],
+				google: ["gemini-3-pro"]
 			},
-			connected: ["opencode", "anthropic", "google"],
+			connected: ["opencode", "anthropic", "google"]
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["opencode"],
+			connectedProviders: ["opencode"]
 		})
 
 		expect(result.size).toBe(1)
@@ -673,25 +745,15 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 		writeProviderModelsCache({
 			models: {
 				ollama: [
-					{
-						id: "ministral-3:14b-32k-agent",
-						provider: "ollama",
-						context: 32768,
-						output: 8192,
-					},
-					{
-						id: "qwen3-coder:32k-agent",
-						provider: "ollama",
-						context: 32768,
-						output: 8192,
-					},
-				],
+					{ id: "ministral-3:14b-32k-agent", provider: "ollama", context: 32768, output: 8192 },
+					{ id: "qwen3-coder:32k-agent", provider: "ollama", context: 32768, output: 8192 }
+				]
 			},
-			connected: ["ollama"],
+			connected: ["ollama"]
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["ollama"],
+			connectedProviders: ["ollama"]
 		})
 
 		expect(result.size).toBe(2)
@@ -705,14 +767,14 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 				anthropic: ["claude-opus-4-6", "claude-sonnet-4-5"],
 				ollama: [
 					{ id: "ministral-3:14b-32k-agent", provider: "ollama" },
-					{ id: "qwen3-coder:32k-agent", provider: "ollama" },
-				],
+					{ id: "qwen3-coder:32k-agent", provider: "ollama" }
+				]
 			},
-			connected: ["anthropic", "ollama"],
+			connected: ["anthropic", "ollama"]
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["anthropic", "ollama"],
+			connectedProviders: ["anthropic", "ollama"]
 		})
 
 		expect(result.size).toBe(4)
@@ -730,14 +792,14 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 					{ provider: "ollama" },
 					{ id: "", provider: "ollama" },
 					null,
-					"string-model",
-				],
+					"string-model"
+				]
 			},
-			connected: ["ollama"],
+			connected: ["ollama"]
 		})
 
 		const result = await fetchAvailableModels(undefined, {
-			connectedProviders: ["ollama"],
+			connectedProviders: ["ollama"]
 		})
 
 		expect(result.size).toBe(2)
@@ -749,10 +811,7 @@ describe("fetchAvailableModels with provider-models cache (whitelist-filtered)",
 describe("isModelAvailable", () => {
 	it("returns true when model exists via fuzzy match", () => {
 		// given
-		const available = new Set([
-			"openai/gpt-5.3-codex",
-			"anthropic/claude-opus-4-6",
-		])
+		const available = new Set(["openai/gpt-5.3-codex", "anthropic/claude-opus-4-6"])
 
 		// when
 		const result = isModelAvailable("gpt-5.3-codex", available)

src/shared/model-availability.ts

@@ -1,4 +1,358 @@
-export { fetchAvailableModels, getConnectedProviders } from "./available-models-fetcher"
-export { isAnyFallbackModelAvailable, isAnyProviderConnected } from "./fallback-model-availability"
-export { __resetModelCache, isModelCacheAvailable } from "./model-cache-availability"
-export { fuzzyMatchModel, isModelAvailable } from "./model-name-matcher"
+import { existsSync, readFileSync } from "fs"
+import { join } from "path"
+import { log } from "./logger"
+import { getOpenCodeCacheDir } from "./data-path"
+import * as connectedProvidersCache from "./connected-providers-cache"
+
+/**
+ * Fuzzy match a target model name against available models
+ * 
+ * @param target - The model name or substring to search for (e.g., "gpt-5.2", "claude-opus")
+ * @param available - Set of available model names in format "provider/model-name"
+ * @param providers - Optional array of provider names to filter by (e.g., ["openai", "anthropic"])
+ * @returns The matched model name or null if no match found
+ * 
+ * Matching priority:
+ * 1. Exact match (if exists)
+ * 2. Shorter model name (more specific)
+ * 
+ * Matching is case-insensitive substring match.
+ * If providers array is given, only models starting with "provider/" are considered.
+ * 
+ * @example
+ * const available = new Set(["openai/gpt-5.2", "openai/gpt-5.3-codex", "anthropic/claude-opus-4-6"])
+ * fuzzyMatchModel("gpt-5.2", available) // → "openai/gpt-5.2"
+ * fuzzyMatchModel("claude", available, ["openai"]) // → null (provider filter excludes anthropic)
+ */
+function normalizeModelName(name: string): string {
+	return name
+		.toLowerCase()
+		.replace(/claude-(opus|sonnet|haiku)-4-5/g, "claude-$1-4.5")
+		.replace(/claude-(opus|sonnet|haiku)-4\.5/g, "claude-$1-4.5")
+}
+
+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)
+
+	// Filter by providers if specified
+	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
+	}
+
+	// Find all matches (case-insensitive substring match with normalization)
+	const matches = candidates.filter((model) =>
+		normalizeModelName(model).includes(targetNormalized),
+	)
+
+	log("[fuzzyMatchModel] substring matches", { targetNormalized, matchCount: matches.length, matches })
+
+	if (matches.length === 0) {
+		return null
+	}
+
+	// Priority 1: Exact match (normalized full model string)
+	const exactMatch = matches.find((model) => normalizeModelName(model) === targetNormalized)
+	if (exactMatch) {
+		log("[fuzzyMatchModel] exact match found", { exactMatch })
+		return exactMatch
+	}
+
+	// Priority 2: Exact model ID match (part after provider/)
+	// This ensures "glm-4.7-free" matches "zai-coding-plan/glm-4.7-free" over "zai-coding-plan/glm-4.7"
+	// Use filter + shortest to handle multi-provider cases (e.g., openai/gpt-5.2 + opencode/gpt-5.2)
+	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
+	}
+
+	// Priority 3: Shorter model name (more specific, fallback for partial matches)
+	const result = matches.reduce((shortest, current) =>
+		current.length < shortest.length ? current : shortest,
+	)
+	log("[fuzzyMatchModel] shortest match", { result })
+	return result
+}
+
+/**
+ * Check if a target model is available (fuzzy match by model name, no provider filtering)
+ * 
+ * @param targetModel - Model name to check (e.g., "gpt-5.3-codex")
+ * @param availableModels - Set of available models in "provider/model" format
+ * @returns true if model is available, false otherwise
+ */
+export function isModelAvailable(
+	targetModel: string,
+	availableModels: Set<string>,
+): boolean {
+	return fuzzyMatchModel(targetModel, availableModels) !== null
+}
+
+export async function getConnectedProviders(client: any): Promise<string[]> {
+	if (!client?.provider?.list) {
+		log("[getConnectedProviders] client.provider.list not available")
+		return []
+	}
+
+	try {
+		const result = await client.provider.list()
+		const connected = result.data?.connected ?? []
+		log("[getConnectedProviders] connected providers", { count: connected.length, providers: connected })
+		return connected
+	} catch (err) {
+		log("[getConnectedProviders] SDK error", { error: String(err) })
+		return []
+	}
+}
+
+export async function fetchAvailableModels(
+	client?: any,
+	options?: { connectedProviders?: string[] | null }
+): Promise<Set<string>> {
+	let connectedProviders = options?.connectedProviders ?? null
+	let connectedProvidersUnknown = connectedProviders === null
+
+	log("[fetchAvailableModels] CALLED", { 
+		connectedProvidersUnknown,
+		connectedProviders: options?.connectedProviders 
+	})
+
+	if (connectedProvidersUnknown && client) {
+		const liveConnected = await getConnectedProviders(client)
+		if (liveConnected.length > 0) {
+			connectedProviders = liveConnected
+			connectedProvidersUnknown = false
+			log("[fetchAvailableModels] connected providers fetched from client", { count: liveConnected.length })
+		}
+	}
+
+	if (connectedProvidersUnknown) {
+		if (client?.model?.list) {
+			const modelSet = new Set<string>()
+			try {
+				const modelsResult = await client.model.list()
+				const models = modelsResult.data ?? []
+				for (const model of models) {
+					if (model?.provider && model?.id) {
+						modelSet.add(`${model.provider}/${model.id}`)
+					}
+				}
+				log("[fetchAvailableModels] fetched models from client without provider filter", {
+					count: modelSet.size,
+				})
+				return modelSet
+			} catch (err) {
+				log("[fetchAvailableModels] client.model.list error", { error: String(err) })
+			}
+		}
+		log("[fetchAvailableModels] connected providers unknown, returning empty set for fallback resolution")
+		return new Set<string>()
+	}
+
+	const connectedProvidersList = connectedProviders ?? []
+	const connectedSet = new Set(connectedProvidersList)
+	const modelSet = new Set<string>()
+
+	const providerModelsCache = connectedProvidersCache.readProviderModelsCache()
+	if (providerModelsCache) {
+		const providerCount = Object.keys(providerModelsCache.models).length
+		if (providerCount === 0) {
+			log("[fetchAvailableModels] provider-models cache empty, falling back to models.json")
+		} else {
+		log("[fetchAvailableModels] using provider-models cache (whitelist-filtered)")
+		
+		const modelsByProvider = providerModelsCache.models as Record<string, Array<string | { id?: string }>>
+		for (const [providerId, modelIds] of Object.entries(modelsByProvider)) {
+			if (!connectedSet.has(providerId)) {
+				continue
+			}
+			for (const modelItem of modelIds) {
+				// Handle both string[] (legacy) and object[] (with metadata) formats
+				const modelId = typeof modelItem === 'string' 
+					? modelItem 
+					: (modelItem as any)?.id
+				
+				if (modelId) {
+					modelSet.add(`${providerId}/${modelId}`)
+				}
+			}
+		}
+
+			log("[fetchAvailableModels] parsed from provider-models cache", {
+				count: modelSet.size,
+				connectedProviders: connectedProvidersList.slice(0, 5)
+			})
+
+			if (modelSet.size > 0) {
+				return modelSet
+			}
+			log("[fetchAvailableModels] provider-models cache produced no models for connected providers, falling back to models.json")
+		}
+	}
+
+	log("[fetchAvailableModels] provider-models cache not found, falling back to models.json")
+	const cacheFile = join(getOpenCodeCacheDir(), "models.json")
+
+	if (!existsSync(cacheFile)) {
+		log("[fetchAvailableModels] models.json cache file not found, falling back to client")
+	} else {
+		try {
+			const content = readFileSync(cacheFile, "utf-8")
+			const data = JSON.parse(content) as Record<string, { id?: string; models?: Record<string, { id?: string }> }>
+
+			const providerIds = Object.keys(data)
+			log("[fetchAvailableModels] providers found in models.json", { count: providerIds.length, providers: providerIds.slice(0, 10) })
+
+			for (const providerId of providerIds) {
+				if (!connectedSet.has(providerId)) {
+					continue
+				}
+
+				const provider = data[providerId]
+				const models = provider?.models
+				if (!models || typeof models !== "object") continue
+
+				for (const modelKey of Object.keys(models)) {
+					modelSet.add(`${providerId}/${modelKey}`)
+				}
+			}
+
+			log("[fetchAvailableModels] parsed models from models.json (NO whitelist filtering)", {
+				count: modelSet.size,
+				connectedProviders: connectedProvidersList.slice(0, 5)
+			})
+
+			if (modelSet.size > 0) {
+				return modelSet
+			}
+		} catch (err) {
+			log("[fetchAvailableModels] error", { error: String(err) })
+		}
+	}
+
+	if (client?.model?.list) {
+		try {
+			const modelsResult = await client.model.list()
+			const models = modelsResult.data ?? []
+
+			for (const model of models) {
+				if (!model?.provider || !model?.id) continue
+				if (connectedSet.has(model.provider)) {
+					modelSet.add(`${model.provider}/${model.id}`)
+				}
+			}
+
+			log("[fetchAvailableModels] fetched models from client (filtered)", {
+				count: modelSet.size,
+				connectedProviders: connectedProvidersList.slice(0, 5),
+			})
+		} catch (err) {
+			log("[fetchAvailableModels] client.model.list error", { error: String(err) })
+		}
+	}
+
+	return modelSet
+}
+
+export function isAnyFallbackModelAvailable(
+	fallbackChain: Array<{ providers: string[]; model: string }>,
+	availableModels: Set<string>,
+): boolean {
+	// If we have models, check them first
+	if (availableModels.size > 0) {
+		for (const entry of fallbackChain) {
+			const hasAvailableProvider = entry.providers.some((provider) => {
+				return fuzzyMatchModel(entry.model, availableModels, [provider]) !== null
+			})
+			if (hasAvailableProvider) {
+				return true
+			}
+		}
+	}
+
+	// Fallback: check if any provider in the chain is connected
+	// This handles race conditions where availableModels is empty or incomplete
+	// but we know the provider is connected.
+	const connectedProviders = connectedProvidersCache.readConnectedProvidersCache()
+	if (connectedProviders) {
+		const connectedSet = new Set(connectedProviders)
+		for (const entry of fallbackChain) {
+			if (entry.providers.some((p) => connectedSet.has(p))) {
+				log("[isAnyFallbackModelAvailable] model not in available set, but provider is connected", {
+					model: entry.model,
+					availableCount: availableModels.size,
+				})
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+export function isAnyProviderConnected(
+	providers: string[],
+	availableModels: Set<string>,
+): boolean {
+	if (availableModels.size > 0) {
+		const providerSet = new Set(providers)
+		for (const model of availableModels) {
+			const [provider] = model.split("/")
+			if (providerSet.has(provider)) {
+				log("[isAnyProviderConnected] found model from required provider", { provider, model })
+				return true
+			}
+		}
+	}
+
+	const connectedProviders = connectedProvidersCache.readConnectedProvidersCache()
+	if (connectedProviders) {
+		const connectedSet = new Set(connectedProviders)
+		for (const provider of providers) {
+			if (connectedSet.has(provider)) {
+				log("[isAnyProviderConnected] provider connected via cache", { provider })
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+export function __resetModelCache(): void {}
+
+export function isModelCacheAvailable(): boolean {
+	if (connectedProvidersCache.hasProviderModelsCache()) {
+		return true
+	}
+	const cacheFile = join(getOpenCodeCacheDir(), "models.json")
+	return existsSync(cacheFile)
+}

src/shared/model-resolution-pipeline.ts

@@ -1,16 +1,37 @@
 import { log } from "./logger"
-import { readConnectedProvidersCache } from "./connected-providers-cache"
+import * as connectedProvidersCache from "./connected-providers-cache"
 import { fuzzyMatchModel } from "./model-availability"
-import type {
-  ModelResolutionRequest,
-  ModelResolutionResult,
-} from "./model-resolution-types"
+import type { FallbackEntry } from "./model-requirements"
 
-export type {
-  ModelResolutionProvenance,
-  ModelResolutionRequest,
-  ModelResolutionResult,
-} from "./model-resolution-types"
+export type ModelResolutionRequest = {
+  intent?: {
+    uiSelectedModel?: string
+    userModel?: string
+    categoryDefaultModel?: string
+  }
+  constraints: {
+    availableModels: Set<string>
+    connectedProviders?: string[] | null
+  }
+  policy?: {
+    fallbackChain?: FallbackEntry[]
+    systemDefaultModel?: string
+  }
+}
+
+export type ModelResolutionProvenance =
+  | "override"
+  | "category-default"
+  | "provider-fallback"
+  | "system-default"
+
+export type ModelResolutionResult = {
+  model: string
+  provenance: ModelResolutionProvenance
+  variant?: string
+  attempted?: string[]
+  reason?: string
+}
 
 function normalizeModel(model?: string): string | undefined {
   const trimmed = model?.trim()
@@ -53,7 +74,7 @@ export function resolveModelPipeline(
         return { model: match, provenance: "category-default", attempted }
       }
     } else {
-      const connectedProviders = readConnectedProvidersCache()
+      const connectedProviders = constraints.connectedProviders ?? connectedProvidersCache.readConnectedProvidersCache()
       if (connectedProviders === null) {
         log("Model resolved via category default (no cache, first run)", {
           model: normalizedCategoryDefault,
@@ -78,7 +99,7 @@ export function resolveModelPipeline(
 
   if (fallbackChain && fallbackChain.length > 0) {
     if (availableModels.size === 0) {
-      const connectedProviders = readConnectedProvidersCache()
+      const connectedProviders = constraints.connectedProviders ?? connectedProvidersCache.readConnectedProvidersCache()
       const connectedSet = connectedProviders ? new Set(connectedProviders) : null
 
       if (connectedSet === null) {