3 files changed, 43 insertions, 1 deletions

diff --git a/packages/core/src/credentials/claude.ts b/packages/core/src/credentials/claude.ts
index 432e403..7818222 100644
--- a/packages/core/src/credentials/claude.ts
+++ b/packages/core/src/credentials/claude.ts
@@ -483,6 +483,23 @@ export const ANTHROPIC_MODELS_FALLBACK = [
 	"claude-3-opus-20240229",
 ];
 
+/**
+ * Pick the model to use for a Claude "wake" probe from a list of model ids.
+ *
+ * The probe only needs a small/cheap model to register activity against the
+ * subscription, so we target Haiku. Model ids change over time (the old
+ * hardcoded `claude-3-5-haiku-20241022` started returning HTTP 404), so the
+ * caller fetches the live list from `/v1/models` and we resolve by substring.
+ *
+ * Selection: the FIRST id whose name contains "haiku" (case-insensitive).
+ * Anthropic's `/v1/models` returns models newest-first, so first-match
+ * naturally prefers the newest Haiku. Returns `null` when nothing matches so
+ * the caller can surface a clear error instead of probing an invalid model.
+ */
+export function selectHaikuModel(models: string[]): string | null {
+	return models.find((id) => id.toLowerCase().includes("haiku")) ?? null;
+}
+
 // ─── Credential Validation ────────────────────────────────────
 
 export interface ClaudeProfile {
diff --git a/packages/core/src/credentials/index.ts b/packages/core/src/credentials/index.ts
index 46fa5b6..5221dc6 100644
--- a/packages/core/src/credentials/index.ts
+++ b/packages/core/src/credentials/index.ts
@@ -24,6 +24,7 @@ export {
 	refreshAccountCredentials,
 	refreshAccountCredentialsAsync,
 	SYSTEM_IDENTITY,
+	selectHaikuModel,
 	validateAccountCredentials,
 } from "./claude.js";
 export {
diff --git a/packages/core/tests/credentials/wake-probe.test.ts b/packages/core/tests/credentials/wake-probe.test.ts
index 253efec..a97a00c 100644
--- a/packages/core/tests/credentials/wake-probe.test.ts
+++ b/packages/core/tests/credentials/wake-probe.test.ts
@@ -9,7 +9,7 @@ vi.mock("../../src/db/index.js", () => ({
 	}),
 }));
 
-const { buildWakeProbeBody } = await import("../../src/credentials/claude.js");
+const { buildWakeProbeBody, selectHaikuModel } = await import("../../src/credentials/claude.js");
 
 const IDENTITY = "You are Claude Code, Anthropic's official CLI for Claude.";
 
@@ -47,3 +47,27 @@ describe("buildWakeProbeBody", () => {
 		expect(a).toEqual(b);
 	});
 });
+describe("selectHaikuModel", () => {
+	it("returns the id whose name contains 'haiku'", () => {
+		const models = ["claude-sonnet-4-20250514", "claude-haiku-4-5-20251001"];
+		expect(selectHaikuModel(models)).toBe("claude-haiku-4-5-20251001");
+	});
+
+	it("matches case-insensitively", () => {
+		expect(selectHaikuModel(["Claude-HAIKU-Latest"])).toBe("Claude-HAIKU-Latest");
+	});
+
+	it("returns the FIRST match when several models contain 'haiku'", () => {
+		// `/v1/models` returns newest-first, so first-match prefers the newest.
+		const models = ["claude-haiku-4-5-20251001", "claude-3-5-haiku-20241022"];
+		expect(selectHaikuModel(models)).toBe("claude-haiku-4-5-20251001");
+	});
+
+	it("returns null when no model contains 'haiku'", () => {
+		expect(selectHaikuModel(["claude-sonnet-4-20250514", "claude-opus-4-20250514"])).toBeNull();
+	});
+
+	it("returns null for an empty list", () => {
+		expect(selectHaikuModel([])).toBeNull();
+	});
+});