diff --git a/packages/first-class-providers/src/providers.test.ts b/packages/first-class-providers/src/providers.test.ts
index 02192da94..5b6415ef4 100644
--- a/packages/first-class-providers/src/providers.test.ts
+++ b/packages/first-class-providers/src/providers.test.ts
@@ -1,7 +1,6 @@
 import { describe, expect, test } from "bun:test";
 import {
   FIRST_CLASS_PROVIDERS,
-  connectListProviders,
   firstClassPathAsProvider,
   firstClassProviderById,
 } from "./providers.js";
@@ -21,10 +20,6 @@ describe("FIRST_CLASS_PROVIDERS", () => {
     ]);
   });
 
-  test("connectListProviders matches FIRST_CLASS_PROVIDERS", () => {
-    expect(connectListProviders()).toBe(FIRST_CLASS_PROVIDERS);
-  });
-
   test("has no separate Codex connect row", () => {
     expect(FIRST_CLASS_PROVIDERS.some((p) => p.id === "codex")).toBe(false);
     expect(FIRST_CLASS_PROVIDERS.map((p) => p.label)).not.toContain(
diff --git a/packages/first-class-providers/src/providers.ts b/packages/first-class-providers/src/providers.ts
index 3242d8c2b..d93c1b067 100644
--- a/packages/first-class-providers/src/providers.ts
+++ b/packages/first-class-providers/src/providers.ts
@@ -164,11 +164,6 @@ export const FIRST_CLASS_PROVIDERS: readonly FirstClassProviderDef[] = [
   },
 ] as const;
 
-/** Connect-list rows (same as FIRST_CLASS_PROVIDERS; explicit export for hosts). */
-export function connectListProviders(): readonly FirstClassProviderDef[] {
-  return FIRST_CLASS_PROVIDERS;
-}
-
 export function firstClassProviderById(
   id: string,
 ): FirstClassProviderDef | undefined {
diff --git a/packages/opencode-go/src/catalog.ts b/packages/opencode-go/src/catalog.ts
index c8b4e7449..d5f4b4b16 100644
--- a/packages/opencode-go/src/catalog.ts
+++ b/packages/opencode-go/src/catalog.ts
@@ -7,7 +7,7 @@ import {
 import {
   OPENCODE_GO_DEFAULT_MODEL,
   OPENCODE_GO_MODEL_IDS,
-  OPENCODE_GO_MODELS,
+  PROTOCOL_BY_ID,
   type GoProtocol,
 } from "./models.js";
 
@@ -23,10 +23,8 @@ interface GoCatalogEntry {
 }
 
 export function buildGoCatalogEntry(): GoCatalogEntry {
-  const protocols: Record<string, GoProtocol> = {};
-  for (const m of OPENCODE_GO_MODELS) {
-    protocols[m.id] = m.protocol;
-  }
+  const protocols: Record<string, GoProtocol> =
+    Object.fromEntries(PROTOCOL_BY_ID);
   return {
     name: OPENCODE_GO_PROVIDER_ID,
     displayName: OPENCODE_GO_DISPLAY_NAME,
diff --git a/packages/opencode-go/src/identity.ts b/packages/opencode-go/src/identity.ts
index 21329b25d..be1509303 100644
--- a/packages/opencode-go/src/identity.ts
+++ b/packages/opencode-go/src/identity.ts
@@ -3,6 +3,12 @@ import {
   OPENCODE_GO_PROVIDER_ID,
 } from "./constants.js";
 
+/** True when `host` is opencode.ai or a subdomain of it (case-insensitive). */
+export function hostMatchesOpencodeDotAi(host: string): boolean {
+  const normalized = host.trim().toLowerCase();
+  return normalized === "opencode.ai" || normalized.endsWith(".opencode.ai");
+}
+
 /**
  * True when the URL or base is the public OpenCode Go gateway.
  *
@@ -21,10 +27,7 @@ export function isOpenCodeGoURL(urlOrBase: string | undefined): boolean {
   if (trimmed.length === 0) return false;
   try {
     const url = new URL(trimmed);
-    if (
-      url.hostname !== "opencode.ai" &&
-      !url.hostname.endsWith(".opencode.ai")
-    ) {
+    if (!hostMatchesOpencodeDotAi(url.hostname)) {
       return false;
     }
     // Strip trailing slashes, then compare path segments case-insensitively.
diff --git a/packages/opencode-go/src/index.ts b/packages/opencode-go/src/index.ts
index 615e2e7b4..c76d0d226 100644
--- a/packages/opencode-go/src/index.ts
+++ b/packages/opencode-go/src/index.ts
@@ -19,5 +19,6 @@ export {
   isOpenCodeGoProvider,
   isOpenCodeGoProviderId,
   isOpenCodeGoURL,
+  hostMatchesOpencodeDotAi,
 } from "./identity.js";
 export { parseGoAPIError } from "./errors.js";
diff --git a/packages/opencode-go/src/models.ts b/packages/opencode-go/src/models.ts
index 4da311297..4d49c6b29 100644
--- a/packages/opencode-go/src/models.ts
+++ b/packages/opencode-go/src/models.ts
@@ -63,9 +63,10 @@ export const OPENCODE_GO_MODEL_IDS: readonly string[] = OPENCODE_GO_MODELS.map(
 
 export const OPENCODE_GO_DEFAULT_MODEL: GoModelId = "kimi-k2.7-code";
 
-const PROTOCOL_BY_ID = new Map<string, GoProtocol>(
-  OPENCODE_GO_MODELS.map((m) => [m.id, m.protocol]),
-);
+export const PROTOCOL_BY_ID: ReadonlyMap<string, GoProtocol> = new Map<
+  string,
+  GoProtocol
+>(OPENCODE_GO_MODELS.map((m) => [m.id, m.protocol]));
 
 export function protocolForGoModel(modelId: string): GoProtocol | undefined {
   return PROTOCOL_BY_ID.get(modelId);
diff --git a/packages/opencode-go/src/usage.ts b/packages/opencode-go/src/usage.ts
index c9548697f..898502c63 100644
--- a/packages/opencode-go/src/usage.ts
+++ b/packages/opencode-go/src/usage.ts
@@ -99,6 +99,20 @@ export async function fetchGoUsage(
   }
 }
 
+function formatWindowUsage(w: GoUsageWindow): string {
+  if (w.usagePercent !== undefined) return `${Math.round(w.usagePercent)}%`;
+  if (w.usageDollars !== undefined && w.limitDollars !== undefined) {
+    return `$${w.usageDollars.toFixed(2)}/$${w.limitDollars.toFixed(0)}`;
+  }
+  return "ok";
+}
+
+function usageWindowLabel(usage: GoUsage): string {
+  if (usage.rolling5h !== undefined) return "5h";
+  if (usage.weekly !== undefined) return "week";
+  return "month";
+}
+
 export function formatGoUsage(usage: GoUsage): string {
   if (usage.status !== "ok") {
     if (usage.status === "unavailable") return "Go usage unavailable";
@@ -109,17 +123,5 @@ export function formatGoUsage(usage: GoUsage): string {
   }
   const w = usage.rolling5h ?? usage.weekly ?? usage.monthly;
   if (w === undefined) return "Go usage ok";
-  const pct =
-    w.usagePercent !== undefined
-      ? `${Math.round(w.usagePercent)}%`
-      : w.usageDollars !== undefined && w.limitDollars !== undefined
-        ? `$${w.usageDollars.toFixed(2)}/$${w.limitDollars.toFixed(0)}`
-        : "ok";
-  const window =
-    usage.rolling5h !== undefined
-      ? "5h"
-      : usage.weekly !== undefined
-        ? "week"
-        : "month";
-  return `Go ${window} ${pct}`;
+  return `Go ${usageWindowLabel(usage)} ${formatWindowUsage(w)}`;
 }
diff --git a/packages/zen/src/identity.ts b/packages/zen/src/identity.ts
index 83d22ba77..301264261 100644
--- a/packages/zen/src/identity.ts
+++ b/packages/zen/src/identity.ts
@@ -3,11 +3,7 @@
 // helpers; Go's own URL and id keep matching Go first, never Zen.
 
 import { ZEN_DISPLAY_NAME, ZEN_PROVIDER_ID } from "./constants.js";
-
-function hostMatchesOpencodeDotAi(host: string): boolean {
-  const normalized = host.trim().toLowerCase();
-  return normalized === "opencode.ai" || normalized.endsWith(".opencode.ai");
-}
+import { hostMatchesOpencodeDotAi } from "../../opencode-go/src/index.js";
 
 /**
  * Match a bare Zen base URL: an opencode.ai URL whose first path segment is
diff --git a/src/provider/billing-product.ts b/src/provider/billing-product.ts
index e2d89c912..998142d38 100644
--- a/src/provider/billing-product.ts
+++ b/src/provider/billing-product.ts
@@ -1,4 +1,5 @@
 import {
+  hostMatchesOpencodeDotAi,
   isKnownGoModel,
   isOpenCodeGoProvider,
 } from "../../packages/opencode-go/src/index.js";
@@ -25,10 +26,7 @@ export function isBareZenBaseURL(baseURL: string): boolean {
   if (BARE_ZEN_BASES.has(trimmed)) return true;
   try {
     const url = new URL(trimmed);
-    if (
-      url.hostname !== "opencode.ai" &&
-      !url.hostname.endsWith(".opencode.ai")
-    ) {
+    if (!hostMatchesOpencodeDotAi(url.hostname)) {
       return false;
     }
     const path = url.pathname.replace(/\/+$/, "");