diff --git a/packages/opencode/src/cli/cmd/auth.ts b/packages/opencode/src/cli/cmd/auth.ts
index bbaecfd8c711..64a945781ee6 100644
--- a/packages/opencode/src/cli/cmd/auth.ts
+++ b/packages/opencode/src/cli/cmd/auth.ts
@@ -3,7 +3,7 @@ import { cmd } from "./cmd"
 import * as prompts from "@clack/prompts"
 import { UI } from "../ui"
 import { ModelsDev } from "../../provider/models"
-import { map, pipe, sortBy, values } from "remeda"
+import { filter, fromEntries, map, pipe, sortBy, values } from "remeda"
 import path from "path"
 import os from "os"
 import { Config } from "../../config/config"
@@ -14,6 +14,17 @@ import type { Hooks } from "@opencode-ai/plugin"
 
 type PluginAuth = NonNullable<Hooks["auth"]>
 
+export function authPlugin(plugins: Hooks[], provider: string | symbol): PluginAuth | undefined {
+  if (typeof provider !== "string") return
+  const auths = pipe(
+    plugins,
+    filter((x) => x.auth?.provider !== undefined),
+    map((x) => [x.auth!.provider, x.auth!] as const),
+    fromEntries(),
+  )
+  return auths[provider]
+}
+
 /**
  * Handle plugin-based authentication flow.
  * Returns true if auth was handled, false if it should fall through to default handling.
@@ -307,9 +318,9 @@ export const AuthLoginCommand = cmd({
 
         if (prompts.isCancel(provider)) throw new UI.CancelledError()
 
-        const plugin = await Plugin.list().then((x) => x.find((x) => x.auth?.provider === provider))
-        if (plugin && plugin.auth) {
-          const handled = await handlePluginAuth({ auth: plugin.auth }, provider)
+        const auth = await Plugin.list().then((x) => authPlugin(x, provider))
+        if (auth) {
+          const handled = await handlePluginAuth({ auth }, provider)
           if (handled) return
         }
 
@@ -323,9 +334,9 @@ export const AuthLoginCommand = cmd({
           if (prompts.isCancel(provider)) throw new UI.CancelledError()
 
           // Check if a plugin provides auth for this custom provider
-          const customPlugin = await Plugin.list().then((x) => x.find((x) => x.auth?.provider === provider))
-          if (customPlugin && customPlugin.auth) {
-            const handled = await handlePluginAuth({ auth: customPlugin.auth }, provider)
+          const custom = await Plugin.list().then((x) => authPlugin(x, provider))
+          if (custom) {
+            const handled = await handlePluginAuth({ auth: custom }, provider)
             if (handled) return
           }
 
diff --git a/packages/opencode/test/cli/auth-plugin-selection.test.ts b/packages/opencode/test/cli/auth-plugin-selection.test.ts
new file mode 100644
index 000000000000..e19f96a6b506
--- /dev/null
+++ b/packages/opencode/test/cli/auth-plugin-selection.test.ts
@@ -0,0 +1,37 @@
+import { test, expect } from "bun:test"
+import type { Hooks } from "@opencode-ai/plugin"
+
+const plugins = [
+  {
+    auth: {
+      provider: "openai",
+      methods: [{ type: "api", label: "First" }],
+    },
+  },
+  {
+    auth: {
+      provider: "openai",
+      methods: [{ type: "api", label: "Second" }],
+    },
+  },
+] satisfies Hooks[]
+
+test("authPlugin picks last auth provider", async () => {
+  const mod = await import("../../src/cli/cmd/auth")
+  const pick = (mod as Record<string, unknown>).authPlugin as
+    | ((items: Hooks[], provider: string) => Hooks["auth"] | undefined)
+    | undefined
+
+  const result = pick?.(plugins, "openai")
+  expect(result).toBe(plugins[1].auth)
+})
+
+test("authPlugin returns undefined when missing", async () => {
+  const mod = await import("../../src/cli/cmd/auth")
+  const pick = (mod as Record<string, unknown>).authPlugin as
+    | ((items: Hooks[], provider: string) => Hooks["auth"] | undefined)
+    | undefined
+
+  const result = pick?.(plugins, "anthropic")
+  expect(result).toBeUndefined()
+})