fix(agents): use runtime names for default_agent to match ordered agent list

src/plugin-handlers/agent-config-handler.ts

@@ -2,7 +2,7 @@ import { createBuiltinAgents } from "../agents";
 import { createSisyphusJuniorAgentWithOverrides } from "../agents/sisyphus-junior";
 import type { OhMyOpenCodeConfig } from "../config";
 import { isTaskSystemEnabled, log, migrateAgentConfig } from "../shared";
-import { getAgentDisplayName } from "../shared/agent-display-names";
+import { getAgentRuntimeName } from "../shared/agent-display-names";
 import { AGENT_NAME_MAP } from "../shared/migration";
 import { registerAgentName } from "../features/claude-code-session-state";
 import {
@@ -159,10 +159,10 @@ export async function applyAgentConfig(params: {
   if (isSisyphusEnabled && builtinAgents.sisyphus) {
     if (configuredDefaultAgent) {
       (params.config as { default_agent?: string }).default_agent =
-        getAgentDisplayName(configuredDefaultAgent);
+        getAgentRuntimeName(configuredDefaultAgent);
     } else {
       (params.config as { default_agent?: string }).default_agent =
-        getAgentDisplayName("sisyphus");
+        getAgentRuntimeName("sisyphus");
     }
 
     // Assembly order: Sisyphus -> Hephaestus -> Prometheus -> Atlas

src/plugin-handlers/agent-key-remapper.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect } from "bun:test"
 import { remapAgentKeysToDisplayNames } from "./agent-key-remapper"
-import { getAgentDisplayName } from "../shared/agent-display-names"
+import { getAgentDisplayName, getAgentRuntimeName } from "../shared/agent-display-names"
 
 describe("remapAgentKeysToDisplayNames", () => {
   it("remaps known agent keys to display names", () => {
@@ -105,4 +105,47 @@ describe("remapAgentKeysToDisplayNames", () => {
       expect(name).not.toContain("\u200B")
     }
   })
+
+  it("preserves clean keys but rewrites core agent name fields to list-display names for tab cycling", () => {
+    // given agents with raw config-key names
+    const agents = {
+      sisyphus: { name: "sisyphus", prompt: "test", mode: "primary" },
+      hephaestus: { name: "hephaestus", prompt: "test", mode: "primary" },
+      prometheus: { name: "prometheus", prompt: "test", mode: "all" },
+      atlas: { name: "atlas", prompt: "test", mode: "primary" },
+      oracle: { name: "oracle", prompt: "test", mode: "subagent" },
+    }
+
+    // when remapping
+    const result = remapAgentKeysToDisplayNames(agents)
+
+    // then keys stay HTTP-header-safe, but nested names carry stable list ordering
+    expect(Object.keys(result).slice(0, 4)).toEqual([
+      getAgentDisplayName("sisyphus"),
+      getAgentDisplayName("hephaestus"),
+      getAgentDisplayName("prometheus"),
+      getAgentDisplayName("atlas"),
+    ])
+    expect(result[getAgentDisplayName("sisyphus")]).toEqual({
+      name: getAgentRuntimeName("sisyphus"),
+      prompt: "test",
+      mode: "primary",
+    })
+    expect(result[getAgentDisplayName("hephaestus")]).toEqual({
+      name: getAgentRuntimeName("hephaestus"),
+      prompt: "test",
+      mode: "primary",
+    })
+    expect(result[getAgentDisplayName("prometheus")]).toEqual({
+      name: getAgentRuntimeName("prometheus"),
+      prompt: "test",
+      mode: "all",
+    })
+    expect(result[getAgentDisplayName("atlas")]).toEqual({
+      name: getAgentRuntimeName("atlas"),
+      prompt: "test",
+      mode: "primary",
+    })
+    expect(result.oracle).toEqual({ name: "oracle", prompt: "test", mode: "subagent" })
+  })
 })

src/plugin-handlers/agent-key-remapper.ts

@@ -1,4 +1,23 @@
-import { getAgentDisplayName } from "../shared/agent-display-names"
+import { getAgentDisplayName, getAgentRuntimeName } from "../shared/agent-display-names"
+
+function rewriteAgentNameForListDisplay(
+  key: string,
+  value: unknown,
+): unknown {
+  if (typeof value !== "object" || value === null || !("name" in value)) {
+    return value
+  }
+
+  const agent = value as Record<string, unknown>
+  if (typeof agent.name !== "string") {
+    return value
+  }
+
+  return {
+    ...agent,
+    name: getAgentRuntimeName(key),
+  }
+}
 
 export function remapAgentKeysToDisplayNames(
   agents: Record<string, unknown>,
@@ -8,7 +27,7 @@ export function remapAgentKeysToDisplayNames(
   for (const [key, value] of Object.entries(agents)) {
     const displayName = getAgentDisplayName(key)
     if (displayName && displayName !== key) {
-      result[displayName] = value
+      result[displayName] = rewriteAgentNameForListDisplay(key, value)
       // Regression guard: do not also assign result[key].
       // This line was repeatedly re-added and caused duplicate agent rows in the UI.
       // Runtime callers that previously depended on config-key aliases were fixed in:

src/plugin-handlers/config-handler.test.ts

@@ -3,7 +3,7 @@
 import { describe, test, expect, spyOn, beforeEach, afterEach, mock } from "bun:test"
 import type { CategoryConfig } from "../config/schema"
 import type { OhMyOpenCodeConfig } from "../config"
-import { getAgentDisplayName } from "../shared/agent-display-names"
+import { getAgentDisplayName, getAgentRuntimeName } from "../shared/agent-display-names"
 import { resolveCategoryConfig } from "./category-config-resolver"
 
 import * as agents from "../agents"
@@ -479,7 +479,7 @@ describe("default_agent behavior with Sisyphus orchestration", () => {
     await handler(config)
 
     // then
-    expect(config.default_agent).toBe(getAgentDisplayName("hephaestus"))
+    expect(config.default_agent).toBe(getAgentRuntimeName("hephaestus"))
   })
 
   test("canonicalizes configured default_agent when key uses mixed case", async () => {
@@ -503,7 +503,7 @@ describe("default_agent behavior with Sisyphus orchestration", () => {
     await handler(config)
 
     // then
-    expect(config.default_agent).toBe(getAgentDisplayName("hephaestus"))
+    expect(config.default_agent).toBe(getAgentRuntimeName("hephaestus"))
   })
 
   test("canonicalizes configured default_agent key to display name", async () => {
@@ -527,7 +527,7 @@ describe("default_agent behavior with Sisyphus orchestration", () => {
     await handler(config)
 
     // #then
-    expect(config.default_agent).toBe(getAgentDisplayName("hephaestus"))
+    expect(config.default_agent).toBe(getAgentRuntimeName("hephaestus"))
   })
 
   test("preserves existing display-name default_agent", async () => {
@@ -575,7 +575,31 @@ describe("default_agent behavior with Sisyphus orchestration", () => {
     await handler(config)
 
     // #then
-    expect(config.default_agent).toBe(getAgentDisplayName("sisyphus"))
+    expect(config.default_agent).toBe(getAgentRuntimeName("sisyphus"))
+  })
+
+  test("uses runtime default_agent name so OpenCode matches the emitted ordered agent names", async () => {
+    // given
+    const pluginConfig = createPluginConfig({})
+    const config: Record<string, unknown> = {
+      model: "anthropic/claude-opus-4-6",
+      default_agent: "hephaestus",
+      agent: {},
+    }
+    const handler = createConfigHandler({
+      ctx: { directory: "/tmp" },
+      pluginConfig,
+      modelCacheState: {
+        anthropicContext1MEnabled: false,
+        modelContextLimitsCache: new Map(),
+      },
+    })
+
+    // when
+    await handler(config)
+
+    // then
+    expect(config.default_agent).toBe(getAgentRuntimeName("hephaestus"))
   })
 
   test("sets default_agent to sisyphus when configured default_agent is empty after trim", async () => {
@@ -599,7 +623,7 @@ describe("default_agent behavior with Sisyphus orchestration", () => {
     await handler(config)
 
     // then
-    expect(config.default_agent).toBe(getAgentDisplayName("sisyphus"))
+    expect(config.default_agent).toBe(getAgentRuntimeName("sisyphus"))
   })
 
   test("preserves custom default_agent names while trimming whitespace", async () => {

src/shared/agent-display-names.ts

@@ -37,6 +37,13 @@ export function stripAgentListSortPrefix(agentName: string): string {
   return agentName.replace(/^\u200B+/, "")
 }
 
+export function getAgentRuntimeName(configKey: string): string {
+  const displayName = getAgentDisplayName(configKey)
+  const prefix = AGENT_LIST_SORT_PREFIXES[configKey.toLowerCase()]
+
+  return prefix ? `${prefix}${displayName}` : displayName
+}
+
 /**
  * Get display name for an agent config key.
  * Uses case-insensitive lookup for backward compatibility.
@@ -65,10 +72,7 @@ export function getAgentDisplayName(configKey: string): string {
  * See: https://github.com/code-yeongyu/oh-my-openagent/issues/3238
  */
 export function getAgentListDisplayName(configKey: string): string {
-  const displayName = getAgentDisplayName(configKey)
-  const prefix = AGENT_LIST_SORT_PREFIXES[configKey.toLowerCase()]
-
-  return prefix ? `${prefix}${displayName}` : displayName
+  return getAgentRuntimeName(configKey)
 }
 
 const REVERSE_DISPLAY_NAMES: Record<string, string> = Object.fromEntries(