diff --git a/src/agents/prometheus-prompt.ts b/src/agents/prometheus-prompt.ts
index f06fc5b64..e315a9b8b 100644
--- a/src/agents/prometheus-prompt.ts
+++ b/src/agents/prometheus-prompt.ts
@@ -319,8 +319,8 @@ Or should I just note down this single fix?"
 
 **Research First:**
 \`\`\`typescript
-delegate_task(agent="explore", prompt="Find all usages of [target] using lsp_find_references pattern...", background=true)
-delegate_task(agent="explore", prompt="Find test coverage for [affected code]...", background=true)
+delegate_task(subagent_type="explore", prompt="Find all usages of [target] using lsp_find_references pattern...", run_in_background=true)
+delegate_task(subagent_type="explore", prompt="Find test coverage for [affected code]...", run_in_background=true)
 \`\`\`
 
 **Interview Focus:**
@@ -343,9 +343,9 @@ delegate_task(agent="explore", prompt="Find test coverage for [affected code]...
 **Pre-Interview Research (MANDATORY):**
 \`\`\`typescript
 // Launch BEFORE asking user questions
-delegate_task(agent="explore", prompt="Find similar implementations in codebase...", background=true)
-delegate_task(agent="explore", prompt="Find project patterns for [feature type]...", background=true)
-delegate_task(agent="librarian", prompt="Find best practices for [technology]...", background=true)
+delegate_task(subagent_type="explore", prompt="Find similar implementations in codebase...", run_in_background=true)
+delegate_task(subagent_type="explore", prompt="Find project patterns for [feature type]...", run_in_background=true)
+delegate_task(subagent_type="librarian", prompt="Find best practices for [technology]...", run_in_background=true)
 \`\`\`
 
 **Interview Focus** (AFTER research):
@@ -384,7 +384,7 @@ Based on your stack, I'd recommend NextAuth.js - it integrates well with Next.js
 
 Run this check:
 \`\`\`typescript
-delegate_task(agent="explore", prompt="Find test infrastructure: package.json test scripts, test config files (jest.config, vitest.config, pytest.ini, etc.), existing test files (*.test.*, *.spec.*, test_*). Report: 1) Does test infra exist? 2) What framework? 3) Example test file patterns.", background=true)
+delegate_task(subagent_type="explore", prompt="Find test infrastructure: package.json test scripts, test config files (jest.config, vitest.config, pytest.ini, etc.), existing test files (*.test.*, *.spec.*, test_*). Report: 1) Does test infra exist? 2) What framework? 3) Example test file patterns.", run_in_background=true)
 \`\`\`
 
 #### Step 2: Ask the Test Question (MANDATORY)
@@ -473,13 +473,13 @@ Add to draft immediately:
 
 **Research First:**
 \`\`\`typescript
-delegate_task(agent="explore", prompt="Find current system architecture and patterns...", background=true)
-delegate_task(agent="librarian", prompt="Find architectural best practices for [domain]...", background=true)
+delegate_task(subagent_type="explore", prompt="Find current system architecture and patterns...", run_in_background=true)
+delegate_task(subagent_type="librarian", prompt="Find architectural best practices for [domain]...", run_in_background=true)
 \`\`\`
 
 **Oracle Consultation** (recommend when stakes are high):
 \`\`\`typescript
-delegate_task(agent="oracle", prompt="Architecture consultation needed: [context]...", background=false)
+delegate_task(subagent_type="oracle", prompt="Architecture consultation needed: [context]...", run_in_background=false)
 \`\`\`
 
 **Interview Focus:**
@@ -496,9 +496,9 @@ delegate_task(agent="oracle", prompt="Architecture consultation needed: [context
 
 **Parallel Investigation:**
 \`\`\`typescript
-delegate_task(agent="explore", prompt="Find how X is currently handled...", background=true)
-delegate_task(agent="librarian", prompt="Find official docs for Y...", background=true)
-delegate_task(agent="librarian", prompt="Find OSS implementations of Z...", background=true)
+delegate_task(subagent_type="explore", prompt="Find how X is currently handled...", run_in_background=true)
+delegate_task(subagent_type="librarian", prompt="Find official docs for Y...", run_in_background=true)
+delegate_task(subagent_type="librarian", prompt="Find OSS implementations of Z...", run_in_background=true)
 \`\`\`
 
 **Interview Focus:**
@@ -524,17 +524,17 @@ delegate_task(agent="librarian", prompt="Find OSS implementations of Z...", back
 
 **For Understanding Codebase:**
 \`\`\`typescript
-delegate_task(agent="explore", prompt="Find all files related to [topic]. Show patterns, conventions, and structure.", background=true)
+delegate_task(subagent_type="explore", prompt="Find all files related to [topic]. Show patterns, conventions, and structure.", run_in_background=true)
 \`\`\`
 
 **For External Knowledge:**
 \`\`\`typescript
-delegate_task(agent="librarian", prompt="Find official documentation for [library]. Focus on [specific feature] and best practices.", background=true)
+delegate_task(subagent_type="librarian", prompt="Find official documentation for [library]. Focus on [specific feature] and best practices.", run_in_background=true)
 \`\`\`
 
 **For Implementation Examples:**
 \`\`\`typescript
-delegate_task(agent="librarian", prompt="Find open source implementations of [feature]. Look for production-quality examples.", background=true)
+delegate_task(subagent_type="librarian", prompt="Find open source implementations of [feature]. Look for production-quality examples.", run_in_background=true)
 \`\`\`
 
 ## Interview Mode Anti-Patterns
@@ -631,7 +631,7 @@ todoWrite([
 
 \`\`\`typescript
 delegate_task(
-  agent="Metis (Plan Consultant)",
+  subagent_type="metis",
   prompt=\`Review this planning session before I generate the work plan:
 
   **User's Goal**: {summarize what user wants}
@@ -652,7 +652,7 @@ delegate_task(
   4. Assumptions I'm making that need validation
   5. Missing acceptance criteria
   6. Edge cases not addressed\`,
-  background=false
+  run_in_background=false
 )
 \`\`\`
 
@@ -797,9 +797,9 @@ Question({
 // After generating initial plan
 while (true) {
   const result = delegate_task(
-    agent="Momus (Plan Reviewer)",
+    subagent_type="momus",
     prompt=".sisyphus/plans/{name}.md",
-    background=false
+    run_in_background=false
   )
 
   if (result.verdict === "OKAY") {
diff --git a/src/agents/utils.ts b/src/agents/utils.ts
index af2ecdaf0..f3959e3a4 100644
--- a/src/agents/utils.ts
+++ b/src/agents/utils.ts
@@ -139,7 +139,7 @@ function mapScopeToLocation(scope: SkillScope): AvailableSkill["location"] {
 }
 
 export async function createBuiltinAgents(
-  disabledAgents: BuiltinAgentName[] = [],
+  disabledAgents: string[] = [],
   agentOverrides: AgentOverrides = {},
   directory?: string,
   systemDefaultModel?: string,
diff --git a/src/config/schema.ts b/src/config/schema.ts
index f1ce236be..4454add71 100644
--- a/src/config/schema.ts
+++ b/src/config/schema.ts
@@ -18,6 +18,7 @@ const AgentPermissionSchema = z.object({
 
 export const BuiltinAgentNameSchema = z.enum([
   "sisyphus",
+  "prometheus",
   "oracle",
   "librarian",
   "explore",
diff --git a/src/hooks/atlas/index.ts b/src/hooks/atlas/index.ts
index a8809ed60..9852ed8bc 100644
--- a/src/hooks/atlas/index.ts
+++ b/src/hooks/atlas/index.ts
@@ -399,7 +399,7 @@ function isCallerOrchestrator(sessionID?: string): boolean {
    const messageDir = getMessageDir(sessionID)
    if (!messageDir) return false
    const nearest = findNearestMessageWithFields(messageDir)
-   return nearest?.agent === "Atlas"
+   return nearest?.agent?.toLowerCase() === "atlas"
  }
 
 interface SessionState {
diff --git a/src/shared/agent-variant.ts b/src/shared/agent-variant.ts
index ec3e7ec50..463e220a6 100644
--- a/src/shared/agent-variant.ts
+++ b/src/shared/agent-variant.ts
@@ -1,4 +1,5 @@
 import type { OhMyOpenCodeConfig } from "../config"
+import { findCaseInsensitive } from "./case-insensitive"
 
 export function resolveAgentVariant(
   config: OhMyOpenCodeConfig,
@@ -11,7 +12,7 @@ export function resolveAgentVariant(
   const agentOverrides = config.agents as
     | Record<string, { variant?: string; category?: string }>
     | undefined
-  const agentOverride = agentOverrides?.[agentName]
+  const agentOverride = agentOverrides ? findCaseInsensitive(agentOverrides, agentName) : undefined
   if (!agentOverride) {
     return undefined
   }