feat(config): add custom_agents overrides and strict agent validation

src/config/index.ts

@@ -1,11 +1,25 @@
 export {
   OhMyOpenCodeConfigSchema,
+  AgentOverrideConfigSchema,
+  AgentOverridesSchema,
+  CustomAgentOverridesSchema,
+  McpNameSchema,
+  AgentNameSchema,
+  OverridableAgentNameSchema,
+  HookNameSchema,
+  BuiltinCommandNameSchema,
+  SisyphusAgentConfigSchema,
+  ExperimentalConfigSchema,
+  RalphLoopConfigSchema,
+  TmuxConfigSchema,
+  TmuxLayoutSchema,
 } from "./schema"
 
 export type {
   OhMyOpenCodeConfig,
   AgentOverrideConfig,
   AgentOverrides,
+  CustomAgentOverrides,
   McpName,
   AgentName,
   HookName,

src/config/schema-document.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, test } from "bun:test"
+import { createOhMyOpenCodeJsonSchema } from "../../script/build-schema-document"
+
+function asRecord(value: unknown): Record<string, unknown> | undefined {
+  return typeof value === "object" && value !== null ? (value as Record<string, unknown>) : undefined
+}
+
+describe("schema document generation", () => {
+  test("custom_agents schema allows arbitrary custom agent keys with override shape", () => {
+    // given
+    const schema = createOhMyOpenCodeJsonSchema()
+
+    // when
+    const rootProperties = asRecord(schema.properties)
+    const agentsSchema = asRecord(rootProperties?.agents)
+    const customAgentsSchema = asRecord(rootProperties?.custom_agents)
+    const customPropertyNames = asRecord(customAgentsSchema?.propertyNames)
+    const customAdditionalProperties = asRecord(customAgentsSchema?.additionalProperties)
+    const customAgentProperties = asRecord(customAdditionalProperties?.properties)
+
+    // then
+    expect(agentsSchema).toBeDefined()
+    expect(agentsSchema?.additionalProperties).toBeFalse()
+    expect(customAgentsSchema).toBeDefined()
+    expect(customPropertyNames?.pattern).toBeDefined()
+    expect(customAdditionalProperties).toBeDefined()
+    expect(customAgentProperties?.model).toEqual({ type: "string" })
+    expect(customAgentProperties?.temperature).toEqual(
+      expect.objectContaining({ type: "number" }),
+    )
+  })
+})

src/config/schema.test.ts

@@ -530,6 +530,79 @@ describe("Sisyphus-Junior agent override", () => {
       expect(result.data.agents?.momus?.category).toBe("quick")
     }
   })
+
+  test("schema accepts custom_agents override keys", () => {
+    // given
+    const config = {
+      custom_agents: {
+        translator: {
+          model: "google/gemini-3-flash-preview",
+          temperature: 0,
+        },
+      },
+    }
+
+    // when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // then
+    expect(result.success).toBe(true)
+    if (result.success) {
+      expect(result.data.custom_agents?.translator?.model).toBe("google/gemini-3-flash-preview")
+      expect(result.data.custom_agents?.translator?.temperature).toBe(0)
+    }
+  })
+
+  test("schema rejects unknown keys under agents", () => {
+    // given
+    const config = {
+      agents: {
+        sisyphuss: {
+          model: "openai/gpt-5.3-codex",
+        },
+      },
+    }
+
+    // when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // then
+    expect(result.success).toBe(false)
+  })
+
+  test("schema rejects built-in agent names under custom_agents", () => {
+    // given
+    const config = {
+      custom_agents: {
+        sisyphus: {
+          model: "openai/gpt-5.3-codex",
+        },
+      },
+    }
+
+    // when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // then
+    expect(result.success).toBe(false)
+  })
+
+  test("schema rejects built-in agent names under custom_agents case-insensitively", () => {
+    // given
+    const config = {
+      custom_agents: {
+        Sisyphus: {
+          model: "openai/gpt-5.3-codex",
+        },
+      },
+    }
+
+    // when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // then
+    expect(result.success).toBe(false)
+  })
 })
 
 describe("BrowserAutomationProviderSchema", () => {

src/config/schema/agent-overrides.ts

@@ -1,5 +1,6 @@
 import { z } from "zod"
 import { FallbackModelsSchema } from "./fallback-models"
+import { OverridableAgentNameSchema } from "./agent-names"
 import { AgentPermissionSchema } from "./internal/permission"
 
 export const AgentOverrideConfigSchema = z.object({
@@ -55,7 +56,7 @@ export const AgentOverrideConfigSchema = z.object({
     .optional(),
 })
 
-export const AgentOverridesSchema = z.object({
+const BuiltinAgentOverridesSchema = z.object({
   build: AgentOverrideConfigSchema.optional(),
   plan: AgentOverrideConfigSchema.optional(),
   sisyphus: AgentOverrideConfigSchema.optional(),
@@ -70,7 +71,38 @@ export const AgentOverridesSchema = z.object({
   explore: AgentOverrideConfigSchema.optional(),
   "multimodal-looker": AgentOverrideConfigSchema.optional(),
   atlas: AgentOverrideConfigSchema.optional(),
-})
+}).strict()
+
+export const AgentOverridesSchema = BuiltinAgentOverridesSchema
+
+const RESERVED_CUSTOM_AGENT_NAMES = OverridableAgentNameSchema.options
+const RESERVED_CUSTOM_AGENT_NAME_SET = new Set(
+  RESERVED_CUSTOM_AGENT_NAMES.map((name) => name.toLowerCase()),
+)
+const RESERVED_CUSTOM_AGENT_NAME_PATTERN = new RegExp(
+  `^(?!(?:${RESERVED_CUSTOM_AGENT_NAMES.map((name) => name.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")).join("|")})$).+`,
+)
+
+export const CustomAgentOverridesSchema = z
+  .record(
+    z.string().regex(
+      RESERVED_CUSTOM_AGENT_NAME_PATTERN,
+      "custom_agents key cannot reuse built-in agent override name",
+    ),
+    AgentOverrideConfigSchema,
+  )
+  .superRefine((value, ctx) => {
+    for (const key of Object.keys(value)) {
+      if (RESERVED_CUSTOM_AGENT_NAME_SET.has(key.toLowerCase())) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          path: [key],
+          message: "custom_agents key cannot reuse built-in agent override name",
+        })
+      }
+    }
+  })
 
 export type AgentOverrideConfig = z.infer<typeof AgentOverrideConfigSchema>
 export type AgentOverrides = z.infer<typeof AgentOverridesSchema>
+export type CustomAgentOverrides = z.infer<typeof CustomAgentOverridesSchema>

src/config/schema/oh-my-opencode-config.ts

@@ -1,7 +1,7 @@
 import { z } from "zod"
 import { AnyMcpNameSchema } from "../../mcp/types"
 import { BuiltinAgentNameSchema, BuiltinSkillNameSchema } from "./agent-names"
-import { AgentOverridesSchema } from "./agent-overrides"
+import { AgentOverridesSchema, CustomAgentOverridesSchema } from "./agent-overrides"
 import { BabysittingConfigSchema } from "./babysitting"
 import { BackgroundTaskConfigSchema } from "./background-task"
 import { BrowserAutomationConfigSchema } from "./browser-automation"
@@ -38,6 +38,7 @@ export const OhMyOpenCodeConfigSchema = z.object({
   /** Enable model fallback on API errors (default: false). Set to true to enable automatic model switching when model errors occur. */
   model_fallback: z.boolean().optional(),
   agents: AgentOverridesSchema.optional(),
+  custom_agents: CustomAgentOverridesSchema.optional(),
   categories: CategoriesConfigSchema.optional(),
   claude_code: ClaudeCodeConfigSchema.optional(),
   sisyphus_agent: SisyphusAgentConfigSchema.optional(),