diff --git a/assets/oh-my-opencode.schema.json b/assets/oh-my-opencode.schema.json
index 1d7c856ca..c4569442f 100644
--- a/assets/oh-my-opencode.schema.json
+++ b/assets/oh-my-opencode.schema.json
@@ -4261,6 +4261,10 @@
         },
         "replace_plan": {
           "type": "boolean"
+        },
+        "tdd": {
+          "default": true,
+          "type": "boolean"
         }
       },
       "additionalProperties": false
diff --git a/src/config/schema/sisyphus-agent.ts b/src/config/schema/sisyphus-agent.ts
index 76ee2c373..be08dda87 100644
--- a/src/config/schema/sisyphus-agent.ts
+++ b/src/config/schema/sisyphus-agent.ts
@@ -5,6 +5,7 @@ export const SisyphusAgentConfigSchema = z.object({
   default_builder_enabled: z.boolean().optional(),
   planner_enabled: z.boolean().optional(),
   replace_plan: z.boolean().optional(),
+  tdd: z.boolean().default(true).optional(),
 })
 
 export type SisyphusAgentConfig = z.infer<typeof SisyphusAgentConfigSchema>
diff --git a/src/plugin/tool-registry.ts b/src/plugin/tool-registry.ts
index c29ecfce6..5d99cd0b2 100644
--- a/src/plugin/tool-registry.ts
+++ b/src/plugin/tool-registry.ts
@@ -132,6 +132,7 @@ export function createToolRegistry(args: {
     disabledSkills: skillContext.disabledSkills,
     availableCategories,
     availableSkills: skillContext.availableSkills,
+    sisyphusAgentConfig: pluginConfig.sisyphus_agent,
     syncPollTimeoutMs: pluginConfig.background_task?.syncPollTimeoutMs,
     onSyncSessionCreated: async (event) => {
       log("[index] onSyncSessionCreated callback", {
diff --git a/src/tools/delegate-task/background-task.ts b/src/tools/delegate-task/background-task.ts
index bc96423eb..be9b1f5b3 100644
--- a/src/tools/delegate-task/background-task.ts
+++ b/src/tools/delegate-task/background-task.ts
@@ -23,7 +23,8 @@ export async function executeBackgroundTask(
   const { manager } = executorCtx
 
   try {
-    const effectivePrompt = buildTaskPrompt(args.prompt, agentToUse)
+    const tddEnabled = executorCtx.sisyphusAgentConfig?.tdd
+    const effectivePrompt = buildTaskPrompt(args.prompt, agentToUse, tddEnabled)
     const task = await manager.launch({
       description: args.description,
       prompt: effectivePrompt,
diff --git a/src/tools/delegate-task/executor-types.ts b/src/tools/delegate-task/executor-types.ts
index ad8c01879..bfa7fc70b 100644
--- a/src/tools/delegate-task/executor-types.ts
+++ b/src/tools/delegate-task/executor-types.ts
@@ -1,5 +1,5 @@
 import type { BackgroundManager } from "../../features/background-agent"
-import type { CategoriesConfig, GitMasterConfig, BrowserAutomationProvider, AgentOverrides } from "../../config/schema"
+import type { CategoriesConfig, GitMasterConfig, BrowserAutomationProvider, AgentOverrides, SisyphusAgentConfig } from "../../config/schema"
 import type { OpencodeClient } from "./types"
 
 export interface ExecutorContext {
@@ -11,6 +11,7 @@ export interface ExecutorContext {
   sisyphusJuniorModel?: string
   browserProvider?: BrowserAutomationProvider
   agentOverrides?: AgentOverrides
+  sisyphusAgentConfig?: SisyphusAgentConfig
   onSyncSessionCreated?: (event: { sessionID: string; parentID: string; title: string }) => Promise<void>
   syncPollTimeoutMs?: number
 }
diff --git a/src/tools/delegate-task/prompt-builder.ts b/src/tools/delegate-task/prompt-builder.ts
index ddae1ce59..1672eea74 100644
--- a/src/tools/delegate-task/prompt-builder.ts
+++ b/src/tools/delegate-task/prompt-builder.ts
@@ -3,15 +3,24 @@ import { buildPlanAgentSystemPrepend, isPlanAgent } from "./constants"
 import { buildSystemContentWithTokenLimit } from "./token-limiter"
 
 const FREE_OR_LOCAL_PROMPT_TOKEN_LIMIT = 24000
-const PLAN_AGENT_PROMPT_APPEND = `
+const PLAN_AGENT_PROMPT_BASE = `
 
 Additional requirements for this planning request:
 - Answer in English.
 - Write the plan in English.
 - Plan well for ultrawork execution.
-- Use TDD-oriented planning.
 - Include a clear atomic commit strategy.`
 
+const TDD_LINE = "- Use TDD-oriented planning."
+
+function buildPlanAgentPromptAppend(tddEnabled: boolean): string {
+  if (tddEnabled) {
+    return `${PLAN_AGENT_PROMPT_BASE}
+${TDD_LINE}`
+  }
+  return PLAN_AGENT_PROMPT_BASE
+}
+
 function usesFreeOrLocalModel(model: { providerID: string; modelID: string; variant?: string } | undefined): boolean {
   if (!model) {
     return false
@@ -61,10 +70,11 @@ export function buildSystemContent(input: BuildSystemContentInput): string | und
   )
 }
 
-export function buildTaskPrompt(prompt: string, agentName: string | undefined): string {
+export function buildTaskPrompt(prompt: string, agentName: string | undefined, tddEnabled?: boolean): string {
   if (!isPlanAgent(agentName)) {
     return prompt
   }
 
-  return `${prompt}${PLAN_AGENT_PROMPT_APPEND}`
+  const effectiveTdd = tddEnabled ?? true
+  return `${prompt}${buildPlanAgentPromptAppend(effectiveTdd)}`
 }
diff --git a/src/tools/delegate-task/sync-continuation.ts b/src/tools/delegate-task/sync-continuation.ts
index 82618a289..5abe635c1 100644
--- a/src/tools/delegate-task/sync-continuation.ts
+++ b/src/tools/delegate-task/sync-continuation.ts
@@ -19,7 +19,7 @@ export async function executeSyncContinuation(
   executorCtx: ExecutorContext,
   deps: SyncContinuationDeps = syncContinuationDeps
 ): Promise<string> {
-  const { client, syncPollTimeoutMs } = executorCtx
+  const { client, syncPollTimeoutMs, sisyphusAgentConfig } = executorCtx
   const toastManager = getTaskToastManager()
   const taskId = `resume_sync_${args.session_id!.slice(0, 8)}`
   const startTime = new Date()
@@ -83,7 +83,8 @@ export async function executeSyncContinuation(
     }
 
     const allowTask = isPlanFamily(resumeAgent)
-    const effectivePrompt = buildTaskPrompt(args.prompt, resumeAgent)
+    const tddEnabled = sisyphusAgentConfig?.tdd
+    const effectivePrompt = buildTaskPrompt(args.prompt, resumeAgent, tddEnabled)
     const tools = {
       task: allowTask,
       call_omo_agent: true,
diff --git a/src/tools/delegate-task/sync-prompt-sender.ts b/src/tools/delegate-task/sync-prompt-sender.ts
index 502bb6dec..1140344d4 100644
--- a/src/tools/delegate-task/sync-prompt-sender.ts
+++ b/src/tools/delegate-task/sync-prompt-sender.ts
@@ -1,4 +1,5 @@
 import type { DelegateTaskArgs, OpencodeClient, DelegatedModelConfig } from "./types"
+import type { SisyphusAgentConfig } from "../../config/schema"
 import { isPlanFamily } from "./constants"
 import { buildTaskPrompt } from "./prompt-builder"
 import {
@@ -41,11 +42,13 @@ export async function sendSyncPrompt(
     categoryModel: DelegatedModelConfig | undefined
     toastManager: { removeTask: (id: string) => void } | null | undefined
     taskId: string | undefined
+    sisyphusAgentConfig?: SisyphusAgentConfig
   },
   deps: SendSyncPromptDeps = sendSyncPromptDeps
 ): Promise<string | null> {
   const allowTask = isPlanFamily(input.agentToUse)
-  const effectivePrompt = buildTaskPrompt(input.args.prompt, input.agentToUse)
+  const tddEnabled = input.sisyphusAgentConfig?.tdd
+  const effectivePrompt = buildTaskPrompt(input.args.prompt, input.agentToUse, tddEnabled)
   const tools = {
     task: allowTask,
     call_omo_agent: true,
diff --git a/src/tools/delegate-task/sync-task.ts b/src/tools/delegate-task/sync-task.ts
index 554794188..b87001543 100644
--- a/src/tools/delegate-task/sync-task.ts
+++ b/src/tools/delegate-task/sync-task.ts
@@ -126,6 +126,7 @@ export async function executeSyncTask(
       categoryModel,
       toastManager,
       taskId,
+      sisyphusAgentConfig: executorCtx.sisyphusAgentConfig,
     })
     if (promptError) {
       return promptError
diff --git a/src/tools/delegate-task/tools.test.ts b/src/tools/delegate-task/tools.test.ts
index 3a9b9e59e..2a18b0085 100644
--- a/src/tools/delegate-task/tools.test.ts
+++ b/src/tools/delegate-task/tools.test.ts
@@ -3132,6 +3132,35 @@ describe("sisyphus-task", () => {
       // then
       expect(result).toBe(prompt)
     })
+
+    test("excludes TDD line when tddEnabled is false", () => {
+      // given
+      const { buildTaskPrompt } = require("./tools")
+      const prompt = "Create a work plan for this feature"
+
+      // when
+      const result = buildTaskPrompt(prompt, "plan", false)
+
+      // then
+      expect(result).toContain(prompt)
+      expect(result).toContain("Answer in English.")
+      expect(result).toContain("Write the plan in English.")
+      expect(result).toContain("Plan well for ultrawork execution.")
+      expect(result).toContain("Include a clear atomic commit strategy.")
+      expect(result).not.toContain("Use TDD-oriented planning.")
+    })
+
+    test("includes TDD line when tddEnabled is true", () => {
+      // given
+      const { buildTaskPrompt } = require("./tools")
+      const prompt = "Create a work plan for this feature"
+
+      // when
+      const result = buildTaskPrompt(prompt, "plan", true)
+
+      // then
+      expect(result).toContain("Use TDD-oriented planning.")
+    })
   })
 
   describe("modelInfo detection via resolveCategoryConfig", () => {
diff --git a/src/tools/delegate-task/types.ts b/src/tools/delegate-task/types.ts
index fd1c2dd43..bbb0e8e21 100644
--- a/src/tools/delegate-task/types.ts
+++ b/src/tools/delegate-task/types.ts
@@ -1,6 +1,6 @@
 import type { PluginInput } from "@opencode-ai/plugin"
 import type { BackgroundManager } from "../../features/background-agent"
-import type { CategoriesConfig, GitMasterConfig, BrowserAutomationProvider, AgentOverrides } from "../../config/schema"
+import type { CategoriesConfig, GitMasterConfig, BrowserAutomationProvider, AgentOverrides, SisyphusAgentConfig } from "../../config/schema"
 import type {
   AvailableCategory,
   AvailableSkill,
@@ -67,6 +67,7 @@ export interface DelegateTaskToolOptions {
   availableCategories?: AvailableCategory[]
   availableSkills?: AvailableSkill[]
   agentOverrides?: AgentOverrides
+  sisyphusAgentConfig?: SisyphusAgentConfig
   onSyncSessionCreated?: (event: SyncSessionCreatedEvent) => Promise<void>
   syncPollTimeoutMs?: number
 }
diff --git a/src/tools/delegate-task/unstable-agent-task.ts b/src/tools/delegate-task/unstable-agent-task.ts
index ba0ec6152..57f517e18 100644
--- a/src/tools/delegate-task/unstable-agent-task.ts
+++ b/src/tools/delegate-task/unstable-agent-task.ts
@@ -20,12 +20,13 @@ export async function executeUnstableAgentTask(
   systemContent: string | undefined,
   actualModel: string | undefined
 ): Promise<string> {
-  const { manager, client, syncPollTimeoutMs } = executorCtx
+  const { manager, client, syncPollTimeoutMs, sisyphusAgentConfig } = executorCtx
   let cleanupReason: string | undefined
   let launchedTaskID: string | undefined
 
   try {
-    const effectivePrompt = buildTaskPrompt(args.prompt, agentToUse)
+    const tddEnabled = sisyphusAgentConfig?.tdd
+    const effectivePrompt = buildTaskPrompt(args.prompt, agentToUse, tddEnabled)
     const task = await manager.launch({
       description: args.description,
       prompt: effectivePrompt,