feat: add bootstrap hook and soul-evil hook

docs/cli/hooks.md

@@ -256,3 +256,15 @@ grep '"action":"new"' ~/.clawdbot/logs/commands.log | jq .
 ```
 
 **See:** [command-logger documentation](/hooks#command-logger)
+
+### soul-evil
+
+Swaps injected `SOUL.md` content with `SOUL_EVIL.md` during a purge window or by random chance.
+
+**Enable:**
+
+```bash
+clawdbot hooks enable soul-evil
+```
+
+**See:** [soul-evil documentation](/hooks#soul-evil)

docs/concepts/system-prompt.md

@@ -58,6 +58,9 @@ Large files are truncated with a marker. The max per-file size is controlled by
 `agents.defaults.bootstrapMaxChars` (default: 20000). Missing files inject a
 short missing-file marker.
 
+Internal hooks can intercept this step via `agent:bootstrap` to mutate or replace
+the injected bootstrap files (for example swapping `SOUL.md` for an alternate persona).
+
 To inspect how much each injected file contributes (raw vs injected, truncation, plus tool schema overhead), use `/context list` or `/context detail`. See [Context](/concepts/context).
 
 ## Time handling

docs/hooks.md

@@ -203,6 +203,8 @@ Each event includes:
     sessionFile?: string,
     commandSource?: string,    // e.g., 'whatsapp', 'telegram'
     senderId?: string,
+    workspaceDir?: string,
+    bootstrapFiles?: WorkspaceBootstrapFile[],
     cfg?: ClawdbotConfig
   }
 }
@@ -219,6 +221,10 @@ Triggered when agent commands are issued:
 - **`command:reset`**: When `/reset` command is issued
 - **`command:stop`**: When `/stop` command is issued
 
+### Agent Events
+
+- **`agent:bootstrap`**: Before workspace bootstrap files are injected (hooks may mutate `context.bootstrapFiles`)
+
 ### Future Events
 
 Planned event types:
@@ -497,6 +503,40 @@ grep '"action":"new"' ~/.clawdbot/logs/commands.log | jq .
 clawdbot hooks enable command-logger
 ```
 
+### soul-evil
+
+Swaps injected `SOUL.md` content with `SOUL_EVIL.md` during a purge window or by random chance.
+
+**Events**: `agent:bootstrap`
+
+**Output**: No files written; swaps happen in-memory only.
+
+**Enable**:
+
+```bash
+clawdbot hooks enable soul-evil
+```
+
+**Config**:
+
+```json
+{
+  "hooks": {
+    "internal": {
+      "enabled": true,
+      "entries": {
+        "soul-evil": {
+          "enabled": true,
+          "file": "SOUL_EVIL.md",
+          "chance": 0.1,
+          "purge": { "at": "21:00", "duration": "15m" }
+        }
+      }
+    }
+  }
+}
+```
+
 ## Best Practices
 
 ### Keep Handlers Fast

src/agents/bootstrap-hooks.test.ts

@@ -0,0 +1,41 @@
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+
+import { applyBootstrapHookOverrides } from "./bootstrap-hooks.js";
+import {
+  clearInternalHooks,
+  registerInternalHook,
+  type AgentBootstrapHookContext,
+} from "../hooks/internal-hooks.js";
+import { DEFAULT_SOUL_FILENAME, type WorkspaceBootstrapFile } from "./workspace.js";
+
+function makeFile(name = DEFAULT_SOUL_FILENAME): WorkspaceBootstrapFile {
+  return {
+    name,
+    path: `/tmp/${name}`,
+    content: "base",
+    missing: false,
+  };
+}
+
+describe("applyBootstrapHookOverrides", () => {
+  beforeEach(() => clearInternalHooks());
+  afterEach(() => clearInternalHooks());
+
+  it("returns updated files when a hook mutates the context", async () => {
+    registerInternalHook("agent:bootstrap", (event) => {
+      const context = event.context as AgentBootstrapHookContext;
+      context.bootstrapFiles = [
+        ...context.bootstrapFiles,
+        { name: "EXTRA.md", path: "/tmp/EXTRA.md", content: "extra", missing: false },
+      ];
+    });
+
+    const updated = await applyBootstrapHookOverrides({
+      files: [makeFile()],
+      workspaceDir: "/tmp",
+    });
+
+    expect(updated).toHaveLength(2);
+    expect(updated[1]?.name).toBe("EXTRA.md");
+  });
+});

src/agents/bootstrap-hooks.ts

@@ -0,0 +1,31 @@
+import type { ClawdbotConfig } from "../config/config.js";
+import { createInternalHookEvent, triggerInternalHook } from "../hooks/internal-hooks.js";
+import type { AgentBootstrapHookContext } from "../hooks/internal-hooks.js";
+import { resolveAgentIdFromSessionKey } from "../routing/session-key.js";
+import type { WorkspaceBootstrapFile } from "./workspace.js";
+
+export async function applyBootstrapHookOverrides(params: {
+  files: WorkspaceBootstrapFile[];
+  workspaceDir: string;
+  config?: ClawdbotConfig;
+  sessionKey?: string;
+  sessionId?: string;
+  agentId?: string;
+}): Promise<WorkspaceBootstrapFile[]> {
+  const sessionKey = params.sessionKey ?? params.sessionId ?? "unknown";
+  const agentId =
+    params.agentId ??
+    (params.sessionKey ? resolveAgentIdFromSessionKey(params.sessionKey) : undefined);
+  const context: AgentBootstrapHookContext = {
+    workspaceDir: params.workspaceDir,
+    bootstrapFiles: params.files,
+    cfg: params.config,
+    sessionKey: params.sessionKey,
+    sessionId: params.sessionId,
+    agentId,
+  };
+  const event = createInternalHookEvent("agent", "bootstrap", sessionKey, context);
+  await triggerInternalHook(event);
+  const updated = (event.context as AgentBootstrapHookContext).bootstrapFiles;
+  return Array.isArray(updated) ? updated : params.files;
+}

src/agents/cli-runner.ts

@@ -7,6 +7,7 @@ import { createSubsystemLogger } from "../logging.js";
 import { runCommandWithTimeout } from "../process/exec.js";
 import { resolveUserPath } from "../utils.js";
 import { resolveSessionAgentIds } from "./agent-scope.js";
+import { applyBootstrapHookOverrides } from "./bootstrap-hooks.js";
 import { resolveCliBackendConfig } from "./cli-backends.js";
 import {
   appendImagePathsToPrompt,
@@ -76,8 +77,15 @@ export async function runCliAgent(params: {
     await loadWorkspaceBootstrapFiles(workspaceDir),
     params.sessionKey ?? params.sessionId,
   );
+  const hookAdjustedBootstrapFiles = await applyBootstrapHookOverrides({
+    files: bootstrapFiles,
+    workspaceDir,
+    config: params.config,
+    sessionKey: params.sessionKey,
+    sessionId: params.sessionId,
+  });
   const sessionLabel = params.sessionKey ?? params.sessionId;
-  const contextFiles = buildBootstrapContextFiles(bootstrapFiles, {
+  const contextFiles = buildBootstrapContextFiles(hookAdjustedBootstrapFiles, {
     maxChars: resolveBootstrapMaxChars(params.config),
     warn: (message) => log.warn(`${message} (sessionKey=${sessionLabel})`),
   });

src/agents/pi-embedded-runner/compact.ts

@@ -16,6 +16,7 @@ import { isReasoningTagProvider } from "../../utils/provider-utils.js";
 import { resolveUserPath } from "../../utils.js";
 import { resolveClawdbotAgentDir } from "../agent-paths.js";
 import { resolveSessionAgentIds } from "../agent-scope.js";
+import { applyBootstrapHookOverrides } from "../bootstrap-hooks.js";
 import type { ExecElevatedDefaults } from "../bash-tools.js";
 import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "../defaults.js";
 import { getApiKeyForModel, resolveModelAuthMode } from "../model-auth.js";
@@ -182,11 +183,21 @@ export async function compactEmbeddedPiSession(params: {
           await loadWorkspaceBootstrapFiles(effectiveWorkspace),
           params.sessionKey ?? params.sessionId,
         );
-        const sessionLabel = params.sessionKey ?? params.sessionId;
-        const contextFiles: EmbeddedContextFile[] = buildBootstrapContextFiles(bootstrapFiles, {
-          maxChars: resolveBootstrapMaxChars(params.config),
-          warn: (message) => log.warn(`${message} (sessionKey=${sessionLabel})`),
+        const hookAdjustedBootstrapFiles = await applyBootstrapHookOverrides({
+          files: bootstrapFiles,
+          workspaceDir: effectiveWorkspace,
+          config: params.config,
+          sessionKey: params.sessionKey,
+          sessionId: params.sessionId,
         });
+        const sessionLabel = params.sessionKey ?? params.sessionId;
+        const contextFiles: EmbeddedContextFile[] = buildBootstrapContextFiles(
+          hookAdjustedBootstrapFiles,
+          {
+            maxChars: resolveBootstrapMaxChars(params.config),
+            warn: (message) => log.warn(`${message} (sessionKey=${sessionLabel})`),
+          },
+        );
         const runAbortController = new AbortController();
         const toolsRaw = createClawdbotCodingTools({
           exec: {

src/agents/pi-embedded-runner/run/attempt.ts

@@ -17,6 +17,7 @@ import { isSubagentSessionKey } from "../../../routing/session-key.js";
 import { resolveUserPath } from "../../../utils.js";
 import { resolveClawdbotAgentDir } from "../../agent-paths.js";
 import { resolveSessionAgentIds } from "../../agent-scope.js";
+import { applyBootstrapHookOverrides } from "../../bootstrap-hooks.js";
 import { resolveModelAuthMode } from "../../model-auth.js";
 import {
   buildBootstrapContextFiles,
@@ -124,8 +125,15 @@ export async function runEmbeddedAttempt(
       await loadWorkspaceBootstrapFiles(effectiveWorkspace),
       params.sessionKey ?? params.sessionId,
     );
+    const hookAdjustedBootstrapFiles = await applyBootstrapHookOverrides({
+      files: bootstrapFiles,
+      workspaceDir: effectiveWorkspace,
+      config: params.config,
+      sessionKey: params.sessionKey,
+      sessionId: params.sessionId,
+    });
     const sessionLabel = params.sessionKey ?? params.sessionId;
-    const contextFiles = buildBootstrapContextFiles(bootstrapFiles, {
+    const contextFiles = buildBootstrapContextFiles(hookAdjustedBootstrapFiles, {
       maxChars: resolveBootstrapMaxChars(params.config),
       warn: (message) => log.warn(`${message} (sessionKey=${sessionLabel})`),
     });
@@ -251,7 +259,7 @@ export async function runEmbeddedAttempt(
         return { mode: runtime.mode, sandboxed: runtime.sandboxed };
       })(),
       systemPrompt: appendPrompt,
-      bootstrapFiles,
+      bootstrapFiles: hookAdjustedBootstrapFiles,
       injectedFiles: contextFiles,
       skillsPrompt,
       tools,

src/auto-reply/reply/commands-context-report.ts

@@ -9,6 +9,7 @@ import { getSkillsSnapshotVersion } from "../../agents/skills/refresh.js";
 import { buildAgentSystemPrompt } from "../../agents/system-prompt.js";
 import { buildSystemPromptReport } from "../../agents/system-prompt-report.js";
 import { buildToolSummaryMap } from "../../agents/tool-summaries.js";
+import { applyBootstrapHookOverrides } from "../../agents/bootstrap-hooks.js";
 import {
   filterBootstrapFilesForSession,
   loadWorkspaceBootstrapFiles,
@@ -59,7 +60,14 @@ async function resolveContextReport(
     await loadWorkspaceBootstrapFiles(workspaceDir),
     params.sessionKey,
   );
-  const injectedFiles = buildBootstrapContextFiles(bootstrapFiles, {
+  const hookAdjustedBootstrapFiles = await applyBootstrapHookOverrides({
+    files: bootstrapFiles,
+    workspaceDir,
+    config: params.cfg,
+    sessionKey: params.sessionKey,
+    sessionId: params.sessionEntry?.sessionId,
+  });
+  const injectedFiles = buildBootstrapContextFiles(hookAdjustedBootstrapFiles, {
     maxChars: bootstrapMaxChars,
   });
   const skillsSnapshot = (() => {
@@ -143,7 +151,7 @@ async function resolveContextReport(
     bootstrapMaxChars,
     sandbox: { mode: sandboxRuntime.mode, sandboxed: sandboxRuntime.sandboxed },
     systemPrompt,
-    bootstrapFiles,
+    bootstrapFiles: hookAdjustedBootstrapFiles,
     injectedFiles,
     skillsPrompt,
     tools,

src/hooks/bundled/README.md

@@ -32,6 +32,20 @@ Logs all command events to a centralized audit file.
 clawdbot hooks enable command-logger
 ```
 
+### 😈 soul-evil
+
+Swaps injected `SOUL.md` content with `SOUL_EVIL.md` during a purge window or by random chance.
+
+**Events**: `agent:bootstrap`
+**What it does**: Overrides the injected SOUL content before the system prompt is built.
+**Output**: No files written; swaps happen in-memory only.
+
+**Enable**:
+
+```bash
+clawdbot hooks enable soul-evil
+```
+
 ## Hook Structure
 
 Each hook is a directory containing:
@@ -140,6 +154,7 @@ Currently supported events:
 - **command:new**: `/new` command specifically
 - **command:reset**: `/reset` command
 - **command:stop**: `/stop` command
+- **agent:bootstrap**: Before workspace bootstrap files are injected
 
 More event types coming soon (session lifecycle, agent errors, etc.).
 

src/hooks/bundled/soul-evil/HOOK.md

@@ -0,0 +1,72 @@
+---
+name: soul-evil
+description: "Swap SOUL.md with SOUL_EVIL.md during a purge window or by random chance"
+homepage: https://docs.clawd.bot/hooks#soul-evil
+metadata:
+  {
+    "clawdbot":
+      {
+        "emoji": "😈",
+        "events": ["agent:bootstrap"],
+        "requires":
+          { "config": ["hooks.internal.entries.soul-evil.enabled"] },
+        "install": [{ "id": "bundled", "kind": "bundled", "label": "Bundled with Clawdbot" }],
+      },
+  }
+---
+
+# SOUL Evil Hook
+
+Replaces the injected `SOUL.md` content with `SOUL_EVIL.md` during a daily purge window or by random chance.
+
+## What It Does
+
+When enabled and the trigger conditions match, the hook swaps the **injected** `SOUL.md` content before the system prompt is built. It does **not** modify files on disk.
+
+## Files
+
+- `SOUL.md` — normal persona (always read)
+- `SOUL_EVIL.md` — alternate persona (read only when triggered)
+
+You can change the filename via hook config.
+
+## Configuration
+
+Add this to your config (`~/.clawdbot/clawdbot.json`):
+
+```json
+{
+  "hooks": {
+    "internal": {
+      "enabled": true,
+      "entries": {
+        "soul-evil": {
+          "enabled": true,
+          "file": "SOUL_EVIL.md",
+          "chance": 0.1,
+          "purge": { "at": "21:00", "duration": "15m" }
+        }
+      }
+    }
+  }
+}
+```
+
+### Options
+
+- `file` (string): alternate SOUL filename (default: `SOUL_EVIL.md`)
+- `chance` (number 0–1): random chance per run to swap in SOUL_EVIL
+- `purge.at` (HH:mm): daily purge window start time (24h)
+- `purge.duration` (duration): window length (e.g. `30s`, `10m`, `1h`)
+
+**Precedence:** purge window wins over chance.
+
+## Requirements
+
+- `hooks.internal.entries.soul-evil.enabled` must be set to `true`
+
+## Enable
+
+```bash
+clawdbot hooks enable soul-evil
+```

src/hooks/bundled/soul-evil/handler.ts

@@ -0,0 +1,61 @@
+import type { ClawdbotConfig } from "../../../config/config.js";
+import { isSubagentSessionKey } from "../../../routing/session-key.js";
+import { resolveHookConfig } from "../../config.js";
+import type { AgentBootstrapHookContext, HookHandler } from "../../hooks.js";
+import {
+  applySoulEvilOverride,
+  type SoulEvilConfig,
+} from "../../soul-evil.js";
+
+const HOOK_KEY = "soul-evil";
+
+function resolveSoulEvilConfig(entry: Record<string, unknown> | undefined): SoulEvilConfig | null {
+  if (!entry) return null;
+  const file = typeof entry.file === "string" ? entry.file : undefined;
+  const chance = typeof entry.chance === "number" ? entry.chance : undefined;
+  const purge =
+    entry.purge && typeof entry.purge === "object"
+      ? {
+          at: typeof (entry.purge as { at?: unknown }).at === "string"
+            ? (entry.purge as { at?: string }).at
+            : undefined,
+          duration:
+            typeof (entry.purge as { duration?: unknown }).duration === "string"
+              ? (entry.purge as { duration?: string }).duration
+              : undefined,
+        }
+      : undefined;
+  if (!file && chance === undefined && !purge) return null;
+  return { file, chance, purge };
+}
+
+const soulEvilHook: HookHandler = async (event) => {
+  if (event.type !== "agent" || event.action !== "bootstrap") return;
+
+  const context = event.context as AgentBootstrapHookContext;
+  if (context.sessionKey && isSubagentSessionKey(context.sessionKey)) return;
+  const cfg = context.cfg as ClawdbotConfig | undefined;
+  const hookConfig = resolveHookConfig(cfg, HOOK_KEY);
+  if (!hookConfig || hookConfig.enabled === false) return;
+
+  const soulConfig = resolveSoulEvilConfig(hookConfig as Record<string, unknown>);
+  if (!soulConfig) return;
+
+  const workspaceDir = context.workspaceDir;
+  if (!workspaceDir || !Array.isArray(context.bootstrapFiles)) return;
+
+  const updated = await applySoulEvilOverride({
+    files: context.bootstrapFiles,
+    workspaceDir,
+    config: soulConfig,
+    userTimezone: cfg?.agents?.defaults?.userTimezone,
+    log: {
+      warn: (message) => console.warn(`[soul-evil] ${message}`),
+      debug: (message) => console.debug?.(`[soul-evil] ${message}`),
+    },
+  });
+
+  context.bootstrapFiles = updated;
+};
+
+export default soulEvilHook;

src/hooks/internal-hooks.ts

@@ -5,8 +5,20 @@
  * like command processing, session lifecycle, etc.
  */
 
+import type { WorkspaceBootstrapFile } from "../agents/workspace.js";
+import type { ClawdbotConfig } from "../config/config.js";
+
 export type InternalHookEventType = "command" | "session" | "agent";
 
+export type AgentBootstrapHookContext = {
+  workspaceDir: string;
+  bootstrapFiles: WorkspaceBootstrapFile[];
+  cfg?: ClawdbotConfig;
+  sessionKey?: string;
+  sessionId?: string;
+  agentId?: string;
+};
+
 export interface InternalHookEvent {
   /** The type of event (command, session, agent, etc.) */
   type: InternalHookEventType;

src/hooks/soul-evil.test.ts

@@ -0,0 +1,138 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+
+import { describe, expect, it } from "vitest";
+
+import {
+  applySoulEvilOverride,
+  decideSoulEvil,
+  DEFAULT_SOUL_EVIL_FILENAME,
+} from "./soul-evil.js";
+import {
+  DEFAULT_SOUL_FILENAME,
+  type WorkspaceBootstrapFile,
+} from "../agents/workspace.js";
+
+const makeFiles = (overrides?: Partial<WorkspaceBootstrapFile>) => [
+  {
+    name: DEFAULT_SOUL_FILENAME,
+    path: "/tmp/SOUL.md",
+    content: "friendly",
+    missing: false,
+    ...overrides,
+  },
+];
+
+describe("decideSoulEvil", () => {
+  it("returns false when no config", () => {
+    const result = decideSoulEvil({});
+    expect(result.useEvil).toBe(false);
+  });
+
+  it("activates on random chance", () => {
+    const result = decideSoulEvil({
+      config: { chance: 0.5 },
+      random: () => 0.2,
+    });
+    expect(result.useEvil).toBe(true);
+    expect(result.reason).toBe("chance");
+  });
+
+  it("activates during purge window", () => {
+    const result = decideSoulEvil({
+      config: {
+        purge: { at: "00:00", duration: "10m" },
+      },
+      userTimezone: "UTC",
+      now: new Date("2026-01-01T00:05:00Z"),
+    });
+    expect(result.useEvil).toBe(true);
+    expect(result.reason).toBe("purge");
+  });
+
+  it("prefers purge window over random chance", () => {
+    const result = decideSoulEvil({
+      config: {
+        chance: 0,
+        purge: { at: "00:00", duration: "10m" },
+      },
+      userTimezone: "UTC",
+      now: new Date("2026-01-01T00:05:00Z"),
+      random: () => 0,
+    });
+    expect(result.useEvil).toBe(true);
+    expect(result.reason).toBe("purge");
+  });
+
+  it("skips purge window when outside duration", () => {
+    const result = decideSoulEvil({
+      config: {
+        purge: { at: "00:00", duration: "10m" },
+      },
+      userTimezone: "UTC",
+      now: new Date("2026-01-01T00:30:00Z"),
+    });
+    expect(result.useEvil).toBe(false);
+  });
+
+  it("honors sub-minute purge durations", () => {
+    const config = {
+      purge: { at: "00:00", duration: "30s" },
+    };
+    const active = decideSoulEvil({
+      config,
+      userTimezone: "UTC",
+      now: new Date("2026-01-01T00:00:20Z"),
+    });
+    const inactive = decideSoulEvil({
+      config,
+      userTimezone: "UTC",
+      now: new Date("2026-01-01T00:00:40Z"),
+    });
+    expect(active.useEvil).toBe(true);
+    expect(active.reason).toBe("purge");
+    expect(inactive.useEvil).toBe(false);
+  });
+});
+
+describe("applySoulEvilOverride", () => {
+  it("replaces SOUL content when evil is active and file exists", async () => {
+    const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-soul-"));
+    const evilPath = path.join(tempDir, DEFAULT_SOUL_EVIL_FILENAME);
+    await fs.writeFile(evilPath, "chaotic", "utf-8");
+
+    const files = makeFiles({
+      path: path.join(tempDir, DEFAULT_SOUL_FILENAME),
+    });
+
+    const updated = await applySoulEvilOverride({
+      files,
+      workspaceDir: tempDir,
+      config: { chance: 1 },
+      userTimezone: "UTC",
+      random: () => 0,
+    });
+
+    const soul = updated.find((file) => file.name === DEFAULT_SOUL_FILENAME);
+    expect(soul?.content).toBe("chaotic");
+  });
+
+  it("leaves SOUL content when evil file is missing", async () => {
+    const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-soul-"));
+    const files = makeFiles({
+      path: path.join(tempDir, DEFAULT_SOUL_FILENAME),
+    });
+
+    const updated = await applySoulEvilOverride({
+      files,
+      workspaceDir: tempDir,
+      config: { chance: 1 },
+      userTimezone: "UTC",
+      random: () => 0,
+    });
+
+    const soul = updated.find((file) => file.name === DEFAULT_SOUL_FILENAME);
+    expect(soul?.content).toBe("friendly");
+  });
+});

src/hooks/soul-evil.ts

@@ -0,0 +1,209 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+
+import { resolveUserTimezone } from "../agents/date-time.js";
+import type { WorkspaceBootstrapFile } from "../agents/workspace.js";
+import { parseDurationMs } from "../cli/parse-duration.js";
+import { resolveUserPath } from "../utils.js";
+
+export const DEFAULT_SOUL_EVIL_FILENAME = "SOUL_EVIL.md";
+
+export type SoulEvilConfig = {
+  /** Alternate SOUL file name (default: SOUL_EVIL.md). */
+  file?: string;
+  /** Random chance (0-1) to use SOUL_EVIL on any message. */
+  chance?: number;
+  /** Daily purge window (static time each day). */
+  purge?: {
+    /** Start time in 24h HH:mm format. */
+    at?: string;
+    /** Duration (e.g. 30s, 10m, 1h). */
+    duration?: string;
+  };
+};
+
+type SoulEvilDecision = {
+  useEvil: boolean;
+  reason?: "purge" | "chance";
+  fileName: string;
+};
+
+type SoulEvilCheckParams = {
+  config?: SoulEvilConfig;
+  userTimezone?: string;
+  now?: Date;
+  random?: () => number;
+};
+
+type SoulEvilLog = {
+  debug?: (message: string) => void;
+  warn?: (message: string) => void;
+};
+
+function clampChance(value?: number): number {
+  if (typeof value !== "number" || !Number.isFinite(value)) return 0;
+  return Math.min(1, Math.max(0, value));
+}
+
+function parsePurgeAt(raw?: string): number | null {
+  if (!raw) return null;
+  const trimmed = raw.trim();
+  const match = /^([01]?\d|2[0-3]):([0-5]\d)$/.exec(trimmed);
+  if (!match) return null;
+  const hour = Number.parseInt(match[1] ?? "", 10);
+  const minute = Number.parseInt(match[2] ?? "", 10);
+  if (!Number.isFinite(hour) || !Number.isFinite(minute)) return null;
+  return hour * 60 + minute;
+}
+
+function timeOfDayMsInTimezone(date: Date, timeZone: string): number | null {
+  try {
+    const parts = new Intl.DateTimeFormat("en-US", {
+      timeZone,
+      hour: "2-digit",
+      minute: "2-digit",
+      second: "2-digit",
+      hourCycle: "h23",
+    }).formatToParts(date);
+    const map: Record<string, string> = {};
+    for (const part of parts) {
+      if (part.type !== "literal") map[part.type] = part.value;
+    }
+    if (!map.hour || !map.minute || !map.second) return null;
+    const hour = Number.parseInt(map.hour, 10);
+    const minute = Number.parseInt(map.minute, 10);
+    const second = Number.parseInt(map.second, 10);
+    if (
+      !Number.isFinite(hour) ||
+      !Number.isFinite(minute) ||
+      !Number.isFinite(second)
+    ) {
+      return null;
+    }
+    return (hour * 3600 + minute * 60 + second) * 1000 + date.getMilliseconds();
+  } catch {
+    return null;
+  }
+}
+
+function isWithinDailyPurgeWindow(params: {
+  at?: string;
+  duration?: string;
+  now: Date;
+  timeZone: string;
+}): boolean {
+  if (!params.at || !params.duration) return false;
+  const startMinutes = parsePurgeAt(params.at);
+  if (startMinutes === null) return false;
+
+  let durationMs: number;
+  try {
+    durationMs = parseDurationMs(params.duration, { defaultUnit: "m" });
+  } catch {
+    return false;
+  }
+  if (!Number.isFinite(durationMs) || durationMs <= 0) return false;
+
+  const dayMs = 24 * 60 * 60 * 1000;
+  if (durationMs >= dayMs) return true;
+
+  const nowMs = timeOfDayMsInTimezone(params.now, params.timeZone);
+  if (nowMs === null) return false;
+
+  const startMs = startMinutes * 60 * 1000;
+  const endMs = startMs + durationMs;
+  if (endMs < dayMs) {
+    return nowMs >= startMs && nowMs < endMs;
+  }
+  const wrappedEnd = endMs % dayMs;
+  return nowMs >= startMs || nowMs < wrappedEnd;
+}
+
+export function decideSoulEvil(params: SoulEvilCheckParams): SoulEvilDecision {
+  const evil = params.config;
+  const fileName = evil?.file?.trim() || DEFAULT_SOUL_EVIL_FILENAME;
+  if (!evil) {
+    return { useEvil: false, fileName };
+  }
+
+  const timeZone = resolveUserTimezone(params.userTimezone);
+  const now = params.now ?? new Date();
+  const inPurge = isWithinDailyPurgeWindow({
+    at: evil.purge?.at,
+    duration: evil.purge?.duration,
+    now,
+    timeZone,
+  });
+  if (inPurge) {
+    return { useEvil: true, reason: "purge", fileName };
+  }
+
+  const chance = clampChance(evil.chance);
+  if (chance > 0) {
+    const random = params.random ?? Math.random;
+    if (random() < chance) {
+      return { useEvil: true, reason: "chance", fileName };
+    }
+  }
+
+  return { useEvil: false, fileName };
+}
+
+export async function applySoulEvilOverride(params: {
+  files: WorkspaceBootstrapFile[];
+  workspaceDir: string;
+  config?: SoulEvilConfig;
+  userTimezone?: string;
+  now?: Date;
+  random?: () => number;
+  log?: SoulEvilLog;
+}): Promise<WorkspaceBootstrapFile[]> {
+  const decision = decideSoulEvil({
+    config: params.config,
+    userTimezone: params.userTimezone,
+    now: params.now,
+    random: params.random,
+  });
+  if (!decision.useEvil) return params.files;
+
+  const workspaceDir = resolveUserPath(params.workspaceDir);
+  const evilPath = path.join(workspaceDir, decision.fileName);
+  let evilContent: string;
+  try {
+    evilContent = await fs.readFile(evilPath, "utf-8");
+  } catch {
+    params.log?.warn?.(
+      `SOUL_EVIL active (${decision.reason ?? "unknown"}) but file missing: ${evilPath}`,
+    );
+    return params.files;
+  }
+
+  if (!evilContent.trim()) {
+    params.log?.warn?.(
+      `SOUL_EVIL active (${decision.reason ?? "unknown"}) but file empty: ${evilPath}`,
+    );
+    return params.files;
+  }
+
+  const hasSoulEntry = params.files.some((file) => file.name === "SOUL.md");
+  if (!hasSoulEntry) {
+    params.log?.warn?.(
+      `SOUL_EVIL active (${decision.reason ?? "unknown"}) but SOUL.md not in bootstrap files`,
+    );
+    return params.files;
+  }
+
+  let replaced = false;
+  const updated = params.files.map((file) => {
+    if (file.name !== "SOUL.md") return file;
+    replaced = true;
+    return { ...file, content: evilContent, missing: false };
+  });
+  if (!replaced) return params.files;
+
+  params.log?.debug?.(
+    `SOUL_EVIL active (${decision.reason ?? "unknown"}) using ${decision.fileName}`,
+  );
+
+  return updated;
+}