diff --git a/src/config/schema.ts b/src/config/schema.ts
index 08b7d45..1a8b14d 100644
--- a/src/config/schema.ts
+++ b/src/config/schema.ts
@@ -69,6 +69,7 @@ export const HookNameSchema = z.enum([
   "preemptive-compaction",
   "compaction-context-injector",
   "claude-code-hooks",
+  "auto-slash-command",
 ])
 
 export const BuiltinCommandNameSchema = z.enum([
diff --git a/src/hooks/auto-slash-command/constants.ts b/src/hooks/auto-slash-command/constants.ts
new file mode 100644
index 0000000..250b891
--- /dev/null
+++ b/src/hooks/auto-slash-command/constants.ts
@@ -0,0 +1,11 @@
+export const HOOK_NAME = "auto-slash-command" as const
+
+export const AUTO_SLASH_COMMAND_TAG_OPEN = "<auto-slash-command>"
+export const AUTO_SLASH_COMMAND_TAG_CLOSE = "</auto-slash-command>"
+
+export const SLASH_COMMAND_PATTERN = /^\/([a-zA-Z][\w-]*)\s*(.*)/
+
+export const EXCLUDED_COMMANDS = new Set([
+  "ralph-loop",
+  "cancel-ralph",
+])
diff --git a/src/hooks/auto-slash-command/detector.test.ts b/src/hooks/auto-slash-command/detector.test.ts
new file mode 100644
index 0000000..30840ff
--- /dev/null
+++ b/src/hooks/auto-slash-command/detector.test.ts
@@ -0,0 +1,296 @@
+import { describe, expect, it } from "bun:test"
+import {
+  parseSlashCommand,
+  detectSlashCommand,
+  isExcludedCommand,
+  removeCodeBlocks,
+  extractPromptText,
+} from "./detector"
+
+describe("auto-slash-command detector", () => {
+  describe("removeCodeBlocks", () => {
+    it("should remove markdown code blocks", () => {
+      // #given text with code blocks
+      const text = "Hello ```code here``` world"
+
+      // #when removing code blocks
+      const result = removeCodeBlocks(text)
+
+      // #then code blocks should be removed
+      expect(result).toBe("Hello  world")
+    })
+
+    it("should remove multiline code blocks", () => {
+      // #given text with multiline code blocks
+      const text = `Before
+\`\`\`javascript
+/command-inside-code
+\`\`\`
+After`
+
+      // #when removing code blocks
+      const result = removeCodeBlocks(text)
+
+      // #then code blocks should be removed
+      expect(result).toContain("Before")
+      expect(result).toContain("After")
+      expect(result).not.toContain("/command-inside-code")
+    })
+
+    it("should handle text without code blocks", () => {
+      // #given text without code blocks
+      const text = "Just regular text"
+
+      // #when removing code blocks
+      const result = removeCodeBlocks(text)
+
+      // #then text should remain unchanged
+      expect(result).toBe("Just regular text")
+    })
+  })
+
+  describe("parseSlashCommand", () => {
+    it("should parse simple command without args", () => {
+      // #given a simple slash command
+      const text = "/commit"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should extract command correctly
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("commit")
+      expect(result?.args).toBe("")
+    })
+
+    it("should parse command with arguments", () => {
+      // #given a slash command with arguments
+      const text = "/plan create a new feature for auth"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should extract command and args
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("plan")
+      expect(result?.args).toBe("create a new feature for auth")
+    })
+
+    it("should parse command with quoted arguments", () => {
+      // #given a slash command with quoted arguments
+      const text = '/execute "build the API"'
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should extract command and args
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("execute")
+      expect(result?.args).toBe('"build the API"')
+    })
+
+    it("should parse command with hyphen in name", () => {
+      // #given a slash command with hyphen
+      const text = "/frontend-template-creator project"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should extract full command name
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("frontend-template-creator")
+      expect(result?.args).toBe("project")
+    })
+
+    it("should return null for non-slash text", () => {
+      // #given text without slash
+      const text = "regular text"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should return null
+      expect(result).toBeNull()
+    })
+
+    it("should return null for slash not at start", () => {
+      // #given text with slash in middle
+      const text = "some text /command"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should return null (slash not at start)
+      expect(result).toBeNull()
+    })
+
+    it("should return null for just a slash", () => {
+      // #given just a slash
+      const text = "/"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should return null
+      expect(result).toBeNull()
+    })
+
+    it("should return null for slash followed by number", () => {
+      // #given slash followed by number
+      const text = "/123"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should return null (command must start with letter)
+      expect(result).toBeNull()
+    })
+
+    it("should handle whitespace before slash", () => {
+      // #given command with leading whitespace
+      const text = "  /commit"
+
+      // #when parsing
+      const result = parseSlashCommand(text)
+
+      // #then should parse after trimming
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("commit")
+    })
+  })
+
+  describe("isExcludedCommand", () => {
+    it("should exclude ralph-loop", () => {
+      // #given ralph-loop command
+      // #when checking exclusion
+      // #then should be excluded
+      expect(isExcludedCommand("ralph-loop")).toBe(true)
+    })
+
+    it("should exclude cancel-ralph", () => {
+      // #given cancel-ralph command
+      // #when checking exclusion
+      // #then should be excluded
+      expect(isExcludedCommand("cancel-ralph")).toBe(true)
+    })
+
+    it("should be case-insensitive for exclusion", () => {
+      // #given uppercase variants
+      // #when checking exclusion
+      // #then should still be excluded
+      expect(isExcludedCommand("RALPH-LOOP")).toBe(true)
+      expect(isExcludedCommand("Cancel-Ralph")).toBe(true)
+    })
+
+    it("should not exclude regular commands", () => {
+      // #given regular commands
+      // #when checking exclusion
+      // #then should not be excluded
+      expect(isExcludedCommand("commit")).toBe(false)
+      expect(isExcludedCommand("plan")).toBe(false)
+      expect(isExcludedCommand("execute")).toBe(false)
+    })
+  })
+
+  describe("detectSlashCommand", () => {
+    it("should detect slash command in plain text", () => {
+      // #given plain text with slash command
+      const text = "/commit fix typo"
+
+      // #when detecting
+      const result = detectSlashCommand(text)
+
+      // #then should detect
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("commit")
+      expect(result?.args).toBe("fix typo")
+    })
+
+    it("should NOT detect slash command inside code block", () => {
+      // #given slash command inside code block
+      const text = "```bash\n/command\n```"
+
+      // #when detecting
+      const result = detectSlashCommand(text)
+
+      // #then should not detect (only code block content)
+      expect(result).toBeNull()
+    })
+
+    it("should detect command when text has code blocks elsewhere", () => {
+      // #given slash command before code block
+      const text = "/commit fix\n```code```"
+
+      // #when detecting
+      const result = detectSlashCommand(text)
+
+      // #then should detect the command
+      expect(result).not.toBeNull()
+      expect(result?.command).toBe("commit")
+    })
+
+    it("should NOT detect excluded commands", () => {
+      // #given excluded command
+      const text = "/ralph-loop do something"
+
+      // #when detecting
+      const result = detectSlashCommand(text)
+
+      // #then should not detect
+      expect(result).toBeNull()
+    })
+
+    it("should return null for non-command text", () => {
+      // #given regular text
+      const text = "Just some regular text"
+
+      // #when detecting
+      const result = detectSlashCommand(text)
+
+      // #then should return null
+      expect(result).toBeNull()
+    })
+  })
+
+  describe("extractPromptText", () => {
+    it("should extract text from parts", () => {
+      // #given message parts
+      const parts = [
+        { type: "text", text: "Hello " },
+        { type: "tool_use", id: "123" },
+        { type: "text", text: "world" },
+      ]
+
+      // #when extracting
+      const result = extractPromptText(parts)
+
+      // #then should join text parts
+      expect(result).toBe("Hello  world")
+    })
+
+    it("should handle empty parts", () => {
+      // #given empty parts
+      const parts: Array<{ type: string; text?: string }> = []
+
+      // #when extracting
+      const result = extractPromptText(parts)
+
+      // #then should return empty string
+      expect(result).toBe("")
+    })
+
+    it("should handle parts without text", () => {
+      // #given parts without text content
+      const parts = [
+        { type: "tool_use", id: "123" },
+        { type: "tool_result", output: "result" },
+      ]
+
+      // #when extracting
+      const result = extractPromptText(parts)
+
+      // #then should return empty string
+      expect(result).toBe("")
+    })
+  })
+})
diff --git a/src/hooks/auto-slash-command/detector.ts b/src/hooks/auto-slash-command/detector.ts
new file mode 100644
index 0000000..87e17c6
--- /dev/null
+++ b/src/hooks/auto-slash-command/detector.ts
@@ -0,0 +1,65 @@
+import {
+  SLASH_COMMAND_PATTERN,
+  EXCLUDED_COMMANDS,
+} from "./constants"
+import type { ParsedSlashCommand } from "./types"
+
+const CODE_BLOCK_PATTERN = /```[\s\S]*?```/g
+
+export function removeCodeBlocks(text: string): string {
+  return text.replace(CODE_BLOCK_PATTERN, "")
+}
+
+export function parseSlashCommand(text: string): ParsedSlashCommand | null {
+  const trimmed = text.trim()
+
+  if (!trimmed.startsWith("/")) {
+    return null
+  }
+
+  const match = trimmed.match(SLASH_COMMAND_PATTERN)
+  if (!match) {
+    return null
+  }
+
+  const [raw, command, args] = match
+  return {
+    command: command.toLowerCase(),
+    args: args.trim(),
+    raw,
+  }
+}
+
+export function isExcludedCommand(command: string): boolean {
+  return EXCLUDED_COMMANDS.has(command.toLowerCase())
+}
+
+export function detectSlashCommand(text: string): ParsedSlashCommand | null {
+  const textWithoutCodeBlocks = removeCodeBlocks(text)
+  const trimmed = textWithoutCodeBlocks.trim()
+
+  if (!trimmed.startsWith("/")) {
+    return null
+  }
+
+  const parsed = parseSlashCommand(trimmed)
+
+  if (!parsed) {
+    return null
+  }
+
+  if (isExcludedCommand(parsed.command)) {
+    return null
+  }
+
+  return parsed
+}
+
+export function extractPromptText(
+  parts: Array<{ type: string; text?: string }>
+): string {
+  return parts
+    .filter((p) => p.type === "text")
+    .map((p) => p.text || "")
+    .join(" ")
+}
diff --git a/src/hooks/auto-slash-command/executor.ts b/src/hooks/auto-slash-command/executor.ts
new file mode 100644
index 0000000..2d4582f
--- /dev/null
+++ b/src/hooks/auto-slash-command/executor.ts
@@ -0,0 +1,193 @@
+import { existsSync, readdirSync, readFileSync } from "fs"
+import { join, basename, dirname } from "path"
+import { homedir } from "os"
+import {
+  parseFrontmatter,
+  resolveCommandsInText,
+  resolveFileReferencesInText,
+  sanitizeModelField,
+  getClaudeConfigDir,
+} from "../../shared"
+import { isMarkdownFile } from "../../shared/file-utils"
+import { discoverAllSkills, type LoadedSkill } from "../../features/opencode-skill-loader"
+import type { ParsedSlashCommand } from "./types"
+
+interface CommandScope {
+  type: "user" | "project" | "opencode" | "opencode-project" | "skill"
+}
+
+interface CommandMetadata {
+  name: string
+  description: string
+  argumentHint?: string
+  model?: string
+  agent?: string
+  subtask?: boolean
+}
+
+interface CommandInfo {
+  name: string
+  path?: string
+  metadata: CommandMetadata
+  content?: string
+  scope: CommandScope["type"]
+}
+
+function discoverCommandsFromDir(commandsDir: string, scope: CommandScope["type"]): CommandInfo[] {
+  if (!existsSync(commandsDir)) {
+    return []
+  }
+
+  const entries = readdirSync(commandsDir, { withFileTypes: true })
+  const commands: CommandInfo[] = []
+
+  for (const entry of entries) {
+    if (!isMarkdownFile(entry)) continue
+
+    const commandPath = join(commandsDir, entry.name)
+    const commandName = basename(entry.name, ".md")
+
+    try {
+      const content = readFileSync(commandPath, "utf-8")
+      const { data, body } = parseFrontmatter(content)
+
+      const isOpencodeSource = scope === "opencode" || scope === "opencode-project"
+      const metadata: CommandMetadata = {
+        name: commandName,
+        description: data.description || "",
+        argumentHint: data["argument-hint"],
+        model: sanitizeModelField(data.model, isOpencodeSource ? "opencode" : "claude-code"),
+        agent: data.agent,
+        subtask: Boolean(data.subtask),
+      }
+
+      commands.push({
+        name: commandName,
+        path: commandPath,
+        metadata,
+        content: body,
+        scope,
+      })
+    } catch {
+      continue
+    }
+  }
+
+  return commands
+}
+
+function skillToCommandInfo(skill: LoadedSkill): CommandInfo {
+  return {
+    name: skill.name,
+    path: skill.path,
+    metadata: {
+      name: skill.name,
+      description: skill.definition.description || "",
+      argumentHint: skill.definition.argumentHint,
+      model: skill.definition.model,
+      agent: skill.definition.agent,
+      subtask: skill.definition.subtask,
+    },
+    content: skill.definition.template,
+    scope: "skill",
+  }
+}
+
+function discoverAllCommands(): CommandInfo[] {
+  const userCommandsDir = join(getClaudeConfigDir(), "commands")
+  const projectCommandsDir = join(process.cwd(), ".claude", "commands")
+  const opencodeGlobalDir = join(homedir(), ".config", "opencode", "command")
+  const opencodeProjectDir = join(process.cwd(), ".opencode", "command")
+
+  const userCommands = discoverCommandsFromDir(userCommandsDir, "user")
+  const opencodeGlobalCommands = discoverCommandsFromDir(opencodeGlobalDir, "opencode")
+  const projectCommands = discoverCommandsFromDir(projectCommandsDir, "project")
+  const opencodeProjectCommands = discoverCommandsFromDir(opencodeProjectDir, "opencode-project")
+
+  const skills = discoverAllSkills()
+  const skillCommands = skills.map(skillToCommandInfo)
+
+  return [
+    ...opencodeProjectCommands,
+    ...projectCommands,
+    ...opencodeGlobalCommands,
+    ...userCommands,
+    ...skillCommands,
+  ]
+}
+
+function findCommand(commandName: string): CommandInfo | null {
+  const allCommands = discoverAllCommands()
+  return allCommands.find(
+    (cmd) => cmd.name.toLowerCase() === commandName.toLowerCase()
+  ) ?? null
+}
+
+async function formatCommandTemplate(cmd: CommandInfo, args: string): Promise<string> {
+  const sections: string[] = []
+
+  sections.push(`# /${cmd.name} Command\n`)
+
+  if (cmd.metadata.description) {
+    sections.push(`**Description**: ${cmd.metadata.description}\n`)
+  }
+
+  if (args) {
+    sections.push(`**User Arguments**: ${args}\n`)
+  }
+
+  if (cmd.metadata.model) {
+    sections.push(`**Model**: ${cmd.metadata.model}\n`)
+  }
+
+  if (cmd.metadata.agent) {
+    sections.push(`**Agent**: ${cmd.metadata.agent}\n`)
+  }
+
+  sections.push(`**Scope**: ${cmd.scope}\n`)
+  sections.push("---\n")
+  sections.push("## Command Instructions\n")
+
+  const commandDir = cmd.path ? dirname(cmd.path) : process.cwd()
+  const withFileRefs = await resolveFileReferencesInText(cmd.content || "", commandDir)
+  const resolvedContent = await resolveCommandsInText(withFileRefs)
+  sections.push(resolvedContent.trim())
+
+  if (args) {
+    sections.push("\n\n---\n")
+    sections.push("## User Request\n")
+    sections.push(args)
+  }
+
+  return sections.join("\n")
+}
+
+export interface ExecuteResult {
+  success: boolean
+  replacementText?: string
+  error?: string
+}
+
+export async function executeSlashCommand(parsed: ParsedSlashCommand): Promise<ExecuteResult> {
+  const command = findCommand(parsed.command)
+
+  if (!command) {
+    return {
+      success: false,
+      error: `Command "/${parsed.command}" not found. Use the slashcommand tool to list available commands.`,
+    }
+  }
+
+  try {
+    const template = await formatCommandTemplate(command, parsed.args)
+    return {
+      success: true,
+      replacementText: template,
+    }
+  } catch (err) {
+    return {
+      success: false,
+      error: `Failed to load command "/${parsed.command}": ${err instanceof Error ? err.message : String(err)}`,
+    }
+  }
+}
diff --git a/src/hooks/auto-slash-command/index.test.ts b/src/hooks/auto-slash-command/index.test.ts
new file mode 100644
index 0000000..42edb13
--- /dev/null
+++ b/src/hooks/auto-slash-command/index.test.ts
@@ -0,0 +1,275 @@
+import { describe, expect, it, beforeEach, mock } from "bun:test"
+import type {
+  AutoSlashCommandHookInput,
+  AutoSlashCommandHookOutput,
+} from "./types"
+
+const logMock = mock(() => {})
+
+mock.module("../../shared", () => ({
+  log: logMock,
+  parseFrontmatter: (content: string) => ({ data: {}, body: content }),
+  resolveCommandsInText: async (text: string) => text,
+  resolveFileReferencesInText: async (text: string) => text,
+  sanitizeModelField: (model: unknown) => model,
+  getClaudeConfigDir: () => "/mock/.claude",
+}))
+
+mock.module("../../shared/file-utils", () => ({
+  isMarkdownFile: () => false,
+}))
+
+mock.module("../../features/opencode-skill-loader", () => ({
+  discoverAllSkills: () => [],
+}))
+
+mock.module("fs", () => ({
+  existsSync: () => false,
+  readdirSync: () => [],
+  readFileSync: () => "",
+}))
+
+const { createAutoSlashCommandHook } = await import("./index")
+
+function createMockInput(sessionID: string, messageID?: string): AutoSlashCommandHookInput {
+  return {
+    sessionID,
+    messageID: messageID ?? `msg-${Date.now()}-${Math.random()}`,
+    agent: "test-agent",
+    model: { providerID: "anthropic", modelID: "claude-sonnet-4-5" },
+  }
+}
+
+function createMockOutput(text: string): AutoSlashCommandHookOutput {
+  return {
+    message: {
+      agent: "test-agent",
+      model: { providerID: "anthropic", modelID: "claude-sonnet-4-5" },
+      path: { cwd: "/test", root: "/test" },
+      tools: {},
+    },
+    parts: [{ type: "text", text }],
+  }
+}
+
+describe("createAutoSlashCommandHook", () => {
+  beforeEach(() => {
+    logMock.mockClear()
+  })
+
+  describe("slash command replacement", () => {
+    it("should replace message with error when command not found", async () => {
+      // #given a slash command that doesn't exist
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-notfound-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("/nonexistent-command args")
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should replace with error message
+      const textPart = output.parts.find((p) => p.type === "text")
+      expect(textPart?.text).toContain("<auto-slash-command>")
+      expect(textPart?.text).toContain("not found")
+    })
+
+    it("should wrap replacement in auto-slash-command tags", async () => {
+      // #given any slash command
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-tags-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("/some-command")
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should wrap in tags
+      const textPart = output.parts.find((p) => p.type === "text")
+      expect(textPart?.text).toContain("<auto-slash-command>")
+      expect(textPart?.text).toContain("</auto-slash-command>")
+    })
+
+    it("should completely replace original message text", async () => {
+      // #given slash command
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-replace-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("/test-cmd some args")
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then original text should be replaced, not prepended
+      const textPart = output.parts.find((p) => p.type === "text")
+      expect(textPart?.text).not.toContain("/test-cmd some args\n<auto-slash-command>")
+      expect(textPart?.text?.startsWith("<auto-slash-command>")).toBe(true)
+    })
+  })
+
+  describe("no slash command", () => {
+    it("should do nothing for regular text", async () => {
+      // #given regular text without slash
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-regular-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("Just regular text")
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not modify
+      expect(output.parts[0].text).toBe(originalText)
+    })
+
+    it("should do nothing for slash in middle of text", async () => {
+      // #given slash in middle
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-middle-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("Please run /commit later")
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not detect (not at start)
+      expect(output.parts[0].text).toBe(originalText)
+    })
+  })
+
+  describe("excluded commands", () => {
+    it("should NOT trigger for ralph-loop command", async () => {
+      // #given ralph-loop command
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-ralph-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("/ralph-loop do something")
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not modify (excluded command)
+      expect(output.parts[0].text).toBe(originalText)
+    })
+
+    it("should NOT trigger for cancel-ralph command", async () => {
+      // #given cancel-ralph command
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-cancel-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("/cancel-ralph")
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not modify
+      expect(output.parts[0].text).toBe(originalText)
+    })
+  })
+
+  describe("already processed", () => {
+    it("should skip if auto-slash-command tags already present", async () => {
+      // #given text with existing tags
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-existing-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput(
+        "<auto-slash-command>/commit</auto-slash-command>"
+      )
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not modify
+      expect(output.parts[0].text).toBe(originalText)
+    })
+  })
+
+  describe("code blocks", () => {
+    it("should NOT detect command inside code block", async () => {
+      // #given command inside code block
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-codeblock-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("```\n/commit\n```")
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not detect
+      expect(output.parts[0].text).toBe(originalText)
+    })
+  })
+
+  describe("edge cases", () => {
+    it("should handle empty text", async () => {
+      // #given empty text
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-empty-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("")
+
+      // #when hook is called
+      // #then should not throw
+      await expect(hook["chat.message"](input, output)).resolves.toBeUndefined()
+    })
+
+    it("should handle just slash", async () => {
+      // #given just slash
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-slash-only-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput("/")
+      const originalText = output.parts[0].text
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should not modify
+      expect(output.parts[0].text).toBe(originalText)
+    })
+
+    it("should handle command with special characters in args", async () => {
+      // #given command with special characters
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-special-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output = createMockOutput('/execute "test & stuff <tag>"')
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should handle gracefully (not found, but processed)
+      const textPart = output.parts.find((p) => p.type === "text")
+      expect(textPart?.text).toContain("<auto-slash-command>")
+      expect(textPart?.text).toContain("/execute")
+    })
+
+    it("should handle multiple text parts", async () => {
+      // #given multiple text parts
+      const hook = createAutoSlashCommandHook()
+      const sessionID = `test-session-multi-${Date.now()}`
+      const input = createMockInput(sessionID)
+      const output: AutoSlashCommandHookOutput = {
+        message: {},
+        parts: [
+          { type: "text", text: "/commit " },
+          { type: "text", text: "fix bug" },
+        ],
+      }
+
+      // #when hook is called
+      await hook["chat.message"](input, output)
+
+      // #then should detect from combined text and modify first text part
+      const firstTextPart = output.parts.find((p) => p.type === "text")
+      expect(firstTextPart?.text).toContain("<auto-slash-command>")
+    })
+  })
+})
diff --git a/src/hooks/auto-slash-command/index.ts b/src/hooks/auto-slash-command/index.ts
new file mode 100644
index 0000000..8182a88
--- /dev/null
+++ b/src/hooks/auto-slash-command/index.ts
@@ -0,0 +1,82 @@
+import {
+  detectSlashCommand,
+  extractPromptText,
+} from "./detector"
+import { executeSlashCommand } from "./executor"
+import { log } from "../../shared"
+import {
+  AUTO_SLASH_COMMAND_TAG_OPEN,
+  AUTO_SLASH_COMMAND_TAG_CLOSE,
+} from "./constants"
+import type {
+  AutoSlashCommandHookInput,
+  AutoSlashCommandHookOutput,
+} from "./types"
+
+export * from "./detector"
+export * from "./executor"
+export * from "./constants"
+export * from "./types"
+
+const sessionProcessedCommands = new Set<string>()
+
+export function createAutoSlashCommandHook() {
+  return {
+    "chat.message": async (
+      input: AutoSlashCommandHookInput,
+      output: AutoSlashCommandHookOutput
+    ): Promise<void> => {
+      const promptText = extractPromptText(output.parts)
+
+      if (
+        promptText.includes(AUTO_SLASH_COMMAND_TAG_OPEN) ||
+        promptText.includes(AUTO_SLASH_COMMAND_TAG_CLOSE)
+      ) {
+        return
+      }
+
+      const parsed = detectSlashCommand(promptText)
+
+      if (!parsed) {
+        return
+      }
+
+      const commandKey = `${input.sessionID}:${input.messageID}:${parsed.command}`
+      if (sessionProcessedCommands.has(commandKey)) {
+        return
+      }
+      sessionProcessedCommands.add(commandKey)
+
+      log(`[auto-slash-command] Detected: /${parsed.command}`, {
+        sessionID: input.sessionID,
+        args: parsed.args,
+      })
+
+      const result = await executeSlashCommand(parsed)
+
+      const idx = output.parts.findIndex((p) => p.type === "text" && p.text)
+      if (idx < 0) {
+        return
+      }
+
+      if (result.success && result.replacementText) {
+        const taggedContent = `${AUTO_SLASH_COMMAND_TAG_OPEN}\n${result.replacementText}\n${AUTO_SLASH_COMMAND_TAG_CLOSE}`
+        output.parts[idx].text = taggedContent
+
+        log(`[auto-slash-command] Replaced message with command template`, {
+          sessionID: input.sessionID,
+          command: parsed.command,
+        })
+      } else {
+        const errorMessage = `${AUTO_SLASH_COMMAND_TAG_OPEN}\n[AUTO-SLASH-COMMAND ERROR]\n${result.error}\n\nOriginal input: ${parsed.raw}\n${AUTO_SLASH_COMMAND_TAG_CLOSE}`
+        output.parts[idx].text = errorMessage
+
+        log(`[auto-slash-command] Command not found, showing error`, {
+          sessionID: input.sessionID,
+          command: parsed.command,
+          error: result.error,
+        })
+      }
+    },
+  }
+}
diff --git a/src/hooks/auto-slash-command/types.ts b/src/hooks/auto-slash-command/types.ts
new file mode 100644
index 0000000..60253e7
--- /dev/null
+++ b/src/hooks/auto-slash-command/types.ts
@@ -0,0 +1,23 @@
+export interface AutoSlashCommandHookInput {
+  sessionID: string
+  agent?: string
+  model?: { providerID: string; modelID: string }
+  messageID?: string
+}
+
+export interface AutoSlashCommandHookOutput {
+  message: Record<string, unknown>
+  parts: Array<{ type: string; text?: string; [key: string]: unknown }>
+}
+
+export interface ParsedSlashCommand {
+  command: string
+  args: string
+  raw: string
+}
+
+export interface AutoSlashCommandResult {
+  detected: boolean
+  parsedCommand?: ParsedSlashCommand
+  injectedMessage?: string
+}
diff --git a/src/hooks/index.ts b/src/hooks/index.ts
index 9a59971..efa76cd 100644
--- a/src/hooks/index.ts
+++ b/src/hooks/index.ts
@@ -23,3 +23,4 @@ export { createInteractiveBashSessionHook } from "./interactive-bash-session";
 export { createEmptyMessageSanitizerHook } from "./empty-message-sanitizer";
 export { createThinkingBlockValidatorHook } from "./thinking-block-validator";
 export { createRalphLoopHook, type RalphLoopHook } from "./ralph-loop";
+export { createAutoSlashCommandHook } from "./auto-slash-command";
diff --git a/src/index.ts b/src/index.ts
index e2a75d8..f155493 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -25,6 +25,7 @@ import {
   createEmptyMessageSanitizerHook,
   createThinkingBlockValidatorHook,
   createRalphLoopHook,
+  createAutoSlashCommandHook,
 } from "./hooks";
 import { createGoogleAntigravityAuthPlugin } from "./auth/antigravity";
 import {
@@ -259,6 +260,10 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
     ? createRalphLoopHook(ctx, { config: pluginConfig.ralph_loop })
     : null;
 
+  const autoSlashCommand = isHookEnabled("auto-slash-command")
+    ? createAutoSlashCommandHook()
+    : null;
+
   const backgroundManager = new BackgroundManager(ctx);
 
   const todoContinuationEnforcer = isHookEnabled("todo-continuation-enforcer")
@@ -310,6 +315,7 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
     "chat.message": async (input, output) => {
       await claudeCodeHooks["chat.message"]?.(input, output);
       await keywordDetector?.["chat.message"]?.(input, output);
+      await autoSlashCommand?.["chat.message"]?.(input, output);
 
       if (ralphLoop) {
         const parts = (output as { parts?: Array<{ type: string; text?: string }> }).parts;