diff --git a/src/hooks/keyword-detector/detector.ts b/src/hooks/keyword-detector/detector.ts
index 852d04f63..99a9e2ee8 100644
--- a/src/hooks/keyword-detector/detector.ts
+++ b/src/hooks/keyword-detector/detector.ts
@@ -14,6 +14,12 @@ export function removeCodeBlocks(text: string): string {
   return text.replace(CODE_BLOCK_PATTERN, "").replace(INLINE_CODE_PATTERN, "")
 }
 
+const SLASH_COMMAND_LEAD_PATTERN = /^\s*\/[a-zA-Z][\w-]*(?:\s|$)/
+
+export function looksLikeSlashCommand(text: string): boolean {
+  return SLASH_COMMAND_LEAD_PATTERN.test(text)
+}
+
 function resolveMessage(
   message: string | ((agentName?: string, modelID?: string) => string),
   agentName?: string,
diff --git a/src/hooks/keyword-detector/hook.ts b/src/hooks/keyword-detector/hook.ts
index 85408e84c..e44c46f93 100644
--- a/src/hooks/keyword-detector/hook.ts
+++ b/src/hooks/keyword-detector/hook.ts
@@ -1,7 +1,7 @@
 import type { PluginInput } from "@opencode-ai/plugin"
 import type { KeywordDetectorConfig } from "../../config/schema/keyword-detector"
 import type { DetectedKeyword } from "./detector"
-import { detectKeywordsWithType, extractPromptText } from "./detector"
+import { detectKeywordsWithType, extractPromptText, looksLikeSlashCommand } from "./detector"
 import { isPlannerAgent, isNonOmoAgent } from "./constants"
 import { log } from "../../shared"
 import {
@@ -58,6 +58,11 @@ export function createKeywordDetectorHook(
         return
       }
 
+      if (looksLikeSlashCommand(promptText)) {
+        log(`[keyword-detector] Skipping slash command invocation`, { sessionID: input.sessionID })
+        return
+      }
+
       const currentAgent = getSessionAgent(input.sessionID) ?? input.agent
 
       // Skip all keyword injection for non-OMO agents (e.g., OpenCode-Builder, Plan)
diff --git a/src/hooks/keyword-detector/hyperplan.test.ts b/src/hooks/keyword-detector/hyperplan.test.ts
index 12e293d81..a83b8f169 100644
--- a/src/hooks/keyword-detector/hyperplan.test.ts
+++ b/src/hooks/keyword-detector/hyperplan.test.ts
@@ -201,6 +201,67 @@ describe("keyword-detector hyperplan keyword", () => {
     expect(textPart!.text).toContain("hyperplan refactor stuff")
   })
 
+  test("should NOT inject hyperplan when user invokes /hyperplan slash command", async () => {
+    // given - main session typing the slash command form
+    const sessionID = "hyperplan-slash-session"
+    getMainSessionSpy = spyOn(sessionState, "getMainSessionID").mockReturnValue(sessionID)
+    const toastCalls: string[] = []
+    const hook = createKeywordDetectorHook(createMockPluginInput({ toastCalls }))
+    const output = {
+      message: {} as Record<string, unknown>,
+      parts: [{ type: "text", text: "/hyperplan refactor the auth module" }],
+    }
+
+    // when - keyword detection runs on slash-command-prefixed text
+    await hook["chat.message"]({ sessionID }, output)
+
+    // then - the slash command path owns the message; keyword detector must not double-inject
+    const textPart = output.parts.find(p => p.type === "text")
+    expect(textPart).toBeDefined()
+    expect(textPart!.text).toBe("/hyperplan refactor the auth module")
+    expect(textPart!.text).not.toContain("<hyperplan-mode>")
+    expect(toastCalls).not.toContain("Hyperplan Mode Activated")
+  })
+
+  test("should NOT inject hyperplan when user invokes /hpp shorthand slash command", async () => {
+    // given - main session and shorthand slash command
+    const sessionID = "hyperplan-slash-shorthand-session"
+    getMainSessionSpy = spyOn(sessionState, "getMainSessionID").mockReturnValue(sessionID)
+    const hook = createKeywordDetectorHook(createMockPluginInput())
+    const output = {
+      message: {} as Record<string, unknown>,
+      parts: [{ type: "text", text: "/hpp investigate the build pipeline" }],
+    }
+
+    // when - keyword detection runs
+    await hook["chat.message"]({ sessionID }, output)
+
+    // then - keyword detector should yield to the slash command system
+    const textPart = output.parts.find(p => p.type === "text")
+    expect(textPart).toBeDefined()
+    expect(textPart!.text).toBe("/hpp investigate the build pipeline")
+    expect(textPart!.text).not.toContain("<hyperplan-mode>")
+  })
+
+  test("should still inject hyperplan when slash appears mid-message (not a slash command)", async () => {
+    // given - text contains a slash later but does not start with one
+    const sessionID = "hyperplan-mid-slash-session"
+    getMainSessionSpy = spyOn(sessionState, "getMainSessionID").mockReturnValue(sessionID)
+    const hook = createKeywordDetectorHook(createMockPluginInput())
+    const output = {
+      message: {} as Record<string, unknown>,
+      parts: [{ type: "text", text: "hyperplan: refactor src/auth/handler.ts" }],
+    }
+
+    // when - keyword detection runs on free-form text that mentions hyperplan first
+    await hook["chat.message"]({ sessionID }, output)
+
+    // then - hyperplan should still fire (this is a real keyword invocation, not a slash command)
+    const textPart = output.parts.find(p => p.type === "text")
+    expect(textPart).toBeDefined()
+    expect(textPart!.text).toContain("<hyperplan-mode>")
+  })
+
   test("should skip hyperplan injection when agent name contains 'planner' token", async () => {
     // given - hook running with planner-named agent and a prompt that only triggers hpp
     const sessionID = "hyperplan-planner-session"