diff --git a/src/auto-reply/reply/commands-setunset.ts b/src/auto-reply/reply/commands-setunset.ts
new file mode 100644
index 000000000..137973a5e
--- /dev/null
+++ b/src/auto-reply/reply/commands-setunset.ts
@@ -0,0 +1,38 @@
+import { parseConfigValue } from "./config-value.js";
+
+export type SetUnsetParseResult =
+  | { kind: "set"; path: string; value: unknown }
+  | { kind: "unset"; path: string }
+  | { kind: "error"; message: string };
+
+export function parseSetUnsetCommand(params: {
+  slash: string;
+  action: "set" | "unset";
+  args: string;
+}): SetUnsetParseResult {
+  const action = params.action;
+  const args = params.args.trim();
+  if (action === "unset") {
+    if (!args) {
+      return { kind: "error", message: `Usage: ${params.slash} unset path` };
+    }
+    return { kind: "unset", path: args };
+  }
+  if (!args) {
+    return { kind: "error", message: `Usage: ${params.slash} set path=value` };
+  }
+  const eqIndex = args.indexOf("=");
+  if (eqIndex <= 0) {
+    return { kind: "error", message: `Usage: ${params.slash} set path=value` };
+  }
+  const path = args.slice(0, eqIndex).trim();
+  const rawValue = args.slice(eqIndex + 1);
+  if (!path) {
+    return { kind: "error", message: `Usage: ${params.slash} set path=value` };
+  }
+  const parsed = parseConfigValue(rawValue);
+  if (parsed.error) {
+    return { kind: "error", message: parsed.error };
+  }
+  return { kind: "set", path, value: parsed.value };
+}
diff --git a/src/auto-reply/reply/commands-slash-parse.ts b/src/auto-reply/reply/commands-slash-parse.ts
new file mode 100644
index 000000000..8cf5541e3
--- /dev/null
+++ b/src/auto-reply/reply/commands-slash-parse.ts
@@ -0,0 +1,46 @@
+export type SlashCommandParseResult =
+  | { kind: "no-match" }
+  | { kind: "empty" }
+  | { kind: "invalid" }
+  | { kind: "parsed"; action: string; args: string };
+
+export type ParsedSlashCommand =
+  | { ok: true; action: string; args: string }
+  | { ok: false; message: string };
+
+export function parseSlashCommandActionArgs(raw: string, slash: string): SlashCommandParseResult {
+  const trimmed = raw.trim();
+  const slashLower = slash.toLowerCase();
+  if (!trimmed.toLowerCase().startsWith(slashLower)) {
+    return { kind: "no-match" };
+  }
+  const rest = trimmed.slice(slash.length).trim();
+  if (!rest) {
+    return { kind: "empty" };
+  }
+  const match = rest.match(/^(\S+)(?:\s+([\s\S]+))?$/);
+  if (!match) {
+    return { kind: "invalid" };
+  }
+  const action = match[1]?.toLowerCase() ?? "";
+  const args = (match[2] ?? "").trim();
+  return { kind: "parsed", action, args };
+}
+
+export function parseSlashCommandOrNull(
+  raw: string,
+  slash: string,
+  opts: { invalidMessage: string; defaultAction?: string },
+): ParsedSlashCommand | null {
+  const parsed = parseSlashCommandActionArgs(raw, slash);
+  if (parsed.kind === "no-match") {
+    return null;
+  }
+  if (parsed.kind === "invalid") {
+    return { ok: false, message: opts.invalidMessage };
+  }
+  if (parsed.kind === "empty") {
+    return { ok: true, action: opts.defaultAction ?? "show", args: "" };
+  }
+  return { ok: true, action: parsed.action, args: parsed.args };
+}
diff --git a/src/auto-reply/reply/config-commands.ts b/src/auto-reply/reply/config-commands.ts
index b78baa459..fc924985c 100644
--- a/src/auto-reply/reply/config-commands.ts
+++ b/src/auto-reply/reply/config-commands.ts
@@ -1,4 +1,5 @@
-import { parseConfigValue } from "./config-value.js";
+import { parseSetUnsetCommand } from "./commands-setunset.js";
+import { parseSlashCommandOrNull } from "./commands-slash-parse.js";
 
 export type ConfigCommand =
   | { action: "show"; path?: string }
@@ -7,60 +8,31 @@ export type ConfigCommand =
   | { action: "error"; message: string };
 
 export function parseConfigCommand(raw: string): ConfigCommand | null {
-  const trimmed = raw.trim();
-  if (!trimmed.toLowerCase().startsWith("/config")) {
+  const parsed = parseSlashCommandOrNull(raw, "/config", {
+    invalidMessage: "Invalid /config syntax.",
+  });
+  if (!parsed) {
     return null;
   }
-  const rest = trimmed.slice("/config".length).trim();
-  if (!rest) {
-    return { action: "show" };
+  if (!parsed.ok) {
+    return { action: "error", message: parsed.message };
   }
-
-  const match = rest.match(/^(\S+)(?:\s+([\s\S]+))?$/);
-  if (!match) {
-    return { action: "error", message: "Invalid /config syntax." };
-  }
-  const action = match[1].toLowerCase();
-  const args = (match[2] ?? "").trim();
+  const { action, args } = parsed;
 
   switch (action) {
     case "show":
       return { action: "show", path: args || undefined };
     case "get":
       return { action: "show", path: args || undefined };
-    case "unset": {
-      if (!args) {
-        return { action: "error", message: "Usage: /config unset path" };
-      }
-      return { action: "unset", path: args };
-    }
+    case "unset":
     case "set": {
-      if (!args) {
-        return {
-          action: "error",
-          message: "Usage: /config set path=value",
-        };
+      const parsed = parseSetUnsetCommand({ slash: "/config", action, args });
+      if (parsed.kind === "error") {
+        return { action: "error", message: parsed.message };
       }
-      const eqIndex = args.indexOf("=");
-      if (eqIndex <= 0) {
-        return {
-          action: "error",
-          message: "Usage: /config set path=value",
-        };
-      }
-      const path = args.slice(0, eqIndex).trim();
-      const rawValue = args.slice(eqIndex + 1);
-      if (!path) {
-        return {
-          action: "error",
-          message: "Usage: /config set path=value",
-        };
-      }
-      const parsed = parseConfigValue(rawValue);
-      if (parsed.error) {
-        return { action: "error", message: parsed.error };
-      }
-      return { action: "set", path, value: parsed.value };
+      return parsed.kind === "set"
+        ? { action: "set", path: parsed.path, value: parsed.value }
+        : { action: "unset", path: parsed.path };
     }
     default:
       return {
diff --git a/src/auto-reply/reply/debug-commands.ts b/src/auto-reply/reply/debug-commands.ts
index 5f9f8c9fd..089caf2a5 100644
--- a/src/auto-reply/reply/debug-commands.ts
+++ b/src/auto-reply/reply/debug-commands.ts
@@ -1,4 +1,5 @@
-import { parseConfigValue } from "./config-value.js";
+import { parseSetUnsetCommand } from "./commands-setunset.js";
+import { parseSlashCommandOrNull } from "./commands-slash-parse.js";
 
 export type DebugCommand =
   | { action: "show" }
@@ -8,60 +9,31 @@ export type DebugCommand =
   | { action: "error"; message: string };
 
 export function parseDebugCommand(raw: string): DebugCommand | null {
-  const trimmed = raw.trim();
-  if (!trimmed.toLowerCase().startsWith("/debug")) {
+  const parsed = parseSlashCommandOrNull(raw, "/debug", {
+    invalidMessage: "Invalid /debug syntax.",
+  });
+  if (!parsed) {
     return null;
   }
-  const rest = trimmed.slice("/debug".length).trim();
-  if (!rest) {
-    return { action: "show" };
+  if (!parsed.ok) {
+    return { action: "error", message: parsed.message };
   }
-
-  const match = rest.match(/^(\S+)(?:\s+([\s\S]+))?$/);
-  if (!match) {
-    return { action: "error", message: "Invalid /debug syntax." };
-  }
-  const action = match[1].toLowerCase();
-  const args = (match[2] ?? "").trim();
+  const { action, args } = parsed;
 
   switch (action) {
     case "show":
       return { action: "show" };
     case "reset":
       return { action: "reset" };
-    case "unset": {
-      if (!args) {
-        return { action: "error", message: "Usage: /debug unset path" };
-      }
-      return { action: "unset", path: args };
-    }
+    case "unset":
     case "set": {
-      if (!args) {
-        return {
-          action: "error",
-          message: "Usage: /debug set path=value",
-        };
+      const parsed = parseSetUnsetCommand({ slash: "/debug", action, args });
+      if (parsed.kind === "error") {
+        return { action: "error", message: parsed.message };
       }
-      const eqIndex = args.indexOf("=");
-      if (eqIndex <= 0) {
-        return {
-          action: "error",
-          message: "Usage: /debug set path=value",
-        };
-      }
-      const path = args.slice(0, eqIndex).trim();
-      const rawValue = args.slice(eqIndex + 1);
-      if (!path) {
-        return {
-          action: "error",
-          message: "Usage: /debug set path=value",
-        };
-      }
-      const parsed = parseConfigValue(rawValue);
-      if (parsed.error) {
-        return { action: "error", message: parsed.error };
-      }
-      return { action: "set", path, value: parsed.value };
+      return parsed.kind === "set"
+        ? { action: "set", path: parsed.path, value: parsed.value }
+        : { action: "unset", path: parsed.path };
     }
     default:
       return {