diff --git a/src/github/commands.ts b/src/github/commands.ts
index b4f9d662e9..1fe6150eae 100644
--- a/src/github/commands.ts
+++ b/src/github/commands.ts
@@ -371,6 +371,7 @@ export function buildPublicAgentCommandComment(args: {
   const commandName = args.command.name as GittensoryMentionCommandName;
   const sections = commandSections(
     commandName,
+    args.env,
     args.bundle,
     args.officialMiner,
     args.maintainerDigest,
@@ -707,6 +708,7 @@ function feedbackPromptSections(answerId: string | null | undefined): string[] {
 
 function commandSections(
   command: GittensoryMentionCommandName,
+  env: GittensoryFooterEnv,
   bundle: AgentRunBundle | null | undefined,
   officialMiner: GittensorContributorSnapshot | null | undefined,
   maintainerDigest: MaintainerQueueDigest | null | undefined,
@@ -716,7 +718,7 @@ function commandSections(
 ): string[] {
   switch (command) {
     case "help":
-      return helpSections(unknownVerb);
+      return helpSections(env, unknownVerb);
     case "ask":
       return askSections(bundle, question);
     case "miner-context":
@@ -761,7 +763,21 @@ function actionCommandHelpSections(): string[] {
   ];
 }
 
-function helpSections(unknownVerb?: string | undefined): string[] {
+/** The public command-reference doc link for `@gittensory help` (#4670). `new URL(path, origin)` -- same
+ *  idiom as the sibling `maintainerControlPanelUrl` in footer.ts -- so a `PUBLIC_SITE_ORIGIN` with or
+ *  without a trailing slash both resolve correctly instead of risking a double slash from naive
+ *  concatenation. Falls back to the literal path string only if origin resolution itself throws (an
+ *  operator-misconfigured PUBLIC_SITE_ORIGIN should degrade the link, not crash comment rendering). */
+function commandReferenceUrl(env: GittensoryFooterEnv): string {
+  const origin = env.PUBLIC_SITE_ORIGIN ?? GITTENSORY_SITE_URL;
+  try {
+    return new URL("/docs/gittensory-commands", origin).toString();
+  } catch {
+    return `${GITTENSORY_SITE_URL}/docs/gittensory-commands`;
+  }
+}
+
+function helpSections(env: GittensoryFooterEnv, unknownVerb?: string | undefined): string[] {
   return [
     "**Commands**",
     "",
@@ -788,7 +804,7 @@ function helpSections(unknownVerb?: string | undefined): string[] {
     "",
     ...actionCommandHelpSections(),
     "",
-    `- Full command reference (syntax, roles, gate boundary): ${GITTENSORY_SITE_URL}/docs/gittensory-commands`,
+    `- Full command reference (syntax, roles, gate boundary): ${commandReferenceUrl(env)}`,
   ];
 }
 
@@ -1697,4 +1713,5 @@ export const githubCommandsInternals = {
   askSections,
   helpSections,
   actionCommandHelpSections,
+  commandReferenceUrl,
 };
diff --git a/test/unit/github-commands.test.ts b/test/unit/github-commands.test.ts
index e2633b8dbb..01654fd228 100644
--- a/test/unit/github-commands.test.ts
+++ b/test/unit/github-commands.test.ts
@@ -133,11 +133,11 @@ describe("GitHub mention commands", () => {
   });
 
   it("helpSections renders did-you-mean only for close unknown verbs (#2170)", () => {
-    const typo = githubCommandsInternals.helpSections("reveiw");
+    const typo = githubCommandsInternals.helpSections({}, "reveiw");
     expect(typo.join("\n")).toContain("Did you mean `@gittensory review`?");
-    const far = githubCommandsInternals.helpSections("zzzz");
+    const far = githubCommandsInternals.helpSections({}, "zzzz");
     expect(far.join("\n")).not.toContain("Did you mean");
-    const bare = githubCommandsInternals.helpSections();
+    const bare = githubCommandsInternals.helpSections({});
     expect(bare.join("\n")).not.toContain("Did you mean");
     expect(bare.join("\n")).toContain("**Commands**");
   });
@@ -152,7 +152,7 @@ describe("GitHub mention commands", () => {
   });
 
   it("helpSections documents every PR action command with authorization notes (#2167)", () => {
-    const body = githubCommandsInternals.helpSections().join("\n");
+    const body = githubCommandsInternals.helpSections({}).join("\n");
     expect(body).toContain("**PR action commands**");
     expect(body).toContain("maintainer or collaborator authorization");
     expect(body).toContain("pause` and `resume` affect only auto-review");
@@ -175,11 +175,23 @@ describe("GitHub mention commands", () => {
   });
 
   it("helpSections links to the public command reference doc (#2171)", () => {
-    const body = githubCommandsInternals.helpSections().join("\n");
+    const body = githubCommandsInternals.helpSections({}).join("\n");
     expect(body).toContain("https://gittensory.aethereal.dev/docs/gittensory-commands");
     expect(body).toContain("Full command reference");
   });
 
+  it("helpSections' command reference link follows a self-hoster's PUBLIC_SITE_ORIGIN, trailing slash and all (#4670)", () => {
+    const body = githubCommandsInternals.helpSections({ PUBLIC_SITE_ORIGIN: "https://my-instance.example.com/" }).join("\n");
+    expect(body).toContain("https://my-instance.example.com/docs/gittensory-commands");
+    expect(body).not.toContain("gittensory.aethereal.dev");
+  });
+
+  it("commandReferenceUrl falls back to the default site when PUBLIC_SITE_ORIGIN is malformed", () => {
+    expect(githubCommandsInternals.commandReferenceUrl({ PUBLIC_SITE_ORIGIN: "not a url" })).toBe(
+      "https://gittensory.aethereal.dev/docs/gittensory-commands",
+    );
+  });
+
   it("isGittensoryActionCommand distinguishes action verbs from Q&A commands", () => {
     for (const action of ["gate-override", "review", "pause", "resume", "resolve", "configuration", "explain"] as const) {
       expect(isGittensoryActionCommand(action)).toBe(true);