diff --git a/doc/DEVELOPING.md b/doc/DEVELOPING.md
index ffbb7fa3..4659bb4b 100644
--- a/doc/DEVELOPING.md
+++ b/doc/DEVELOPING.md
@@ -246,7 +246,7 @@ Agent-oriented invite onboarding now exposes machine-readable API docs:
 
 - `GET /api/invites/:token` returns invite summary plus onboarding and skills index links.
 - `GET /api/invites/:token/onboarding` returns onboarding manifest details (registration endpoint, claim endpoint template, skill install hints).
-- `GET /api/invites/:token/onboarding.txt` returns a plain-text onboarding doc intended for both human operators and agents (llm.txt-style handoff).
+- `GET /api/invites/:token/onboarding.txt` returns a plain-text onboarding doc intended for both human operators and agents (llm.txt-style handoff), including optional inviter message and suggested network host candidates.
 - `GET /api/skills/index` lists available skill documents.
 - `GET /api/skills/paperclip` returns the Paperclip heartbeat skill markdown.
 
diff --git a/server/src/__tests__/invite-onboarding-text.test.ts b/server/src/__tests__/invite-onboarding-text.test.ts
index f72bb570..0b807c55 100644
--- a/server/src/__tests__/invite-onboarding-text.test.ts
+++ b/server/src/__tests__/invite-onboarding-text.test.ts
@@ -41,6 +41,9 @@ describe("buildInviteOnboardingTextDocument", () => {
     expect(text).toContain("/api/invites/token-123/accept");
     expect(text).toContain("/api/join-requests/{requestId}/claim-api-key");
     expect(text).toContain("/api/invites/token-123/onboarding.txt");
+    expect(text).toContain("Suggested Paperclip base URLs to try");
+    expect(text).toContain("http://localhost:3100");
+    expect(text).toContain("host.docker.internal");
   });
 
   it("includes loopback diagnostics for authenticated/private onboarding", () => {
@@ -69,6 +72,7 @@ describe("buildInviteOnboardingTextDocument", () => {
 
     expect(text).toContain("Connectivity diagnostics");
     expect(text).toContain("loopback hostname");
+    expect(text).toContain("If none are reachable");
   });
 
   it("includes inviter message in the onboarding text when provided", () => {
diff --git a/server/src/routes/access.ts b/server/src/routes/access.ts
index 340c7d70..59fd2add 100644
--- a/server/src/routes/access.ts
+++ b/server/src/routes/access.ts
@@ -377,6 +377,46 @@ function buildOnboardingDiscoveryDiagnostics(input: {
   return diagnostics;
 }
 
+function buildOnboardingConnectionCandidates(input: {
+  apiBaseUrl: string;
+  bindHost: string;
+  allowedHostnames: string[];
+}): string[] {
+  let base: URL | null = null;
+  try {
+    if (input.apiBaseUrl) {
+      base = new URL(input.apiBaseUrl);
+    }
+  } catch {
+    base = null;
+  }
+
+  const protocol = base?.protocol ?? "http:";
+  const port = base?.port ? `:${base.port}` : "";
+  const candidates = new Set<string>();
+
+  if (base) {
+    candidates.add(base.origin);
+  }
+
+  const bindHost = normalizeHostname(input.bindHost);
+  if (bindHost && !isLoopbackHost(bindHost)) {
+    candidates.add(`${protocol}//${bindHost}${port}`);
+  }
+
+  for (const rawHost of input.allowedHostnames) {
+    const host = normalizeHostname(rawHost);
+    if (!host) continue;
+    candidates.add(`${protocol}//${host}${port}`);
+  }
+
+  if (base && isLoopbackHost(base.hostname)) {
+    candidates.add(`${protocol}//host.docker.internal${port}`);
+  }
+
+  return Array.from(candidates);
+}
+
 function buildInviteOnboardingManifest(
   req: Request,
   token: string,
@@ -402,6 +442,11 @@ function buildInviteOnboardingManifest(
     bindHost: opts.bindHost,
     allowedHostnames: opts.allowedHostnames,
   });
+  const connectionCandidates = buildOnboardingConnectionCandidates({
+    apiBaseUrl: baseUrl,
+    bindHost: opts.bindHost,
+    allowedHostnames: opts.allowedHostnames,
+  });
 
   return {
     invite: toInviteSummaryResponse(req, token, invite),
@@ -435,6 +480,7 @@ function buildInviteOnboardingManifest(
         deploymentExposure: opts.deploymentExposure,
         bindHost: opts.bindHost,
         allowedHostnames: opts.allowedHostnames,
+        connectionCandidates,
         diagnostics: discoveryDiagnostics,
         guidance:
           opts.deploymentMode === "authenticated" && opts.deploymentExposure === "private"
@@ -474,7 +520,7 @@ export function buildInviteOnboardingTextDocument(
     claimEndpointTemplate: { method: string; path: string };
     textInstructions: { path: string; url: string };
     skill: { path: string; url: string; installPath: string };
-    connectivity: { diagnostics?: JoinDiagnostic[]; guidance?: string };
+    connectivity: { diagnostics?: JoinDiagnostic[]; guidance?: string; connectionCandidates?: string[] };
   };
   const diagnostics = Array.isArray(onboarding.connectivity?.diagnostics)
     ? onboarding.connectivity.diagnostics
@@ -546,6 +592,27 @@ export function buildInviteOnboardingTextDocument(
     onboarding.connectivity?.guidance ?? "Ensure Paperclip is reachable from your OpenClaw runtime.",
   );
 
+  const connectionCandidates = Array.isArray(onboarding.connectivity?.connectionCandidates)
+    ? onboarding.connectivity.connectionCandidates.filter((entry): entry is string => Boolean(entry))
+    : [];
+
+  if (connectionCandidates.length > 0) {
+    lines.push("", "## Suggested Paperclip base URLs to try");
+    for (const candidate of connectionCandidates) {
+      lines.push(`- ${candidate}`);
+    }
+    lines.push(
+      "",
+      "Test each candidate with:",
+      "- GET <candidate>/api/health",
+      "",
+      "If none are reachable: ask your human operator for a reachable hostname/address and help them update network configuration.",
+      "For authenticated/private mode, they may need:",
+      "- pnpm paperclipai allowed-hostname <host>",
+      "- then restart Paperclip and retry onboarding.",
+    );
+  }
+
   if (diagnostics.length > 0) {
     lines.push("", "## Connectivity diagnostics");
     for (const diag of diagnostics) {