My browser says 127.0.0.1 is blocked when connecting an AI agent
Your approval already worked. WarmySender recorded it. The last step is the browser handing you back to the app running on this computer — Claude, ChatGPT, Cursor, Codex, OpenClaw, Hermes Agent, or any other agent that speaks MCP. If the browser then shows “127.0.0.1 is blocked” or “localhost refused to connect”, that hop never landed. The agent is still waiting on this same computer. Nothing is broken on your WarmySender account.
WarmySender runs outreach on autopilot with AI agents across cold email, email warmup, LinkedIn, Instagram and multichannel sequences, plus real-time email verification. Connecting an agent never sends a message itself and can never raise a limit — WarmySender’s scheduler paces every action inside safe caps, whether you or the agent asked.
What that message means
After you click Approve, the browser tries to open a short local address on this computer so the agent can finish. Some browsers — or an ad / privacy blocker, or a managed-browser policy — refuse that local address. The error page is from the browser, not from WarmySender. A common heading is “127.0.0.1 is blocked”. Another is “localhost refused to connect” (the agent is not listening on this machine, or not on this browser).
What to do
- Pause the blocker for this page, or allow 127.0.0.1 and localhost. Then click Continue (or start the connection again from the agent — it opens a fresh link each time).
- Or copy the link and open it in a different browser or a private window on the same computer where the agent is running. A private window often has fewer extensions.
- If the agent is running on another machine (remote desktop, SSH, or a development container), open the link on that machine. A browser on your laptop cannot finish a connection for an agent running somewhere else.
The Continue link works once and only for a few minutes. If it expires, start the connection again from the agent — do not keep clicking Approve on an old page.
Which agents this covers
The same last hop appears for Claude, ChatGPT, Cursor, Codex, OpenClaw, and Hermes Agent — plus any agent that speaks MCP and finishes the connection in a browser on this computer. ChatGPT’s coding agent is Codex: if you started the connection from ChatGPT and landed on this error, treat it as Codex on this computer.
If you would rather skip the browser step entirely, a workspace key from Settings still reaches the same workspace. See Connect an AI agent and Connecting an AI agent that asks you to sign in.
Is it safe to continue?
Yes. You already chose which permissions to grant. Continuing only finishes handing those permissions to the agent you approved. The agent never sends a message, invite or DM itself and can never raise a limit. Connecting and disconnecting mailboxes and social accounts stays in the app.
Frequently asked questions
Did the connection fail?
No. Approve already succeeded. The browser just could not open the last local address. Pause the blocker or use another browser on the same computer, then start once more from the agent if the original link has expired.
Why does it say 127.0.0.1 is blocked?
That heading is from the browser. An extension (an ad or privacy blocker) or a managed-browser policy stopped the page from reaching an app on this computer. WarmySender does not block that address.
Why does it say localhost refused to connect?
The agent that started the connection is not listening on this computer — or not in this browser. Open the link where the agent is actually running, on the same machine.
Should I keep clicking Approve?
No. Each Approve creates a fresh one-time link. If the browser is still blocking the last hop, more Approves will not help. Pause the blocker first, or switch browsers, then start from the agent once.
I was connecting ChatGPT — is that different?
ChatGPT’s coding agent is Codex. The same three steps apply: pause the blocker for 127.0.0.1 and localhost, or open the link in another browser on the same computer, then start the connection again from Codex.
Which agents can I connect?
Claude, ChatGPT, Cursor, Codex, OpenClaw, and Hermes Agent — plus any agent that speaks MCP. Sign in from the agent, or use a workspace key. The agent never sends a message itself and can never raise a limit.
It still will not finish — how do I get help?
Email [email protected] with roughly the time it happened and which agent you were connecting. We will look into your account.