Campfire SMS
ntfy is a free, open-source push notification service. Anything that can send an HTTP request, such as a Claude Code hook, can push an alert to the ntfy app on your phone, and you can run your own server. It is built for alerts: getting an answer back to your agent is a part you build yourself. Campfire SMS lets the agent you already run text your phone number and read your reply, with no app and nothing to host. Pick ntfy for free alerts you wire up yourself. Pick Campfire SMS when the agent needs an answer from you.
| Decision | ntfy | Campfire SMS |
|---|---|---|
| What it is | A general push notification service. Scripts, servers, and hooks publish to a topic; your phone subscribes to it. | A hosted SMS bridge between your AI agent and your phone. |
| How it reaches you | A push notification in the ntfy app, or in the ntfy web app. | A text message in your normal SMS inbox. |
| Answering your agent | No chat-style reply. Action buttons can open a link, copy a value, or send an HTTP request to a URL you choose when tapped. | Reply to the text in plain words. The agent retrieves your reply the next time it checks. |
| Connecting your agent | You wire it up, for example with a hook that runs curl -d "Build finished" ntfy.sh/your-topic. | Sign up, verify your phone, and run the one-time install command from your account. |
| Phone app | The ntfy app, or a browser tab with the web app. | None. |
| Open source | Yes. Apache 2.0 and GPLv2, and you can self-host the server. | No. It is a hosted service. |
| Pricing model (as observed) | Free on ntfy.sh without sign-up, or free to self-host. Paid plans: Supporter (2,500 daily messages, listed at $5 to $6 a month depending on billing), Pro (20,000), and Business (50,000). | 40 free messages after phone verification, no card required. Then $8 a month for 500 messages, or one-time packs from $5 for 200. Each text sent or received counts as one message. |
| Best for | Free "it's done" alerts from scripts and hooks, and people who want to self-host. | Questions and results your agent sends you, answered from your phone without building a reply path. |
What ntfy does
ntfy sends push notifications to your phone or desktop from a plain HTTP PUT or POST request. You pick a topic name, subscribe to it in the ntfy app, and anything that can make an HTTP request can publish to it. It is "100% free software," dual-licensed under Apache 2.0 and GPLv2, and you can run your own server. See ntfy.sh.
Without an account, the topic name is the only protection. ntfy's own docs say "the topic is essentially a password," so choose one that is hard to guess. Paid ntfy.sh plans let you reserve topic names.
Alerts vs answers
Most coding-agent pings fall into two groups.
- Alerts tell you something happened: the build passed, the tests failed, the agent stopped. You read them and maybe walk back to your computer. ntfy is very good at this, and it is free.
- Answers are what the agent needs from you before it can continue: "Use the staging database or a local copy?" Here the hard part is the return trip. Your reply has to reach the right agent session, and the agent has to pick it up.
ntfy's action buttons go part of the way. An http button sends a request to a URL you choose when you tap it, so you could add "Approve" and "Deny" buttons. You would host that endpoint, decide what each button means, and have the agent read the result. Campfire SMS does the return trip for you: you type an answer in plain words, and the agent retrieves it through the connector you installed.
The two can work side by side: ntfy for routine build alerts, and Campfire SMS for the questions that need you.
Choose ntfy if…
- You mainly want alerts. You'll read them and respond at your computer.
- You want it free, or you want to run the server yourself.
- You're comfortable writing hooks or scripts and keeping them working.
- You want alerts from more than your agent, such as servers, cron jobs, and home automation, in one app.
Choose Campfire SMS if…
- You want the agent you already run (Codex, Claude Code, Cursor, Grok Bot, OpenCode, or Grok Build) to ask you a question and read your answer.
- You don't want to write hooks, host an endpoint, or keep a topic name secret.
- You'd rather get real texts in your normal inbox than install another app.
- You use Grok Bot and want a text to start its cloud routine while your PC is off.
Setup is three steps: sign up at campfiresms.com, verify your phone (40 free texts, no card), and run the one-time install command from your account. Then send a test text and reply. See the setup guide for each agent.
What Campfire SMS does not do
Campfire SMS is not a general notification service. It doesn't take alerts from servers or scripts outside your connected agent, and you can't self-host it.
- Local agents need a live session. Codex, Claude Code, Cursor, OpenCode, Grok Build, and other local agents need the computer awake and online and the session running. Campfire SMS does not wake a stopped local session. Grok Bot is the exception: an active webhook routine can start it in the cloud when you text.
- Replies don't grant new permissions. A text can steer the task, but the agent keeps the permissions it already had. Native approvals stay in the agent's own interface.
- SMS isn't end-to-end encrypted. Don't text secrets, and keep sensitive detail on the computer.
Try a text and a reply
Campfire SMS starts with 40 free messages after phone verification. No card required. The monthly plan is $8 for 500 messages, and one-time packs never expire. See current pricing and message counting. Your agent's own costs are separate.
Start with a harmless exchange: ask your agent to text you a short status, reply with a question, and check that it reads your exact reply and answers.
ntfy details checked October 16, 2026 against ntfy.sh (features, license, and pricing) and the ntfy publishing docs (topics and action buttons). ntfy.sh shows two prices per plan with a monthly or annual toggle. Prices and plans are as of October 2026 and can change; check the linked pages before you decide. Product names belong to their owners. Campfire SMS is independent of ntfy.
Common questions
Can ntfy notify me when Claude Code finishes?
Yes. ntfy accepts a plain HTTP request, so a Claude Code hook, for example on the Stop or Notification event, can post a message to your ntfy topic. You write and maintain the hook yourself.
Can I reply to my coding agent through ntfy?
Not as a chat reply. ntfy notifications can carry action buttons, and an http button sends a request to a URL you choose when tapped. You could build approve and deny buttons that way, but you host the endpoint and teach the agent to read it. Campfire SMS returns your text reply to the agent without that work.
Is ntfy free?
Yes. You can use the public ntfy.sh server without signing up, or run your own server. As of October 2026, paid ntfy.sh plans start with Supporter (2,500 daily messages), listed at $5 to $6 a month depending on billing, and add reserved topics and higher limits.
Is ntfy private?
Without an account, anyone who knows your topic name can read or post to it. ntfy says the topic is essentially a password, so pick one that is hard to guess, reserve it on a paid plan, or self-host.
Do I need an app for Campfire SMS?
No. Texts arrive in your phone's normal messages app, on an iPhone or an Android phone. ntfy needs its app or the web app to receive notifications.