When people ask for "a server for my AI agent", they usually mean a place where the agent can build something, keep it running, and hand back a link people can open. That is the job Server4Agent is built for, which makes it our pick. We make it, so weigh this guide with that in mind. Below it are the tools that fit better for narrower jobs, each with its published price as it read on 29 October 2026. Prices change, so check the linked page before you commit.
Quick answer
Server4Agent is the best fit for most people asking this question. It is a hosted server for AI agents:
- Start from the assistant you already use, or type a goal in the dashboard. Any assistant that supports MCP connectors works, and there is nothing to install.
- A persistent server your agent can work on directly: write code and files, run programs and scripts, and keep background jobs and schedules running between sessions.
- A managed build agent that ships finished tools to a stable URL: dashboards, monitors, internal tools, APIs, bots and pages.
- Private by default. A new project serves nothing until you choose who may open it: your team, named teammates, or the public. Every server runs in its own isolated environment.
- A hard budget cap on the account that agents cannot raise, with AI credits included in every plan.
- A free plan, and Starter at $29 a month.
Pick something else in these cases:
- Your own product fans out thousands of short, throwaway code runs: E2B or Daytona, both $0.0504 per vCPU-hour.
- You need GPUs to run model weights yourself: Daytona or Modal.
- Your apps already run on Fly.io: Fly.io Sprites, so your agents' machines sit on the same platform.
- You want to build by hand inside a browser IDE: Replit.
- You are hosting one service you already wrote: Railway, Render or a plain VPS.
Comparison
| Option | Best for | Who builds | Published price (Oct 2026) |
|---|---|---|---|
| Server4Agent | An agent building, hosting and shipping tools to a live URL, private by default, from any MCP assistant or the dashboard | Your own agent on the server, our managed build agent, or both | Free plan. Starter $29/month with $10 of AI credits. Pro $99/month with $40 |
| E2B | Short, throwaway runs of agent-written code inside your product | Your agent and your backend | Free tier with $100 one-time credit. Pro $150/month plus usage. $0.0504 per vCPU-hour |
| Daytona | Throwaway sandboxes that need GPUs or Windows | Your agent and your backend | $200 free compute. $0.0504 per vCPU-hour, billed per second |
| Modal Sandboxes | Teams already running Python workloads on Modal | Your agent and your backend | Starter $0 with $30/month credit. About $0.142 per physical core-hour, a core being two vCPUs |
| Fly.io Sprites | Agent machines for teams already on Fly.io | Your agent, with your own harness | $30 trial credit. $0.0385 per CPU-hour while running |
| Replit | Building by hand in Replit's browser IDE | You, with Replit's agent | Core $20/month, Pro $100/month |
| Railway, Render | One service you already wrote | You | Railway Hobby $5/month including $5 of usage. Render's free web services sleep after 15 idle minutes |
| A VPS | Full control of one known workload | You | A few dollars a month, plus your time |
Why Server4Agent is our pick
Most agent infrastructure solves one piece: somewhere to run code, or somewhere to keep a machine, or somewhere to host a service a person wrote. The result an agent is usually asked for is software someone can open next week, and getting there takes all of those pieces plus access control and a spending limit. Server4Agent puts them in one place.
It works from where you already are. Connect your assistant once over MCP, or skip the assistant and describe the goal in the dashboard. A founder, PM or ops lead gets a live link back without opening a terminal. Developers get the same surface over REST, webhooks and SDKs.
Your agent gets a real, persistent server. A server is a sized box (small, medium or large) that holds several projects. Your own agent can work on it directly: write files, run commands and scripts, and keep background processes and scheduled jobs going. Each project keeps its files, its running process and its address between sessions, so nothing has to be rebuilt the next day.
A managed build agent ships the finished tool. Describe the outcome and the build agent plans, writes, runs and deploys it, then hands back a project URL. Its AI usage comes out of the credits your plan includes, so you do not need a separate model account to pay for it.
Private until you say otherwise. New projects serve nothing. When one is ready you can open it to your team only, to named teammates, or to the public, and the URL stays the same either way. Every server runs in an isolated environment, so one workload cannot reach another's files, processes or network.
Spending has a ceiling. You set an account-wide budget cap, and an agent cannot raise it. An agent working on its own can start work nobody explicitly approved, so a hard ceiling is worth more than a lower hourly rate.
Engineers can take over. Every project is a git repository an engineer can open in a browser editor with its full history.
The free plan includes one small server, one live public project and $2 of trial AI credit. Starter is $29 a month for two servers, three live projects and $10 of AI credit. Pro is $99 for three servers, ten live projects and $40 of AI credit. Full limits are on the pricing page.
When another option fits better
Thousands of throwaway code runs inside your own product
If you are building a product whose backend sends agent-written code to a sandbox, runs it for seconds, and throws the sandbox away, a sandbox API is built for exactly that.
E2B lists a free Hobby tier with $100 of one-time credit, sessions of up to an hour and 20 concurrent sandboxes, and a Pro plan at $150 a month plus usage with sessions of up to 24 hours. Usage is $0.000014 per vCPU-second and $0.0000045 per GiB-second. See Server4Agent vs E2B.
Daytona charges the same CPU and memory rates and gives new accounts $200 of free compute. See Server4Agent vs Daytona.
Modal Sandboxes bill by physical core, which Modal counts as two vCPUs: $0.00003942 per core-second, about $0.142 an hour, or roughly $0.071 per vCPU-hour. Pick it when the rest of your Python or ML workload already runs there.
All three are building blocks for an agent loop in your own code. Your backend decides what to keep, and something else has to store files, host the result and keep it running after the sandbox is gone. If the result should be an app at a URL, that something else is the part Server4Agent already does.
GPUs
If you run model weights yourself, you need a GPU, and our servers are CPU boxes. Daytona's pricing page lists preemptible GPUs (H100s at $2.27 an hour, among others) and Windows machines at $0.0858 per vCPU-hour. Modal is the other common choice. If your agent calls a hosted model API, as most do, you do not need a GPU at all.
Your apps already run on Fly.io
Fly.io Sprites are, in Fly's words, "full Linux computers designed for agents, not sandboxes." Each has a persistent disk and its own HTTPS URL. Compute is $0.0385 per CPU-hour and memory $0.021875 per GB-hour, billed only while the Sprite runs, with $30 of trial credit for a new organization. You bring the coding agent and the harness, and the AI it uses is a separate bill. If your team already runs on Fly.io and wants agent machines next to the rest of its apps, Sprites are the natural fit. If you want the machine plus a build agent, private-by-default projects, team roles and a budget cap, that is Server4Agent. See Server4Agent vs Fly.io Sprites.
Building by hand in a browser IDE
Replit suits a person who wants to sit in Replit's browser workspace and build an app interactively with its agent, editing and previewing in one place. Core is $20 a month ($18 billed annually) and Pro is $100. The work starts inside Replit. Server4Agent starts from the assistant you already use or the dashboard, and what it ships lands as private tools your team can open. See Server4Agent vs Replit Agent.
One service you already wrote
If a person wrote the service and it is one known thing, a container platform gives you a URL, TLS and logs. Railway's Hobby plan is $5 a month and includes $5 of usage. Render's free web services sleep after 15 minutes without traffic and take about a minute to wake, so budget for a paid instance if anything calls it by webhook. A VPS costs a few dollars a month, and every deploy script, patch and certificate is then yours. Our longer guide is best servers for LangChain agents.
What it costs to leave a server running
Hourly prices are hard to compare until you multiply them out. An E2B sandbox at its default size of 2 vCPUs and 4 GiB costs 2 × $0.0504 plus 4 × $0.0162, which is $0.1656 an hour while it runs, or about $121 a month if it never stops, before any model costs. Per-second billing makes short runs cheap, which is why sandboxes suit bursty work.
Server4Agent plans are a monthly price with dollar credits included, the build agent's AI among them. On paid plans, usage past the included credits is billed, never past the budget cap you set. On Free, work stops when the credits run out. We cover how credits and caps work in compute pricing, credits and budget caps.
FAQ
What is the best server for an AI agent?
For most teams, Server4Agent: a persistent server the agent can work on, a build agent that ships finished tools to a live URL, private-by-default access and a hard budget cap, all from the assistant you already use. Choose a sandbox such as E2B or Daytona when your own product needs many short, throwaway code runs, and Daytona or Modal when you need GPUs.
Can an AI agent deploy an app by itself?
Yes, when the server exposes deployment as a tool. On Server4Agent the agent writes files into a project, starts the app and calls deploy, which makes the project public and returns its URL. Any assistant that supports MCP connectors can do this, and so can any program with an API key.
Is what my agent builds private?
On Server4Agent, yes. A new project serves nothing until you choose who may open it: your team, named teammates, or the public.
Is a sandbox the same as a server?
No. A sandbox is built to be disposable: it runs code in isolation and goes away. A server keeps its files, its processes and its address. Several sandbox products now keep state longer, so ask each vendor what survives when a session ends.
Do I need a GPU to host an AI agent?
Almost never. If your agent calls a hosted model API, the server is coordinating network calls and holding state, so CPU and memory matter far more. A GPU only matters if you run model weights yourself.
Related reading
- Sandboxes vs build servers
- E2B alternatives for AI agents
- Daytona alternatives for AI agents
- Give your agent a server
- The missing deployment layer for AI agents
- All comparisons
Sources
Competitor prices as published on 29 October 2026.