The short answer: it depends on what the agent is for. If you want agents to take work off your team's plate (research, outreach, content, support, reporting), use a hosted agent platform such as AutoGPT, Lindy, Gumloop or Relevance AI, or a workflow tool with AI such as Make or n8n. If you're building agents into your own product, use a framework: the OpenAI Agents SDK, the Claude Agent SDK, LangGraph, Mastra for TypeScript teams, or Pydantic AI. For customer-facing chat agents, specialist builders like Voiceflow and Botpress fit best.
Disclosure: AutoGPT publishes this guide and is one of the options in it. We checked the product facts against each vendor's own site on October 2, 2026.
First, decide which kind of builder you need
"AI agent builder" covers three very different kinds of product, and startups lose a lot of time comparing across them:
- Agents for your own operations. You want work done: prospect research, investor updates, weekly metrics, support triage. You need a product, not a codebase.
- Agents inside your product. Your customers will use the agent, so you need a framework your engineers control, plus tool access and observability.
- Customer-facing conversational agents. Support or sales chat on your site or in messaging apps. You need a builder designed for conversations and handoffs to humans.
Best for running your startup's operations
| Tool | How you build | Self-host | Best for |
|---|---|---|---|
| AutoGPT | Brief AI Experts in a conversation; visual builder when you need it | Yes, free (source-available) | Recurring work across research, content, sales and ops |
| Lindy | Hosted AI "teammate" | Not advertised | A ready-made assistant for individuals and small teams |
| Gumloop | Collaborative agent builder | Deploys into your own cloud account | Teams that build and share agents together |
| Relevance AI | Specialist agents for specific roles | Not advertised (data residency available) | Role-based agents |
| Make | Visual scenarios with AI agents | No | Visual automation on a budget |
| n8n | Workflows with AI Agent nodes | Yes (fair-code license) | Technical founders who want full control |
AutoGPT: a team of AI Experts
AutoGPT gives you AI Experts for content, sales, research and recurring work. They're specialists such as an SEO content manager, an account executive, a market research analyst, a data analyst or an investor relations manager who turns your fundraising facts into investor updates. Otto, your Head of AI, coordinates them. You share the context, connect your tools, review results and set up routines for recurring jobs. You can start from a ready-made Expert in a single conversation, without building a workflow first. Experts build workflows, too: ask for one and the Expert builds it, runs it and can put it on a schedule. If you're not sure yet how a job should run, test-drive it as a routine, where the Expert works through each run with judgment, and have it build the workflow once you know the steps.
Pro costs $50/month ($42.50/month billed annually) and covers Otto and Expert chat. Workflow runs draw on a credit wallet, and you can set spending controls for each Expert. Eligible new accounts can try Pro free for 7 days (card required). If you'd rather own the stack, self-hosting is free.
Lindy, Gumloop and Relevance AI
All three are hosted products built around agents. Lindy pitches "the AI teammate that will 3x your output." Gumloop, "the multiplayer AI agent builder," suits teams that want to build and share agents together, and it can deploy inside your own AWS, Azure or Google Cloud environment. Relevance AI ("specialist AI agents for every task") is built around agents for specific roles, with data residency options. Lindy and Relevance AI don't advertise self-hosting.
Make and n8n
If your needs are closer to automation than delegation (move data, enrich a lead, post to Slack), a workflow tool with AI steps is cheaper and more predictable. AutoGPT covers this too, since an Expert can build and run the workflow for you. If you'd rather build it yourself, Make is hosted and visual, with credits per module action and 3,000+ apps. n8n is the technical founder's choice: self-hostable under a fair-code license, with deep AI agent nodes and per-execution cloud pricing. Our guides to n8n alternatives and Zapier alternatives for AI agents go deeper.
Best for building agents into your product
- OpenAI Agents SDK (MIT): a lightweight, production-oriented SDK, and the natural choice if you build on OpenAI models.
- Claude Agent SDK (MIT): Anthropic's SDK, built on the same agent harness as Claude Code.
- LangGraph (MIT): stateful, long-running agents with explicit control flow, in Python or JavaScript.
- Mastra (Apache 2.0 core): "the leading TypeScript agent framework," in its own words, and a good fit for Node and Next.js teams.
- Pydantic AI (MIT): type-safe Python agents from the team behind Pydantic.
- Composio (MIT SDK): not a framework but the tool-access layer many teams add, offering "secure access to 1,500+ apps."
Don't start on OpenAI's Agent Builder. OpenAI is deprecating it, and it's scheduled to shut down on November 30, 2026. OpenAI recommends the Agents SDK or ChatGPT Workspace Agents instead.
For a wider survey, including licenses and which projects were archived this year, see the best open-source AI agent platforms.
Best for customer-facing chat agents
Voiceflow and Botpress specialize in conversational agents for support and sales: designing dialogues, connecting knowledge bases and handing off to humans. Botpress publishes MIT-licensed SDKs, tools and integrations on GitHub. If your agent's job is to talk to customers rather than do internal work, start there. If you'd rather build your customer-facing agent on top of AutoGPT, contact us.
A startup checklist before you choose
- Cost model: seats, tasks, credits, executions or usage? Price your three most frequent jobs, not the plan headline.
- Exit plan: can you export your agents and data, or self-host if pricing changes? Relay.app shut down in 2026 and OpenAI's Agent Builder is shutting down, so this isn't hypothetical.
- Review and approvals: can a person approve actions before they happen, especially emails and payments?
- Spending controls: can you cap what each agent spends?
- Integrations: does it connect to the five tools you actually use?
Frequently asked questions
What's the best AI agent builder for a non-technical founder?
A hosted platform you can brief in plain language: AutoGPT (start with a ready-made Expert, no workflow required), Lindy, Gumloop or Relevance AI. If you think in workflows, Make is the most approachable visual builder.
What's the cheapest way for a startup to build AI agents?
Self-host an open-source or source-available platform such as AutoGPT, Dify, Langflow or n8n's Community Edition, and pay only for hosting and model usage. If you have engineers, MIT-licensed frameworks like the OpenAI Agents SDK or LangGraph cost nothing beyond model usage.
Should a startup build agents with a framework or a platform?
Use a platform for agents that run your own operations, and a framework when the agent is part of the product you sell. Plenty of startups do both.
Is OpenAI's Agent Builder still available?
Only to existing users during a transition window. OpenAI is deprecating it, and the product is scheduled to shut down on November 30, 2026.
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