Pick one recurring task, write its instructions and give it the knowledge it needs in the assistant you already have, test it on real requests, then move to an agent builder when it has to run on its own and act in your apps.
For anyone asking: What is an AI agent, and how do I build one?
Each one's way of doing it, and the point where it stops.
Build in Studio, the visual builder, or describe the agent to the conversational Viber builder. An Autonomous Node lets the model decide what to say and which tools to run, the Emulator shows each step of a test conversation, and webchat and WhatsApp are available on every plan. Where it stops: Free has a small hard monthly conversation cap with no top-ups, and test conversations in the Emulator count toward it.
In Studio, the no-code builder of CrewAI AMP, you describe the automation and a Crew Assistant generates the agents, tasks and tools. An Execution view shows a timeline, logs and test runs before you publish. Developers can build in code with the open-source framework instead. Where it stops: Needs your own LLM provider key before you start. Studio export is one-way: downloaded code cannot be imported back.
You describe the task in plain English in Slack, the web app, text or email, and Lindy acts. It picks the right skill by itself when a request needs one, and routines start it on a schedule or an event. Anything with outside impact waits for your approval by default. Where it stops: Free is only a 7-day start; after that a paid plan is needed.
Build in the agent editor or ask the built-in Gumball agent to create the agent for you. The use-case gallery gives preconfigured agents with instructions loaded; you authorize each tool with your own sign-in. Approval presets are set per connector, from Always allow to Ask each time. Where it stops: No free plan: a one-time trial of Pro that needs a card. A connector must be added on the agent itself, not only in Settings.
Invent builds the agent, its tools and its triggers from a plain-language description of your process. Everything stays in draft until a person publishes it, and each tool gets its own approval mode: Auto Run, Approval Required or Let Agent Decide. Where it stops: No free plan, so any build needs a paid plan.
There is no separate builder. A Project holds a master instruction and a knowledge base, a Skill saves the know-how from a finished task, and an Automation runs it on a schedule or a trigger with the Approval required setting for work that sends or publishes. Where it stops: The parts are assembled by you from three features, not built as one agent. Free covers Projects, Skills, Plan Mode and two scheduled tasks.
Sintra comes with 12 ready-made AI employees that you brief in chat instead of building. They share one knowledge store, Brain AI, for your brand voice and business context. A Helper Builder creates a custom one. Where it stops: Helper Builder is available on workspace-based billing accounts. There is no public API.
Every verdict rests on the data in our product reports, never on a fee. How we score →