AI Use Cases

Coding · 17 tools · updated Oct 15, 2026

Which framework should I use to build my own agent?

smolagents leads with an evidence score of 67/100, ahead of Vercel AI SDK (66) and Goose (35). 17 of 17 can be used free, 16 are open source. Best for lightweight agents with open models: smolagents.

Ranked by evidence — GitHub stars, Hacker News mentions, release activity and how much you can use for free. Recomputed nightly. How the score works.

1
smolagents Open source
Minimal Python library for agents that write and execute code as their actions.

+ Code-as-action agents in about a thousand lines of core code that work with any Hub model.
− Running model-written Python needs sandboxing, which is left mostly to you.

Freeopen sourcecliapi
67▲ 21
evidence / 100
2
Vercel AI SDK Open source
TypeScript toolkit for streaming LLM responses, tool calls, and agents across providers and UI frameworks.

+ Unified provider interface and React hooks make streaming chat UIs trivial.
− Major-version upgrades have required significant rewrites.

Free; AI Gateway usage-basedopen sourceapicli
66▲ 103
evidence / 100
3
Goose Open source
Open-source, extensible local AI agent that automates engineering tasks via MCP extensions.

+ MCP-first design means any MCP server becomes a Goose capability with no glue code.
− Less tuned for coding than Claude Code, so results vary widely by model.

Free; bring your own modelopen sourceclimaclinuxwindows
35▼ 24
evidence / 100
4
LangGraph Open source
Graph-based orchestration library for stateful, multi-step agents with persistence and human-in-the-loop.

+ Explicit state graphs with checkpointing make long-running agents debuggable and resumable.
− Steep learning curve and more boilerplate than simpler agent SDKs.

Free; LangGraph Platform hosting is paidopen sourcecliapi
33▼ 25
evidence / 100
5
LangChain Open source
Framework of composable building blocks for LLM apps, with integrations for every model and vector store.

+ Largest integration catalogue of any framework, so almost any provider is one import away.
− Frequent breaking API changes and heavy abstractions make simple things feel over-engineered.

Free; LangSmith observability has paid tiersopen sourcecliapi
32▼ 34
evidence / 100
6
Claude Agent SDK Open source
SDK exposing the Claude Code agent loop, tools, and MCP support for building custom agents in Python or TypeScript.

+ Inherits Claude Code's file, shell, and subagent tooling, so agents are production-grade on day one.
− Tied to Claude models and the Claude Code runtime rather than a provider-agnostic design.

Free; pay Claude API usageopen sourcecliapi
27▼ 21
evidence / 100
7
LlamaIndex Open source
Data framework for RAG and agents that connects LLMs to documents and structured data.

+ Best-in-class document loaders, indexes, and LlamaParse for messy PDFs.
− Agent features are secondary to retrieval and the package surface is sprawling.

Free; LlamaCloud parsing paidopen sourcecliapi
24▼ 42
evidence / 100
8
CrewAI Open source
Python framework for orchestrating role-based multi-agent crews and flows.

+ Role, goal, and task abstractions make multi-agent setups readable in a few lines.
− Agents can loop or burn tokens unpredictably with little low-level control.

Free; CrewAI AMP enterprise platform paidopen sourcecliapi
20▼ 51
evidence / 100
9
Lindy Free tier
No-code platform for AI employees that handle email, scheduling, CRM, and other business workflows.

+ Templates for sales and support agents work with Gmail, Slack, and HubSpot out of the box.
− Credit-based pricing is hard to forecast for always-on agents.

web
15▲ 17
evidence / 100
10
Langflow Open source
Visual low-code builder for RAG and multi-agent flows, acquired by DataStax and now part of IBM.

+ Python-native components can be edited inline, so flows are not limited to built-in nodes.
− Several critical security vulnerabilities in 2025 made exposed instances risky.

Free self-hostedopen sourceweblinuxmacwindows
15▼ 79
evidence / 100
11
AutoGen Open source
Microsoft's framework for multi-agent conversations and event-driven agent applications.

+ AutoGen Studio offers a no-code UI for prototyping agent teams.
− The v0.4 rewrite broke compatibility and the AG2 fork split the community.

Freeopen sourcecliapi
13▼ 59
evidence / 100
12
Dify Open source
Open-source LLMOps platform with a visual builder for agents, RAG pipelines, and workflows.

+ Covers prompt management, knowledge bases, and deployable APIs in one self-hostable app.
− Complex workflows get unwieldy in the visual canvas and version control is weak.

Self-host free; Cloud Professional $59/moopen sourceweblinux
13▼ 87
evidence / 100
13
Flowise Open source
Open-source drag-and-drop builder for LLM chains and agents on top of LangChain.

+ Fastest way to prototype a LangChain chatbot and expose it as an API or embed widget.
− Inherits LangChain's churn and breaks when node versions drift.

Self-host free; Cloud Starter $35/moopen sourceweblinux
13▼ 40
evidence / 100
14
Open-source framework for building and deploying multi-agent systems, optimised for Gemini and Vertex AI.

+ First-class deployment to Vertex AI Agent Engine and support for the A2A protocol.
− Documentation and examples skew heavily to Google Cloud.

Free; pay Gemini usageopen sourcecliapi
13▼ 73
evidence / 100
15
Mastra Open source
TypeScript agent framework with workflows, memory, RAG, and evals from the Gatsby team.

+ Batteries-included TypeScript stack with a local dev playground for inspecting agent runs.
− Newer and smaller than LangChain, with APIs still shifting.

Free; Mastra Cloud paidopen sourcecliapi
13▼ 77
evidence / 100
16
OpenAI Agents SDK Open source
Lightweight SDK for agents with handoffs, guardrails, and tracing, successor to Swarm.

+ Handoffs and built-in tracing are simple to reason about and integrate with the OpenAI dashboard.
− Tuned for OpenAI models; other providers work but lose features.

Free; pay OpenAI API usageopen sourcecliapi
13▼ 80
evidence / 100
17
Pydantic AI Open source
Type-safe Python agent framework from the Pydantic team with structured outputs and dependency injection.

+ Validated, typed outputs and a FastAPI-like developer experience with minimal magic.
− Younger ecosystem with fewer integrations than LangChain.

Free; Logfire observability paidopen sourcecliapi
13▼ 75
evidence / 100

Missing a tool? It gets added when it shows up in the release feed with real traction, not by request.

More in Coding