Best Agentic Frameworks in 2026: When to Use LangGraph, CrewAI, LlamaIndex, Pydantic AI, or No Framework
Posted by Straight_Stomach812@reddit | LocalLLaMA | View on Reddit | 6 comments
Most agent framework debates skip the first question:
Do you need a framework at all?
For one agent calling one or two tools, I would usually skip LangGraph, CrewAI, AutoGen, and most orchestration layers.
Raw model calls plus structured outputs are easier to inspect, cheaper to run, and less painful to debug.
Frameworks start earning their complexity when you need branching control flow, persistent state, retries, human approval gates, memory, multi-agent coordination, or long-running execution.
My rough 2026 map:
| Use case | Pick |
|---|---|
| Stateful production workflow | LangGraph |
| Fast multi-agent prototype | CrewAI |
| RAG-heavy agent | LlamaIndex |
| Deterministic retrieval pipeline | Haystack |
| Type-safe Python service | Pydantic AI |
| Persistent memory assistant | Letta |
| Code-executing lightweight agents | Smolagents |
| Browser automation | Browser Use |
| Open-source coding agent | OpenHands / Goose |
| TypeScript product | Mastra |
| Streaming AI UI | Vercel AI SDK |
My personal rule:
If the workflow is simple, avoid the framework.
If the workflow needs state, approvals, retries, audit trails, or complex routing, use LangGraph.
If the goal is to prototype a multi-agent role pipeline quickly, use CrewAI.
If retrieval is the real problem, start with LlamaIndex or Haystack before adding an agent layer.
If long-term memory is the product, look at Letta.
If browser control is the job, Browser Use is the more relevant category.
The biggest mistake I see is choosing an agent framework before defining the job.
A good agent spec should say what the agent can do, which tools it can call, what state it needs, when a human must approve, and what failure looks like.
Without that, the framework debate is mostly noise.
m5j@reddit
honestly the "no framework" option is underrated.
i started with one and ripped it out, the abstractions were hiding the exact failure modes i needed to see. ended up on a plain queue + postgres and i can actually reason about what happens when a step dies or runs twice. what's pushing you toward picking one?
rashaniquah@reddit
yup, it's just a LLM call in a loop...
jwpbe@reddit
best pee pee poo poo in 2026 for my poopgentic workflow
Jipok_@reddit
Have you used this yourself more than a couple of times? Or did you just find frameworks and ask LLM to provide you with a "conclusion"?
__JockY__@reddit
Don’t be sleeping on the Claude SDK. It’s not so open, but it’s really good with open models (I have never tried it with cloud models so can’t comment on that).
Effective_Degree2225@reddit
anyone used DSPy ?