Agent framework tier lists are opinion: of 4 dismissed projects, only AutoGen's README steers users away.
Tier lists of agent frameworks for production are going around. They put a single framework in the top tier, call LangGraph the best fit for controlled, sequential work in regulated industries but weak for fully autonomous tasks, dismiss CrewAI, AutoGen, Haystack and Pydantic AI, and rate building from scratch highest for control.
- 3 layersruntime, framework, harness: how LangChain's docs sort what tier lists rank together
- 1 of 4dismissed projects whose own README steers users elsewhere (AutoGen)
- 3primitives in the OpenAI Agents SDK
- 7durable execution engines Pydantic AI lists
- Agent frameworks can be ranked in one list, with a single framework in the top tier for production.A tier is a judgement, and none of the project pages cited here publishes a head-to-head measurement on a shared production task. The projects do not even claim the same job. LangChain's documentation sorts the field into 3 layers: runtimes that keep an agent running (LangGraph, beside Temporal and Inngest), frameworks that supply abstractions and integrations (LangChain, CrewAI, the OpenAI Agents SDK, Google ADK and LlamaIndex among them) and harnesses that ship tools, prompts and subagents (Deep Agents and the Claude Agent SDK among them). That sorting is one vendor's view, and the projects describe themselves differently again. Agno calls itself a framework and runtime for agent platforms, with a REST API, storage in your own database and a control plane. The OpenAI Agents SDK calls itself a lightweight package with 3 primitives: agents, handoffs (or agents used as tools) and guardrails. Pydantic AI calls itself a typed agent loop. CrewAI, Haystack, Pydantic AI, Microsoft Agent Framework and the OpenAI Agents SDK all describe themselves as production-ready or production-grade, so the label separates nobody.Runtimes, frameworks, and harnesses (LangChain docs)
- LangGraph is the best fit for controlled, sequential work in regulated industries.The control half matches what LangGraph says about itself: a low-level orchestration runtime for long-running, stateful agents, where hand-coded deterministic steps and model-driven steps sit in one graph, so some of the logic stays predictable and open to audit while the rest is left to the model. It lists persistence, so a run that fails can pick up where it stopped, and human-in-the-loop review, where a person can read and edit the agent's state mid-run. Two details do not come from the documentation. Sequential undersells it: LangGraph's workflows guide builds parallel calls, routing, orchestrator-worker and looping tool-calling agents as graphs. And the overview never mentions regulated industries; it names Klarna, Uber and J.P. Morgan as users, which is the vendor's own list and says nothing about compliance. Best is the ranking's opinion.LangGraph overview
- LangGraph is weak for fully autonomous tasks.The true part: LangGraph describes itself as a runtime and leaves the agent to you. Its overview says it does not abstract prompts or architecture, and it sends people who want a higher-level start to LangChain's prebuilt agents, so an autonomous agent on bare LangGraph is more code to write. That is not a ceiling on autonomy. LangChain's agents are built on top of LangGraph. LangChain's product comparison points teams building more autonomous agents for complex, non-deterministic tasks to a harness, and its own harness, Deep Agents, adds a virtual file system, subagents and an optional to-do list for planning. The Deep Agents overview says it uses the LangGraph runtime for durable execution, streaming and human review. The autonomy comes from the layer above; the runtime underneath is the same one.Deep Agents overview (LangChain docs)
- CrewAI, AutoGen, Haystack and Pydantic AI are not worth considering for production.1 of the 4 dismissals has a primary source behind it. AutoGen's own README says the project is in maintenance mode, will receive no further features, is community managed, and that anyone starting out should use Microsoft Agent Framework instead. Microsoft describes that framework as the direct successor to both AutoGen and Semantic Kernel, built by the same teams, with graph-based workflows, checkpointing and human-in-the-loop support. The other 3 carry no such notice in their READMEs or documentation, and each describes a specific job. CrewAI tells production users to start with a Flow, a structured, event-driven workflow that holds state, and to call a Crew of autonomous agents only inside a step that needs one. Pydantic AI lists typed outputs and tools, durable execution on 7 engines including Temporal and DBOS, and built-in human approval. Haystack, from deepset, builds retrieval and agent applications as pipelines of reusable components. Whether any of them suits your system is a test to run, and no tier list has run it for you.AutoGen README (maintenance mode notice)
- Building from scratch ranks highest because it gives the most control.Anthropic's guidance backs the starting point. It advises calling the model API directly first, says many agent patterns take a few lines of code, and warns that frameworks add layers which can hide the underlying prompts and responses, make debugging harder and tempt teams into complexity they do not need. It names wrong assumptions about what a framework does under the hood as a common source of customer error. The same article is not against frameworks: it lists 4, Anthropic's own Claude Agent SDK among them, says they make it easy to get started, tells teams that use one to understand the code underneath, and encourages cutting abstraction layers on the way to production. Control also has a bill. By their own documentation, saved state that survives a restart and a pause for human approval come built into LangGraph, Microsoft Agent Framework and Pydantic AI on a durable engine; a from-scratch build has to write and maintain each one it needs, plus its own tracing. OpenAI and Anthropic both present it as a choice of who owns the loop. OpenAI's SDK docs say to call the Responses API directly when you want to own the loop, tool dispatch and state, to use the SDK when you want the runtime to manage them, and that many applications do both. Anthropic's SDK docs draw the same line between its Agent SDK, which runs the agent loop for you, and its Client SDK, where you write the tool loop yourself.Building effective agents (When and how to use frameworks)
the line to remember
Pick the layer before the brand: start with direct model calls, add a runtime, framework or harness only for what it ships that you need, and read any tier list as opinion.
For your product
Start from what the system must survive. A process with fixed steps, sign-off points and an audit trail needs explicit workflow control, saved state and human approval, which LangGraph, CrewAI Flows, Microsoft Agent Framework workflows and Pydantic AI on a durable engine all document. An open-ended task needs an agent loop with tools, and most of the same projects offer one as well. Ask a vendor 3 things: which parts of the flow are fixed in code and which are left to the model, what happens to a run when the server restarts halfway, and whether your own team can read and debug the prompts the framework sends. Check the maintenance status in the project's own repository before you commit; AutoGen's README shows why. A prototype on direct API calls is cheap and tells you which of these features you need before you adopt anything. Microsoft's own guide adds the cheapest option of all: if an ordinary function can handle the task, write the function and skip the agent.
Sources: Building effective agents (Anthropic) · Agent SDK overview (Agent SDK compared with the Client SDK) (Anthropic) · LangGraph overview (LangChain) · Runtimes, frameworks, and harnesses (LangChain) · Workflows and agents (LangGraph) (LangChain) · Deep Agents overview (LangChain) · CrewAI documentation: Introduction (Crews and Flows) (CrewAI) · CrewAI documentation: Human Feedback in Flows (CrewAI) · AutoGen README (maintenance mode notice) (Microsoft) · Microsoft Agent Framework overview (Microsoft) · Microsoft Agent Framework README (Microsoft) · Pydantic AI overview (Pydantic) · OpenAI Agents SDK documentation (OpenAI) · Agno README (Agno) · Introduction to Haystack (deepset)