Tool
LangChain
Free tier: Yes · Up to 5,000 base traces per month, then pay as you go.
From: $39/mo
Checked October 16, 2026
- Strength. We imported langchain 1.4.6, including create_agent, for composing tool-calling workflows in code.
- Weakness. LangSmith's developer plan includes 5,000 base traces per month before usage billing, and Plus is $39 per seat per month.
Checked October 15, 2026
Open-source libraries for agents, chains, and tool calling, plus optional LangSmith traces.
LangChain is a set of libraries for composing agent and tool-calling workflows. LangSmith, the tracing product on the same site, is separate: the pricing page we read listed a $0 developer plan and a paid Plus plan. We imported the Python package locally and did not call a model.
Best for
- Developers composing agent workflows in code
- Teams that want run traces via LangSmith
Not ideal for
- People who want only a visual builder
- A finished consumer chat product
What we checked
Smoke-tested means we ran a local install or import in an isolated environment. We did not create an account, pay, or call a model.
Hands-on: pip install + import langchain; from langchain.agents import create_agent (langchain==1.4.6). No account, no payment, no model call.
Install/import only; no API key, no LLM invoke, no signup.
Related tools
AutoGen (Microsoft)
Microsoft open-source Python library for multi-agent conversations. Newest release we found is from 2025.
Smoke-testedOpen sourceAgentChecked October 15, 2026
Free tier: Check pricing (opens in a new tab)
From: Check pricing (opens in a new tab)
Checked October 16, 2026
- Strength. We imported autogen-agentchat 0.7.5 locally, and the library is open source with no product paywall.
- Weakness. The newest Python release we found is dated September 30, 2025, older than the peers we checked.
CrewAI
Open-source framework for crews of role-based agents that split a job into tasks.
Smoke-testedOpen sourceNew releaseAgentChecked October 15, 2026
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From: Check pricing (opens in a new tab)
Checked October 16, 2026
- Strength. We imported crewai 1.15.28, an open-source framework that splits a job across role-based agents.
- Weakness. The cloud free plan includes 50 workflow executions per month, and paid use above that is custom Enterprise pricing.
LlamaIndex
Open-source framework for retrieval and agents. The cloud free plan includes 10,000 credits.
Smoke-testedOpen sourceAgentChecked October 15, 2026
Free tier: Yes · 10,000 credits.
From: $50/mo
Checked October 16, 2026
- Strength. We imported llama-index-core 0.14.25, and the cloud free plan includes 10,000 credits.
- Weakness. Cloud Starter is $50 per month after the 10,000 free credits.
AutoGPT
Open-source agent project with a platform beta. Site and repo checked; local install not run.
Docs checkedOpen sourceNew releaseAgentChecked October 15, 2026
Free tier: No
From: $50/mo
Trial: 7 days
Checked October 16, 2026
- Strength. The open-source repo is the free path, and a platform beta release was published on October 14, 2026.
- Weakness. The hosted plan we checked starts at $50 per month after a 7-day trial, so it is not a free product.