fast-agent vs LangChain
fast-agent and LangChain are both agent frameworks for Python. fast-agent is published by evalstate and LangChain by LangChain. On GitHub, LangChain has 148,371 stars and fast-agent has 3,945. Both were last active in Oct 2026. The table lines up where they differ (publisher, license, GitHub stars and weekly downloads) and has the install commands for both. Everything here comes from the listings' public sources and is refreshed daily. fast-agent describes itself as: CLI-first Python agent framework and coding agent with MCP, A2A and Agent Skills support, live streaming and human input. LangChain: Python framework of interoperable components and integrations for building agents and LLM apps, with LangGraph and Deep Agents layered above it. Licenses: fast-agent Apache-2.0, LangChain MIT.
Updated Oct 26, 2026 · Built from catalog data; how we rank and grade
fast-agent
evalstate
CLI-first Python agent framework and coding agent with MCP, A2A and Agent Skills support, live streaming and human input.
LangChain
LangChain
Python framework of interoperable components and integrations for building agents and LLM apps, with LangGraph and Deep Agents layered above it.
Who should pick which
- Pick fast-agent if you want MCP support built in.
- Pick fast-agent if you need several agents working together.
- Pick LangChain if you want a stable release (fast-agent is marked beta).
- LangChain has the larger community: 148,371 GitHub stars against 3,945.
From listing data only. We don't pick a winner on security beyond the grades; read how grades work.
Side by side
| Fact | fast-agent | LangChain |
|---|---|---|
| Type | Harness | Harness |
| Publisher | evalstate | LangChain |
| License | Apache-2.0 | MIT |
| Pricing | Not stated | Not stated |
| Runs | Not stated | Not stated |
| Auth | Not stated | Not stated |
| Hosts supported | Not stated | Not stated |
| Tools | Not listed yet | Not listed yet |
| Security grade | –Security: not graded yet | –Security: not graded yet |
| Freshness grade | AFreshness: A | AFreshness: A |
| GitHub stars | 3,945 | 148,371 |
| Weekly downloads | 19,494 | 37,334,710 |
| Last release | Oct 22, 2026 | Oct 22, 2026 |
| Last activity | Oct 22, 2026 | Oct 24, 2026 |
Facts from each listing's public sources, checked daily. Tool lists arrive with tool scans.
Install
fast-agent
pip install fast-agent-mcp
LangChain
pip install langchain
Also consider
- 0.853score
LlamaIndex
LlamaIndex
Open-source Python toolkit for RAG and agents over your own data, with event-driven workflows and 300+ integration packages.
HarnessAFreshness: A★ 52.6K↓ 1.4M/wk - 0.748score
LangGraph
LangChain
Low-level Python orchestration framework for long-running stateful agents, with durable execution, human review points and short- and long-term memory.
HarnessAFreshness: A★ 43.8K↓ 13.1M/wk - 0.732score
CrewAI
CrewAI
Open-source Python framework for multi-agent workflows, with role-based Crews and event-driven Flows.
HarnessAFreshness: A★ 60.1K↓ 644.6K/wk
Questions
- Is fast-agent or LangChain more popular?
- LangChain has more GitHub stars (148,371 against 3,945). Stars measure attention, not quality, so check freshness and docs too.
- Are fast-agent and LangChain open source?
- Yes: fast-agent is Apache-2.0 and LangChain is MIT.
Related
Cite this page
fast-agent vs LangChain. Agent Mart. https://agentmart.dev/compare/fast-agent-vs-langchain (last updated 2026-10-26)