LangChain vs Mastra

LangChain

The default starting point for agent development: no other framework matches its integration catalog, documentation volume or hiring-market familiarity. The catch is churn and depth — major versions have repeatedly rewritten core APIs, and once you need observability or managed deployment you are steered toward the paid LangSmith platform.

Pros

• +Integrations for 1,000+ models, tools, vector stores and databases
• +MIT license with a large contributor community
• +LangGraph runtime adds persistence, rewind and human-in-the-loop control
• +Python and JavaScript keep parity for most features

Cons

• −History of breaking API changes between major versions
• −Layers of abstraction complicate debugging versus direct SDK calls
• −Production observability and deployment funnel into commercial LangSmith

Mastra

Mastra brings the same team that scaled Gatsby to millions in revenue into the agent-framework space, and the open-source core with a large provider list is a credible starting point for TypeScript teams. It competes directly with more established orchestration frameworks, so the deciding factor is usually which one already fits a team's existing stack.

Pros

• +Apache 2.0 open-source core with a large, active GitHub following
• +Built-in workflow, memory, and observability primitives rather than requiring separate tools
• +Backed by experienced founders and well funded, reducing near-term abandonment risk

Cons

• −TypeScript-only, so it does not serve Python-first agent teams
• −Enterprise licensing terms and pricing are not published publicly
• −Being newer than incumbents like LangChain means a smaller base of production war stories

Is LangChain cheaper than Mastra?

LangChain is free to use; Mastra starts at $250/mo.

Does LangChain or Mastra have a free tier?

Both: LangChain is free to use, and Mastra has a free tier.

Which has a public API, LangChain or Mastra?

Mastra ships a public API, as of our last verification. A public API for LangChain is not confirmed by us — check its developer docs before you plan an integration.