Best TypeScript and JavaScript frameworks for AI agents
For teams shipping agents inside Node or web stacks. Each of these frameworks offers a TypeScript or JavaScript SDK.
Ranked by score on our 100-point rubric (how we score). Scores are initial editorial estimates from public information, not hands-on tests. Pricing is labeled verified (checked on the vendor's official pricing page, with date) or unverified.
Quick picks
| # | Tool | Tier | Score |
|---|---|---|---|
| 1 | LangGraph Stateful graph-based agent orchestration | A | 80 |
| 2 | OpenAI Agents SDK Lightweight framework for multi-agent apps | A | 77 |
| 3 | Claude Agent SDK Build agents on the Claude Code harness | A | 76 |
| 4 | Mastra TypeScript agent framework | A | 73 |
The ranking
-
LangChain's low-level framework for building controllable, long-running multi-agent workflows.
- Best for
- You need production agents with explicit control flow and persistence.
- Skip it if
- You want a no-code tool or a quick script.
- Pricing
- LangSmith Developer $0/seat; Plus $39/seat/mo then pay-as-you-go ✓ verified on the official pricing page, Oct 18, 2026
- Platforms
- API · Python SDK · JS SDK
-
Open-source SDK with agents, handoffs, guardrails and tracing; works with many model providers.
- Best for
- You want a minimal, well-documented agent SDK.
- Skip it if
- You need a visual builder.
- Pricing
- Free and open source; pay for model usage unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- Python SDK · JS SDK
-
Anthropic's SDK exposing the Claude Code agent loop, tools, and context management for custom agents.
- Best for
- You want Claude Code's proven agent loop inside your own product.
- Skip it if
- You need to use non-Claude models.
- Pricing
- Free SDK; pay for Claude API usage unverified editorial summary, not yet confirmed on an official pricing page
- Platforms
- Python SDK · TypeScript SDK
-
Open-source TypeScript framework for agents, workflows, RAG and evals.
- Best for
- You build agents in TypeScript.
- Skip it if
- Your team is Python-only.
- Pricing
- Open-source framework; Mastra platform Starter $0/mo; Teams $250/mo ✓ verified on the official pricing page, Oct 18, 2026
- Platforms
- TypeScript SDK
Head-to-head comparisons
FAQ
What is the best AI tool for building agents in TypeScript and JavaScript?
LangGraph ranks first with 80/100 (A-tier). Stateful graph-based agent orchestration. Use it when you need production agents with explicit control flow and persistence. Next in our ranking: OpenAI Agents SDK (77/100, A-tier) and Claude Agent SDK (76/100, A-tier).
Which AI tools for building agents in TypeScript and JavaScript have a free tier?
In our pricing data, LangGraph (verified), OpenAI Agents SDK (unverified), Claude Agent SDK (unverified) and Mastra (verified) list a free tier. "Unverified" means it is an editorial summary we have not yet confirmed on the vendor's official pricing page, so check the vendor before relying on it.
Are there open-source options for building agents in TypeScript and JavaScript?
Yes. LangGraph, OpenAI Agents SDK, Claude Agent SDK and Mastra are listed as open source or open weights. Check each project's license before commercial use.
How are these tools ranked?
Each tool is scored out of 100 on our public rubric: job fit (30), ease (15), value (15), momentum (15), openness and portability (10), trust and maturity (10) and a builder/gamer bonus (5). S-tier is 85+, A-tier 70–84, B-tier 55–69 and C-tier below 55. Current scores are initial editorial estimates from public information, not hands-on tests, and sponsors can't buy points.