Mastra vs CrewAI: When to Choose Which (and How They Work Together)
Mastra and CrewAI solve different problems. A practical guide to choosing between the TypeScript and Python agent frameworks — and four patterns for using them together.
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Mastra vs CrewAI: when to choose which
Two of the most talked-about AI agent frameworks of 2026 aren't actually competing for the same job. Mastra is a TypeScript framework built for AI features that live inside your product; CrewAI is a Python framework built for teams of agents doing open-ended knowledge work. Pick by the shape of your problem — and know that the best answer for plenty of companies is both.
The 30-second answer
Building AI into a web product your users touch? Mastra. Same language as your app, durable human-in-the-loop workflows, evals and tracing in the box. Automating multi-step knowledge work behind the scenes? CrewAI. Role-based crews for the open-ended parts, deterministic Flows for the production backbone, enterprise governance if you need it. New to either framework? Start with our explainers: What is Mastra? and What is CrewAI?
At a glance
Mastra
- Language: TypeScript
- Mental model: agents + durable, graph-based workflows
- Sweet spot: user-facing AI inside web products
- Superpower: suspend/resume workflows — human-in-the-loop as a first-class primitive
- Pedigree: Gatsby founders, YC W25, v1.0 in Jan 2026
CrewAI
- Language: Python
- Mental model: role-based agent crews + event-driven Flows
- Sweet spot: back-office knowledge-work pipelines
- Superpower: role decomposition — problems staffed like a human team
- Pedigree: João Moura, 2023, 50k+ GitHub stars, enterprise AMP platform
Choose Mastra when…
- Your product and engineering team are TypeScript — the agent ships in the same repo, type system, and deploy pipeline as your app.
- The AI is a product feature: an in-app assistant, AI search, a copilot on the dashboard.
- You need approval gates — workflows that pause for a human and resume days later without losing state.
- You want evals, tracing, and tool-call observability without assembling three vendors.
Choose CrewAI when…
- Your team — or the team that will own this — is Python-first (data, ML, automation engineers).
- The job is open-ended knowledge work that decomposes into roles: research → analysis → writing, triage → enrichment → routing.
- It runs behind the scenes on a schedule or trigger, not inside your product's UI.
- You need enterprise governance — RBAC, PII masking, audit trails — without building it yourself.
How they work together
"Which framework?" is often the wrong question — the better one is "which framework where?" Four patterns we see work in practice:
Product in TypeScript, crew in Python
Mastra owns the user-facing agent in your app; CrewAI runs as an internal service for heavy research or enrichment pipelines. They talk over an API or a job queue — each framework where it's strongest.
Bridge with MCP
Both frameworks speak the Model Context Protocol. Expose your tools — CRM, database, docs — as MCP servers once, and agents on either stack use the same integrations instead of duplicating them per language.
Deterministic shell, autonomous core
Let a Mastra workflow or CrewAI Flow own the auditable backbone — triggers, branches, retries, approvals — and hand only the genuinely open-ended steps to an autonomous agent or crew.
Right tool per team
Your web team ships Mastra; your data team ships CrewAI. The contract between them is an API, not a framework mandate. Uniformity is not worth making either team work in a language they don't love.
Our take
We're a TypeScript shop, so our default for in-product AI is Mastra — the agent code lives next to the product code, and durable approval workflows fit how our clients actually operate. We reach for CrewAI when the job is batch knowledge work, when a client's Python team will own the pipeline, or when role decomposition genuinely fits the problem. Neither is "more production-ready" in the abstract; production-readiness lives in your evals, your observability, and your failure handling — whichever framework you pick.
Common questions
Go deeper on either framework: What is Mastra? · What is CrewAI?
Not sure which fits your roadmap?
We've shipped both. Bring us the problem — we'll recommend the stack, scope the build, and ship it.