Comparisons / Haystack vs Mastra
Haystack vs Mastra: Which Agent Framework to Use?
Haystack by deepset is a framework for building NLP and LLM pipelines. Mastra is a TypeScript-first framework for building AI agents, from the team behind Gatsby. Here is how they compare — paradigm, ecosystem, and the use cases each one is actually built for.
By the numbers
Haystack
24.7k
2.7k
Python
Apache-2.0
2019-11-14
deepset
Mastra
22.7k
1.8k
TypeScript
MIT
2024-08-06
Mastra AI
244.0k
GitHub stats as of April 2026. Stars indicate community interest, not necessarily quality or fit for your use case.
| Concept | Haystack | Mastra |
|---|---|---|
| Agent | `Agent` component with `ChatGenerator`, tool definitions, and message routing | `new Agent({ model, instructions, tools })` with automatic tool dispatch |
| Tools | `Tool` dataclass with function reference, name, description, parameters schema | `createTool({ name, schema, execute })` with Zod validation |
| Pipeline Architecture | `Pipeline()` with `add_component()` and `connect()` — a directed graph of typed components | — |
| RAG / Retrieval | `DocumentStore` + `Retriever` + `PromptBuilder` + `Generator` wired in a `Pipeline` | — |
| Memory | `ChatMessageStore` with `ConversationMemory` component in pipeline | Short-term thread memory + long-term vector memory across sessions |
| Deployment | Pipeline YAML serialization, `Hayhooks` REST server | — |
| Workflows | — | `Workflow` class with `.step()`, `.then()`, `.branch()` for orchestration |
| RAG | — | Built-in document syncing, chunking, embedding, and vector search |
| Studio | — | Mastra Studio: local GUI for testing agents, viewing traces, debugging |
Haystack vs Mastra, head to head
Haystack Haystack by deepset is a framework for building NLP and LLM pipelines.
Mastra Mastra is a TypeScript-first framework for building AI agents, from the team behind Gatsby.
Both wrap the same underlying agent pattern — an LLM call, a tool dispatch, a loop — in different abstractions. The choice between them is mostly about which mental model and ecosystem fits the team you have, not which one is technically more capable.
Pick Haystack if
Pick Haystack if haystack earns its complexity when you're building RAG pipelines with multiple retrieval stages, document processing, and production deployment needs. But for straightforward agents with a few tools, the plain Python version is simpler to write and debug. Haystack is the right fit when the tradeoffs in its intro line up with how your team actually wants to work day-to-day; Mastra would force you to translate.
Pick Mastra if
Pick Mastra if mastra is the best option for TypeScript teams that want a batteries-included agent framework without leaving the Node.js ecosystem. The workflow engine and Studio are genuinely productive. For simple agents or Python teams, the plain approach avoids an unnecessary dependency. Mastra is the right fit when the tradeoffs in its intro line up with how your team actually wants to work day-to-day; Haystack would force you to translate.
What both add
Both Haystack and Mastra pull in a class hierarchy and a dependency tree to wrap what is, at the core, an HTTP POST in a while loop. If your use case is straightforward — one provider, a handful of tools, a single agent — the framework cost may exceed the framework benefit. The lesson below shows the same pattern in ~60 lines without either dependency.
Or build your own in 60 lines
Both Haystack and Mastra implement the same 8 patterns. An agent is a function. Tools are a dict. The loop is a while loop. The whole thing composes in ~60 lines of Python.
No framework. No dependencies. No opinions. Just the code.
Build it from scratch →