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Agent Framework Comparison for Vibe Coders

Jamin Mahmood-Wiebe

Jamin Mahmood-Wiebe

Exploded-view layers: a glass panel etched with a decision tree floating above a steel panel with a conveyor gear
Article

All 14 Tools at a Glance

Every open-source core library here is free — costs only appear at the managed-hosting layer. Vercel Workflows is the one exception to the "self-hostable library" pattern: it's a platform feature, not a package you can lift out. Details, hosted-tier pricing, and license terms for each tool follow below.

Agent Framework Comparison: Why "Which Tool Is Best" Is the Wrong Question

In short: Every comparison article on AI agent frameworks lines up a handful of tools in a table and crowns a winner. The problem: the tools aren't in the same race. Some decide what an agent does. Others make sure that decision still runs on Monday morning when Vercel restarts the process.

Two Layers, One Mix-Up

This article covers 14 tools and sorts them by layer first, fit second.

Ask five vibe coders which agent framework is best and you'll get five different answers — not because the question is hard, but because it's imprecise. Comparing LangGraph to Windmill is like weighing a programming language against a cron scheduler. Both potentially belong in the same stack. Neither replaces the other.

The dividing line

Reasoning layer — decides what the agent does next. Takes in state, calls a model, picks a tool, updates state. This is the thinking logic.

Orchestration layer — makes sure the run survives. Retries after a crash, schedules, queues, cost control, observability across hundreds of parallel runs. This is the operational logic.

Eight tools sit in the first layer: Pydantic AI, LangGraph, Mastra, Vercel AI SDK, OpenAI Agents SDK, Google ADK, Microsoft Agent Framework, and LlamaIndex. Six sit in the second: Vercel Workflows, Windmill, Trigger.dev, Inngest, Prefect, and DBOS. Taking a vibe-coding project from prototype to something production-ready usually needs one tool from each column, not one tool that "wins." At IJONIS, we see this exact mix-up constantly with solo builders trying to scale their first agent past a chat prototype.

For how a single agent is built internally, How to Build an AI Agent: The 5 Parts is the right starting point. For how ten or twenty agents get governed across a company, Agent Operating System (Agent OS): Orchestrating AI Agents is the next step — it covers the governance layer that sits above the tools discussed here.

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Data as of publication

Prices, licenses, and GitHub star counts in this article were verified directly against official sources on July 16, 2026, and re-verified on July 20, 2026. Some younger repos (Microsoft Agent Framework, DBOS) see weekly changes in adoption numbers — treat star counts as directional, not exact-to-the-day. Star counts are also a lagging signal: several of the most-starred agent projects on GitHub have not shipped a release in over a year. Check the commit history before you trust the badge.

Reasoning Frameworks Compared

Eight tools decide what an agent does next. Three are pure agent frameworks: Pydantic AI, LangGraph, Mastra. Two are official vendor SDKs: OpenAI Agents SDK, Google ADK. One sits a layer deeper (Vercel AI SDK), one is the successor to two well-known frameworks (Microsoft Agent Framework), and one comes from the RAG world (LlamaIndex).

Pydantic AI — the type-safe Python approach

Pydantic AI comes from the team behind Pydantic, the validation library already embedded in OpenAI's Software Development Kit (SDK), Google's Agent Development Kit (ADK), and Anthropic's SDK. The framework itself is open source and free, no licensing fees.

Core idea: agent outputs are typed and validated through Pydantic models before they get used downstream. That catches an entire class of errors that would otherwise only surface at runtime with unstructured responses from a large language model (LLM). Pydantic AI is model-agnostic — OpenAI, Anthropic, Gemini, Mistral, Bedrock, Vertex AI, Ollama, and more run through the same interface.

Important for the architecture: Pydantic AI is stateless by default. Every agent.run() call is isolated unless you pass message history explicitly. There's no built-in persistence layer. That's not a gap — it's exactly why Pydantic AI almost always gets paired with an orchestration layer once a run outlives a single request.

LangGraph — the graph approach with built-in crash recovery

LangGraph models agent behavior as a graph of nodes and edges instead of a linear chain — part of the LangChain ecosystem, available for both Python and TypeScript.

The key difference from Pydantic AI: LangGraph ships with native crash recovery. If an agent crashes mid-run, it can resume from the last checkpoint after a restart — inside the LangGraph runtime itself, not through an external queue. That makes LangGraph the natural pick for complex, multi-step workflows with branching and loops.

The open-source library is MIT-licensed and free. For managed hosting, LangSmith offers three tiers: Developer free (up to 5,000 traces/month, no self-hosting), Plus starting at $39 per seat/month (up to 10,000 traces, still cloud-only), Enterprise at custom pricing — self-hosting or a hybrid deployment only becomes available here. Self-hosting isn't extra-cost, it's simply absent from the lower tiers.

Production references show up consistently across multiple 2026 comparisons: Uber, Klarna, LinkedIn, JPMorgan, BlackRock, Cisco, and Replit are frequently cited as LangGraph users — making LangGraph currently the broadest production foundation among the reasoning frameworks in this article.

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LangChain or LangGraph? They stopped being alternatives

This is the most common point of confusion in the whole space, so it's worth stating plainly: LangChain v1.0 shipped as a stable release on October 17, 2025, and its agent abstraction now runs on top of the LangGraph runtime. You are not choosing between them. Picking LangChain's agent API means you are running LangGraph underneath, whether you think about it or not. LangChain remains one of the most-starred Python repositories in the field at roughly 142,000 stars (as of July 20, 2026); LangGraph is the execution engine it now delegates to.

Mastra — TypeScript-native, built for the Vercel stack

Mastra positions itself explicitly as the TypeScript-native counterpart to the Python-heavy frameworks — built by the Gatsby team, YC W25 batch, backed by $13M in funding. Launched October 2024, hit 1.0 in January 2026, and crossed 22,000+ GitHub stars in 15 months.

The framework itself is Apache 2.0-licensed and free, including agents, workflows, and a built-in memory system. Notably, Mastra deploys directly to serverless platforms like Vercel or Cloudflare Workers — a difference from LangGraph Platform, which doesn't support serverless deployment in its lower tiers.

Mastra Cloud, the managed offering, has three tiers. Starter is free: 100K observability events, then $10 per 100K, 24 CPU hours included, 15-day data retention. Teams starts at $250/month with 1M events, 250 CPU hours, and 6-month retention. Enterprise is custom-priced with Role-Based Access Control (RBAC), Single Sign-On (SSO), and guaranteed data residency in a Virtual Private Cloud (VPC).

If you're already building in Next.js/TypeScript — the classic vibe-coding stack via Cursor, Claude Code, or Vercel v0 — Mastra is often the path of least resistance: no second language, no Python toolchain running in parallel to the existing project. Mastra technically builds on top of the Vercel AI SDK (see next section) but adds graph workflows, checkpointing, and memory the SDK doesn't ship natively.

Vercel AI SDK — the layer underneath, not Mastra's competitor

The Vercel AI SDK isn't an agent framework in the same sense as Mastra or LangGraph — it's the deeper layer Mastra itself is built on. Positioning in their own words: "the TypeScript toolkit to build AI-powered applications and agents with React, Next.js, Vue, Svelte, and Node.js." TypeScript-only, Apache 2.0-licensed, with roughly 25,600 GitHub stars (as of July 16, 2026) — fully free and self-hostable since it's a library, not a hosted service.

The SDK offers three surfaces: AI SDK Core (a unified interface across 25+ model providers), AI SDK UI (framework-agnostic hooks like useChat for streaming into React/Vue/Svelte), and more recently Harnesses for agent loops. What's missing is exactly what Mastra adds: native crash recovery, checkpointing, and built-in memory for long-running agents. Vercel's own docs point to a separate "Workflows" product for agents that need to "suspend, resume, and survive function timeouts" — a signal the base library isn't built for that.

Cost model: the SDK itself is free. Real costs come either directly from your chosen model provider, or through the Vercel AI Gateway, which passes tokens through with no markup — free to start (limited model selection, lower rate limits) and paid via purchased Gateway credits.

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Keep serverless timeouts in mind

Deploy an agent through Vercel's serverless functions, and function timeouts cap how long a single agent run can take — the exact limit differs across Pro and Enterprise plans. Fine for short, fast agents. For long-running, multi-step workflows, that's exactly where an orchestration layer like Trigger.dev or Inngest becomes relevant — neither is bound to function timeouts.

OpenAI Agents SDK — minimal wiring, deep in OpenAI's own stack

The OpenAI Agents SDK is the official successor to Swarm, OpenAI's earlier experimentation framework — in their own words: "a production-ready upgrade... in a lightweight, easy-to-use package with very few abstractions." Available as an official Python and TypeScript library, MIT-licensed, with roughly 27,900 GitHub stars for the Python variant (as of July 16, 2026).

The core primitives are deliberately minimal: Agents (model plus instructions plus tools), Handoffs (delegation between agents), and Guardrails (input/output validation). The framework works natively with OpenAI models, but supports other providers through LiteLLM adapters. Costs match standard OpenAI API pricing plus separate fees for hosted tools like web search or Code Interpreter.

The real drawback versus LangGraph or Mastra: per multiple 2026 comparisons, the SDK cannot handle graph-based orchestration or run agents in parallel — good for handoff chains with minimal wiring, a real architectural ceiling for anything more complex. One more thing worth knowing: tracing is enabled by default and sends data to OpenAI's own dashboard unless you explicitly swap in a custom tracing processor — an opt-out pattern, not opt-in.

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Assistants API is sunsetting

OpenAI's older Assistants API sunsets on August 26, 2026 — just weeks from this article's publication. The recommended replacement is the Responses API combined with the Agents SDK. If you're still building on the Assistants API, migrate now, not in August.

Google ADK — the youngest of the three big SDKs

The Google Agent Development Kit launched at Google Cloud Next in April 2025, making it the youngest framework in this comparison. Their own positioning: "Build production agents, not prototypes."

Python is the most mature implementation; official TypeScript, Go, Java, and Kotlin versions also exist — broader language coverage than any other tool here, though the Kotlin implementation and parts of Python are still described as beta by third-party comparisons.

Apache 2.0-licensed, with roughly 20,600 GitHub stars for the Python variant (as of July 16, 2026). ADK itself is free; real costs come from Gemini API usage — a free tier exists, and paid usage runs between $0.10 and $15 per million tokens depending on the model.

The strength is native support for the Agent2Agent Protocol (A2A) and one-command deployment to Vertex AI Agent Engine, including managed infrastructure, authentication, and Cloud Trace observability. ADK also supports non-Gemini models through LiteLLM, Ollama, and vLLM integrations. Google uses ADK internally for its own products, Agentspace and Customer Engagement Suite.

The downside: multiple independent 2026 comparisons rank ADK as the least mature of the three big SDKs — smaller community, fewer external production references than LangGraph or the OpenAI Agents SDK. The consistent recommendation: ADK pays off mainly when a project is already committed to Google Cloud or Gemini Enterprise. Without that commitment, several sources describe LangGraph as the safer bet.

Microsoft Agent Framework — the successor to AutoGen and Semantic Kernel

Microsoft Agent Framework reached version 1.0 on April 3, 2026, unifying two older Microsoft frameworks: "combines AutoGen's simple agent abstractions with Semantic Kernel's enterprise features — session-based state management, type safety, middleware, telemetry — and adds graph-based workflows for explicit multi-agent orchestration," per their own documentation.

Python and .NET are fully production-ready (GA); a Go version exists only as a preview. Fully open source under the MIT license, free, with roughly 12,200 GitHub stars currently — meaningfully fewer than AutoGen's historical 59,800 stars, mostly because the unified repository has only existed since April 2026.

Per the official AutoGen repository, AutoGen is "in maintenance mode. It will not receive new features or enhancements and is community managed going forward... New users should start with Microsoft Agent Framework." That's more precise than "discontinued" — AutoGen lives on, just without further development from Microsoft itself. Semantic Kernel carries a similar status since roughly October 2025 per several independent sources, though less explicitly documented than AutoGen's case.

The honest take for vibe coders: Microsoft Agent Framework is architecturally and documentation-wise enterprise-first — governance, observability, typed graph workflows, Azure Foundry integration, explicit legal disclaimers around third-party models. It works outside Azure too (OpenAI, Anthropic, and Ollama are directly supported), but the docs and case studies skew heavily corporate. For a pure TypeScript project in a Next.js stack, it's not a natural fit either way — only 2.5% of the repository is TypeScript.

LlamaIndex — RAG-first, with agent capabilities layered on

LlamaIndex now describes itself as "the leading document agent and OCR platform" — a notably document- and retrieval-centric framing, even for its own agent product, AgentWorkflow. Python is the primary language with roughly 50,900 GitHub stars, MIT-licensed and free for the open-source core.

Important gotcha for TypeScript teams: LlamaIndex.TS was officially discontinued and archived as of April 30, 2026. If you're building in the Next.js/Vercel stack, there's effectively no actively maintained option here anymore — a clear difference from Mastra or the Vercel AI SDK.

LlamaIndex is strongest when retrieval is the central problem — agents that need to search and merge many heterogeneous data sources, not general-purpose agent orchestration. Customers like Rakuten, Salesforce, and Experian use it accordingly for document-heavy use cases. Earlier complaints about frequent breaking changes (version 0.10, 2024) have largely settled per current sources — the API is considered meaningfully more stable in 2026.

Commercial pricing runs through LlamaCloud/LlamaParse, separate from the free open-source core: Free at $0 (10,000 credits, up to 100 users), Starter at $50/month (40,000 credits included), Pro at $500/month (400,000 credits included), Enterprise custom.

Orchestration Infrastructure Compared

Six tools make sure an agent run survives a crash, hits a schedule, and keeps costs under control: Vercel Workflows, Windmill, Trigger.dev, Inngest, Prefect, and DBOS.

Vercel Workflows — the one already in your deploy target

If your project deploys to Vercel, this is the option to rule out before you evaluate anything else, because it's the only one that adds no new vendor, no new dashboard, and no new bill.

Vercel Workflows reached general availability in April 2026 and turns durable execution into a language-level primitive rather than an external service. You mark a function with a "use workflow" directive and its individual steps with "use step"; Vercel checkpoints each step so a run survives crashes, redeploys, and function timeouts. There's no YAML, no separate queue to provision, and no worker fleet to keep alive. Both JavaScript/TypeScript and Python are supported.

The practical significance for the audience of this article: the serverless timeout problem described in the Vercel AI SDK section above is the single most common reason a vibe-coding agent breaks in production, and Vercel's own answer to it now sits inside the platform. A workflow can sleep for months and resume on schedule, which is exactly the shape of a long-running agent job.

Pricing follows the platform rather than a separate product tier: the Hobby plan includes 50,000 workflow events per month at no cost, with paid plans scaling from there. That matters because it's the only tool in this section where a solo builder incurs no incremental vendor cost at all.

The honest trade-off is portability. Windmill, Trigger.dev, Inngest, and DBOS are libraries or servers you can move; Vercel Workflows is a platform feature. Building on it means the durability layer of your agent leaves with you only if you rewrite it. For a solo project already committed to Vercel, that's usually an acceptable trade. For anything expecting to move hosts later, it isn't.

Windmill — polyglot, self-hosting-first

Windmill turns scripts into webhooks, workflows, and UIs — with support for Python, TypeScript, Go, Rust, and Bash in the same workflow. That makes Windmill the option when you're not locked into a single language.

The Community Edition is self-hosted, free, with unlimited executions, up to three workspaces, and 50 users — but under AGPLv3 license. That's a copyleft license with its own obligations for derivative works, a detail worth catching during legal review, not after. Self-hosted Enterprise starts at $120/month plus $20 per developer, including a commercial license, unlimited audit logs, and SAML support.

Trigger.dev — TypeScript-focused, permissive license

Trigger.dev is built for TypeScript projects that need long-running tasks, schedules, and event-driven workflows without running their own servers — exactly the setup most vibe-coding projects already run on.

Unlike Windmill, Trigger.dev runs under Apache 2.0 license — permissive, self-hosting is free with no feature restrictions. Managed hosting starts at $0 (20 concurrent runs, $5 compute credit included, 1-day log retention), Hobby at $10/month, Pro at $50/month (200+ concurrent runs, 30-day retention), Enterprise at custom pricing including SSO and SOC 2 reports.

Inngest — event-driven, with granular flow control

Inngest models work as functions that subscribe to events — a different mental model from Trigger.dev, which calls tasks directly, closer to a remote function call. Neither model is objectively better; the fork is about the shape of the work, not quality.

The server and CLI run under the Server Side Public License (SSPL) with delayed publication under Apache 2.0; the SDKs themselves are Apache 2.0-licensed. Self-hosting is documented and supported, though it sits less at the center of the positioning than it does for Trigger.dev.

Pricing per the official page: Hobby free (50K executions/month, 5 concurrent executions, 3 users), Pro starting at $99/month (1M+ executions, 100+ concurrent executions, 15 users, tiered overage pricing across every dimension), Enterprise custom with SAML and audit trails.

The standout feature is a named flow-control toolkit: concurrency, throttling, batching, debounce, priority, and singleton runs — all configurable in one line of code, globally, per function, or per tenant. At roughly 5,600 GitHub stars, Inngest is meaningfully smaller than Windmill or Trigger.dev, but well-funded with a $21M Series A (September 2025, led by Altimeter).

Prefect — Python-native pipeline orchestration

Prefect positions itself as "workflow orchestration for data, ML, and agents" — but competes more directly with Airflow and Dagster in the data-engineering space than with Trigger.dev or Windmill in the agent-backend space. Any Python function becomes a workflow via @flow and @task decorators, with minimal boilerplate.

Apache 2.0-licensed, with roughly 23,400 GitHub stars — noticeably more than Inngest or DBOS, a result of being on the market since 2018. The self-hosted Prefect Server is free with unlimited runs. Prefect Cloud pricing (per independent sources, not directly confirmed on Prefect's own page): Hobby free (2 users, 5 deployments), Starter $100/month, Team starting at $100 per user/month with a 4-user minimum, Enterprise custom.

For a typical vibe-coding project — a SaaS app with AI agents in the backend — Prefect is rarely the obvious pick. The positioning, case studies, and decorator model consistently point toward data and ML pipeline orchestration, not product backends.

DBOS — durable execution without a separate server

DBOS takes a fundamentally different architectural approach from everything else in this section: there's no separate orchestration server. Durability comes from checkpointing execution state as rows in the Postgres database your app already has — no extra cluster, no extra infrastructure.

The roots trace to three years of joint MIT-Stanford research, co-founded by Turing Award laureate Mike Stonebraker and Databricks co-founder Matei Zaharia. The company was founded in 2024 and raised $8.5M in seed funding.

Open-source core is MIT-licensed, free, self-hosted with no limits. Official SDKs exist for Python, TypeScript, Go, and Java. Pricing: Pro at $99/month (2 users, up to 3 apps, 1M checkpoints included), Teams at $499/month (10 users, up to 10 apps, 10M checkpoints, SOC 2 and HIPAA compliance), Enterprise custom with a self-hosted "Conductor" option.

DBOS advertises roughly 10x less code than Temporal for the same durability guarantee — a vendor claim, not independently benchmarked, though a public benchmark repository exists.

The real trade-off: there's no Temporal-comparable web UI for debugging across a full execution history. For most backend services, DBOS is a reasonable lightweight starting point, with Temporal as the fallback once scale genuinely gets extreme.

Two Fallback Options for Extreme Scale

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What about CrewAI, AutoGen, n8n?

CrewAI builds on a "Crew" abstraction — agents with defined roles collaborating together. Popular, but without loop limits, costs can run away fast: one documented run without caps hit over $400 in uncontrolled spend. AutoGen, as covered above, is in maintenance mode and has been absorbed into Microsoft Agent Framework. n8n isn't a code-first framework at all — it's a no-code workflow platform with an AI agent node, a different axis (visual vs. code-based) that cuts across the reasoning/orchestration split rather than replacing it.

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Temporal as a reference point for extreme scale

Temporal is the enterprise-grade version of durable execution — built by engineers who previously worked on AWS SQS/SWF and Uber Cadence. The self-hosted server is MIT-licensed; the real cost is running the cluster. Temporal Cloud starts at $100/month for one million Actions. Overkill for a single vibe-coding project — relevant once workflows run for weeks or months, with very high fan-out or multi-region requirements. Windmill, Trigger.dev, Inngest, Prefect, and DBOS cover the vast majority of real projects before that threshold is reached.

What This Article Leaves Out, and Why

Fourteen tools is a selection, not a census. Several well-known projects were considered and cut. Naming them and giving the reason is more useful than pretending they don't exist, and in a few cases the reason for cutting them is itself the argument of this article. Every star count and release date in this section was queried directly against the GitHub API on July 20, 2026.

Tools that prove the split rather than competing in it

DSPy (roughly 36,200 stars) optimizes and compiles prompts against a metric. BAML (roughly 8,600 stars, Apache 2.0) is a domain-specific language and compiler that generates type-safe clients for structured model output. Neither is an agent runtime. You'd use both inside an agent built with something from the reasoning column. Comparing DSPy to LangGraph is a category error, which is precisely why the layer model is worth having.

A genuinely different reasoning approach

Smolagents from Hugging Face (roughly 28,400 stars, Apache 2.0) has agents write and execute Python code as their action space instead of emitting JSON tool calls. All eight reasoning frameworks above use JSON tool calling. Leaving Smolagents out makes that layer look more uniform than it is, so it's worth knowing the alternative exists.

Strong tools with a language or platform mismatch

Eino from ByteDance (roughly 12,400 stars) does reasoning and durable checkpointing well, but it's Go. Restate, built in Berlin by co-creators of Apache Flink, is architecturally the best serverless fit in the durable-execution field — handlers run as ordinary HTTP endpoints — but it ships under the Business Source License, not an open-source license, which belongs in a legal review rather than a footnote. Hatchet (MIT, roughly 7,500 stars) has the cleanest free-tier economics of any orchestrator here, self-hosted on Postgres alone.

AgentScope from Alibaba and Ant Group deserves particular mention, because it's the most capable tool here that Western framework coverage consistently ignores. Roughly 28,000 stars, Apache 2.0, two peer-reviewed papers, and genuinely spanning both layers: an agent framework plus a runtime with tool sandboxing, memory, and deployment. It's also the most portable option in this article — a permissive license, swappable model providers, and five interchangeable sandbox backends, with no proprietary runtime underneath. The reason it's excluded is narrow and practical: it is Python-only, with no TypeScript SDK, which rules it out for the Next.js stack most vibe coders build in. For a Python project it's a serious candidate and worth evaluating alongside Pydantic AI.

Two vendor SDKs sitting above the reasoning layer

The Claude Agent SDK from Anthropic and Strands Agents from AWS both operate one level above the eight reasoning frameworks: they supply harness primitives like subagents, hooks, permissions, and Model Context Protocol (MCP) wiring rather than a graph runtime. Either can sit on top of a framework from the reasoning column.

One licensing detail is worth stating because it's documented nowhere obvious: the Claude Agent SDK's Python package is MIT-licensed, while the TypeScript package is proprietary ("© Anthropic PBC. All rights reserved."). Same product surface, two different legal positions. For a TypeScript-first project, that asymmetry belongs in the evaluation.

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An open-source license does not always mean a portable runtime

Cloudflare's Agents SDK is genuinely MIT-licensed, which reads as safe. But agents built with it are Durable Objects, a proprietary Cloudflare primitive with no open implementation and no compatible alternative anywhere else. You get code portability, not runtime portability: the license lets you take the source, and the architecture means it won't run once you do. This is the sharpest version of a trap worth checking for generally — read what the code depends on, not just the license file.

Large projects deliberately excluded

Agno has roughly 41,300 stars, more than most tools covered above, but has drifted from framework toward platform. Dify is the most-adopted agent platform on GitHub at roughly 149,500 stars — and carries the licensing trap most coverage omits. Despite being routinely described as Apache 2.0, Dify ships under a modified Apache license that forbids operating it as a multi-tenant service and requires retaining Dify branding. For a side project that might become a SaaS one day, that's worth reading before you build on it, not after.

Tools whose star count is a historical artifact

Several of the highest-starred agent repositories on GitHub are effectively dormant: MetaGPT (roughly 69,400 stars, last release March 2025) and OpenManus (roughly 57,500 stars, last release April 2025) between them hold more stars than the actively developed projects in this article combined. Stars measure a moment of attention, usually the 2023–2025 hype wave. They do not measure whether anyone is still maintaining the code. Sort a framework shortlist by stars and you will systematically rank dead projects above live infrastructure.

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Check the commit log, not the star count

Before adopting any agent framework, open its GitHub repository and look at two things: the date of the last release, and whether recent commits are real changes or automated dependency bumps. A repository with a recent timestamp and six months of nothing but bot commits is not maintained. This check takes thirty seconds and is the highest-value due diligence available in this field.

The Argument Against Buying Both Layers From One Vendor

There's a category this article has treated only in passing: platforms that sell reasoning and orchestration together as a single product. Every major cloud now offers one. The pitch is real convenience, and the case against it is stronger than convenience.

The vendors themselves keep the layers separate

AWS Bedrock AgentCore, Microsoft Foundry Agent Service, Databricks Agent Bricks, Cloudflare's Agents SDK, and Google's agent platform are all explicitly model-agnostic, and all of them advertise that as a feature. Microsoft's documentation promises you can "swap models without changing your agent code." Databricks markets access to every leading model, open source included. If reasoning and orchestration were genuinely one decision, at least one vendor with a commercial incentive to fuse them would have shipped a fixed model and sold the bundle. None has. They ship the seam and then charge for both sides of it.

The billing confirms it. These platforms ship reasoning and orchestration as separately named, separately metered, and separately released products. AgentCore bills runtime, memory, gateway, and identity as distinct line items, and parts of it remain in preview while the runtime is generally available. A single buying decision does not have two meters and two release dates.

Vendor failure is the real argument

Then there's the part that turns this from a modeling preference into a risk position.

3 of 7independent agent platforms died or pivoted in ~12 months
Nov 2026OpenAI's own Agent Builder shuts down
2layers, one interface contract

Humanloop shut down on September 8, 2025 following an acqui-hire by Anthropic that explicitly did not include the platform's assets, leaving customers with a sunset notice. Portia AI's organization was renamed and its SDK repository now returns a 404. Vellum pivoted away from being a developer platform entirely. And OpenAI deprecated its own Agent Builder in June 2026, with shutdown scheduled for November 30, 2026.

The lesson is structural, not anecdotal. When you buy both layers from one vendor, a vendor failure takes both at once. When you buy them separately, the same failure costs you one layer and you re-point the other. A builder running an open-source reasoning framework against a hosted orchestrator loses half a stack when the orchestrator dies. Humanloop's customers had to migrate everything.

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Separable is not the same as independent

The honest version of this argument has a caveat. The two layers are separable, but they're not free of each other. Prompt caching behavior, structured-output modes, native tool-calling formats, and reasoning-budget controls all differ between model providers, and swapping a model can genuinely break orchestration logic built around the old one. The accurate framing is two decisions with one interface contract between them. Anyone claiming model swaps are cost-free is selling something.

One more practical note for solo builders: what these full-stack platforms actually sell is governance. Catalog-level data lineage, per-agent enterprise identity, network isolation, role-based access control, audit trails. Those are answers to a compliance officer's questions. A solo builder does not have a compliance officer. Buying a full-stack platform to obtain orchestration usually means paying for enterprise apparatus you will never open.

Decision Logic: Two Questions, Not One Ranking

14tools, 2 buying decisions
$0starting cost across every core library
AGPLv3license difference often missed

Question 1 — Reasoning: which language, which provider, how much state control?

Match the pick to the language you're already building in first. Then decide whether you're comfortable locking into one model provider, and how much branching your agent actually needs.

  • Pydantic AI: Python stack. Maximum type safety. Simple to moderate workflows.
  • LangGraph: Python or TypeScript. Complex branching. Built-in crash recovery wanted.
  • Mastra: TypeScript stack. Serverless deployment. Existing Next.js/Vercel environment.
  • Vercel AI SDK: only need model calls and streaming, not a full agent framework.
  • OpenAI Agents SDK: committed to OpenAI models. Simple handoff chains. Minimal wiring wanted.
  • Google ADK: already on Google Cloud or Gemini Enterprise.
  • Microsoft Agent Framework: .NET stack or committed Azure environment.
  • LlamaIndex: retrieval across many data sources is the core problem, not general agent logic.

Question 2 — Orchestration: how much control, which language, which license?

  • Vercel Workflows: already deploying to Vercel. No extra vendor wanted. Platform lock-in acceptable.
  • Windmill: multiple languages in the project. Strong data-residency focus. AGPL acceptable.
  • Trigger.dev: pure TypeScript stack. Apache 2.0 preferred. Simple onboarding wanted.
  • Inngest: event-driven mental model. Granular flow control (throttling, batching, debounce) matters.
  • Prefect: Python-heavy data or ML pipeline, not primarily a product backend.
  • DBOS: Postgres already running. No separate orchestration server wanted.
  • Temporal: workflows running weeks or months. Scaling well past solo operation.

The combination that works most often in practice: one reasoning framework for the decision logic, orchestrated through Vercel Workflows, Windmill, Trigger.dev, Inngest, or DBOS for everything involving schedules, retries, and cost control. If you already deploy to Vercel, start by checking whether Workflows covers your case before adding a third-party orchestrator — the cheapest tool is the one you don't have to introduce.

Teams that pick only the reasoning framework and leave orchestration to chance end up building exactly the problem described in Agent OS: Orchestrating AI Agents — the moment more than one agent hits production.

FAQ: Agent Framework Comparison

What's the difference between LangGraph and Windmill?

LangGraph is a reasoning framework — it decides what an agent does next, based on state and model output. Windmill is an orchestration platform — it makes sure a run survives retries, schedules, and queues. Both potentially belong in the same stack; they don't compete for the same job. In short: LangGraph thinks, Windmill makes sure the thinking still runs tomorrow.

Is Pydantic AI better than LangGraph?

Neither — they solve slightly different problems. Pydantic AI wins on type safety and simplicity for Python teams building shorter, cleanly structured agent runs. LangGraph wins on native crash recovery and graph-based modeling for more complex, branching workflows with many intermediate steps. The choice depends on how complex your agent logic is, not a general quality ranking.

Do I need Mastra if I'm already using Vercel AI SDK?

Vercel AI SDK is built primarily for model calls and streaming, not full agent workflows with memory and multi-step logic. Mastra technically builds on the AI SDK and adds exactly what's missing: graph workflows, checkpointing, and built-in memory. For simple chat interfaces, the AI SDK alone is often enough; for agents with multiple steps and state, Mastra becomes relevant.

Trigger.dev or Inngest — what's the difference?

Both are TypeScript-focused orchestration tools with a similar target audience, but a different mental model. Trigger.dev calls tasks directly, closer to a remote function call. Inngest models work as functions subscribing to events, with a named flow-control toolkit for throttling, batching, and debounce. Trigger.dev runs under the permissive Apache 2.0 license; Inngest under SSPL with delayed Apache 2.0 publication. For most vibe-coding projects, programming style decides more than any hard technical limit.

What does it cost to get started with these 14 frameworks?

Every open-source core library here is free — none of them charges a licensing fee just to use the code. Costs appear at the managed-hosting or model-usage layer: LangSmith Plus starting at $39 per seat, Mastra Cloud Teams starting at $250/month, Windmill Enterprise starting at $120/month, Trigger.dev Pro starting at $50/month, Inngest Pro starting at $99/month, DBOS Pro starting at $99/month, Prefect Starter around $100/month. Vercel Workflows is the exception to the self-hosting pattern: it's included in the Vercel plan you already pay for, with 50,000 workflow events per month on the free Hobby tier, but it can't be lifted out and run elsewhere. Self-hosting remains possible for nearly all the others, under different license terms — from AGPLv3 (Windmill Community) to SSPL (Inngest server) to Apache 2.0 and MIT for most of the rest.

Which framework fits a solo vibe-coding project?

For a TypeScript stack with no server ops of your own: Mastra for reasoning, and Vercel Workflows for orchestration if you're already deploying there, otherwise Trigger.dev or Inngest — all serverless-capable, no cluster to run. For a Python project prioritizing type safety: Pydantic AI plus DBOS, if you're already running Postgres and don't want a separate orchestration server. Committed to one model provider and fine with minimal wiring: OpenAI Agents SDK or Google ADK, depending on which cloud ecosystem you're already in.

Should I use an all-in-one agent platform instead of picking two tools?

Usually not, as a solo builder. The convenience is real, but three of the seven independent full-stack agent platforms tracked for this article either shut down or pivoted away from the category within roughly twelve months, and OpenAI's own Agent Builder is scheduled to shut down on November 30, 2026. Buying both layers from one vendor means a single vendor failure takes out your reasoning and your durability at the same time. There's also a cost argument: what these platforms mainly sell beyond the tooling is governance — audit trails, per-agent identity, network isolation, data lineage. Those solve a compliance officer's problems, and a solo project doesn't have one.

Is a high GitHub star count a good way to pick an agent framework?

No, and it's actively misleading in this field. Stars accumulate permanently but measure attention at a moment, usually the 2023–2025 agent hype wave. Two of the most-starred agent repositories on GitHub, MetaGPT (roughly 69,400 stars) and OpenManus (roughly 57,500 stars), have not shipped a release since March and April 2025 respectively — together more stars than the actively maintained tools in this article combined. Check the date of the last release and whether recent commits are real changes or automated dependency updates. That thirty-second check tells you more than the star badge ever will.


Not sure which combination fits your project? IJONIS builds agent architectures from framework selection through production — including for solo builders taking a prototype into real operation. Talk to us about your specific situation, or dig deeper with How to Build an AI Agent: The 5 Parts and Agent OS: Orchestrating AI Agents.

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