Tandem vs. AI SDK Vercel: Which Should Product Teams Choose for 2026?

TL;DR

Tandem is a ready-to-deploy AI copilot that embeds inside your product with a single script tag, enabling users to complete tasks, navigate features, and get help without engineering work. Vercel's AI SDK is an open-source TypeScript toolkit with 2+ million weekly downloads that provides primitives for building custom AI features from scratch.

The core difference: Tandem gives you a finished AI copilot product. AI SDK gives you the building blocks to construct one yourself.

Choose Tandem when you need in-app user guidance now, your goal is activation, support deflection, or feature adoption, and you want to ship without engineering cycles.

Choose AI SDK when you're building entirely custom AI functionality, need low-level control over LLM calls, prompts, and tools, or want complete provider portability.

What is Tandem?

Tandem is an AI copilot that lives inside your product interface. It sees what users see on screen in real-time, answers questions, provides guidance, and completes actions on behalf of users—without requiring backend integration for UI-based tasks.

Key capabilities

• Visual context awareness: The AI sees the actual UI state, not a pre-indexed knowledge base. No RAG pipeline, no vector database, no stale context problems.

• Task execution: Tandem can click buttons, fill forms, navigate interfaces, and complete multi-step workflows for users.

• Proactive guidance: Detects user confusion and triggers help automatically—something an SDK cannot do out of the box.

• No-code configuration: Product managers control tone, playbooks, guardrails, and behaviors from a dashboard without code changes.

Validated results

According to Tandem's published case studies:

• At Aircall, Tandem lifted adoption of advanced features by 10–20%

• At Qonto, it helped over 100,000 users discover and activate paid features including insurance and card upgrades

• Tandem is used by companies including Qonto, Aircall, Sellsy, and Kraken

"Using Tandem feels like infusing a bit of magic into our product. It effectively addresses our navigation challenges, enabling our users to extract more value from Qonto. As a result, we see an increase in activation and a decrease in company-wide support tickets."

— Maxime Champoux, Head of Product at Qonto

Tandem was founded in 2024 by Christophe Barre and Manuel Darcemont, launched at Hexa (the startup studio behind Front, Spendesk, Aircall, and Swan), and raised $3.8M in seed funding led by Tribe Capital.

What is Vercel's AI SDK?

Vercel's AI SDK is an open-source TypeScript toolkit designed to help developers build AI-powered applications. It provides a unified API for calling different LLM providers (OpenAI, Anthropic, Google, and others) with consistent interfaces for streaming, structured output, and tool calling.

Core components

• AI SDK Core: Server-side functions like generateText, streamText, generateObject for LLM interactions

• AI SDK UI: Client-side hooks (useChat, useCompletion, useObject) for building chat interfaces

• Provider abstraction: Switch between OpenAI, Anthropic, Google, and other models by changing a single line

Technical strengths

AI SDK excels at:

• Provider portability: Unified API means you can swap openai('gpt-4o') for anthropic('claude-3-5-sonnet') without rewriting application logic

• Streaming: First-class support for streaming responses with partial updates

• Structured output: Generate typed JSON objects with Zod schema validation

• Framework support: Works with React, Next.js, Vue, Svelte, and Node.js

As of AI SDK 5 (released July 2025), the toolkit includes typed chat messages, agentic loop control, and dynamic tooling capabilities.

"Vercel's @aisdk is insanely good. Docs are fantastic. Great abstractions where you want them, doesn't force unnecessary ones."

— Developer review from ai-sdk.dev

Head-to-Head Comparison

What you're actually building

AI SDK gives you control over plumbing. Tandem gives you control over experience.

The hidden SDK tax

When you choose AI SDK, you're also signing up to build:

Context acquisition: The fundamental difference

AI SDK approach: Stuff context into the prompt. Build a RAG pipeline. Maintain a vector database. Decide what to index. Keep it fresh.

Tandem approach: The AI sees what the user sees in real-time. No RAG pipeline to build, no vector DB to maintain, no "which docs do I index?" decisions.

Limitation to note: Tandem cannot see backend state that isn't rendered on screen. If something isn't visible to the user, it's invisible to Tandem too.

When to Choose Each

Choose Tandem when:

1. You need in-app guidance now — not next quarter

2. Your goal is activation, onboarding, or support deflection — the use cases Tandem was built for

3. You don't want to build or maintain an AI feature — you want outcomes

4. You need a visual copilot that can click, fill forms, and navigate your UI

5. Engineering bandwidth is precious — your team should be building product, not infrastructure

Choose AI SDK when:

1. You're building custom AI functionality from scratch — chatbots, content generators, AI-native products

2. You need low-level control over prompts, model selection, and tool orchestration

3. Provider portability matters — you want to switch models without major rewrites

4. You have dedicated engineering capacity for AI feature development

5. Your use case is unique — not user guidance or support, but something novel

The honest framing

You're not trading control for convenience. You're trading infrastructure control you never wanted for experience control you actually need.

Nobody wakes up excited to manage prompt versioning or stream parsing. They wake up wanting users to activate faster.

"Can't we just build Tandem with AI SDK?"

Technically, yes. Tandem could be built using AI SDK as a foundation.

But that's missing the point. The question isn't whether you can build it—it's whether you should.

Building a production-grade in-app copilot requires:

• Real-time screen understanding (not just prompt engineering)

• UI interaction layer (clicking, typing, navigating)

• Proactive trigger logic (detecting when users need help)

• Guardrails and safety (prompt injection, off-topic handling)

• Escalation to humans (with full context handoff)

• Action confirmation flows ("Are you sure you want to delete this?")

• Monitoring and analytics infrastructure

• Ongoing model maintenance

AI SDK gives you generateText() and streamText(). The rest is on you.

What About MCP (Model Context Protocol)?

Tandem can act on your UI without backend integration—clicks, form fills, navigation all work out of the box.

MCP integration is only needed when you want Tandem to trigger backend actions like creating a record, starting a workflow, or calling an API. For many use cases, no MCP setup is required at all.

This is different from AI SDK, where you define all tool capabilities and integrations from scratch.

Summary: Product vs. Primitives

Frequently Asked Questions

Is Tandem or AI SDK better for user onboarding?

Tandem is purpose-built for user onboarding, activation, and support deflection. It can see screen state, guide users contextually, and complete tasks on their behalf. AI SDK provides no onboarding-specific functionality—you would need to build everything from scratch.

Can I use both Tandem and AI SDK?

Yes. Tandem handles in-app user guidance while AI SDK powers other custom AI features in your product. They serve different purposes and can coexist.

Does AI SDK support visual context like Tandem?

No. AI SDK is a toolkit for LLM interactions. It doesn't include screen understanding, UI interaction, or real-time visual context capabilities. Those would need to be built separately.

What engineering resources does each require?

Tandem: Single script tag to integrate. Product managers can configure behavior without engineering. No backend changes required for UI-based actions.

AI SDK: Requires TypeScript/JavaScript engineering. You build the AI feature, UI, error handling, monitoring, and safety layers yourself.

How do they handle multiple LLM providers?

Tandem: Manages model selection internally. You focus on the experience, not the infrastructure.

AI SDK: Provider-agnostic with first-class support for OpenAI, Anthropic, Google, and others. Switching providers requires changing one line of code (though prompts may need adjustment).

Which is more cost-effective?

Depends on your engineering costs. If your team's time costs $150–200/hour and building an equivalent copilot takes 3–6 months, Tandem's subscription is likely more economical. If you have dedicated AI engineering capacity and need maximum flexibility, AI SDK (which is free and open-source) may be the better investment.

Next Steps

Evaluating for your team?

If you're a CPO, Director of Product, or CTO trying to decide between building AI features internally or adopting a purpose-built solution, contact Tandem to discuss your specific use case.

We can help you evaluate:

• Whether your use case fits Tandem's strengths

• The build vs. buy tradeoff for your team

• Integration requirements for your product

This comparison reflects publicly available information about Tandem (usetandem.ai) and Vercel AI SDK (ai-sdk.dev) as of December 2025. Features and capabilities may change.