Montage — The runtime for agentic user interfaces vs Pi Web: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of Montage — The runtime for agentic user interfaces and Pi Web — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
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Montage — The runtime for agentic user interfaces
Montage
A model-agnostic SDK that renders agentic, interactive UIs, hydrates artifacts faster, and reduces token usage across underlying models.
Key features
- Model-agnostic SDK: A single SDK and runtime that works with any underlying model provider, enabling developers to render agentic UI components without locking into a specific LLM.
- Agentic UI Rendering: Renders rich, interactive components (agentic widgets) that encapsulate agent behavior, state, and UI in a reusable format for web applications.
- Faster Hydration: Optimized client/server hydration flow to initialize interactive artifacts quickly, reducing perceived latency for end users.
- Token Usage Reduction: Built-in optimizations for prompt/state management that cut token usage across models, lowering operational costs and improving efficiency.
- Stateful Artifact Management: Manages and persists the state and lifecycle of interactive artifacts and their events, simplifying developer handling of agent-driven UI.
- Seamless Front-end Integration: Designed to integrate with common front-end workflows and frameworks, allowing easy embedding of agentic interfaces into existing apps.
- Model Swapping and Fallbacks: Enables switching or combining different underlying models without reauthoring UI logic, supporting fallbacks and provider-agnostic strategies.
- Developer Tooling: Provides developer-oriented APIs and runtime controls to debug, test, and tune agentic components and their interactions.
- Single SDK to render rich, interactive agentic UI components
- Runtime that hydrates interactive artifacts faster
- Reduces token usage across underlying models
- Model-agnostic operation that works with any underlying model
- Focus on rendering agentic interfaces and interactive components
Best for
- Embedding conversational, agent-driven widgets in web apps to handle complex, interactive user workflows without rebuilding front-end UI each time.
- Prototyping agentic interfaces quickly using the single SDK to iterate on UI/agent behavior while swapping underlying models for evaluation.
- Reducing LLM operational costs by leveraging Montage’s prompt and state optimizations to cut token usage across responses and background context.
- Hydrating server-rendered interactive artifacts on the client for faster startup and seamless handoff from server logic to agent-driven interactions.
- Integrating multiple model providers and failover strategies so applications can route requests to different models without changing UI code.
- Managing long-lived, stateful agent interactions (e.g., multi-step assistants or tool-using agents) with built-in lifecycle and state management.
- Build interactive agentic user interfaces with a single SDK
- Embed agent-driven UI components into applications while minimizing token costs
- Hydrate and rehydrate interactive artifacts quickly for responsive UX
- Integrate agentic UI rendering on top of different underlying language models
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Pi Web
agegr
Local web UI for the Pi coding agent — browse sessions, switch worktrees, manage models, and chat beside your project files in a browser.
Key features
- Session Browser: Reads local Pi session files and organizes prior conversations by project for quick resume.
- Fork and Continue: Continue from any earlier message or fork a session into a separate route to try alternatives safely.
- Git Worktree Switcher: Switch between Git worktrees from the sidebar to work on multiple branches in parallel.
- File Preview: Side-by-side chat and project file browser that previews source, docs, images, audio, and PDFs.
- Model and Skill Manager: Configure models, API keys, run model tests, and toggle skills from the web UI instead of CLI flags.
- Local-Only Runtime: Runs on http://127.0.0.1 by default so session data and code never leave the developer's machine.
Best for
- Resume Prior Work: Reopen a conversation from last week by project instead of scrolling terminal history.
- Safe Experimentation: Fork a session to try a risky refactor without losing the original conversation state.
- Parallel Branch Work: Switch Git worktrees mid-session to jump between feature branches in one workspace.
- Model Comparison: Rerun the same task against different configured models to compare output quality.
- In-Browser Code Review: Preview generated diffs and project files beside the chat without leaving the browser.