flue vs siift: Features, Pricing & Which Is Better (2026)

A side-by-side comparison of flue and siift — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.

flue

Astro

Free

Open-source TypeScript agent harness framework for building autonomous agents and AI workflows.

Agent Harness: A programmable TypeScript harness giving any model sessions, tools, skills, instructions, and filesystem access.
Autonomous Agents: Build agents that keep context across conversations and events while working toward a goal.
Workflows: Run structured automations where your code guides agent reasoning from input to finished result.
Secure Sandboxes: Give agents an isolated environment to use tools, modify files, and complete real work safely.
Durable Execution: Agents preserve progress and recover through failures and restarts.
Subagents and Tools: Delegate tasks to specialized subagents and give agents typed actions for APIs and data.
MCP and Observability: Connect tools via Model Context Protocol and monitor agents with OpenTelemetry and Braintrust.

Building Autonomous Agents: Create Claude Code or Codex-style agents that complete open-ended tasks independently.
Structured Workflows: Automate multi-step processes where code controls the agent's reasoning path.
Safe Tool Use: Run agents in a secure sandbox so they can take real actions without risk to your systems.
Local or Hosted Deployment: Run agents from the CLI during development, then deploy to a hosted runtime.
Tool Integration: Connect agents to authenticated services through MCP servers.

Freemium

An agentic AI operating system that helps founders map, validate and execute business strategy on one intelligent canvas.

Intelligent Business Canvas: A visual workspace that maps ideas, assumptions, actions and results into decision-ready filters so the whole business can be seen at once.
Living Memory System: A scalable agentic memory that learns as the business evolves and keeps context aligned across tools, data and teammates.
AI-Scored Validation: Automated, continuous research that grades assumptions into evidence so founders know what is validated and what is still risky.
Five-Stage Execution Loop: Guided progression through Ideate, Validate, Build, Go To Market and Scale, each with its own AI-driven workflow.
Safe Stack Automations: Human-in-the-loop actions across 80+ popular applications so approved work executes without leaving the canvas.
Shareable Workspaces: Collaborative views that let teammates, advisors and other stakeholders work from the same strategy context.
Proactive Next-Step Guidance: Personalized, iterative advice that surfaces the highest-leverage action rather than a generic checklist.
Credit-Based AI Usage: Monthly request credits scaled by plan and weighted by task complexity, with unlimited projects even on the free tier.

Idea Validation: De-risking a new business concept by turning founder assumptions into automatically researched, scored evidence before building.
Strategy Mapping: Turning a cloud of unstructured ideas into a visual mind-map that exposes blindspots across the business model.
Go-To-Market Planning: Iterating on sales and marketing with an AI-native loop that tests which channels actually produce revenue.
Product Prioritization: Helping product leaders decide what to build next based on verified market opportunities rather than intuition.
Scaling Diagnostics: Systematizing an existing business to surface its current growth constraints and reverse-engineer fixes.
Advisor Collaboration: Sharing a single live strategy workspace with co-founders, advisors and investors instead of static decks.