AgentLoop vs sleek.design: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of AgentLoop and sleek.design — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
AgentLoop
Edward Yi
AgentLoop turns a single ChatGPT plan into unattended Codex worker + independent-critic cycles that build against your local rubric until the work passes.
Key features
- Fresh Worker Per Cycle: Each build cycle spawns a clean Codex worker with fresh context so long-running loops do not accumulate stale state or memory drift.
- Independent Critic Process: A separate fresh process grades every result against your rubric so passing tests never become permission to stop looking.
- Rubric in GUIDELINES.md: Definition-of-done lives as plain Markdown in your repo and is read on every cycle, so standards persist while prompts do not.
- Evidence Carried in Files: Worker output, critic verdicts, and fixes are written to project files so the next cycle inherits the actual state of the work.
- Bounded Goal + Cycle Budget: You cap the loop with a goal.md and cycle budget so unattended runs stop at a predictable ceiling.
- MCP Status Interface: Ask ChatGPT for status through MCP so you can monitor cycles, verdicts, transcripts, and cost without opening the dashboard.
- Local-first Install: git clone the pinned v1.1.0 release and run node src/daemon.js — no npm install, no hosted workspace, MIT licensed.
Best for
- Shipping a bounded feature: Add a CSV export across UI, API, and regression suite while the critic enforces end-to-end behavior and edge cases.
- Migration work: Run an unattended migration where fresh workers apply the change and the critic verifies each step against a rubric.
- Hardening pass: Give AgentLoop a hardening goal so it iterates on defects the existing test suite misses, like malformed input handling.
- Product polish loop: Point AgentLoop at a polish goal with clear acceptance criteria and let it converge to VERDICT: PASS.
- Unattended overnight runs: Kick off a long loop, monitor cycle verdicts, and cancel from the dashboard or via MCP when the receipt looks right.
- Enforcing team standards: Codify team engineering standards in GUIDELINES.md so every worker builds against the same definition of done.
sleek.design
Sleek
AI-powered mobile app mockup generator that creates iOS and Android app designs instantly without a designer.
Key features
- Instant Mockup Generation: Converts text prompts or app ideas into polished iOS and Android screen designs within seconds, enabling rapid visualization of concepts.
- Cross-Platform Output: Produces both iOS and Android style mockups, ensuring platform-consistent layouts and components for each target OS.
- Chat-Based Iteration: Supports iterative refinement by allowing users to refine designs through conversational inputs, speeding up the design iteration loop.
- Figma & Code Export (Export Capability): Provides options to export designs to Figma or generate developer-friendly assets/code snippets for easier handoff (noted in third-party sources).
- Template and Variation Generation: Generates multiple layout variations and templates from a single idea to explore alternative UI directions quickly.
- No-Designer Workflow: Enables non-designers to produce high-quality app screens without hiring a designer, reducing time and cost in early-stage prototyping.
- Generate mobile app mockups from text prompts or ideas
- Support for iOS and Android screen designs and templates
- Chat-driven iteration to refine designs interactively
- Export designs to Figma
- Export design assets or code (export to code mentioned)
- Web-based interface — no local installation required
- Aimed at rapid prototyping and eliminating need for a dedicated designer
- Free access / Freemium availability as indicated on site
- No public API or official documentation referenced in provided content
Best for
- Early Concept Validation: Founders and product managers can turn an app idea into visual screens instantly to validate concepts with stakeholders or users.
- Rapid Prototyping for MVPs: Teams can generate initial screen designs for minimum viable products to accelerate development planning and user testing.
- Design Iteration without Specialists: Non-designers can iterate UI layouts and copy via chat-driven refinements to explore multiple directions quickly.
- Handoff to Engineering or Designers: Exported Figma files or code snippets streamline collaboration by providing ready assets for developers or detail work by designers.
- User Testing and Feedback: Create varied screen versions quickly to run A/B tests or user interviews to collect early usability feedback.
- Rapidly create UI screens and prototypes from product ideas
- Iterate on app visual designs with non-designers via chat
- Export screens to Figma for further design work or handoff
- Generate starter code or assets for developer handoff
- Create demo screens for pitches, user testing, or stakeholder reviews