CleanSlop vs Pencil: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of CleanSlop and Pencil — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
CleanSlop
CleanSlop
Scans vibe-coded apps for launch-blocking issues like leaked keys and data exposure, and reports what to fix first, right from your coding agent.
Key features
- Agent-Native Scanning: Tell Claude Code, Codex, Cursor or other agents to scan with CleanSlop and fix findings where you build.
- System-Level Code Mapping: Maps routes, background jobs, data and external services so each finding follows a real call path.
- Prioritized Reports: Findings grouped as needs attention, worth a look and minor, worst first.
- Evidence for Every Finding: Shows where each issue lives in your code and why it was flagged.
- Plain-English Fixes: Explains what is wrong, why it matters and what to do about it.
- Copy for LLM: Hands any report to your AI tool so it can apply the fixes.
- GitHub App Integration: Scan only the repositories you select, read-only access.
- Expert Triage Calls: Book a 15-minute call with a CleanSlop engineer to walk through findings.
Best for
- A solo founder checks a Next.js and Supabase app built with an AI coding assistant before launching.
- A developer discovers an exposed AI API key bundled into browser code and moves it to a server route.
- A side-project builder verifies that one user's data cannot be read by another through database policies.
- A Claude Code user runs a scan from the terminal and has the agent fix the top findings.
- A team lead gets a short prioritized list instead of hundreds of linter warnings.
- An indie hacker books an expert triage call to confirm an ambiguous finding.
Pencil
Pencil (Pencil Works)
In-IDE design canvas that lets engineers design UI and convert designs directly into code to speed development.
Key features
- In-IDE Design Canvas: Provides a visual design canvas embedded inside developers' IDEs so users can create and edit UI designs without context switching to external design apps.
- Design-to-Code Export: Converts designs into code-friendly artifacts or components (land in code) to reduce manual implementation and speed delivery of production UI.
- Local MCP Server & Discovery: Runs a local MCP-style service that writes config (e.g., ~/.claude.json) so external tools and agents can discover Pencil, read its port/command, and integrate programmatically.
- Auto-Configuration & Port Sync: Supports auto-setup and auto-sync behaviors (project or global scope) so integrations (like OpenCode) automatically add Pencil to their configs and update ports when Pencil restarts.
- Project-Scoped Integration: Can be configured per-project or globally, allowing teams to make Pencil available only within specific repositories or across all projects for consistent workflows.
- Tooling & CLI Support: Exposes status, setup, and sync actions for partner tools and agent plugins (e.g., pencil_status, pencil_setup, pencil_sync) to manage connectivity and lifecycle programmatically.
- Canvas-based UI design embedded into developer workflows/IDEs
- Design-to-code export so visual designs can be converted into code artifacts
- Runs a local MCP/config server and writes runtime config to a file (e.g., ~/.claude.json) for tooling integrations
- Integration plugins (example: OpenCode pencil-sync) that auto-setup Pencil in project/global configs and auto-sync ports after restarts
- CLI/tools for status, setup and sync (pencil_status, pencil_setup, pencil_sync) to manage Pencil integration lifecycle
- Support for project or global scope configuration (config added to ~/.config/opencode/opencode.jsonc or ./opencode.json)
- Automatic port/config backup and validation when updating third-party tool configs
Best for
- IDE-native UI Implementation: Designers and engineers create UI layouts directly inside an IDE and export components to the codebase, eliminating design handoffs and manual translation.
- Agent-enabled Code Generation: Integrate with developer agents or automation (via Pencil's MCP config) to let bots generate, update, or wire up UI code from canvas designs automatically.
- Project-scoped Tooling Integration: Add Pencil to a single project's config to enable team members to access the same design-canvas tooling and keep design artifacts synchronized with that repository.
- Auto-recovery After Restarts: Use automatic port-sync and setup tools so external tooling (like OpenCode) recovers connectivity after Pencil restarts without manual reconfiguration.
- Rapid Prototyping and Iteration: Quickly prototype UI ideas inside the IDE, iterate in-context with code, and validate implementations faster by seeing designs translate to code artifacts immediately.
- Cross-tool Workflow Automation: Connect Pencil with CI, linters, or component libraries via its MCP endpoint to automate tasks like component registration, export, or style enforcement from designs.
- Embed visual design work directly inside developers' IDEs to reduce context switching
- Automatically export or convert canvas designs into code components or project assets
- Auto-configure developer tools and agents to use the locally running Pencil service
- Keep IDE/tooling configurations in sync when Pencil restarts or changes port
- Integrate Pencil with automation agents or local development frameworks to enable programmatic access to designs