Frequently Asked Questions

Zoo Design Studio is a unified Hybrid CAD platform built on our proprietary geometry engine. It combines AI-driven generation and editing of boundary-representation CAD models with familiar sketch and feature tree workflows, brings code to CAD through KCL, and includes Zookeeper, our conversational AI agent.

Zoo Design Studio is available as a desktop application and in a web browser. On desktop, you can keep projects in a local Directory library or in Personal Cloud. The browser uses Personal Cloud. See Project Libraries for the differences.

Visit our downloads page to install the desktop application.

Zoo Design Studio is available for free, and the Free plan includes the usage included with the Free plan of Zookeeper reasoning time. We have paid tiers that include additional Zookeeper reasoning time. You can view our pricing here.

No. Zoo Design Studio is CAD software that anyone can use and download for free. Paid subscription tiers offer additional plan-specific features and capabilities. Visit our pricing page for current details.

An internet connection is required for modeling, rendering, Zookeeper, and syncing projects with Personal Cloud. Keeping a project in a local Directory library does not make Zoo Design Studio an offline CAD application.

Zoo Design Studio has solid modeling features like extrude, sweep, loft, revolve, shell, hole, booleans, etc. For a full list of features, visit our documentation.

Yes. Assemblies have been supported in Zoo Design Studio since v1.0. However, Assembly Mates are still on our roadmap.

We constantly ship updates to Zoo Design Studio. We do not currently follow a scheduled release cadence, which allows us to release exciting features and bug fixes as quickly as we can. To get a better idea of upcoming releases, check out Zoo's roadmap.

See Supported Import Formats for the current file extensions, support status, and import behavior. Formats under active development are explicitly labeled Experimental.

See Supported Export Formats for the formats currently available from Zoo Design Studio and guidance on choosing one.

On desktop, a Directory library keeps projects in a folder you choose on your computer. Personal Cloud stores projects in your Zoo account and keeps a working copy on the device where you open them. Cloud Sync keeps Personal Cloud projects up to date across devices.

Adding a Directory library does not upload its projects. Projects stay in that library unless you move them to Personal Cloud or publish them to Aquarium, which also moves them to Personal Cloud. Local project storage is separate from modeling: Zoo Design Studio still uses cloud services to run your code and render models. See Project Libraries.

Create the project in Personal Cloud or use "Move to library" to move a Directory project there. With Cloud Sync enabled, wait for "Cloud synced" before switching devices. Sign in with the same Zoo account on the other device or in the browser, then open the project from Personal Cloud.

Cloud Sync uploads your KCL code, project metadata, and other project files, including binary files, unless they are excluded. It respects project .gitignore rules and excludes version-control metadata such as .git, Zoo internal metadata, and generated project thumbnails. The .gitignore files themselves are uploaded.

Cloud Sync does not detect secrets in your files. Exclude sensitive paths before syncing. Keep a separate copy of important excluded files or local Git history: updates to the managed cloud working folder can remove them. See Which Files Sync? for details.

No. Cloud Sync keeps the current project available across your devices; it does not provide version history, branches, or a way to recover earlier revisions. Keep separate backups, and use a Directory library with Git if you need a version-control workflow.

Cloud Sync is not live collaboration. It can combine some independent file changes, but conflicting edits can require you to choose the local or cloud version for the whole project. Wait for "Cloud synced" before switching devices. If you see "Cloud conflict", review the differences and preserve any work you need before choosing a version. See Resolve a Conflict.

On desktop, use "Move to library" to move the project from Personal Cloud to a Directory library. Download the project first if it is cloud-only, and keep Cloud Sync enabled for the move. Turning Cloud Sync off only pauses synchronization; it does not remove the cloud copy.

Moving out of Personal Cloud permanently deletes the remote project and any Aquarium publication backed by it, while preserving and moving the selected local folder. The cloud project will no longer be available in the browser or on other devices. Back up important work before moving it. See Stop Syncing.

Deleting from Personal Cloud deletes the cloud project, its local working copy on the current device if one exists, and any Aquarium publication backed by that project. The deletion propagates to other devices and has no undo. Read the confirmation dialog and keep a separate backup of anything you need. See Delete a Synced Project.

Zookeeper is the AI CAD agent built into Zoo Design Studio. It can create and edit parametric CAD models from prompts, images, and sketches.

Click the sparkles icon in the right control bar. Zookeeper opens as a pane alongside your active project, where it can use your model, selections, renders, and KCL as context.

Visit the Zookeeper FAQs to learn more about its capabilities, workflows, and limitations.

KCL (KittyCAD Language) is Zoo's own scripting language for describing CAD geometries and rendering them within Zoo Design Studio. Every CAD function in Zoo Design Studio generates KCL. Using KCL in Zoo Design Studio is completely optional and is not required. KCL allows designers to leverage the benefits of code in the CAD ecosystem. Learn more by reading our KCL book.

No! Coding with KCL (Zoo's CAD coding language) is completely optional. However, it can be quite powerful. If your curiosity gets the best of you, you can learn more about getting started with KCL for coding in CAD on our Community Page.

Yes, the Zoo Design Studio application is open source and you can find it on GitHub. However, our CAD geometry engine is not open source.

Check out our developer documentation to get started designing your own modeling tools.

Anyone can ask questions, discuss workflows, and get help through our Community Forum or Discord. Paid customers who are signed in can also submit a private support ticket for issues that need direct assistance.

You can report bugs through our Community Forum or Discord. For Zoo Design Studio bugs, you can also open a GitHub issue. Please include reproduction steps, screenshots, logs, or example files when possible. Paid customers who need private assistance can also submit a support ticket while signed in.

If an update is needed, a notification will appear the next time you open Zoo Design Studio. Once the update is complete, you will need to restart your application for it to take effect. You can also click "Settings" in the bottom toolbar, click to the "About" section, and view your current version or check for updates.

You can use our Community Page to see if someone else has requested the same thing. If no one has, make a new request using the feature category.

Zookeeper is an AI agent for CAD built into Zoo Design Studio. It turns text prompts, images, and sketches into real, parametric CAD models.

Describe your goals and constraints, then delegate tasks such as creating geometry, validating designs, and analyzing manufacturability. Every model remains fully editable through familiar sketch and feature-tree workflows, with human-readable KCL as its source of truth.

Anyone from beginners and non-engineers to expert CAD users and enterprise teams can benefit from Zookeeper. It speeds up design by turning plain text requests into editable parametric KCL models for newcomers, while saving time for more experienced users with rapid prototyping, project-aware edits, and repeatable workflows that scale for teams.

Zookeeper is a pane on the right side. Click the sparkles icon in the right control bar to open it. It's context-aware and works with your active project to create or edit designs.

Zookeeper can generate a wide range of CAD models, from simple primitives and brackets to mechanical parts, enclosures, mounts, assemblies, and 3D-printable components, all from prompts or images. It can also edit existing models, interpret selected geometry and renders, and update the active project by producing or modifying parametric KCL code.

Yes - Describe what you want and Zookeeper will try to generate the geometry as parametric KCL. If generation fails or needs tweaking, it will suggest prompt refinements or follow-up edits.

Yes - Zookeeper analyzes your active project and offers context-aware suggestions (e.g., add fillets, mounting holes, or adjust dimensions) to help you decide the next modeling steps. It can also propose small edits or refinements you can apply immediately. It conducts relevant research, proposes design constraints and parameters, and generates a clear design plan before producing a CAD model.

Yes - Zookeeper understands and uses your selections in the active project. When you select faces, edges, bodies, or code regions, Zookeeper uses that context to make targeted edits, add features, or generate more precise prompts.

Yes - Zookeeper can view and interpret the project's renders and multiview snapshots to understand geometry and suggest or make context-aware edits. It uses those visual cues alongside selections and KCL to produce more accurate modifications. The team added engine-level tools that allow the agent to inspect, snapshot, and debug geometry while generating production-ready CAD.

Yes - You can ask Zookeeper questions about modeling, KCL, design decisions, or your active project. It can research using the internet, explain tradeoffs, and make manufacturing-aware suggestions. When you ask, Zookeeper can also perform edits, apply changes, or generate models directly in your design. The Enterprise version of Zookeeper can also be asked questions relevant to your design rules and internal company knowledge.

Yes. Zookeeper can derive surface area, volume, and center of mass from the geometry in the active project and return results in common units (for example, mm³ or m²). To calculate mass, you must provide the material density and its units; Zookeeper does not automatically infer density from project metadata.

Be specific about what you want (dimensions, constraints, intended use) and include selections or reference geometry in the active project - clear prompts produce more accurate KCL results. Iterate: review the generated model, tweak parameters or ask for targeted edits, and accept Zookeeper's suggestions (fillets, holes, thickness changes) to quickly refine the design.

Zookeeper understands natural-language prompts (primarily English) and can read and work with KCL code and selected geometry in your project. It also accepts many major languages (Spanish, French, German, Chinese, etc.) with varying accuracy, though the best results are typically in English.

Auto Mode helps Zookeeper choose the right model for your prompt automatically.

If you're on the Free Plan, you won't need to pick between Standard and Thoughtful mode. Instead, Zookeeper will use Auto Mode to select the model that makes the most sense for what you're asking. Some prompts need deeper reasoning, while others can be answered just as well with a faster, lighter model.

This helps free users get more out of their included reasoning time by avoiding unnecessary use of more expensive reasoning when it isn't needed. Fancy when it matters, efficient when it doesn't.

Users on paid plans can choose between Standard and Thoughtful mode themselves.

KCL (KittyCAD Language) is Zoo Design Studio's domain-specific, parametric CAD programming language. KCL projects are collections of .kcl files (entrypoint: main.kcl) that programmatically create 3D geometry using primitives, sketches, transforms, booleans, and parameters.

Zookeeper is our built-in CAD design assistant inside Zoo Design Studio that helps you work with KCL: it can generate new KCL models from plain-language prompts, edit your existing .kcl code, answer questions about KCL, and propose design changes, acting as an intelligent, context-aware partner while you design.

Yes - Zookeeper can read your KCL code, explain syntax and structure, and help fix or improve scripts. It can also suggest idiomatic KCL patterns and make project-aware edits when you ask.

Yes - Zookeeper can read and understand your KCL code, explain what it does, and use that context to suggest fixes or make targeted edits to the active project.

Yes - Zookeeper references official KCL materials (including the KCL Book) to ensure advice and code follow best practices. See the KCL Book for details.

Yes - Zookeeper can identify and fix KCL errors by analyzing your project and selected code, then applying targeted edits. If an automatic fix can't be applied, it will explain the issue and suggest a clear repair or simplified prompt for you to approve.

Yes - Zookeeper can explain mechanical design concepts, recommend best practices (tolerances, fastening, draft, fillets), and help apply them to your model. It can provide guidance and simple calculations, but it doesn't replace engineering validation or guarantee manufacturability or structural performance.

• Can: create and edit KCL CAD models, explain KCL and design concepts, inspect rendered snapshots, analyze geometry, and generate downloadable STEP or STL exports.

• Cannot: run physical tests, guarantee manufacturability or structural safety, or perform detailed engineering simulations.

• Interaction rules: works on the active project through Zoo Design Studio's built-in tools and can return rendered snapshots and generated export files in chat.

• Knowledge bounds: limited to its training and available docs; ask for clarification when requests are vague.

• Change Zoo Design Studio application settings.

• Directly manipulate your interactive viewport; you still rotate, pan, and zoom it manually. Zookeeper can render separate snapshots from requested camera views for inspection.

• Open or switch to other projects.

• Read files outside the active project directory.

• Access your Zoo account or personal account information.

Zookeeper will continue working while it is making progress and has the information and tools it needs. The amount of time and number of attempts vary with the complexity of the task. If it cannot continue, it will explain what is blocking it and may ask for clarification, approval, or a smaller request. Breaking a complex task into specific steps can help it make steady progress.

When a prompt fails, Zookeeper may inspect the error and try to correct the problem automatically. If it still cannot complete the request, it will explain what went wrong and suggest a next step, such as clarifying the request, breaking it into smaller steps, or making a manual edit. The number of automatic retries varies by task.

Yes. Zookeeper can make mistakes - it may misunderstand intent, produce incorrect geometry, or suggest designs that aren't manufacturable or safe. Always review and validate changes, run your own checks, and give clear, specific instructions or corrections when needed.

Yes. Add an AGENTS.md file to a project to give Zookeeper persistent project-level instructions, constraints, or KCL conventions. Zookeeper reads those rules while working in that project. You can also provide one-time instructions in an individual prompt. Project instructions are separate from global, account-wide personality settings, which are not currently supported.

Break the task into smaller steps. Ask Zookeeper for a design plan first, then request geometry changes one feature at a time. Example flow:

1. "Create the rectangular base."

2. "Add corner holes."

3. "Fillet the edges."

Working incrementally (and giving clear dimensions or constraints) gets better results than one large, vague prompt.

Select the exact geometry and give a concise instruction.

• In the UI, highlight the face/edge/body or select the relevant lines in the code before asking.

• Use clear, specific commands (e.g., "change this hole diameter to 5 mm" or "fillet these two edges with 2 mm").

• Reference named parts or parameters if available (e.g., "modify mount_plate.thickness").

• Provide constraints or intent when helpful (fit a M4 screw, keep wall ≥2 mm).

Doing this ensures Zookeeper applies changes to the correct part rather than guessing.

You can report bugs in several ways.

1. Submit a GitHub issue

2. Report bugs on our Discord server

3. Ask our team via our Community Forum

Yes! Zookeeper is built on the Agent API, and will call any Zoo tool necessary to get the job done. It supports uploading images, documents, 3D models and text as sources to work from.

Zookeeper usage is included with Zoo Design Studio plans as monthly reasoning time.

• Free plans include the usage included with the Free plan per month

• Plus plans include the usage included with the Plus plan per month

• The Pro plan has the Zookeeper allowance shown on the pricing page

If you use up the reasoning time included in your plan, usage pauses by default. You can enable pay-as-you-go at your plan's current rate or upgrade to a higher plan.

Enterprise plans are tailored to each organization, including its team size, deployment needs, support requirements, and workflows. Contact our team to discuss custom or volume pricing.

Yes. Zoo can work with your CAD files, engineering documents, specifications, and design standards to support organization-specific modeling and automation workflows. Contact our team to discuss your requirements and whether an Enterprise pilot is a good fit.

You'll need a representative subset of native CAD files with full feature trees plus associated engineering documentation and guidelines. Neutral formats like STEP and IGES typically lose parametric intelligence and are not ideal for model customization. We can explore a Team Pilot with additional support if your company is lacking access to 3D CAD data.

Plan for up to 100 representative models from a focused part family to start; broader coverage usually improves robustness. Include associated design standards, product requirements, and manufacturing guidelines to align outputs with your internal rules.

A typical pilot follows a clear sequence: jointly select a target part family and success metrics; provide representative native CAD files, standards, and documentation; let Zoo fine-tune your private model; evaluate it against reference designs and internal rules; then expand to additional families and workflows. Success is measured by editability, guideline compliance, accuracy against reference parts, and time saved per iteration.

Yes. Zoo can fine-tune a private model on your organization's CAD data and engineering knowledge so its output better reflects your part families, standards, and workflows. Contact our team to discuss your use case.

Zoo supports enterprise dataset-conversion and model-customization workflows for native CAD data, including SolidWorks, Creo/ProE, Siemens NX, and CATIA V4/V5/V6. This list is not exhaustive; we can evaluate other CAD platforms and formats based on your dataset and workflow during a pilot. Support varies by product version, file complexity, and how much feature-tree history or design intent the source files preserve. Contact our team to discuss your files and determine the best ingestion and conversion approach.

Zoo works best today with solid-modeled parts and well-defined mechanical part families. Surface-heavy use cases are at an earlier stage, with broader support expected to grow throughout 2027. Zoo supports assemblies, but does not yet support mating or a full assembly constraint solver.

Production-ready 2D drawings, mates for assemblies, and STEP to KCL are also on the roadmap.

Your data remains your IP. By default, Enterprise training is isolated in a single-tenant setup, and private model weights are not shared with other customers. Zoo only needs the rights required to process your data and train the private model delivered to your team.

Independent auditors have verified Zoo's security controls through a SOC 2 Type II audit. Zoo's US Regulated region is suitable for processing or storing export-restricted (ITAR) information and runs on US-based cloud infrastructure that meets ITAR baselines. Customer-controlled deployment options include private cloud, government cloud, and on-premises environments. See the Zoo Trust Center for the current report and security details.

Zoo's Engine API, Agent API, and File Format API can create and edit geometry, run AI-assisted CAD workflows, and convert files within your own applications and internal systems. Zoo MCP connects Zoo-backed CAD tools to Claude, Codex, and other MCP-compatible AI clients. For PLM, custom, or organization-specific integrations, contact our team to discuss your workflow.

The Free plan includes the Zoo Design Studio access shown on the pricing page. It includes the usage included with the Free plan of Zookeeper reasoning time per month when the included usage is spent entirely in Zookeeper. The same the monthly usage included with the Free plan of included usage can instead be spent on direct API or Zoo MCP activity. The Free plan uses the data policy shown on the pricing page.

We'll notify you when you're close to or have used up your included usage. You can upgrade at any time from your account settings. If you run out, billable usage pauses by default. You can enable pay-as-you-go at your plan's current rate or upgrade to a higher plan with more included usage.

Included monthly usage normally refreshes at your account's monthly anniversary boundary, evaluated in UTC. Legacy accounts that still use calendar-month billing periods refresh on the first day of each month at 00:00 UTC instead. This usage refresh is separate from your subscription charge or renewal date, and it remains monthly whether you pay for your subscription monthly or annually. New accounts receive the usage included with their current plan when the account is created. When a refresh date applies to your account, you can see the exact next refresh time on your Billing page.

The refresh replaces your remaining monthly included-usage balance with the full monthly amount included in your current plan, so unused monthly usage does not roll over or accumulate. Changing plans can also update your available allowance immediately.

Promotional or other usage granted separately by Zoo is not replaced during the monthly refresh. Usage draws from the monthly plan allowance first, then from separately granted usage. You can see your combined remaining balance on your Billing page.

After all available usage is exhausted, billable usage pauses by default. You can continue on a pay-as-you-go basis if you enable it and have a valid payment method, or upgrade to a plan with more included usage. Otherwise, usage remains paused until the next monthly refresh.

Pay-as-you-go lets you continue using billable Zoo services after you have exhausted the usage included with your Free or paid plan, as well as any usage granted separately. Additional usage is charged at the applicable pay-as-you-go rate.

The setting is off by default. While off, billable usage pauses after your available usage is exhausted, so you will not incur overage charges. You can turn pay-as-you-go on or off from your Billing page. A valid payment method is required before pay-as-you-go charges can be incurred.

Zoo now requires explicit consent before usage can continue beyond your available included usage and generate overage charges. Previously, eligible accounts could continue on a pay-as-you-go basis without enabling a separate setting.

Requiring an explicit opt-in gives you direct control over whether your usage should stop at your plan's limit or continue as paid overage usage. You can review or change your choice at any time from your Billing page.

Turning pay-as-you-go off does not affect the usage already included with your plan. You can continue using Zoo until all included and separately granted usage has been exhausted.

After that usage is exhausted, billable usage pauses instead of generating additional charges. Usage can resume when your monthly allowance refreshes, when you receive additional usage, when you upgrade to a plan with more included usage, or when you turn pay-as-you-go back on. Turning it off does not reverse charges for usage that has already occurred.

The Pro plan has the Zookeeper allowance shown on the pricing page. API usage outside Zoo Design Studio is separate: it uses any included API usage available on your account first, then continues at pay-as-you-go rates only if you have enabled pay-as-you-go and have a valid payment method.

No. Unlimited use applies to eligible activity inside Zoo Design Studio. Zoo MCP connects an external AI client to Zoo through your API token, so its hosted Zoo operations are treated as API usage outside Zoo Design Studio.

An MCP tool can run locally or make one or more Zoo API calls, so an MCP tool call is not itself the billing unit. Billable API requests use any available included usage first and then pay-as-you-go if it is enabled. See the API pricing FAQ and API pricing for details.

Available billing intervals and annual savings vary by plan. Use the monthly and annual controls on the pricing page to see the current options and prices returned for each plan.

Canceling does not schedule your subscription to end on its next renewal date. It downgrades your account to the Free plan immediately, whether your subscription is billed monthly or annually. Any unused paid time in your current billing period is prorated automatically.

Your Zoo account and data are not deleted, but your paid-plan benefits end immediately. After cancellation, your access is limited to what the Free plan includes; currently, the Free plan includes the Zoo Design Studio access shown on the pricing page. You can upgrade again at any time.

If you want to avoid the next renewal while keeping paid access through the remainder of your current billing period, the current cancellation flow does not provide that option. Review your subscription and billing dates on your Billing page before canceling.

We accept credit cards for all paid plans. For Team or Enterprise plans, if you need custom billing, please contact us.

Yes, you can always upgrade or downgrade your plan to another tier without losing your data.

Visit our Getting Started documentation and YouTube channel for the latest onboarding resources.

The Free plan includes the usage included with the Free plan of Zookeeper reasoning time per month when its the monthly usage included with the Free plan of included usage is spent entirely in Zookeeper. The same included usage can instead be spent on direct API or Zoo MCP activity. If you use all of it, you can continue on a pay-as-you-go basis if it is enabled and you have a payment method, upgrade to a plan with more included usage, or wait for the next monthly refresh. Usage normally refreshes at your account's monthly anniversary boundary (UTC); legacy accounts that still use calendar-month billing periods refresh on the first day of each month at 00:00 UTC instead. Check your Billing page for your next refresh time. Plans with unlimited Zookeeper usage in Zoo Design Studio are identified on the pricing page.

Visit the Zoo Enterprise FAQs for information about custom pricing, pilots, model customization, security, deployment, and integrations.

API calls are charged by the second at your plan's current rate.

Rounding: For each completed call, we round its duration up to the next whole second, multiply by the per-second rate, then round the monetary result to the nearest cent.

Short calls policy: Historically, sub-10-second calls were not billed. Since October 14, 2025, they have been billed per second with the same rate and rounding.

Note: because we round each call to cents, many tiny calls can sum to a hair more than one long call with the same total seconds. This is standard for usage billing. If that ever meaningfully impacts you, tell us.

For more information on how the math works, see Jess's blog post here.

Included monthly API usage varies by plan. Check the current allowance on the Zoo Design Studio pricing page or your Billing page. Billable activity draws from available included usage first; after it is exhausted, API usage pauses unless pay-as-you-go is enabled and the account has a valid payment method.

Zoo MCP does not have a separate subscription or flat per-tool-call fee. Tools that call Zoo's hosted services use your Zoo API token and are billed as API usage outside Zoo Design Studio. Unlimited Zoo Design Studio usage does not make Zoo MCP usage unlimited.

An MCP tool can make no API calls, one API call, or multiple API calls. Billing is based on the underlying successful, billable API requests and persistent API sessions, not the number of MCP tool calls. Available included usage is applied first, followed by pay-as-you-go only when it is enabled. Your AI client, such as Claude or Codex, may charge separately.

See your Billing page for your available usage and pay-as-you-go settings.

Charged API calls are billed by the second at your plan's current rate. For more information on how the math works, see Jess's blog post here.

No, you are not charged if the API call fails.

Generally no. GET requests are free, except for WebSocket-style GETs used for real-time features: endpoints that start with /ws/modeling/commands or /ws/ml/copilot are billable.

In general, successful POST requests are billable, with some exclusions. The only GET endpoints that are billable are WebSocket-style GETs for real-time features: endpoints that start with /ws/modeling/commands or /ws/ml/copilot.

See the API Reference for the current list of available endpoints. To review the API calls charged to your account, visit Developer settings.

No. Endpoints that start with /user or /org are free and not billed.

No. Endpoints that start with /oauth2 are free and not billed.

The following endpoints, endpoint prefixes, and patterns are free and never billed:

• /_meta
• /user
• /logout
• /apps
• /events
• /org
• /ml/custom
• /store
• /_internal
• /auth
• /oauth2
• /debug
• Any endpoint containing shortlinks
• /file/execute/
• /projects/public/{id}/vote
• /ws/ml/reasoning/{id}

Agent API requests do not have a fixed completion time. Duration depends on the complexity of the task, the tools required, and the number of iterations the agent performs. Integrations should not assume a specific completion window.

Yes. We are working on our machine learning endpoints every day, but it is still experimental. Some results may not be as good as you expect.

The Agent API streams conversational responses and tool results. For CAD-generation tasks, those results can include editable KCL project files. Producing formats such as STEP requires a separate modeling and export step.

For assistance with APIs, you can ask a question on our Community Page or discuss on our Discord!

For bugs, mention it to us on our Community Page.

Please email us directly. We would love to chat with your specific needs and see how we can best help you.