Terms of Use

The terms under which Kiln is provided.

Kiln Terms of Use

Last updated: 2026-06-15 · Version 3.0

Plain-English summary — These terms govern your use of Kiln, operated by Hadron Labs Inc. Kiln has two sides:

  1. Locally-installed software — the open-source CLI, the MCP server, slicing, and printer control run on your machine — we can't see that data. (When you choose to route a job to an external fulfillment provider through Kiln, our servers handle that routing and billing — see §6.) You're responsible for what you print, for printer safety, and for the actions of any AI agent you authorize to drive the MCP tools. These Terms govern your use of that software even though the code itself is open source.
  2. The web workshop at app.kiln3d.com — a git-style cloud layer for 3D designs: versioned designs, branches, commits, PR-style reviews, releases, cherry-picks, and team collaboration via orgs. What you push here lives on our servers.

One agreement, every surface. These Terms cover your use of all of Kiln — the open-source CLI and MCP server, the web workshop, the REST API, the marketing site, and every paid tier. The open-source code is licensed to you under AGPL-3.0 (a copyleft license — see §4.1); these Terms govern how you use every surface, including the local CLI and MCP server where printer control and AI-agent risk live.

Tiers in one line. The Free and Pro tiers are for personal, non-commercial use. If you sell what you print, fulfill client orders, or run a print business, you need Business or Enterprise.

We provide the software "as is" (except where a written SLA says otherwise), cap each side's liability, and require binding arbitration for disputes (with a 30-day opt-out and a small-claims exception). If any of that is a dealbreaker, don't use Kiln.

One inbox, transparent by design. Every "email us at…" reference in these Terms routes to adam@kiln3d.com. Kiln is a small team; one founder reads everything. Put the topic in the subject line so the right thing gets prioritized (e.g., [DMCA], [Arbitration Opt-Out], [Billing], [Security], [DPA]).

1. The agreement and definitions

1.1 The agreement

These Terms of Use (the "Terms") form a binding legal agreement between you and Hadron Labs Inc., a Delaware corporation with its principal place of business in California ("Kiln", "we", "us", or "our"). By downloading, installing, accessing, or using any part of the Kiln software or services — including the open-source Kiln CLI, the MCP server, the web workshop at app.kiln3d.com, the REST API at api.kiln3d.com, the marketing site at kiln3d.com, and any paid tier subscription — you agree to these Terms. If you don't agree, don't use Kiln.

If you are using Kiln on behalf of an organization, you represent that you have authority to bind that organization, and "you" refers to both you personally and the organization.

These Terms incorporate our Privacy Policy by reference.

1.2 Definitions

In these Terms:

  • "Customer" means the individual or entity bound by these Terms.
  • "Customer Data" (also referred to as "Your Content" in §11) means data, files, designs, models, prompts, configurations, branches, version commits, comments, or other content uploaded by, or generated for, the Customer in the course of using Kiln.
  • "Order Form" means a written ordering document referencing these Terms, including online checkout.
  • "Documentation" means the user-facing documentation we publish at kiln3d.com/docs and within Kiln.
  • "Free tier" means the no-cost tier of Kiln available without a paid subscription, including use of the open-source CLI and MCP server, the local printing and design tools, an account on the web workshop, and the limited free fulfillment allowance described in §6. The Free tier is licensed for personal, non-commercial use (see §4.2).
  • "SLA" means a written Service Level Agreement between you and us (referenced at compliance/SLA.md, available on request and, where applicable, incorporated by reference into your Order Form).
  • "DPA" means a Data Processing Addendum between you and us (see §6.2).

1.3 Supplemental terms and precedence

We may publish supplemental terms for specific features (for example, Enterprise Single-Tenant for on-premise or air-gapped deployments, or USDC payment terms). Where supplemental terms conflict with these Terms, the supplemental terms control for that specific feature. Except as a supplemental term, SLA, or DPA expressly provides otherwise, these Terms govern.

2. Eligibility

You may use Kiln only if:

  1. You are at least 16 years old (EU/UK) or at least 13 years old (other jurisdictions), and of legal age to form a binding contract in your jurisdiction. To create or hold a paid account (Pro, Business, or Enterprise), you must be at least 18 years old, or the age of majority in your jurisdiction if higher;
  2. You are not barred from using Kiln under the laws of the United States or the laws of your country of residence (including the export controls and sanctions restrictions in §19);
  3. You are not located in, organized under the laws of, or a resident of a country or territory subject to US comprehensive sanctions (currently: Cuba, Iran, North Korea, Syria, Russia, Belarus, the Crimea region of Ukraine, the Donetsk and Luhansk regions, and any others added by OFAC); and
  4. You are not on the US Specially Designated Nationals (SDN) List, the Entity List, or any equivalent restricted-parties list maintained by any other government.

Kiln is not directed to children, and we do not knowingly allow account creation by anyone under the minimum ages stated above.

You are responsible for complying with all applicable laws in your jurisdiction, including laws governing manufacturing, intellectual property, export controls, product safety, consumer protection, and privacy.

3. Your account

3.1 Account creation

Paid tiers and the web workshop require an account. You create one by signing in via Google, Apple, GitHub, or an email magic link. We rely on these identity providers to verify your email address; you must ensure the email tied to your OAuth identity is current and accessible. When creating an account you must provide accurate, current, and complete information, and keep it current.

3.2 Account security

You are responsible for:

  • Keeping your account credentials, session tokens, API tokens, OAuth identities, and recovery codes confidential;
  • All activity that occurs under your account, whether or not authorized by you — including all actions taken by AI agents you have configured or authorized;
  • Promptly notifying us at adam@kiln3d.com if you suspect unauthorized access.

We are not liable for losses arising from your failure to secure your account.

3.3 One account per person or organization

You may not create multiple accounts to evade quotas, rate limits, fee tiers, the fulfillment free-tier allowance, or any other system limit. We may suspend or terminate accounts created in bad faith to circumvent restrictions.

4. License to use Kiln

4.1 Open-source components

The Kiln CLI, the MCP server, and the public tool surface are released under the GNU Affero General Public License v3.0 (AGPL-3.0) — a copyleft open-source license, not a permissive one. Your rights and obligations for that code are governed by the license text in the LICENSE file of the Kiln repository. These Terms do not restrict the rights granted to you by AGPL-3.0 for that code. These Terms do, however, govern your use of every Kiln surface — including the locally-installed CLI and MCP server — because the safety, acceptable-use, AI-agent-risk, and other obligations below attach to use, not to the underlying code.

4.2 Grant of license; tier-scoped use

Subject to your compliance with these Terms, any applicable Order Form, and payment of applicable fees, Hadron Labs Inc. grants you a limited, non-exclusive, non-transferable, non-sublicensable, revocable license to access and use:

  • the web workshop at app.kiln3d.com,
  • the REST API at api.kiln3d.com,
  • the tier features unlocked by your subscription, and
  • the proprietary components of the Kiln platform that are not released under AGPL-3.0 (including kiln-pro and the orchestration infrastructure),

scoped to your tier as follows:

  • Free and Pro tiers — for your personal, non-commercial use only.
  • Business and Enterprise tiers — for your internal business and commercial use, including producing items for sale, fulfilling client or custom orders, and operating a commercial print business.

For an Enterprise Single-Tenant deployment (on-premise or air-gapped), the scope, hosting, and use rights are governed by the applicable Enterprise Single-Tenant supplemental terms and Order Form, which control over this §4.2 to the extent they differ (for example, where the deployment is not a hosted service).

You may not sublicense, resell, or redistribute the paid services except as expressly permitted in writing by us or under your Order Form. All rights not expressly granted are reserved.

4.3 Reserved rights

All rights not expressly granted are reserved. The Kiln name, the kiln-arch logomark, the kiln3d.com and app.kiln3d.com domain trade dress, and all other Kiln brand assets are the trademarks of Hadron Labs Inc. You may not use them without our prior written permission, except for nominative fair use (e.g., referring to the product in documentation or articles).

5. Subscriptions, billing, and refunds

5.1 Paid tiers

Kiln offers paid subscription tiers (currently Pro, Business, and Enterprise). Tier features, limits, and prices are listed at kiln3d.com/pricing, and Business and Enterprise tiers may be provided pursuant to an Order Form that sets the subscription term, fees, and any additional tier-specific terms. We may change tier features or pricing with at least 30 days' notice to your account email; changes take effect at your next renewal. Fees are exclusive of taxes (see §7).

5.2 Auto-renewal

Unless you cancel (or, for an Order Form, unless either party gives the notice of non-renewal described below) before the renewal date, your subscription automatically renews at the end of each billing cycle (monthly or annual, depending on the plan you chose) and your payment method is charged the then-current price. This is the same model used by services like Netflix, Spotify, and GitHub. You authorize Hadron Labs Inc. (via Stripe, and, where you elect USDC payment, via Circle — see §5.9) to charge your payment method on each renewal until you cancel.

For subscriptions under an Order Form, each term automatically renews for a successive term of equal length at the then-current list price unless either party gives at least 30 days' written notice of non-renewal before the end of the current term. We will email you at least 30 days before any material change in renewal pricing.

5.3 Cancellation

You can cancel your subscription at any time via /app/settings/billing or by emailing adam@kiln3d.com. Cancellation takes effect at the end of the current paid period — you retain access through the period you've already paid for. We do not issue pro-rated refunds for partial billing periods (see §5.6 for exceptions).

5.4 Failed payments and dunning

If a renewal charge fails, we will:

  1. Notify you by email immediately;
  2. Automatically retry the charge up to 4 times over 15 days;
  3. Grace your entitlement for up to 15 days from the failed charge — your tier remains active while we retry;
  4. Mark the entitlement as "payment_failed" after 15 days, which reverts you to the Free tier until payment is resolved;
  5. Cancel the subscription after 30 days of continuous failure.

For subscriptions under an Order Form, we may suspend or terminate your access to Kiln if your account is in arrears for more than 60 days following notice of non-payment (see §14.2).

You can update your payment method at any time via the Stripe billing portal, accessible from /app/settings/billing.

5.5 Free trials

Any free trial we offer will clearly state its duration and the recurring charge that begins at its end. You must cancel before the trial ends to avoid being charged. One free trial per customer.

5.6 Refunds

  • Monthly subscriptions: non-refundable except where required by law. Cancel to stop future charges.
  • Annual subscriptions: refundable within 14 days of the initial charge for any reason, pro-rated for the days used. After 14 days, non-refundable.
  • SLA service credits. Where you have a written SLA, refunds and service credits for SLA-eligible incidents (for example, uptime-commitment misses) are governed by that SLA. Outside of SLA credits, statutory consumer rights, and the express refund paths in this §5.6, fees paid are non-refundable.
  • Fulfillment orchestration fees: if a fulfillment order fails during manufacturing or is cancelled by the provider, we refund the orchestration fee automatically. For delivery defects, contact the manufacturer for a reprint or refund of the manufacturing cost; we refund the orchestration fee upon confirmation the provider has issued their refund.
  • Refund requests must be made within 30 days of the original charge.
  • Refunds are processed through the original payment method and may take 3–10 business days to appear on your statement. For USDC payments made via Circle, refunds are issued in USDC to the originating wallet or, where that is not possible, by another method we reasonably determine.

5.7 Chargebacks

If you dispute a charge directly with your bank or card network without first contacting us, we may suspend or terminate your account while the chargeback is resolved. Before initiating a chargeback, please email adam@kiln3d.com — we almost always resolve billing issues without card-network involvement.

5.8 Spend caps on fulfillment orders

To protect you from runaway charges — including charges caused by an AI agent or automated workflow misfiring — we cap how much you can spend through Kiln on external fulfillment (Craftcloud and any future fulfillment provider routed through Kiln):

  • Per-order cap: a single fulfillment order may not exceed $500.00 USD, summing the manufacturing provider's quoted price and any orchestration fee charged under §6.
  • Monthly cap: your cumulative fulfillment spend in any calendar month (UTC) may not exceed $2,000.00 USD, summed over every fulfillment order placed that month, including each order's manufacturer total and orchestration fee.

If a job would exceed either cap, Kiln refuses the order before any charge is created. You receive a clear error identifying which cap was reached; nothing is deducted from your card.

These caps apply to all paid tiers and protect your downside only — they do not commit Kiln to any minimum order size, nor guarantee that an order under the cap will be accepted. We may adjust these caps in future versions of these Terms under the change-notification rules in §22; an increase or decrease is a material change and will be communicated at least 30 days before it takes effect.

Adjusting your caps from the web. Paid users can raise either cap above the default through the web app at app.kiln3d.com/settings/billing/spend-caps. Cap raises require two-factor authentication and are limited to values at or above the protective default ($500 / $2,000); you may not lower a cap below those defaults.

Adjusting your caps from the CLI or an MCP agent (opt-in). Power users can opt in to a CLI/MCP path under the same web-app settings page, by enabling Allow CLI / MCP cap changes. When opt-in is enabled, the same two-factor challenge is required for every change — your CLI or AI agent will display the requested change and ask you for the current 6-digit code from your authenticator app. The opt-in toggle itself can only be flipped from the web app and itself requires two-factor authentication.

Rate limit and lockout. Cap-change attempts are rate-limited across all surfaces: a maximum of three attempts in any rolling 24-hour window. The third attempt (whether successful or not) pauses further cap-change requests for 24 hours and triggers an email to your account with the attempt details. This protects you against a compromised agent or session.

Audit and revert. Every change is logged with the surface ('web', 'cli', or 'mcp'), an IP, and a user-agent string. Each change triggers an email confirmation with a 24-hour revert link. No agent can self-approve an order or raise a cap without your authenticator code — possession of your second factor is the load-bearing security primitive across every surface.

Per-order one-shot approvals. When an order would exceed your standing caps, Kiln refuses it with a clear error containing an approve_url. From the web — or from your CLI/MCP if opt-in is enabled — you can mint a single-use, 5-minute approval token bound to that specific order; the agent then resubmits the order with the token and the cap is bypassed for that order only.

5.9 Payment processors

Payment is processed through Stripe, Inc. and, where you elect USDC stablecoin payment, through Circle Internet Financial. You authorize us to charge your designated payment method for all fees due. Your use of a payment processor is also subject to that processor's own terms; where USDC payment supplemental terms apply, they control for that payment method per §1.3.

6. Orchestration fees, privacy, and data processing

6.1 Orchestration fees for fulfillment

When you route a print job to an external fulfillment provider through Kiln, we charge an orchestration fee for order routing, provider management, status tracking, and platform infrastructure:

  • Orchestration fee: 5% of the manufacturing provider's quoted price
  • Minimum fee: $0.25 per order
  • Maximum fee: $200.00 per order
  • Free monthly allowance (all tiers): your first 3 fulfillment orders each calendar month are fee-free

Fees are charged at the time the order is placed with the manufacturing provider. Local printing — on your own printers, using your own materials — is and will remain free. We never charge for file management, slicing, status monitoring, or any other operation that doesn't involve an external manufacturer.

Free fulfillment allowance is for personal, non-commercial use. The 3 fee-free fulfillment orders each account receives per calendar month are provided for personal, non-commercial use only. Producing items for sale, fulfilling client or custom orders, or otherwise operating a commercial print business requires a Business subscription or higher, regardless of the free allowance — the fee-free orders do not grant a commercial-use right that §4.2 reserves to the Business and Enterprise tiers.

6.2 Privacy, security, and data processing (DPA / SCCs)

Our handling of personal data is governed by our Privacy Policy, incorporated into these Terms by reference. Our security posture — including encryption, access controls, audit logging, subprocessors, and the compliance roadmap — is published at kiln3d.com/security.

For Business and Enterprise customers processing personal data, a Data Processing Addendum (DPA) incorporating the Standard Contractual Clauses (SCCs) and Article 28 GDPR terms is available on request. Once executed, the DPA supersedes any conflicting language in these Terms with respect to the processing of personal data, and is the path required by §10(17) before you upload special-category personal data. Contact adam@kiln3d.com with subject [DPA] to request one.

7. Applicable taxes

Depending on your jurisdiction, applicable taxes (sales tax, VAT, GST, or JCT) may be added to subscription fees and orchestration fees:

Jurisdiction Tax Reverse charge available?
United States State sales tax (CA, TX, NY, WA, FL, IL, MA and others per nexus) No
European Union VAT at buyer's country rate (19–25%) Yes, with valid EU VAT ID
United Kingdom 20% VAT Yes, with valid UK VAT number
Canada Federal GST (5%) + applicable provincial tax (HST / PST / QST) No
Australia 10% GST Yes, for GST-registered buyers
Japan 10% JCT (consumption tax) Yes

Fees are exclusive of taxes, and taxes are your responsibility unless we are required by law to collect them. Tax on orchestration fees is calculated on the orchestration fee only, not on the manufacturing cost. The manufacturing provider is responsible for any taxes on their charges.

Preview the tax for any order with the tax_estimate tool before placing it. We display the full fee + tax breakdown before charging. No hidden fees.

8. Your responsibilities — 3D printing safety

By using Kiln you acknowledge and agree that:

  1. You are responsible for what you print. Kiln does not monitor, filter, or restrict the geometry of files you download, generate, slice, or send to your printer. The decision to print any object is yours alone. You are responsible for ensuring that every object you produce complies with applicable laws — including laws governing firearms, weapons, regulated medical devices, automotive safety parts, and intellectual property (patent, trademark, copyright, and trade secret laws).

  2. You are responsible for printer safety. Kiln includes safety systems that enforce physical limits — temperature caps, speed limits, G-code validation, bed-boundary checks, and blocked command detection. These reduce risk; they do not eliminate it. Unattended 3D printing carries inherent fire and mechanical hazards. Follow your printer manufacturer's operating, maintenance, and safety guidelines. Keep a working smoke detector and fire extinguisher near any unattended printer.

  3. You are responsible for maintaining your printer. Well-maintained hardware is a prerequisite for any of Kiln's safety checks to work. Worn thermistors, loose wiring, improperly-levelled beds, and degraded hotends are outside Kiln's ability to detect.

9. Automated control risks — AI-agent operation

This section is deliberately prominent because it describes the risk profile of Kiln's most distinctive feature.

Kiln exposes tools over the Model Context Protocol (MCP) that third-party AI agents — such as Claude, Claude Code, Cursor, and other MCP clients — can invoke to perform physical operations on your printer, including homing, motion, heating, extrusion, bed levelling, file uploads, and unattended print execution. Kiln agents may initiate printer motion, heating, and material extrusion autonomously based on your instructions or inferred intent. These agents operate on your behalf under your configuration; Kiln does not select, direct, or supervise them.

Kiln validates tool inputs and refuses unsafe operations where they are deterministically detectable (off-bed geometry, missing homing sequences, temperatures exceeding the printer's mechanical limits, G-code with blocked commands, blocked command dialects). These validations reduce but do not eliminate the risk of physical harm. Kiln cannot and does not guarantee that the invoking agent will call tools correctly, in the correct sequence, or in accordance with your intent.

You remain solely responsible for:

  • Reviewing previews and agent-proposed actions before confirming them.
  • Supervising unattended prints.
  • Any physical damage, personal injury, lost work, or loss of equipment arising from agent behavior or misbehavior — including agents making mistakes, misinterpreting your intent, or invoking tools in harmful sequences.
  • Complying with your printer manufacturer's operating, maintenance, and safety guidelines.

Hadron Labs Inc. assumes no liability for agent actions, agent errors, agent misinterpretation of user intent, or any physical, financial, or other consequences arising from the automated execution of tools in this software. This disclaimer is in addition to §15 (Disclaimer of Warranties) and §16 (Limitation of Liability).

10. Acceptable use

You agree not to use Kiln to:

  1. Violate any applicable law, regulation, sanction, or third-party right.
  2. Manufacture items that are illegal in your jurisdiction, including firearms, firearm components, firearm accessories that are regulated in your jurisdiction, counterfeit currency, counterfeit goods, counterfeit trademarks, or items that infringe the intellectual-property rights of others.
  3. Manufacture medical devices, automotive safety parts, aerospace components, structural load-bearing parts, or other items subject to certification requirements you have not met.
  4. Print objects depicting child sexual abuse material (CSAM) or other content illegal under the laws of the United States.
  5. Circumvent Kiln's safety systems, rate limits, paywalls, tier gating, entitlement checks, authentication, or other technical protection measures — including by sharing license tokens across unrelated entities.
  6. Reimplement, substitute, or pass off non-Kiln code as a Kiln paid feature in order to obtain that benefit without the corresponding subscription.
  7. Reverse-engineer, decompile, or attempt to derive the source code of proprietary (non-AGPL) components of Kiln, except to the extent such restrictions are prohibited by applicable law.
  8. Use Kiln to build a product that directly competes with Kiln, or to benchmark Kiln for the purpose of public comparison, without a separate written agreement or our prior written consent.
  9. Resell access to Kiln or the paid services to third parties without our written authorization or except as expressly permitted under your Order Form.
  10. Interfere with or disrupt the integrity or performance of Kiln's services, including through denial-of-service attacks, malicious code, or attempts to gain unauthorized access; or probe, scan, or test the vulnerability of the service or breach any security measure, except under a coordinated security-disclosure program we operate or authorize.
  11. Scrape, harvest, or otherwise collect data from other users — including bulk-downloading other people's designs, branches, versions, PR comments, reflog entries, or org membership rosters.
  12. Impersonate another person, entity, or Kiln representative — including in PR descriptions, commit messages, branch names, comments, or org invites.
  13. Send spam, bulk unsolicited messages, or any content that violates the acceptable-use policies of integrated third parties (Google, Apple, GitHub, Stripe, Circle, Craftcloud, MyMiniFactory, Cults3D).
  14. Abuse the workshop's collaboration features: sending unsolicited org or team invites, forking designs to harass their authors, opening PRs in bad faith, or using reflog access to build profiles of other users' activity patterns.
  15. Use the opt-in community datasets (community_prints, community_recoveries) to attempt to re-identify or fingerprint individual contributors.
  16. Circumvent the workshop's permission model — attempting to read or modify designs, branches, versions, or org data you have not been granted access to by the owner or by your role.
  17. Upload Customer Data that we do not have a lawful basis to process on your behalf, including special-category personal data (as defined under applicable data-protection law) unless that processing is covered by a Data Processing Addendum (DPA) entered into under §6.2.

We may suspend or terminate your account for violations of this §10 without prior notice where we believe an immediate response is needed to protect users or third parties. Our notice-and-cure practice for non-urgent violations — and the limits on it — is set out in §14.2.

11. Your content and intellectual property

11.1 Your content stays yours

You retain all right, title, and interest in and to the files, models, prompts, configurations, branches, version commits, PR descriptions, PR comments, release notes, cherry-picks, features, presets, and every other artifact you upload to or generate with Kiln ("Your Content", also defined as Customer Data in §1.2). We do not claim ownership of Your Content. When you push a new version of a design to the web workshop's git-for-3D layer, you own every commit in the history just like you'd own every commit you push to a personal GitHub repo.

AI and automated output. Output produced by AI or automated features within Kiln from your inputs is owned by you, subject to any third-party rights in the underlying inputs you provide. You are responsible for ensuring you have the rights to those inputs.

11.2 The license you grant to us

To operate the service on your behalf, you grant us a worldwide, non-exclusive, royalty-free, sub-licensable license to host, store, copy, transmit, display, process, and modify Your Content solely to the extent necessary to provide the Kiln service to you and to comply with our legal obligations — for example:

  • storing your commit history in the git-for-3D cloud layer so you can pull past versions;
  • auto-generating thumbnail previews so you can browse your library visually;
  • propagating commits, branches, PR comments, and releases to collaborators you have explicitly granted access to via an org or team role;
  • routing a model file to a fulfillment provider you selected;
  • storing slicer configurations, features, or presets you choose to save to the cloud;
  • retaining event logs for debugging.

This license ends when Your Content is deleted or your subscription terminates, subject to our legitimate retention requirements documented in the Privacy Policy (backups, legal holds) and the export window in §14.3.

We will not use Your Content to train machine-learning models, to generate derivative products, for marketing, or for any purpose other than operating the service for you — unless you explicitly opt in via a clearly-labeled consent flow. Today we have no ML pipeline trained on user content, and we are not collecting data for that purpose. If we ever build one (for example, to improve slice-quality prediction or failure-mode detection), we will ask your permission first and let you decline without losing any features. This commitment is stronger than the industry norm because Kiln is built by and for people who care about IP ownership of what they design and print.

11.3 Your representations about Your Content

You represent and warrant that you have all rights necessary to upload and use Your Content through Kiln, and that Your Content does not infringe any third party's IP rights, violate any law, or breach any agreement you are subject to. You are solely responsible for the accuracy, quality, and legality of Your Content and for any consequences of uploading it.

11.4 Designs owned by organizations

When you create or push to a design that belongs to an organization (an "Org Design"), the design itself is owned by the organization, not by you personally — even if you authored individual commits to it. While you are a member of the org:

  • You can push, pull, open PRs, comment, and release per the role the org's admin has granted you;
  • Your individual commits remain attributed to you in the reflog and version history (the "authorship" of each commit);
  • The underlying design files belong to the org and cannot be extracted by you alone.

When you leave an org (or are removed):

  • Your access to the org's designs ends immediately;
  • Your authorship attribution on prior commits remains in the history, so collaborators can see who wrote which part (standard git-style audit trail);
  • On your written request, we will anonymize your authorship on Org Design commits — we replace your name with "a former collaborator." We cannot remove your commits from the history without destroying other contributors' work, so we do not offer that.

Ownership of the org itself (and any Org Designs) transfers to the remaining admins if you, as owner, leave. If no admin remains, the org enters a 30-day wind-down period during which a new owner can be appointed; if none is, the org and all its designs are permanently deleted.

11.5 Public designs and the community datasets

If Kiln adds a "make design public" feature in the future, and you explicitly opt in to making a design public, you grant Kiln and other users a non-exclusive right to view and clone the public version of that design, subject to any license you attach to it (e.g., CC-BY-NC-SA, MIT, proprietary). You remain the copyright owner; public sharing does not transfer ownership.

If you opt in to contribute to the community datasets (community_prints, community_recoveries) by explicitly calling a community_share tool, you grant Kiln and every user a perpetual, irrevocable, royalty-free, worldwide license to use the anonymized contribution for research, training of success-rate models, and aggregate analytics that benefit the Kiln user community. The ingestion pipeline strips your email, auth_user_id, tenant_id, file names, and geometry before storage — only printer model, material, settings hash, outcome, and quality grade are retained. Because the data is anonymized at ingestion, we cannot identify or retract individual contributions once they're in the dataset. Only opt in if you are comfortable with permanent donation of that (anonymized) record.

11.6 Feedback

If you submit feedback, feature requests, or suggestions to us ("Feedback"), you grant us a perpetual, irrevocable, royalty-free, worldwide license to use Feedback for any purpose without obligation. Don't send us Feedback you want to keep proprietary.

11.7 Our intellectual property

Kiln — including the workshop UI, the REST API, the Documentation, and all underlying software, designs, logos, and trademarks — is owned by Hadron Labs Inc. or its licensors and is protected by intellectual-property laws. Except for the limited rights granted in §4 and the rights granted to you under AGPL-3.0 for the open-source components, no rights in Kiln are transferred to you.

12. Third-party services and content

Kiln connects to third-party services — Google / Apple / GitHub OAuth, Stripe, Circle, Supabase, Fly.io, Vercel, Craftcloud, MyMiniFactory, Cults3D, and others. Your use of those services is subject to each provider's own terms of use and privacy policy. We are not a party to the contract between you and any third-party service, and we are not responsible for acts, omissions, content, or availability of third-party services.

Content downloaded from third-party marketplaces is governed by the respective marketplace's terms and the licenses attached to individual listings. You are responsible for verifying the license on any model you download before you print, sell, or redistribute it.

If you believe content accessible through Kiln infringes your copyright, send a notice under the Digital Millennium Copyright Act (17 U.S.C. §512) to our designated agent:

DMCA Agent, Hadron Labs Inc. Email: adam@kiln3d.com

Your notice must include all elements required by §512(c)(3):

  1. Physical or electronic signature of the copyright owner or authorized agent;
  2. Identification of the copyrighted work claimed to be infringed;
  3. Identification of the infringing material and information reasonably sufficient to let us locate it (including URL);
  4. Your contact information;
  5. A statement that you have a good-faith belief that the use is not authorized by the copyright owner, its agent, or the law;
  6. A statement, under penalty of perjury, that the information in the notice is accurate and that you are authorized to act on behalf of the copyright owner.

Counter-notices may be sent to the same email and must include the elements required by §512(g)(3).

We will respond to valid DMCA notices by removing or disabling access to the identified material and will terminate the accounts of users who are repeat infringers.

14. Suspension and termination

14.1 By you

You can terminate your account at any time via /app/settings/account → Delete account or by emailing adam@kiln3d.com. Termination cancels all active subscriptions effective at the end of the current paid period.

14.2 By us

We may suspend or terminate your account, without prior notice, if:

  1. You materially breach these Terms (including §10 Acceptable Use);
  2. You pose a security risk to us or other users;
  3. We are required to do so by law or by an order of a court or governmental authority;
  4. Your account has been inactive for 12+ months and has no active paid subscription;
  5. We discontinue the service or any part of it — we will provide at least 90 days' notice for a full discontinuation.

For a subscription under an Order Form, either party may also terminate for the other party's material breach that remains uncured 30 days after written notice describing the breach, and we may suspend or terminate where your account is in arrears for more than 60 days following notice of non-payment.

Notice and cure (non-urgent violations). For non-urgent violations, we will provide notice and a reasonable opportunity to cure where practicable; immediate suspension is reserved for security incidents, illegal use, or behavior that materially harms other customers or third parties. This is the single notice-and-cure standard referenced by §10.

14.3 Effect of termination

On termination, the following cascade applies:

Access:

  • Your access to paid services ends immediately;
  • Access to org-owned designs via any org you were a member of ends immediately;
  • Sessions on every device are invalidated.

Data export window:

  • For 30 days following termination (or such other period set out in your Order Form), we will make Customer Data available for export through the service's data-export functionality, so you can retrieve a copy before deletion.

Your personal designs and workshop content:

  • All designs, branches, versions, releases, cherry-picks, features, presets, and related metadata that you personally own (not org-owned) are retained for 90 days in case you reinstate. After 90 days they are permanently deleted along with your account. (The 30-day export window above runs inside this 90-day retention period; the two are complementary — the export window is when you can pull a copy, the retention period is how long the data remains before permanent deletion.)

Org-owned designs (where you contributed):

  • Org-owned designs remain with the org. Your individual commits remain attributed to you in the history (like GitHub); the org's admins can request anonymization of your authorship (replacing your name with "a former collaborator") per §11.4.
  • Orgs that you personally own transition to the remaining admins or enter a 30-day wind-down per §11.4.

PR comments on others' designs:

  • Comments you posted on others' PRs remain visible on the host design's history to preserve review context. On written request to adam@kiln3d.com we will anonymize your authorship.

Community dataset contributions:

  • Anonymized contributions to community_prints and community_recoveries remain in the dataset — they cannot be retracted because we can't trace records back to you after ingestion (see §11.5).

Billing:

  • Outstanding charges remain due;
  • Refunds are governed by §5.6;
  • Invoices and payment records are retained per Privacy Policy §7 retention schedule (7 years for tax compliance).

After the export window and retention periods above, Customer Data is purged in accordance with the retention schedule in our Privacy Policy.

Surviving sections:

The following Sections survive termination: §1.2 (definitions), §1.3 (supplemental terms and precedence), §4.1 (open-source and use scope), §4.3 (reserved rights), §5.6 (refunds), §5.7 (chargebacks), §5.9 (payment processors, as to amounts due), §6.1 (orchestration fees, as to amounts due), §6.2 (privacy and data processing / DPA-SCC hook), §8 (your responsibilities — printing safety), §9 (automated control risks), §10 (acceptable use, including the anti-circumvention and paywall-integrity provisions), §11 (your content and intellectual property, including §11.4 org designs, §11.5 public + community data licenses, §11.6 feedback, and §11.7 our IP), §12 (third-party services), §13 (DMCA), §15 (warranties), §16 (liability), §17 (confidentiality), §18 (indemnification), §19 (export), §20 (governing law), §21 (arbitration), §22.2 (your ongoing representations, while you continue to use Kiln), §23 (notices), §24 (general), and any then-current SLA and DPA to the extent they by their nature should survive.

15. Disclaimer of warranties

Each party represents that it has the authority to enter into these Terms and that its performance will not violate any other agreement to which it is a party. (Your separate, ongoing representations about authority, accuracy, compliance, and sanctions status are set out in §22.2.)

EXCEPT AS EXPRESSLY SET OUT IN A WRITTEN SERVICE LEVEL AGREEMENT (SLA), KILN, THE WEB WORKSHOP, THE REST API, THE CLI, THE MCP SERVER, THE PAID SERVICES, AND ANY CONTENT, TOOLS, OR INTEGRATIONS MADE AVAILABLE THROUGH THEM ARE PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, OR STATUTORY.

Without limiting the foregoing, we expressly disclaim all warranties of merchantability, fitness for a particular purpose, non-infringement, quiet enjoyment, system integration, accuracy, title, and any warranties arising from a course of dealing, usage, or trade practice.

We do not warrant that:

  • The service will be uninterrupted, secure, or error-free;
  • Defects will be corrected;
  • The service will meet your requirements;
  • Any data will be preserved against loss or corruption;
  • AI-agent actions will be correct, safe, or in accordance with your intent.

Any uptime, availability, or support commitment is only as set out in a written SLA, and applies only to the surfaces that SLA names.

Some jurisdictions do not allow exclusion of certain implied warranties; in those jurisdictions, the exclusions above apply to the maximum extent permitted by law.

16. Limitation of liability

TO THE MAXIMUM EXTENT PERMITTED BY LAW:

  1. Excluded damages. Neither party — including, as to Hadron Labs Inc., its officers, directors, employees, contractors, and affiliates — will be liable for any indirect, incidental, consequential, special, exemplary, or punitive damages, including lost profits, lost revenue, lost data, lost goodwill, loss of anticipated savings, business interruption, or procurement of substitute goods or services, even if advised of the possibility of such damages.

  2. Liability cap (mutual). Each party's total cumulative liability arising out of or related to these Terms or your use of Kiln, for all claims of every kind, will not exceed the greater of (a) $500 USD, or (b) the fees you paid to us in the 12 months preceding the event giving rise to the claim, regardless of the theory of liability.

  3. 3D printing + AI-agent physical harm. To the extent permitted by law, the limitations in (1) and (2) above apply to any claim arising from physical damage, property loss, personal injury, or death caused by printer operation, AI-agent actions, fulfillment orders, or any other operation of Kiln.

  4. Carve-outs from the cap. The liability cap in (2) does not apply to:

    a. Customer's indemnification obligations under §18;

    b. a party's intentional or grossly-negligent breach of its confidentiality obligations under §17 — provided that, for the avoidance of doubt, this carve-out does not override the disclaimer in §15 that we do not warrant any data will be preserved, and does not convert a good-faith security incident or ordinary data loss or corruption into uncapped liability;

    c. Customer's infringement or misappropriation of Kiln's intellectual-property rights, and Customer's breach of §10(7) (reverse-engineering of proprietary components) or §10(8) (building a competing product). For the avoidance of doubt, this carve-out does not lift the cap on any claim that Kiln infringed, misused, or exceeded its license to Your Content — such claims, if any, remain subject to the cap in (2), without prejudice to carve-out (4)(d) for matters that cannot lawfully be limited;

    d. liability that cannot lawfully be limited or excluded under applicable law, including (in jurisdictions that so provide) liability for fraud, willful misconduct, gross negligence, or death or personal injury caused by a party's negligence — in each case only to the extent such liability cannot lawfully be limited; and

    e. Customer's payment obligations to us.

  5. Negligence and injury (jurisdictional floor). Some jurisdictions do not permit the exclusion or limitation of liability for fraud, for gross negligence or willful misconduct, or for personal injury or death caused by negligence. In those jurisdictions, and as reflected in carve-out (4)(d), each party's liability for those matters is limited only to the extent permitted by law — nothing in this §16 limits liability that cannot lawfully be limited. For the avoidance of doubt, the only uncapped exposure for the mishandling of Customer Data is the fenced confidentiality carve-out in (4)(b); a good-faith security incident or ordinary data loss or corruption is governed by §15 and remains subject to the cap.

  6. Essential bargain. You understand and agree that the limitations in this §16 are an essential element of the bargain between you and us, and that absent these limitations we would not provide the service at the fees we charge or at all.

17. Confidentiality

Each party (the "Receiving Party") may receive confidential information from the other (the "Disclosing Party"), including non-public business plans, technical specifications, pricing, security details, and Customer Data ("Confidential Information"). The Receiving Party will:

  1. use Confidential Information only to perform its obligations under these Terms;
  2. protect Confidential Information with at least the same care it uses for its own confidential information of similar importance, and no less than reasonable care; and
  3. limit access to its employees, contractors, and agents bound by confidentiality obligations no less protective than these.

Confidential Information does not include information that is or becomes publicly known through no fault of the Receiving Party, was known to the Receiving Party without restriction before disclosure, is independently developed without use of Confidential Information, or is rightfully received from a third party without confidentiality obligations.

The Receiving Party may disclose Confidential Information if compelled by law, provided it gives the Disclosing Party prior notice (where legally permitted) and reasonable cooperation in seeking a protective order.

Liability for breach of this §17 is subject to §16, including the mutual cap and the limited confidentiality carve-out in §16(4)(b) (uncapped exposure only for an intentional or grossly-negligent confidentiality breach, and not for a good-faith security incident or ordinary data loss, which §15 addresses).

18. Indemnification

Indemnification under these Terms runs one way: from Customer to Kiln. Kiln gives no indemnity, including no defense against third-party intellectual-property claims.

18.1 By Customer

You agree to defend, indemnify, and hold harmless Hadron Labs Inc., its officers, directors, employees, contractors, and affiliates from and against any claims, damages, losses, liabilities, costs, and expenses (including reasonable attorneys' fees) arising out of or related to:

  1. Your use or misuse of Kiln;
  2. Your Content or the objects you manufacture;
  3. Your violation of these Terms, including §10 (Acceptable Use);
  4. Your violation of any applicable law or third-party right;
  5. Actions taken by AI agents you authorized or configured;
  6. Your failure to supervise unattended prints or follow printer manufacturer guidance; and
  7. Your products or services, to the extent the claim does not arise from Kiln itself.

Consumer limitation. If you are an individual using Kiln for personal, non-commercial purposes (the Free or Pro tier), your obligations under this §18 are limited to third-party claims, do not extend to Kiln's own first-party losses, and do not apply to the extent a claim arises from Kiln's own negligence or breach of these Terms. This limitation does not apply to Business or Enterprise customers.

18.2 Procedure

Kiln will give Customer prompt notice of the claim; Customer will control the defense and settlement (provided that no settlement imposing a non-monetary obligation or admission on Kiln is made without Kiln's consent) and will provide reasonable cooperation at Customer's expense. We reserve the right to assume the exclusive defense and control of any matter otherwise subject to indemnification by you, at your expense, and you agree to cooperate with our defense of any claim.

19. Export controls and sanctions

Kiln is subject to US export control laws, including the Export Administration Regulations (15 C.F.R. §§ 730–774) and the economic-sanctions programs administered by the US Treasury Department's Office of Foreign Assets Control (OFAC).

You agree that you will not — directly or indirectly — export, re-export, transfer, or release Kiln or any of its technical data:

  1. To any country, entity, or person subject to US sanctions or export restrictions listed in §2;
  2. For any use prohibited under US export laws, including the design or production of nuclear, chemical, or biological weapons, missile technology, or unmanned aerial vehicles; or
  3. In contravention of export or import laws of your own jurisdiction.

You are responsible for obtaining any licenses or authorizations required for your use of Kiln under the laws applicable to you.

20. Governing law

These Terms, and any dispute arising out of or related to these Terms or your use of Kiln, are governed by the laws of the State of Delaware, USA, without regard to its conflict-of-laws rules. The United Nations Convention on Contracts for the International Sale of Goods does not apply.

21. Binding arbitration and class-action waiver

READ THIS SECTION CAREFULLY — IT AFFECTS YOUR LEGAL RIGHTS, INCLUDING YOUR RIGHT TO FILE A LAWSUIT IN COURT.

21.1 Informal resolution first

Before initiating arbitration, you and we agree to try to resolve any Dispute (defined in §21.2) informally through good-faith negotiation for at least 30 days after written notice of the Dispute. This informal-resolution step does not apply to, and does not delay, (a) a small-claims action permitted by §21.3, or (b) a request for injunctive relief permitted by §21.8 — those fast paths remain available immediately.

21.2 Agreement to arbitrate

If the Dispute is not resolved under §21.1, you and Hadron Labs Inc. agree that any dispute, claim, or controversy arising out of or relating to these Terms, the Privacy Policy, Kiln, or the relationship between you and us (a "Dispute") will be resolved by binding arbitration conducted by the American Arbitration Association (AAA) under its Consumer Arbitration Rules (or, for Business or Enterprise tier customers, its Commercial Arbitration Rules), as modified by this §21.

The arbitration will be conducted in English in San Jose, California, USA, unless you and we agree otherwise (including by mutual agreement to proceed remotely). For individual consumer claims under $10,000, at your option, you may elect to participate in the arbitration by telephone, videoconference, or written submission only (no in-person appearance required). A single arbitrator will preside.

The arbitrator will issue a reasoned written award, which is final and binding. Judgment on the award may be entered in any court of competent jurisdiction.

21.3 Small-claims exception

Either you or we may bring an individual claim in small-claims court in a jurisdiction where both parties are subject to personal jurisdiction, so long as the claim remains in small claims. If a small-claims case is transferred, removed, or appealed outside of small-claims court, this §21 resumes and the case must continue in arbitration. The §21.1 informal-resolution step is not a precondition to a small-claims filing.

21.4 Class-action waiver

YOU AND WE EACH AGREE THAT CLAIMS MAY BE BROUGHT ONLY IN YOUR OR OUR INDIVIDUAL CAPACITY, AND NOT AS A PLAINTIFF OR CLASS MEMBER IN ANY PURPORTED CLASS, COLLECTIVE, CONSOLIDATED, PRIVATE ATTORNEY GENERAL, OR REPRESENTATIVE PROCEEDING. The arbitrator may not consolidate the claims of more than one person and may not preside over any form of class or representative proceeding. If this class-action waiver is found unenforceable, then the entire §21 (except the small-claims exception) will be null and void, but the remainder of these Terms will continue to apply.

21.5 30-day opt-out right

You can opt out of this arbitration agreement by emailing adam@kiln3d.com within 30 days of first accepting these Terms (or of first accepting any material change to this §21). Include your name, email, and a clear statement that you opt out of the arbitration agreement. Opting out does not affect any other part of these Terms.

If you opt out, all Disputes between you and us will be resolved in the state or federal courts located in Santa Clara County, California (or, at your option for consumer claims, in the state or federal courts located in your district of residence), and you and we consent to the personal jurisdiction of those courts.

21.6 Federal Arbitration Act

These arbitration provisions are governed by the Federal Arbitration Act (9 U.S.C. § 1 et seq.) and federal arbitration law. They will remain in effect after termination of these Terms or your account.

21.7 Fees

For consumer claims of $10,000 or less, Hadron Labs Inc. will pay all AAA filing, administration, and arbitrator fees. For larger claims, AAA's standard fee allocation applies, and either party may seek fee-shifting per applicable law.

21.8 Injunctive relief carve-out

Either party may bring an action in court — without first negotiating under §21.1 and without first arbitrating — to protect its intellectual property rights or confidential information, or to prevent unauthorized access to the service (injunctive relief only). Any damages claim remains subject to §21.2.

22. Changes to these Terms; your ongoing representations

22.1 How we change these Terms

We may update these Terms from time to time. When we make changes, we will:

  1. Update the "Last updated" date and increment the version number at the top;
  2. Maintain a visible version history at kiln3d.com/terms, with prior versions of the canonical document preserved in its public change history (the version-controlled history of the canonical TERMS_OF_USE.md file, reachable from kiln3d.com/terms);
  3. For material changes (changes to fees, cancellation terms, liability, arbitration, acceptable-use restrictions, or other terms that meaningfully reduce your rights or expand your obligations), email you at the address on your account at least 30 days before the change takes effect, and require re-acceptance during your next signin if possible.

Non-material changes (clarifications, typos, reorganization) take effect immediately and are noted in the version history.

Enterprise term-lock. For Enterprise customers under a signed Order Form, the Terms in effect at the start of the current term continue to apply for the duration of that term unless the parties agree otherwise in writing.

Continued use of Kiln after the effective date of a change constitutes acceptance of the revised Terms. If you don't agree with a change, cancel your subscription before the effective date.

22.2 Your ongoing representations

You represent and warrant, on each date you use Kiln, that:

  1. You have full legal right and authority to enter into these Terms (and, where you act for an organization, to bind it — see §1.1; this is your individual counterpart to the mutual authority representation in §15);
  2. All information you provide to us is accurate, current, and complete;
  3. You will use Kiln in compliance with these Terms and applicable law; and
  4. Neither you nor any entity on whose behalf you use Kiln is located in a sanctioned jurisdiction (§2) or listed on any restricted-parties list (§2, §19).

These representations survive termination for so long as you continue to use Kiln (see §14.3).

23. Notices

We communicate with you via the email address on your account. It is your responsibility to keep that email current and accessible. Notices from us are deemed received when sent to your account email.

You may send notices to us at:

Hadron Labs Inc., Legal Department Email: adam@kiln3d.com Postal mail: Hadron Labs Inc., c/o Harvard Business Services, Inc. (Registered Agent), 16192 Coastal Hwy, Lewes, DE 19958, USA

Notices are effective on receipt.

24. General

24.1 Entire agreement

These Terms — together with the Privacy Policy, any applicable SLA, any DPA, any Order Form, any supplemental terms, and any other documents expressly incorporated by reference — constitute the entire agreement between you and us regarding Kiln and supersede all prior or contemporaneous understandings on the subject. In the event of a conflict, a supplemental term, SLA, or DPA controls over these Terms only for the specific feature or subject matter it governs (see §1.3 and §6.2).

24.2 Severability and reformation

If any provision of these Terms is held to be invalid or unenforceable, that provision will be modified to the minimum extent necessary to make it enforceable while preserving the parties' original intent, or, if it cannot be so modified, struck to the minimum extent necessary; in either case, the remaining provisions will remain in full force and effect.

24.3 No waiver

Our failure to enforce any provision is not a waiver. A waiver is effective only if in writing signed by an authorized representative of Hadron Labs Inc.

24.4 Assignment

You may not assign or transfer these Terms or any rights or obligations hereunder without our prior written consent, except to a successor in connection with a merger, acquisition, or sale of substantially all of your assets. We may assign these Terms in connection with a merger, acquisition, reorganization, sale of assets, or by operation of law. Any assignment or transfer in violation of this section is void.

24.5 No agency; no third-party beneficiaries

Nothing in these Terms creates a partnership, agency, joint venture, or employment relationship between you and us; the parties are independent contractors. There are no third-party beneficiaries to these Terms.

24.6 Force majeure

Neither party is liable for failure or delay in performance caused by acts beyond its reasonable control, including acts of God, natural disasters, war, terrorism, civil unrest, labor actions, government actions, internet or telecommunications failures, power outages, and pandemics. The affected party will notify the other and use reasonable efforts to resume performance.

24.7 Headings; interpretation

Headings are for convenience only and do not affect interpretation. "Including" means "including without limitation." References to "you" and "we" include successors and permitted assigns.

24.8 Language

These Terms are drafted in English. Any translation is provided for convenience, and the English version controls in the event of inconsistency.

24.9 US Government rights

If you are a US Government end user, Kiln and its documentation are "Commercial Items" as defined in FAR 2.101, consisting of "Commercial Computer Software" and "Commercial Computer Software Documentation" per 48 C.F.R. 12.212 and 48 C.F.R. 227.7202. Consistent with those provisions, Kiln is licensed to US Government end users only as Commercial Items and with only those rights granted to all other end users under these Terms.

25. Contact

By using Kiln, you confirm that you have read, understood, and agreed to these Terms of Use.