Anthropic announces "Built with Claude 4.5" challenge for developers

NO PURCHASE NECESSARY TO ENTER OR WIN.

HOW TO ENTER. Beginning on September 30, 2025 at 9am ET through October 7, 2025 at 9am ET, share a post on either (i) X reposting (with comments) the original competition announcement post from the @alexalbert__ X account, or (ii) Anthropic’s #share-your-project channel on the “Claude Developers” Discord Server, that features something cool you’ve built with Claude. Your post must include 1) what you built, 2) how you built it in a week or less, 3) screenshots or demos, 4) a description of how you used Claude Sonnet 4.5 and its features. You may enter as many posts as you want, but you can only be selected as a winner once per calendar year. Use of any robotic, automatic, programmed, or similar entry method or entering more than the number of times permitted will void all entries and result in disqualification.

ELIGIBILITY. To participate, you must (i) reside in the United States , Argentina, Austria, Barbados, Bermuda, France, Germany, Ireland, Japan, Latvia, New Zealand, Serbia, South Africa, South Korea, Switzerland, or the United Kingdom, and (ii) be at least 18 years of age. Employees of Anthropic, PBC and its affiliates and their immediate family members are not eligible. Void where prohibited. The contest is void where prohibited by law or where registration, bonding, local judging or localization is required for Anthropic. BY ENTERING THE COMPETITION, YOU AGREE TO CONFORM (AND, AS APPLICABLE, THAT YOU HAVE CONFORMED) TO ALL APPLICABLE LAWS AND REGULATIONS.

WINNER SELECTION CRITERIA. Anthropic will review all posts by October 10, 2025, and pick four winners. We reserve the right to determine the winners in our sole judgment and our determination is final, but in our discretion may take into consideration factors such as number of reposts/likes/comments, community interest and discussion (e.g., level of engagement among the X or Discord community), and what we found most compelling or unique. Potential winners will be notified by X or Discord Direct Message (as applicable) and must respond with the requested information within 72 hours of the date notice is sent. Failure to respond within the applicable time period will result in forfeiture of prize and Anthropic shall have the option to award the prize to an alternate winner. The return of any prize notification or prize as undeliverable may result in disqualification and an alternate winner may be selected. You may not enter any posts demonstrating use of Claude (i) in violation of Anthropic’s Terms of Service; (ii) to reverse engineer, copy, recreate a third party’s products or services; or (iii) in violation of applicable law. Your use of Claude is subject to Anthropic’s Terms of Service.

PRIZES. Each winner will receive one year of Claude Max 20X access (currently a $2400 value) and $1000 in API credits. Prizes will be given in the form of a credit to your current Claude account. Total aggregate prize value: approximately $13,600. Limit one prize per person per year. No substitution or transfer of prize permitted by winner. You are responsible for any taxes incurred in connection with prizes you receive.

PRIVACY. Anthropic will use your X or Discord handle and the information in your post to administer the contest and contact you, including in connection with administering prizes and using or publicizing any of your submissions, in each case as set forth in our Privacy Policy.

LIMITATION OF LIABILITY. ANTHROPIC MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, REGARDING ANY PRIZE OR YOUR PARTICIPATION IN THE CONTEST. TO THE FULLEST EXTENT PERMITTED BY LAW, WE WILL NOT HAVE ANY OBLIGATION OR LIABILITY, WHETHER IN CONTRACT, WARRANTY, TORT (INCLUDING NEGLIGENCE) OR OTHERWISE, FOR ANY INCIDENTAL, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL, OR EXEMPLARY DAMAGES OR LOSS OF REVENUE, PROFIT, SAVINGS, OR BUSINESS ARISING FROM OR OTHERWISE RELATED TO THESE OFFICIAL RULES OR THE CONTEST, EVEN IF WE OR OUR REPRESENTATIVES HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. TO THE FULLEST EXTENT PERMITTED BY LAW, THE AGGREGATE LIABILITY OF ANTHROPIC TO YOU FOR ALL CLAIMS ARISING OUT OF OR RELATING TO THESE RULES AND THE COMPETITION, WHETHER IN CONTRACT, TORT, OR OTHERWISE, IS LIMITED TO $10. THESE EXCLUSIONS OF POTENTIAL DAMAGES WERE AN ESSENTIAL ELEMENT IN SETTING CONSIDERATION UNDER THESE RULES.

ADDITIONAL ACKNOWLEDGMENTS. YOU ACKNOWLEDGE THAT CERTAIN JURISDICTIONS HAVE LAWS REGARDING CONTESTS THAT MAY PREVENT SPONSOR FROM AWARDING YOU A PRIZE. IF YOU ARE A WINNER AND THIS HAPPENS TO BE THE CASE WITH YOUR JURISDICTION, YOU ACKNOWLEDGE THAT YOU MAY NOT BE ABLE TO RECEIVE ANY PRIZE AT ALL, AND THEREFORE YOU AGREE NOT TO DISPUTE, CHALLENGE, OR MAKE ANY CLAIMS AGAINST THIS OUTCOME IN ANY MANNER WHATSOEVER. BY ENTERING THIS COMPETITION, YOU ACKNOWLEDGE THE RISKS, AND UNDERSTAND THAT YOU MAY WIN BUT NOT BE ABLE TO RECEIVE A PRIZE.

WINNERS LIST. For information on winners, mail a self-addressed, stamped envelope to Anthropic Contest Team; 548 Market St, PMB 90375; San Francisco, CA 94104 . Requests must be received no later than January 7, 2026.

CANCELLATION, SUSPENSION OR AMENDMENT. If we are not capable of running the Contest as planned, we reserve the right in our sole discretion to cancel, terminate, modify, or suspend the Contest, including if the Contest is not capable of being run as planned or in the event of fraud or other Contest-related problems. You hereby acknowledge and agree that you shall not assert any claims, demands, or actions of any kind arising from or in connection with the cancellation, suspension or amendment of the Contest.

CHOICE OF LAW. These Official Rules will be governed by, and construed and interpreted in accordance with, the laws of the State of California without giving effect to conflict of law principles. You and Anthropic agree that any disputes arising out of or relating to these Official Rules will be resolved exclusively in the state or federal courts located in San Francisco, California, and you and Anthropic submit to the personal and exclusive jurisdiction of those courts. By accessing our Services, you waive any claims that may arise under the laws of other jurisdictions.