John Morris
Also known as Jack Morris, John X. Morris
John Morris is an AI researcher and cofounder and head of research at Engram whose work examines text embeddings, language model inversion and memorization capacity. As an undergraduate at the University of Virginia, he helped create the TextAttack framework in 2020, and he completed a computer science PhD at Cornell University in 2025 with Alexander Rush and Vitaly Shmatikov. With collaborators at Cornell, he developed unsupervised text deidentification in October 2022 and the Vec2Text method in October 2023, which recovered 92% of 32-token inputs exactly from their embeddings and won an EMNLP Outstanding Paper Award in December 2023. His May 2025 study on language model memorization estimated that GPT-style models store approximately 3.6 bits per parameter and received an Outstanding Paper Honorable Mention at ICML 2026, and in June 2026 Engram emerged from stealth with $98 million in funding.
Timeline
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2019–2020
TextAttack at Virginia
As an undergraduate at the University of Virginia, he gets started in research and creates TextAttack in 2019 and 2020. In April 2020, he coauthors the TextAttack paper with Eli Lifland, Jin Yong Yoo, Jake Grigsby, Di Jin and Yanjun Qi, introducing a Python framework for adversarial attacks, data augmentation and adversarial training in NLP.
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October 2022
Unsupervised text deidentification
In October 2022, he coauthors Unsupervised Text Deidentification, proposing an unsupervised method that masks words that leak personally identifying information.
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2023
Vec2Text and an EMNLP award
In October 2023, he posts Text Embeddings Reveal (Almost) As Much As Text with Volodymyr Kuleshov, Vitaly Shmatikov and Alexander M. Rush. Its multi-step method, Vec2Text, iteratively corrects and re-embeds text to recover 92% of 32-token text inputs exactly from their embeddings, and the four Cornell Tech researchers receive an Outstanding Paper Award at EMNLP in December 2023.
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2024
Contextual document embeddings
In August 2024, he is a fourth-year computer science PhD candidate at Cornell University and a visiting researcher with FAIR at Meta, after working as a Google Brain Resident before Cornell. In October 2024, he and Alexander M. Rush post Contextual Document Embeddings, which encodes neighbor document information into each document representation and achieves state-of-the-art results on the MTEB benchmark.
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May 2025
Measuring language model capacity
In May 2025, he posts How much do language models memorize? with Chawin Sitawarin, Chuan Guo, Narine Kokhlikyan, G. Edward Suh, Alexander M. Rush, Kamalika Chaudhuri and Saeed Mahloujifar. The team trains hundreds of transformer language models, from 500K to 1.5B parameters, and estimates that GPT-style models have a capacity of approximately 3.6 bits per parameter.
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2025
A Cornell doctorate
He completes his computer science PhD at Cornell University in 2025, where he works with Alexander Rush and Vitaly Shmatikov and shows how knowledge of an encoder extracts meaning from text embeddings.
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2026
An ICML honorable mention
How much can language models memorize?, the conference version of his capacity paper, receives an Outstanding Paper Honorable Mention at ICML 2026. It appears in the 2026 proceedings of the 43rd International Conference on Machine Learning.
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As of October 2026
Co-founding Engram
He is a cofounder and head of research at Engram, an AI startup cofounded with Jessy Lin, Scott Linderman and others that trains language models on an organization's own knowledge. Engram emerges from stealth in June 2026 with $98 million in funding from General Catalyst, Kleiner Perkins, Sequoia Capital and other investors to build a learned memory layer for AI, and it announces work with Microsoft, Notion and Harvey.
Career
- Since 2026EngramCofounder
- From 2024FAIR (Meta)Visiting researcher
- Google BrainResident
Education
Sources and credits
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- About – Jack Morris
- TextAttack: A Framework for Adversarial Attacks, Data Augmentation, and Adversarial Training in NLP
- [2210.11528] Unsupervised Text Deidentification
- Text Embeddings Reveal (Almost) As Much As Text
- Researchers Win Award for Study on Text Embedding Privacy Risks
- Inverting Language Models – Stanford NLP Seminar
- Contextual Document Embeddings
- How much do language models memorize?
- Jack Morris: Bio, Work & Ideas | AI Engineer
- ‘Rosetta stone’ for database inputs reveals serious security issue | Cornell Chronicle
- Research – Jack Morris
- How much can language models memorize?
- ICML Poster How much can language models memorize?
- Engram Launches With $98 Million To Build AI Memory Layer For Enterprises
- Announcing our investment in Engram, the memory dream team
- Our Investment in Engram
- Data-Free LLM Evaluation - SPAR Project

