Top accelerator startups

14,448 startups · 29 programs

Nessie

Active · The shared context layer for recursive companies.

9signal of 100 · rising 7
  • went through YCProgram · this site+4
  • team of 2Team size · YC's directory+2.5
  • hiringHiring · Titles (titles.fru.dev), YC+2

A sum of public facts, not a judgement and not investment advice.

Competitors

Adjacent

Also from F25 in AI

All of F25

Founders

  • Anna ZhangFounder/CEO
  • Tiger WangFounder/CTO

About Nessie

Knowledge work is being restructured by AI. Strategy happens in Claude. Research happens in ChatGPT. Building happens in Claude Code and Codex. Meetings get recorded, notes get written, agents run for hours and leave behind traces nobody reads. The people defining the next decade of work are already thinking with AI every day. But none of that thinking compounds. Every session starts from zero. The reasoning behind decisions, the context behind strategies, the evolution of ideas across hundreds of conversations - all of it evaporates. Nessie is the infrastructure that makes it permanent. We auto-sync AI conversations and agent traces across every major provider - ChatGPT, Claude, Gemini, Perplexity, Claude Code, Codex, Cursor, OpenClaw, Hermes, and more - alongside meetings, notes, and email from tools like Granola, Read AI, Plaud, and Obsidian. Everything a team produces with AI flows into one place and compounds over time. Nessie turns that raw, heterogeneous data into an ontology: the live state of a company. Not a static schema but a continuously updated record of what the company knows, what it has decided, who owns what, and how its thinking has evolved, kept current as new work flows in. It is queryable from any agent through our CLI, MCP connector, and plugins, shareable across a team with real permissions, and deployable on-prem for organizations that need it. Then the loop closes. Once a company’s state is legible to its agents, every agent run becomes training signal: which skills worked, which failed, which workflows keep repeating. Nessie feeds that signal back as reviewable improvements to the skills, prompts, and processes the team runs on. This is what makes a company recursive: its agents get better from its own history, the people working with them get better too, and the compounding never stops. Where we are going: the AI-native organization runs thousands of agents that are powerful but amnesiac. Nessie is the layer that gives them, and the humans steering them, a shared memory. Science has journals, law has case law, software has git; AI-native knowledge work has had nothing. We are building it. Founded by two Yale CS grads and former Amazon engineers in San Francisco. Backed by BoxGroup, Pioneer Fund, Y Combinator, Precursor, and more. https://nessielabs.com

YC batch
F25 · Fall 2025
Status, per YC
Active
Category
AI
Team size
2
Location
San Francisco, CA, USA
Founded
2025
Checked
6h ago

Changes seen

Team sizeOct 29, 2026

Team went from 3 to 2 people.

One-linerOct 26, 2026

Rewrote its one-liner; it read "The shared context layer for recursive companies - your work, your…"

Nessie in F25: 146 companies, 88% AI

LinkedIn

Nessie: questions

Which YC batch was Nessie in?

Nessie was in Y Combinator's Fall 2025 batch (F25).

Is Nessie still active?

Y Combinator lists Nessie as active.

Who founded Nessie?

Nessie's founders, as listed on its YC page: Anna Zhang (Founder/CEO), Tiger Wang (Founder/CTO).

Where is Nessie based?

Nessie lists San Francisco, CA, USA as its location on YC's directory.