Jcode YC Application

Summer 2026Active

San Francisco

Jcode went through Y Combinator in the Summer 2026 batch as a Consumer company. Below: what the company does, who founded it, and its application to YC, reconstructed question by question in the real YC form.

YC batch: Summer 2026
Industry: Consumer
Location: San Francisco
Team size: 1
Status: Active
Launched: 2026

Founders

Jeremy HuangFounder/CEO

What Jcode does

An agent is LLM + harness: We work purely on that second component. We do research to produce the most capable harness. Our harness has 18k stars on github

Jcode's YC application, reconstructed

Y Combinator application

Jcode, Summer 2026 batch. The real form questions, answered from public data.

Founders2
Company7
Progress7
Idea4
Equity3
Curious2
Batch Preference1

Company

Company name

Jcode

Describe what your company does in 50 characters or less.

The harness company

What is your company going to make? Please describe your product and what it does or will do.

We're building Jcode Harness, the infrastructure that makes LLM agents usable in practice. An agent is always an LLM plus a harness; we focus entirely on building, researching, and open-sourcing the harness part. Our harness repo has reached 18,000 GitHub stars from developers who use it to connect models and tools, run experiments, and debug agent behaviors.

Where do you live now, and where would the company be based after YC?

San Francisco, CA. The company will stay based here after YC.

Explain your decision regarding location.

We're in San Francisco because that's where we're already building and where AI/developer infra communities are. It gives access to early technical users and collaborators.

21 more answers in the full application

Founders, Progress, Idea, Equity, Curious, Batch Preference are in the full version. Create a free account to open it in YC Insights, next to every other YC batch.

See full application

Frequently Asked Questions

Is this the real Jcode YC application?

No. Y Combinator keeps submitted applications private. This is a reconstruction: the real YC form questions, answered from Jcode's public data (launch notes, founder backgrounds, product description). It shows how a company like Jcode would present itself to YC, not the text they submitted.