Fundraising Fox

Arcjet

San Francisco, US · Founded 2023 · 15 employees on LinkedIn · 2 known investors

Find your way into Arcjet

501 people in our graph share verified history with the Arcjet team — schools, employers, funds. One of them is your warm intro.

Mariaunlockedknows David Mytton · together at University of Oxford (overlapped)
×4knows the team · via University of Oxford
×5knows the team · via Seedcamp
knows the team · via Arcjet
knows the team · via University of Birmingham

Arcjet provides inline security controls for AI workflows and agents, enforcing action-boundary protections such as blocking unauthorized tool calls, preventing data exfiltration, and capping token usage. It targets developers building AI-powered applications, offering prompt injection detection, data loss prevention, and agent tool scoping enforced in real time.

AI & Machine LearningCybersecurityDeveloper Tools

Founders & leadership

Arcjet was founded in 2023 by David Mytton.

DMDavid Mytton
David Myttonin𝕏Founder · CEOHe publishes the console.dev newsletter focused on developer tools and is pursuing an Engineering Science PhD in sustainable computing at the University of Oxford.

Investors · 2

Andreessen HorowitzMenlo Park · $500K – $50M
SeedcampLondon · $378K – $1.1M

Funding

SEC filings, press & company announcements

$20.3M disclosed across 3 of 6 rounds · 2023–2025

▶$8.5MraisedMay 2025 · 7 investors · Other Technology
Rule 506(b)
Officers, directors & promoters on the filing
  • David MyttonExecutive Officer, Director
Offering amount
$8.6M
Amount sold
$8.5M
First sale
Apr 2025
Incorporated
Corporation, Delaware, 2023
Federal exemptions
06b
Full filing on SEC EDGAR ↗
▶$3.5MraisedJun 2023 · 24 investors · Other Technology
Rule 506(b)
Officers, directors & promoters on the filing
  • David MyttonExecutive Officer, Director
Offering amount
$3.5M
Amount sold
$3.5M
First sale
Jun 2023
Incorporated
Corporation, Delaware, 2023
Federal exemptions
06b
Full filing on SEC EDGAR ↗

Source: SEC EDGAR Form D. Amounts as filed; amended filings shown once at their latest values.

In the news

Arcjet Raises $8.3M to Tackle Surge in AI-Powered Cyberattacks and Malicious Bots with In-Code Defensetheaiinsider.tech · Oct 2025Arcjet raises $8.3m to fight AI-driven cyberattacksfintech.global · Oct 2025Introducing Arcjet’s local AI security model + announcing Series A fundingblog.arcjet.com · Oct 2025Revolutionizing developer security: Arcjet secures $3.6m led by Andreessen Horowitzfintech.global · Sep 2024Arcjet raises $3.6M seed funding to help developers protect their apps in production - Seedcampseedcamp.com · Sep 2024

Frequently asked questions

What does Arcjet do?
Arcjet provides inline security controls for AI workflows and agents, enforcing action-boundary protections such as blocking unauthorized tool calls, preventing data exfiltration, and capping token usage. It targets developers building AI-powered applications, offering prompt injection detection, data loss prevention, and agent tool scoping enforced in real time.
Who founded Arcjet?
Arcjet was founded by David Mytton in 2023.
Who are Arcjet's investors?
Arcjet's investors include Andreessen Horowitz, Seedcamp.
How much funding has Arcjet raised?
Arcjet has disclosed $20.3M raised across 3 of its 6 known rounds.
Where is Arcjet headquartered?
Arcjet is headquartered in San Francisco, US.