Startup profile for Arcjet: latest funding, latest known valuation, total disclosed funding, investors, status, sources, and why the company is interesting. Part of the Venture Capital Tracker startup directory.
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Arcjet funding, valuation and investors

Developer-first application security platform (bot protection, rate limiting).

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Funding, valuation & investors

Answer-first snapshot

Latest funding

Series A

$8.3M · 2025

Latest known valuation

Not publicly disclosed

Total disclosed equity funding

$12M

Excludes debt, grants, acquisitions, secondaries, and IPO proceeds.

Current status

private

series a · London, UK

Investors in latest funding

Lead: Plural

Other: Andreessen Horowitz

Sources: latest funding Last verified: 2026-07-25

Overview

Arcjet builds in-code security for modern JavaScript applications on Next.js, Node.js, Bun, SvelteKit, Vercel, Netlify, and Fly.io. Developers add SDK middleware to protect routes with bot detection, rate limiting, email validation, Shield WAF rules, and an optional local AI security model that analyzes requests in the deployment environment. Founded by David Mytton, Arcjet raised a $3.6M seed in 2024 led by Andreessen Horowitz (Zane Lackey) and an $8.3M Series A in 2025 led by Plural with a16z participating. The company reports 1,000+ developers and 500+ production applications using the platform.

Why Arcjet is interesting

Arcjet embeds bot detection and rate limits directly in Next.js/Node/Bun routes — Zane Lackey (ex-Signal Sciences) led a16z seed before Plural led Series A.

Product & use cases

Arcjet ships security as npm SDK rules — detectBot, tokenBucket rate limits, protectSignup, Shield WAF — evaluated per request with user/session context inside app code rather than external WAF-only appliances.

  • Blocking AI scrapers and unwanted bots from API and content routes
  • Rate limiting signup forms and AI endpoints by user tier or token budget
  • OWASP Top 10 protection via Shield WAF integrated into Next.js middleware

Key facts

  • Seed (2024): $3.6M led by a16z (Zane Lackey); Seedcamp participated (company blog)
  • Series A (2025): $8.3M led by Plural; a16z re-upped (company blog)
  • 1,000+ developers, 500+ production apps per Series A announcement
  • Co-investors not in VCT directory: Seedcamp, Plural, Ott Kaukver angels

Funding history (newest first)

Series A

2025 $8.3M

Source: https://blog.arcjet.com/introducing-arcjets-local-ai-security-model-announcing-series-a-funding/

Seed

2024 $3.6M

Source: https://blog.arcjet.com/launching-the-future-of-developer-security-seed-funding-from-a16z/

Investors in our directory

Funds linked from Arcjet's profile — open a fund page for stage focus and related deal articles.

Andreessen Horowitz

Competitive landscape

Edge: Native SDK integration for JS frameworks developers already use — dynamic rules based on auth, billing plan, and IP reputation vs. generic edge WAFs with limited app context.

Application security is shifting from perimeter appliances to embedded controls as AI bots scrape content and abuse signup flows. Arcjet targets the JavaScript ecosystem where Vercel/Next.js deployments dominate startups. Cloudflare remains the incumbent at scale, but Arcjet's bet is developers want fine-grained, code-native rules — especially for AI token budgets and bot allowlists — without operating separate security appliances.

  • Cloudflare incumbent

    Edge WAF and bot management at scale; Arcjet targets in-app contextual decisions for JS developers.

  • Signal Sciences (Fastly) adjacent

    a16z's Zane Lackey co-founded Signal Sciences; Arcjet applies similar philosophy to developer-native SDK model.

  • Vercel Firewall / platform WAFs adjacent

    Hosting-level protection; Arcjet adds per-route logic inside application code.

Notable stories

  • Founder David Mytton previously built server monitoring company Server Density before starting Arcjet to embed security where developers write code.
  • a16z partner Zane Lackey co-founded Signal Sciences (acquired by Fastly) — direct lineage in the seed investment thesis.
  • Arcjet launched a local AI security model in 2025 that runs expert analysis per request entirely in the customer's environment.

Industries

Cybersecurity Developer Tools

Related funding articles

Venture Capital Tracker pieces that cover Arcjet's financing or category context.

FAQs about Arcjet

Practical answers founders, operators, and investors typically search for.

Arcjet is a developer-first security platform with SDKs for Next.js, Node, Bun, and SvelteKit offering bot protection, rate limiting, email validation, and WAF rules in application code.
Andreessen Horowitz led the $3.6M seed. Plural led the $8.3M Series A with a16z participating. See /fund/andreessen-horowitz.
Developers configure detectBot rules in SDK middleware — allow or deny bot categories (AI crawlers, scrapers, search engines) per route with LIVE or DRY_RUN modes.
Cloudflare operates at the edge globally. Arcjet embeds per-request decisions inside your JS app with access to user auth, billing tier, and custom logic.
Next.js, Node.js, Bun, SvelteKit, and deployments on Vercel, Netlify, Fly.io per company documentation.
2025 — $8.3M led by Plural, announced alongside Arcjet's local AI security model.
David Mytton, previously founder of Server Density.
Yes. Arcjet explicitly markets protection against AI crawlers and includes token-bucket rate limiting for AI API budgets.
Arcjet publishes open-source SDKs on GitHub (arcjet-js) under Apache-2.0; the hosted service requires an API key.
London, UK (founder David Mytton is UK-based).
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