developers and security teams running AI agents that take actions in apps, APIs and databases

How much does Arcjet cost?

Paid plans start at $25/mo, per Arcjet's pricing page on 2026-10-17.

No. Its pricing page showed no free plan on 2026-10-17.

Is Arcjet still maintained?

Actively maintained: site updated 11 days ago.

We do not audit vendors. What Arcjet publishes, read 2026-10-17: a trust center.

How do I cancel Arcjet?

In its own words (terms of service, 2026-10-17): “To cancel any Subscription, you must notify us at least three (3) days before the start of the next Subscription Term by using the appropriate functionalities of the Service or by contacting us at support@arcjet.com .”

Does Arcjet give refunds?

In its own words (terms of service, 2026-10-17): “Except as may be expressly stated in these Terms, any applicable Service Order, or in the Pricing and Payment Terms, all Fees must be paid in advance, payment obligations are non-cancelable once incurred (subject to any cancellation rights set forth in these Terms), and Fees paid are non-refundable.”

What are alternatives to Arcjet?

In Security, by use: Lakera, Constellation Gate AI, SovereignShield, Kalpit Labs, Wardstone, PromptGuard.

Arcjet

Checks each action an AI agent takes against prompt injection, PII, bot and policy rules before the call runs, and logs the decision.

From $25/moActively maintained

SecuritySecurityFor developers+1

arcjet.com ↗GitHub LinkedIn X YouTube Crunchbase+3

Open arcjet.comAlternatives Set it up for my team Is Arcjet yours? Claim the card →

At a glanceswept Oct 12, 2026

≈ 738visits/mo

Use not read yet · estimate, read Oct 13, 2026

Arcjet738
#1 Cloudflare4.9M

For: developers and security teams running AI agents that take actions in apps, APIs and databases
Price: From $25/mopricing page, read Oct 17, 2026
Activity: Actively maintainedsite updated 11 days ago
Runs as: SDK
Used for: block prompt injection in user input and tool output
redact personal data before it reaches the model
stop runaway agent loops from exhausting token budgets
read off arcjet.com on Oct 17, 2026

Worth knowingcomputed from what we read · each with its source

Used more than 77% of the 421 tools on its shelfINITE Atlas →
On the web since 2011, older than 96% of its shelfINITE Atlas
Has an MCP server (1 in the registry)public registry →
Publishes llms.txt, a file written for AI assistantsarcjet.com ↗

Pricingpricing page, read Oct 17, 2026

From $25/mo

pricing page

The companyeach fact with its source · read Oct 17, 2026

Domain since2011domain registered
Raised$8.3M · Series Aper the press · 2025-10 ↗
HeadquartersSan Francisco, USper their site

Your datawhat they publish, each line with its page · read Oct 17, 2026

Trust centertheir owntrust center ↗
Privacy policy updated2026-01-21privacy policy ↗
Security contactsecurity.txt

These are Arcjet's own statements, read from its pages. We did not audit them. A line that is missing was not found on the pages we read; it does not mean the practice is absent.

How a program reaches itfound, not claimed · read Oct 17, 2026

MCP servercom.arcjet/mcpverified in the MCP registry
Stateanswers, requires sign-inchecked 2026-10-17
Address to connectapi.arcjet.com/mcp
MCP docsdocs.arcjet.com/mcp-serverthe vendor's page ↗

MCP server details →

This card as JSON, for your agent →

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.

Alternatives in Securityby use, among tools still maintained

Figure and bar: visits/mo, estimate · year: online since

#1
Lakera
Detects and prevents prompt injection attacks, data leakage, and jailbreaks in AI applications with real-time threat detection.
2.9k
Active
Free plan
1993
#2
Constellation Gate AI
Intercepts AI requests to block prompt injection attacks, reduce token usage by 20%, and audit all traffic.
2
Active
From $20/user/mo
#3
SovereignShield
Blocks prompt injection attacks and prevents unauthorized actions in AI agent requests before they reach the model.
24 linking domains
Active
From $5 once
#4
Kalpit Labs
Detects and blocks prompt injection, jailbreaks, and data leaks in LLM applications in real time.
Emerging
Maintained
#5
Wardstone
Detects prompt injection attacks, jailbreaks, harmful content, and PII leakage in LLM inputs and outputs.
298
Active
From $199/mo
#6
PromptGuard
Inspects requests to LLM applications and blocks prompt injection, jailbreak attempts, and personally identifiable information leaks.
12
Active
From $99/mo

All 8 alternatives to Arcjet →

All Security tools →

Not it? Say what you need

beta

Three tools from the Atlas for the job you describe, each with what fits and what does not.

From people who use itnot part of the reading

No notes yet. What do you use Arcjet for?

Questions this page answers

What is Arcjet?
Checks each action an AI agent takes against prompt injection, PII, bot and policy rules before the call runs, and logs the decision. It is listed in the Atlas under Security.
Who is Arcjet for?
developers and security teams running AI agents that take actions in apps, APIs and databases
How much does Arcjet cost?
Paid plans start at $25/mo, per Arcjet's pricing page on 2026-10-17.
Is Arcjet free?
No. Its pricing page showed no free plan on 2026-10-17.
Is Arcjet still maintained?
Actively maintained: site updated 11 days ago.

Is Arcjet safe?
We do not audit vendors. What Arcjet publishes, read 2026-10-17: a trust center.
How do I cancel Arcjet?
In its own words (terms of service, 2026-10-17): “To cancel any Subscription, you must notify us at least three (3) days before the start of the next Subscription Term by using the appropriate functionalities of the Service or by contacting us at [email protected] .”
Does Arcjet give refunds?
In its own words (terms of service, 2026-10-17): “Except as may be expressly stated in these Terms, any applicable Service Order, or in the Pricing and Payment Terms, all Fees must be paid in advance, payment obligations are non-cancelable once incurred (subject to any cancellation rights set forth in these Terms), and Fees paid are non-refundable.”
What are alternatives to Arcjet?
In Security, by use: Lakera, Constellation Gate AI, SovereignShield, Kalpit Labs, Wardstone, PromptGuard.

How we read a tool

No votes, no reviews, no vendor claims. Every week a crawler reads each tool's own site and a few public registries, and the words on the card are bands over what it read.

Use: visits to the site (estimated), installs from npm and PyPI, presence in Chrome's usage report.
Activity: the newest release on GitHub, npm or PyPI; the newest dated page on the site; open roles on a public jobs board.
Price: the vendor's own pricing page, read with the date. A figure is printed only when it is on that page.
The line and the use cases are written by us from the homepage, one tool at a time, and refused when they repeat the vendor's marketing.

How AI assistants read each site — the reading vendors ask us about — is on each tool's own visibility page.

How we read every tool → · By INITE Atlas Desk