SafePrompt · Prompt injection detection API
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SafePrompt
Prompt injection detection API for LLM apps and agents.

Prompt injection API pricing

Every plan runs the same detection engine. Start free to evaluate your own traffic. Paid adds production volume, your own allow and block phrases, IP threat intelligence, higher rate limits, and one toggle that keeps your traffic out of the shared network. That sharing starts on, and you switch it off in dashboard settings.

Cancel anytime
No setup fees
No per-request fees

Pricing last reviewed: 12 September 2026

How much does prompt injection detection cost?

How many checks will your app use?

Count each text item you submit. A user message plus four retrieved chunks uses five validations; retries add checks. Choose a plan for both monthly volume and peak requests per second.

Agent and retrieval screening · Coverage and workload testing · Security and data sharing

Free

$0/month

Covers a side project at no cost

No card. Start with your email.

10,000 validations a month
10 requests/second
Self-serve signup, no card
The same detection engine as every paid plan
Pattern matching plus AI semantic analysis
Requests session tracking where enabled; your app isolates conversations
Blocked attacks join the shared network defence that every plan runs on (opt-out on paid plans)
Export supported records with record limits; delete eligible records. Retained hashes are excluded from self-service export and deletion. Contact [email protected] for additional access or erasure requests.
Default phrase lists included
See your top 3 attacks in the dashboard
RECOMMENDED

Starter

$29/month

Covers a live app with real users

Instant access • Cancel anytime

500,000 validations a month
50 requests/second

Everything in Free, plus:

IP threat intelligence, so repeat attackers are known before they reach you
Keep your traffic out of the shared network with one toggle
25 allow phrases to guide business-context validation
25 block phrases to guide validation
Edit the default phrase lists to match your app
The same detection engine, with paid threat-intelligence controls
Usage analytics dashboard (24h / 7d / 30d timeline)
Detection-method breakdown
Top-10 attack categories
SCALE

Business

$99/month

Covers a team running at volume

Instant access • Cancel anytime

1,000,000 validations a month

Everything in Starter, plus:

Email support, 2 business day target
100 allow phrases to guide business-context validation
100 block phrases to guide validation
100 requests/second
We run the infrastructure, you run one API call
Network-wide attack campaign feed
Auto-discovered pattern proposals
Full attack taxonomy (14 categories)

No overage billing, ever

A paid plan renews at the same price each month until you cancel, and there is no overage billing. Requests past your plan's monthly limit come back as an HTTP 429 carrying the date your quota resets, and your traffic flows again on that date or the moment you upgrade.

Frequently Asked Questions

How much does prompt injection detection cost?

Every plan runs the same detection engine, starting at $0/month. The free tier gives you 10,000 validations a month. Starter is $29/month for 500,000 validations. Business is $99/month for 1,000,000 validations. No per-request fees, no hidden costs, and no credit card for the free tier.

Is there a free prompt injection API?

Yes. SafePrompt gives you 10,000 API validations a month at no cost, on the same detection engine paid plans run: pattern detection, external reference detection and AI validation. No credit card. Confirm your email, then obtain your key in the dashboard. Blocked attacks from free-tier traffic join the shared network defence. Paid plans can turn that contribution off in Privacy Settings.

What's included in SafePrompt's free tier?

The free tier includes 10,000 validations a month, the full detection engine (the same one paid plans run), pattern and AI validation, deployment-enabled session tracking without guaranteed conversation isolation, and the shared network defence. Dashboard/API export supports selected records, with record limits and retained hashes excluded. Self-service deletion does not remove retained hashes separately; contact [email protected] for additional access or erasure requests. Paid plans add production volume, IP threat correlation and an intelligence opt-out.

Is the free plan really free?

Yes. Confirm your email and obtain your key in the dashboard: 10,000 validations a month, no card and no time limit. The one condition is that attacks blocked on the free plan join the shared network defence; paid plans can switch that off. While sharing is on, a paid account contributes safe and blocked prompts to the intelligence sample store; Free contributes blocked prompts. Request metadata logging and deployment-enabled session storage are separate.

Can I change plans later?

Yes. Upgrade any time, downgrade at the end of any billing cycle. No contracts and no penalties.

Can I cancel anytime?

Yes. Cancel any time from your dashboard. No cancellation fees and no questions asked.

Do I need a credit card for free?

No card is required. Confirm your email, get your key in the dashboard, then follow the quick start to evaluate your first request.

What's included in all plans?

Every plan runs the same engine: pattern detection, AI validation, deployment-enabled session tracking without guaranteed conversation isolation and the shared network defence.

Can I upgrade from Free to Starter?

Yes. Upgrade from your dashboard settings any time. Your new quota is live as soon as payment confirms.

Do I get locked into a specific LLM provider?

SafePrompt checks the text before it reaches your model, so it works with OpenAI, Anthropic, Google, Mistral and anything else you run. Switch providers any time with no change on your side, and export your data from the dashboard on any plan.

Why pay when open-source tools like LLM Guard are free?

SafePrompt is one API call with nothing to run: no model to host, no GPU to size, no rules to maintain, and a free tier so you can start today. Run LLM Guard self-hosted if your data can never leave your own machines.