Kastra

Kastra

Runtime authorization for AI agents — enforce policy before actions execute

73/100Safe BetFree planFreemium

Kastra fills a genuine gap: pre-execution enforcement for AI agents, not just monitoring. Ideal for teams running Claude Code or Cursor who need fine-grained control and signed audit trails. If you trust your AI completely, this is overkill; if you've been burned by unintended side effects, it's essential.

Verified 14d ago · liveness 73/100 · cite: rightaichoice.com/tools/kastra

Best for
  • Development teams running AI coding agents like Claude Code or Cursor
  • Platform teams enforcing consistent governance across all AI agent actions
  • DevSecOps engineers integrating policy-as-code into AI infrastructure pipelines
  • Compliance officers requiring signed audit trails and real-time control
Not ideal for
  • Projects not using AI coding agents or autonomous agent workflows
  • Teams seeking passive monitoring without real-time enforcement
  • Organizations that already trust their AI agents fully and have no compliance requirements
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IntermediateSolo developer: under 5 minutes for the macOS app + CLI, zero-setup for basic local enforcement. Team: 30 minutes to an hour to connect the cloud control plane and define policies. Enterprise self-hosted: a few hours of setup for air-gapped infrastructure.CLI · API · Plugin · DesktopAPI availableVerified 14d ago
Pricing
Free plan
FreemiumFree tier3 plans4 hidden costs
Learning curve
Intermediate
Solo developer: under 5 minutes for the macOS app + CLI, zero-setup for basic local enforcement. Team: 30 minutes to an hour to connect the cloud control plane and define policies. Enterprise self-hosted: a few hours of setup for air-gapped infrastructure.
Runs on
CLIAPIPluginDesktop
API available · 7 integrations
Who it's for
Solo developer using Claude Code locallyPlatform engineer at a startupSecurity engineer in a regulated industry
Live sentiment
Is Kastra actually worth it?

We scan live Reddit threads, YouTube comments, X posts, G2 reviews and other communities — and hand you an honest verdict in under a minute.

  • Honest verdict, not marketing
  • Real pros & cons from real users
  • Attributed quotes with receipts
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Skip it if

Skip Kastra if you don't use AI coding agents or autonomous workflows, or if you only need post-hoc monitoring without real-time enforcement.

The 30-second take
Biggest gripe

Team and Enterprise pricing are custom-quoted, so you may face sales friction and potential minimums.

Price reality

Kastra's free tier is the strongest entry point—solo developers get real enforcement with zero cost, which beats many competitors that charge per seat. For teams, custom pricing is likely higher than monitoring-only tools, but you're paying for pre-execution enforcement, not just logs.

In short

Kastra — Runtime authorization for AI agents — enforce policy before actions execute. Best for Development teams running AI coding agents like Claude Code or Cursor, Platform teams enforcing consistent governance across all AI agent actions, DevSecOps engineers integrating policy-as-code into AI infrastructure pipelines. Free to use.

What people actually say about Kastra — is it worth it?

We ran a structured research pass across product reviews, community discussions, and post-purchase forum threads to surface the patterns vendors won't publish themselves. Below: the recurring strengths, the hidden costs people mention most, and the cohort that consistently regrets adopting this tool.

75 mentions across 5 sources (Hacker News, YouTube, Product Hunt, Bluesky, Lemmy) · researched Jul 23, 2026.

35% positive65% critical

Average across the 5 sources that answered — each source counts once, not each post.

Recurring strengths
  • +Proactive runtime enforcement instead of reactive monitoring.
  • +Cross-framework support for Claude, Cursor, Codex, and OpenClaw.
  • +Policy-based permissions that don't rely on agent's judgment.
  • +Real-time approval workflows for risky operations.
  • +Audit logging of all agent actions for compliance.
Recurring frustrations
  • No public evidence against red-teamed or adversarial agents.
  • Unclear how nested tool calls are policed downstream.
  • Community feedback limited to launch platforms only.
  • No long-term reliability or performance data available.
  • Integrations and platform support not yet fully documented.
Patterns worth knowing
Proactive enforcement over reactive monitoring is the right approach for agent security.
Seen on Product Hunt, Hacker News
Cross-framework support is a key differentiator and practical pain reliever.
Seen on Product Hunt
Skepticism about real-world efficacy against adversarial agents and edge cases.
Seen on Product Hunt
Learning curve
beginnerProductive in ~5 minutes
Hidden costs people mention
  • Enterprise pricing not publicly listed — may be expensive for small teams.
  • Potential overage charges for high volume of agent actions beyond free tier limits.

Viability Score

73/100
Safe Bet

How well maintained and how widely used is Kastra? Built from what the vendor actually publishes (docs, changelog, tutorials, integrations, pricing), whether the site is live, and how much real users discuss it. How we calculate this

Recent activity
90
Traction
100
Site health
95
User sentiment
35
What the vendor publishes
40

Last calculated: September 2026

How we score →

Key Features

  • Policy Decision Point (PDP) with sub-millisecond latency
  • Intercepts every agent action before execution
  • Custom policies for shell commands
  • Custom policies for file edits
  • Custom policies for network access
  • Custom policies for database actions
  • Custom policies for browser actions
  • Real-time approval workflows for sensitive actions
  • Audit trail with ed25519-signed append-only traces
  • SIEM streaming to Datadog, Splunk, S3
  • Kastra Recon scans agent history for risky actions
  • Supports Claude Code, Cursor, Codex CLI, OpenClaw
  • macOS GUI app and CLI for local governance
  • Cloud control plane with US, EU, AP regions
  • Self-hosted and air-gapped deployment options

About Kastra

FreemiumIntermediateAPI availableCLI · API · Plugin · Desktop

Kastra is a runtime authorization layer that sits between AI agents and the systems they act on, intercepting every action they attempt — shell commands, file edits, API calls, browser clicks — and checking them against policy before execution. Built for developers, platform teams, and security engineers running AI coding agents like Claude Code, Cursor, Codex CLI, and OpenClaw, Kastra's Policy Decision Point (PDP) evaluates each request in under a millisecond with four checks: identity, scope, guardrail, and audit. You get a macOS GUI app and CLI for local governance, plus a cloud control plane with regions in the US, EU, and AP. Unlike monitoring-only tools, Kastra enforces decisions in real time, blocking risky operations before they happen. It also supports custom policies for shell, file, network, database, and browser actions, with real-time approval workflows for sensitive actions. Kastra Recon scans agent history to identify past risky actions and draft policies automatically. Every decision is recorded in an audit trail with ed25519-signed append-only traces, and you can stream logs to SIEM tools like Datadog, Splunk, and S3. Policy-as-code is a core principle: policies are typed, versioned, and reviewed like code. Kastra is SOC 2 Type II in audit, ISO 27001 Stage 2, and offers a HIPAA BAA. It supports self-hosted and air-gapped deployments. Recently launched on Hacker News for policy enforcement across Claude Code, Cursor, and Codex, Kastra markets itself as the governance layer that catches what monitoring alone misses — real enforcement before actions execute.

Behind the Verdict

Kastra is the first tool we've seen that doesn't just watch AI agents — it stops them. Most governance tools today are 'monitoring plus alerts,' which is fine until a bad action executes and you're cleaning up the mess. Kastra's PDP sits right before execution, so policy violations get blocked in real time. That's a fundamental difference, and for teams that have been burned by an agent running a destructive command or deleting a file, it's the difference between a near miss and a catastrophe. We'd reach for this when you have a policy team or compliance requirements that need actual controls, not just logs. The ed25519-signed append-only audit trail is a serious feature — it's the kind of thing auditors ask for, and it's rare to see that level of integrity built into an AI governance tool. The fact that you can stream to Datadog, Splunk, or S3 means you can slot it into your existing security stack without ripping anything out. Where it bites: the list of supported agents is still narrow. Claude Code, Cursor, Codex CLI, and OpenClaw are covered, but if you're on Copilot or Gemini, you're out of luck. Also, the pricing model is freemium with custom tiers for Team and Enterprise, which is fine for solo devs but means larger orgs will need to talk to sales to get a number. That's a hurdle if you're trying to budget for a security tool. Compared to monitoring-focused alternatives, Kastra is in a different league for real enforcement. But if you don't need that level of control — say, you're just curious about what your agent does — a monitoring tool is probably enough and cheaper. If you need compliance-grade controls, Kastra's signed audit trail and policy-as-code approach make it a strong contender. In practice, the free tier is a smart way to test it on your local

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Real-world workflow fit

Concrete scenarios for the personas Kastra actually fits — and what changes day-one when you adopt it.

Solo developer using Claude Code locally

You install the macOS app and CLI, point it at your project, and set a few policies (e.g., block file edits outside the project directory). Kastra intercepts Claude Code's next command and blocks any disallowed action.

Outcome: You get immediate protection against risky changes without writing a single policy manually—zero-setup starts working in minutes.

Platform engineer at a startup

You roll out Kastra to your team, connect it to the cloud control plane, and stream audit logs to Datadog. You define a policy that requires approval for any production database write.

Outcome: You get centralized enforcement across the team's agents, with SIEM visibility and a signed audit trail for compliance.

Security engineer in a regulated industry

You deploy Kastra self-hosted in an air-gapped environment, integrate it with your agents, and configure policies that block any network calls to unauthorized endpoints.

Outcome: You've established a compliant authorization layer with ed25519-signed traces, ready for audits.

Use Cases

Limitations

  • Pricing for Team and Enterprise tiers is not publicly visible; you must contact sales.
  • Policy enforcement capabilities vary per integrated agent.
  • Self-hosted and air-gapped deployments are available but require setup.
  • Post-inference validation can guard model outputs but adds latency.

as of 2026-08-26

Verification history

We have re-verified Kastra 4 times since . Each pass re-reads the vendor's own pages and re-checks every listed field against that evidence; passes where nothing had changed are marked as such.

  1. re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
  2. re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
  3. re-checked, vendor evidence unchanged
  4. re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it

Free to cite with attribution — this page re-verifies continuously.

12-month cost

Project the real annual outlay, including the implied monthly cost when only an annual tier is published.

Annual total
Free
Over 12 months
Effective monthly
Free
Billed monthly

Vendor list price only. Add-on usage, seat overages, and contract minimums are surfaced under Hidden costs & gotchas.

Plans compared

For each published Kastra tier: who it actually fits, and what it adds vs. the previous tier. Cross-reference the cost calculator above for projected annual outlay.

Free

$0/mo

Ideal for

Solo developers who want zero-setup, local enforcement for their AI coding agents with no cost.

What this tier adds

Starting tier: includes macOS GUI, CLI, and basic audit logs—free forever, no contract.

Team

Custom

Ideal for

Teams that need centralized policy management, multi-region support, and SIEM integration.

What this tier adds

Adds cloud control plane, US/EU/AP regions, SIEM streaming, and advanced policy management—custom pricing.

Enterprise

Custom

Ideal for

Security-conscious enterprises requiring self-hosted or air-gapped deployment, HIPAA BAA, and SSO/SAML.

What this tier adds

Adds self-hosted/air-gapped options, HIPAA BAA, SSO/SAML, and dedicated support—custom contract.

Hidden costs & gotchas

What the public pricing page doesn't put in bold. Captured from pricing-page footnotes, contract terms, and recurring complaints.

  • Team and Enterprise pricing are custom-quoted, so you may face sales friction and potential minimums.
  • Self-hosted/air-gapped deployments require setup effort and possibly dedicated infrastructure.
  • Post-inference validation adds latency to agent actions, which could slow down high-frequency workflows.
  • Enforcement coverage varies per agent—some actions may not be interceptable, meaning you might need additional tooling.

Where the pricing makes sense

The company stage and team size where Kastra's pricing actually pencils out — and where peers do it cheaper.

Kastra's free tier is the strongest entry point—solo developers get real enforcement with zero cost, which beats many competitors that charge per seat. For teams, custom pricing is likely higher than monitoring-only tools, but you're paying for pre-execution enforcement, not just logs.

Setup time & first value

How long it actually takes to get something useful out of Kastra — broken out by persona, not the marketing-page minute.

Solo developer: under 5 minutes for the macOS app + CLI, zero-setup for basic local enforcement. Team: 30 minutes to an hour to connect the cloud control plane and define policies. Enterprise self-hosted: a few hours of setup for air-gapped infrastructure.

Switching to or from Kastra

How to bring data in from common predecessors and how to get it back out — written for the switcher, not the buyer.

Migrating in
  • From monitoring-only tools (e.g., LangSmith, Helicone): Kastra adds real-time enforcement—keep your logs, but start blocking disallowed actions.
Migrating out
  • To a custom authorization service: export your policies and audit logs, then wire your agents to the new PDP.

Integrations

Resources & Guides

Tutorials & Learning

YouTube returned 6 videos for “Kastra”, and we withheld 6: 6 could not be judged, because “Kastra” is a single word that other videos use for other things. We are showing none, because we could not prove any of them are about Kastra.

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Frequently Asked Questions

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