Kastra vs MentionBird: Features, Pricing & Which Is Better (2026)

A side-by-side comparison of Kastra and MentionBird — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.

Kastra

Kastra Labs Inc

Freemium

Kastra is the runtime authorization layer for AI: it decides in sub-milliseconds what agents, models, and tools are allowed to do before they act.

Sub-Millisecond Policy Decisions: Every prompt, tool call, and API request is evaluated in under a millisecond so enforcement never becomes the bottleneck.
Deterministic Policy Engine: Rules are written and evaluated deterministically, not by an LLM judge, so the same input always produces the same allow/deny.
Kastra Edge (Local Enforcement): A local enforcement component that runs next to the agent so decisions happen even without a network round-trip.
Cryptographic Audit Trails: Signed logs of every decision give security and compliance teams tamper-evident evidence of agent behavior.
Coding Agent Integrations: First-class hooks for Claude Code, Cursor, Codex, and OpenClaw let policies wrap the tool calls those agents already make.
Kastra Recon: Discovers what actions an agent actually attempts in a codebase or environment, so policies can be authored from observed behavior instead of guesses.
Zero Implicit Trust Model: Nothing an agent asks to do runs until it is explicitly allowed by policy, aligning agent access with zero-trust principles.

Guardrails for Coding Agents: Prevent an autonomous coding agent from dropping tables, force-pushing to main, or leaking secrets during long runs.
Enterprise Rollout Approvals: Give security teams a control plane before letting employee-facing AI agents access internal APIs.
Regulated-Industry Agent Deployments: Provide the auditable authorization trail required in finance, healthcare, or government agent pilots.
Multi-Agent Systems: Enforce per-agent scopes so a research agent can read data but only a deploy agent can trigger production changes.
Incident Forensics: Reconstruct exactly what an AI agent was allowed or blocked from doing after a suspicious action.

Paid

AI search visibility platform that shows which sources ChatGPT, Gemini, Perplexity and Claude cite for your prompts and how to get your brand named.

AI Prompt Tracking: Monitor the exact prompts buyers ask AI, with daily runs across supported AI platforms.
AI Citation Tracking: See which pages, reviews and YouTube videos AI cites for each prompt and whether your brand appears in them.
AI Ranking Advice: Get a per-prompt plan of recommended actions rated by effort and impact to earn mentions.
Competitor Tracking: Compare share of AI recommendations against each competitor, week over week.
Multi-Platform Coverage: Covers ChatGPT, Gemini, Perplexity and Claude, with Grok, AI Overviews, Copilot and DeepSeek on the Custom plan.
MCP and API Access: Connect Claude or ChatGPT directly to your visibility data and ask questions about it.
Free AI Tools: No-login tools such as an AI Crawler Accessibility Checker and an AI Visibility Report.

Generative Engine Optimization: Finding which sources AI relies on for category prompts and earning placements in them.
Competitive Benchmarking: Seeing which rivals AI recommends instead of your brand and for which prompts.
Agency Client Reporting: Reporting client AI visibility and the next fixes to make.
Content Planning: Using ranking advice to decide which guides and product-page details to publish.
Launch Monitoring: Tracking whether a new product starts getting named in AI answers over time.