Best alternative to Astra

middleBrick is a black-box API security scanner that submits only read-only methods (GET and HEAD) plus text-only POST for LLM probes. It does not modify, patch, or block any system. You submit a target URL and receive a risk score from A to F with prioritized findings, completed in under a minute. Because it is black-box, it works with any language, framework, or cloud deployment without agents, SDKs, or code access.

The scanner detects issues across 12 categories mapped to the OWASP API Top 10 (2023). It also maps findings to PCI-DSS 4.0 and SOC 2 Type II, and it supports audit evidence for controllable security controls. Specific detections include authentication bypass and JWT misconfigurations (including alg=none, HS256, expired or missing claims), BOLA and IDOR via sequential ID enumeration and active adjacent-ID probing, BFLA and privilege escalation through admin endpoint probing and role/permission leakage, property authorization over-exposure and internal field leakage, input validation issues such as CORS wildcard usage (with and without credentials) and dangerous HTTP methods, rate limiting and resource consumption signals via header detection and oversized responses, data exposure including PII patterns (email, Luhn-validated card numbers, context-aware SSN), API key formats (AWS, Stripe, GitHub, Slack), and error or stack-trace leakage, encryption misconfigurations like missing HTTPS redirect, HSTS, and cookie flags, SSRF indicators involving URL-accepting parameters and internal IP probing, and inventory management issues such as missing versioning and legacy path patterns. The scanner additionally covers LLM/AI security with 18 adversarial probes across Quick, Standard, and Deep tiers, including system prompt extraction, instruction override, DAN and roleplay jailbreaks, data exfiltration, cost exploitation, encoding bypasses, translation-embedded injection, few-shot poisoning, markdown injection, multi-turn manipulation, indirect prompt injection, token smuggling, tool-abuse, nested instruction injection, and PII extraction. OpenAPI 3.0, 3.1, and Swagger 2.0 files are parsed with recursive $ref resolution, and spec definitions are cross-referenced against runtime findings to highlight undefined security schemes, sensitive fields, deprecated operations, and missing pagination.

Authenticated scanning is available from the Starter tier and above, supporting Bearer, API key, Basic auth, and Cookie methods. Domain verification is enforced through a DNS TXT record or an HTTP well-known file, ensuring only the domain owner can scan with credentials. The scanner forwards a strict header allowlist limited to Authorization, X-API-Key, Cookie, and X-Custom-* headers. Safety controls include read-only methods only, with destructive payloads never sent. Private IPs, localhost, and cloud metadata endpoints are blocked at multiple layers. Customer scan data is deletable on demand and purged within 30 days of cancellation; data is never sold and is not used for model training.

The Web Dashboard centralizes scans, reports, and score trends, and it can generate branded compliance PDFs. The CLI (middlebrick npm package) supports commands such as middlebrick scan <url> with JSON or text output. A GitHub Action provides CI/CD gating, failing the build when the score drops below a defined threshold, and an MCP Server enables scanning from AI coding assistants like Claude and Cursor. The API client allows custom integrations for programmatic access. For ongoing risk management, the Pro tier offers scheduled rescans (every 6 hours, daily, weekly, or monthly), diff detection across scans to highlight new findings, resolved findings, and score drift, email alerts rate-limited to one per hour per API, and HMAC-SHA256 signed webhooks that auto-disable after 5 consecutive failures.

Free tier provides 3 scans per month with CLI access. Starter at 99 dollars per month supports 15 APIs, monthly scans, dashboard access, email alerts, and the MCP Server. Pro at 499 dollars per month covers 100 APIs, with additional APIs at 7 dollars each, plus continuous monitoring, GitHub Action gates, CI/CD integration, Slack and Teams alerts, compliance reports, and signed webhooks. Enterprise at 2000 dollars per month offers unlimited APIs, custom rules, SSO, audit logs, SLA, and dedicated support. For most teams, middleBrick is a practical alternative because it emphasizes scan speed under a minute, clear risk scoring, and broad detection coverage without requiring agents or code access, while remaining more focused than platforms that bundle additional governance workflows.