How SBO3L compares
Agent-policy is a crowded space. Most projects answer "can the agent do this?". SBO3L also answers "can anyone offline prove what the agent did?" — that's the cryptographic trust layer. Below: features hand-checked against each project's docs as of 2026-04.
— means the project could ship the feature with effort but doesn't today.
| Feature | SBO3L | OPA | Casbin | Guardrails AI | LangChain callbacks |
|---|---|---|---|---|---|
| Local policy engine (no remote daemon required) | ✓ | ✓ | ✓ | ✗ | — |
| Cryptographically signed decision receipts | ✓ | ✗ | ✗ | ✗ | ✗ |
| Hash-chained audit log (tamper-evident) | ✓ | ✗ | ✗ | ✗ | ✗ |
| Offline capsule verification (no network) | ✓ | — | — | ✗ | ✗ |
| On-chain anchor (Ethereum L2) | ✓ | ✗ | ✗ | ✗ | ✗ |
| ENS-based agent identity | ✓ | ✗ | ✗ | ✗ | ✗ |
| Threshold signing (FROST 2-of-3) | ✓ | ✗ | ✗ | ✗ | ✗ |
| Multi-tenant isolation w/ RLS | ✓ | — | — | ✗ | ✗ |
| Built-in budget tracking + USD-string parser | ✓ | ✗ | ✗ | ✗ | ✗ |
| WASM-deployable verifier (browser, mobile) | ✓ | ✓ | ✓ | ✗ | ✗ |
| Framework adapters (>=10 frameworks) | ✓ | — | — | ✓ | ✓ |
| Bench: P50 decision latency < 200µs | ✓ | ✓ | ✓ | — | — |
Where each tool wins
- OPA: the most-deployed Rego-based policy engine; if you already have OPA infrastructure, SBO3L plugs in via the receipt layer rather than replacing the policy engine.
- Casbin: RBAC/ABAC ergonomics in 30+ languages; SBO3L doesn't try to compete on language reach.
- Guardrails AI: LLM output validation (JSON schemas, regex, semantic checks); SBO3L is the upstream "should this LLM tool-call execute at all" layer, not a replacement.
- LangChain callbacks: in-process telemetry; SBO3L's adapters slot into the same hook points but emit signed receipts instead of opaque trace events.
Where SBO3L wins
The cryptographic-receipt + audit-chain + on-chain-anchor stack is uniquely SBO3L. If a regulator, auditor, or sponsor asks "prove this agent acted within policy on 2026-03-15 at 14:22:01 UTC", SBO3L answers with a self-contained capsule any third party can verify offline against the agent's public Ed25519 key. No other project in this matrix produces an artifact with that property.