CAIN42-PROOF-PACKAGE (Evolution 5), 2026-09-24. PRE-PRODUCTION, self-attested, one host.

A disposable 4-node CAIN-42 cluster (fast path on) committed consensus authorizations for
kv_write calls with a bound security context, scope and expiry. The real MCPGate interceptor,
with the consensus authorization gate, then let exactly the 4 authorized calls reach a sandbox
tool (each effect checked), and blocked 9 attacks: replay, action substitution, capability
escalation, identity substitution, security-context drift, forged quorum certificate, forged
certificate body, no authorization, expired authorization. Every decision is a signed,
hash-chained proof. The package also carries a DAG run (40 requests, crash-restart) and a manifest of SHA-256
digests signed with a package key.

Verify with one command (Python 3.8+, pip install cryptography, no CAIN code):

  BASE=https://cainstudio.online/proof/bundle/cain42-proof-package-2026-09-24    # or https://mcpgate.online/proof/bundle/cain42-proof-package-2026-09-24
                                                    # or https://clawx.click/evidence/cain42-proof-package-2026-09-24
  mkdir -p pkg/verifiers && cd pkg
  for f in calls.json dag_evidence.json gate_proofs.json membership.json sandbox_state.json   ; do curl -so $f "$BASE/$f"; done
  for v in cain_proof_verify verify_pbft_qc_bundle verify_dag_bundle; do curl -so verifiers/$v.py "$BASE/verifiers/$v.py.txt"; done
  python3 verifiers/cain_proof_verify.py .        # expect FINAL RESULT: VERIFIED

FINAL RESULT is VERIFIED only if every section is. Change any byte and it is INVALID or INCOMPLETE.
Not claimed: independent failure domains; that the live cluster or the live MCPGate runs this gate;
formal verification; a 72-hour soak; third-party review. Source is not published (git commitment in manifest).