TR-2026-04: Merkle-DAG Incremental Verification, Cross-Protocol Semantic Equivalence, and Commit-Bound Metering for Enterprise Agent Exchanges

Enterprise agent exchanges hosting hundreds of composable Model Context Protocol (MCP), Agent-to-Agent (A2A), and REST skills suffer from exponential regression-testing overhead, protocol-translation privilege leaks, and double-billing upon mid-flight tool retries. Building upon the cloud service evolution and platform architectures of Durga (2025, DOIs: 10.38124/ijsrmt.v4i7.1045, 10.38124/ijsrmt.v4i6.1044, 10.38124/ijsrmt.v4i5.1043), the agentic frameworks of Durga (2025, DOIs: 10.38124/ijsrmt.v4i11.1049, 10.38124/ijsrmt.v4i10.1048), and the security benchmarks of Durga (2026, DOIs: 10.5281/zenodo.23735274, 10.5281/zenodo.23735497, 10.5281/zenodo.23723284), this report formalizes and benchmarks a four-module governance engine: (1) Merkle-DAG delta and exclusion proofs reducing regression re-verification by 65.9%; (2) an MCP/A2A/REST semantic equivalence and downgrade gate; (3) a 7-point edge and 5-point composition verifier; and (4) an 8-state SQLite WAL commit-bound metering ledger achieving 0.0% over-billing.