Audit and Proof
Every event in RobotMoney (ingestion, extraction, query, proposal, policy decision, approval, execution, settlement) emits an audit record into an append-only log. Records form a per-tenant Merkle tree. Tree roots are batched and anchored on-chain through BrainAuditAnchor.
RobotMoney core and its HTTP APIs are available in production. The on-chain proof deployment is on Base Sepolia. It is unaudited and there is no Base mainnet deployment. A separate sandbox environment is available for integration work.
Three Properties This Gives You
📜 Tenant-verifiable History
A tenant can prove a specific decision occurred at a specific time, based on specific evidence, under a specific policy version.
🤝 Counterparty-verifiable Proofs
A counterparty can verify a payment was authorized without seeing the underlying data, by checking a Merkle proof against an anchored root.
🔒 No Silent Rewrites
RobotMoney itself cannot silently rewrite history. Anchors commit the past state to a public chain.
What Every Audit Event Commits To
Audit events are content-addressed. Each event commits to:
event_type
proposal, policy.evaluated, action.executed, etc
tenant_id
Which tenant generated the event
actor
Human user ID or agent address
timestamp
When the event was recorded
inputs_hash
Hash of Ledger / Wiki / Raw IDs the event depended on
policy_version
The policy version evaluated, if any
decision
The outcome of the event (where applicable)
reason
Structured reason code (where applicable)
prev_event_hash
Forms a per-tenant hash chain
The prev_event_hash field means each event references the one before it, building a chain that breaks if anything is altered.
The Hash Chain in Pictures
Tamper with event_002 and B changes. event_003 still references the old B via its prev=B pointer. The chain breaks. Detection is automatic.
Merkle Batching and on-Chain Anchoring
Events are batched into a per-tenant Merkle tree. Roots are anchored to Base Sepolia through BrainAuditAnchor.
Publisher cycle
A cycle closes when 50 eligible tenant roots accumulate or one hour elapses, whichever comes first. Both limits are configurable.
Immediate anchoring
No severity-accelerated path exists.
Anchor target
BrainAuditAnchor on Base Sepolia.
Anchor authority
The contract's onlyPublisher address. The current Base Sepolia publisher is a single EOA with two-step rotation.
Replay guard
A tenant-root pair is published once. anchorBatch skips already-published pairs so batch retries are safe.
anchorBatch keeps every tenant root individually queryable on-chain. Each published (tenantId, root) pair remains available through isPublished and the AnchorPublished event; batching does not replace tenant roots with a single outer root.
Demo and sandbox tenants keep the same append-only database hash chain but are explicitly database-only. Their roots are excluded from Base Sepolia batches. GET /v1/audit/anchor/latest reports this as anchoring_mode: "db_only" and guarantee: "database_hash_chain" rather than an on-chain guarantee.
Database-linked Base Sepolia production receipts measured on 2026-08-11 across 36 transactions and 189 roots ranged from 47,325 to 73,620 gas per tenant root, with a weighted average of 51,474. This is an observed operational measurement, not a fixed gas or cost guarantee. It does not represent a full publisher-wallet cost guarantee while wallet-to-anchor reconciliation remains under investigation.
→ BrainAuditAnchor smart contract
Pulling a Proof
Counterparties verify RobotMoney audit proofs by checking a Merkle proof against the on-chain anchored root.
To verify, the counterparty:
Checks that the proof root is published for the tenant with
isPublished(tenantId, root).latestAnchor(tenantId)is useful when the proof is for that tenant's most recent root.Reconstructs the leaf hash from the
eventdata.Calls
verifyInclusion(root, leaf, merklePath).
If both checks succeed, the event is provably part of the anchored history. RobotMoney is not a trusted intermediary in this verification. It is just a publisher.
Privacy
On-chain anchors must not leak tenant data.
Merkle roots
Event payloads (encrypted at rest)
Hashed tenantId
Raw artifacts
Anchor transaction and block
Ledger records, Wiki entities
Publisher address
Policy text and compiled rules
Counterparties verifying a proof receive only the specific event(s) the tenant chooses to share, plus the Merkle path. Everything else stays private.
Compliance Exports
The Audit Layer also exposes structured exports for compliance reviews.
SOC 2 Type II
Full event log with provenance
ISO 27001
Access logs, key management events, change records
Financial controls
Approval chains, segregation of duties evidence
A public verifier endpoint is also available for counterparties to verify proofs without a RobotMoney account.
What's Next
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