Data Flow

End-to-end: from a webhook landing in the Raw Layer to an action executing on a rail and proof anchoring on Base.

The Full Flow

Source → Raw → Ledger → Wiki → Policy → Agent → Rail → Audit

Step	What Happens
1	A webhook or scheduled pull lands in Raw
2	Extractors normalise it into Ledger records
3	Wiki updates incrementally (entity resolution, narrative summarisation, embedding refresh)
4	An agent proposes an action referencing Ledger context
5	Policy evaluates the proposal: allow, confirm, or reject
6	If approved, the Agent Layer executes through an external rail (bank API, payment processor, smart account on Base)
7	Every step writes an Audit event with cryptographic links back to preceding ones

Step-by-Step Trace

Imagine a payments agent paying an invoice. Here is what every layer does.

Step 1: Raw Lands

External event:
  Plaid webhook arrives with new bank transactions.

Brain action:
  - Verify webhook signature.
  - Hash payload (SHA-256).
  - Store in Azure Blob at a tenant-prefixed, content-addressed path.
  - Emit audit event: source.received

Step 2: Ledger Structures

Extractor input:
  Raw artifact (Plaid transaction list).

Extractor output:
  N Ledger records (transactions), each carrying:
    raw_refs:            [sha256:abc...]
    extractor_version:   plaid-v2.1
    confidence:          0.97

Brain action:
  - Apply deterministic extractor.
  - Reconcile against existing records (deduplication).
  - Emit audit event: ledger.appended

Step 3: Wiki Updates

Wiki input:
  New Ledger records.

Wiki action:
  - Entity resolution: is this counterparty already known?
  - Update relationships in the graph.
  - Re-summarise affected narratives.
  - Refresh embeddings for any changed text.
  - Recompute rolling summaries if a period boundary was crossed.
  - Emit audit event: wiki.updated

Step 4: Agent Proposes

Agent input:
  Invoice ID, tenant context, Wiki citations.

Agent output:
  Proposal: { type: "pay_invoice", invoice_id: "inv_8231",
              amount: 7800, counterparty_id: "cp_x" }

Brain action:
  - Record proposal as audit event.
  - Forward to Policy Engine.

Step 5: Policy Evaluates

Policy input:
  Proposal + active policy version (v3) + Ledger state.

Policy evaluation:
  - Counterparty status: approved
  - Amount: $7,800 (above $5,000 threshold)
  - Outcome: confirm, approvers=[role:cfo]

Brain action:
  - Persist the policy decision and trace.
  - Notify required approvers.
  - Emit audit event: policy.evaluated

Step 6: Approval

Approver input:
  Proposal with Ledger references (invoice, PO,
  vendor history, prior payments).

Approver action:
  Approves through an authenticated member session or linked approval surface.

Brain action:
  - Record the member approval in the database.
  - Move action to executable.
  - Emit audit event: action.approved

Step 7: Execution

Two paths, depending on the rail:

Off-chain rail

Brain action:
  - Construct bank API request server-side.
  - Use tenant's stored bank credentials.
  - Submit transfer.
  - Capture rail receipt.
  - Emit audit event: action.executed

On-chain via smart account

Brain action:
  - Build the call: BrainSmartAccount.executeViaSessionKey(nonce, target, value, data)
      target:    recipient (e.g. USDC transfer)
      signed by: the granted session key (KMS-held)
  - On-chain executeViaSessionKey enforces:
      ✓ session key granted, not paused or revoked
      ✓ within the key's spend caps (per-tx, per-window)
      ✓ bound to the policyVersion set at grant time
      ✓ nonce not replayed
  - Tx executes on Base.
  - Emit audit event: action.executed

Step 8: Audit Anchors

Audit Layer:
  - Append event to per-tenant hash chain.
  - Continue building Merkle tree for the current batch.

Anchorer:
  - Hourly:
      Compute Merkle root.
      EIP-712 sign with anchorer key.
      Submit to BrainAuditAnchor on Base L2.
  - On-chain: RootAnchored event emitted.

End-to-End Provenance

Every step links back to every previous step.

Settlement receipt
         └── Action executed
         └── Recorded member approval
               └── Policy verdict (v3)
                     └── Wiki citations
                           └── Ledger records
                                 └── Raw artifacts (Azure Blob SHA-256 hashes)

A single Merkle proof against an anchored root verifies the entire chain.

There is no point in this flow where Brain holds funds. Money moves directly between the tenant's accounts and counterparties on the tenant's chosen rails.

What's Next

Tenant Isolation

How tenants are separated at every layer.

Tenant Isolation

Security and Compliance

Non-negotiable principles and compliance posture.

Security and Compliance

BrainSmartAccount

The on-chain validator.

BrainSmartAccount