Proof API

The Proof API returns the canonical, single-artifact record of how a financial action was decided, gated, executed, and anchored. It's the flagship trust artifact: one fetch, every dimension. Policy decision, §6 gate trace, evidence chain, audit Merkle proof, on-chain anchor, rail receipt, plain-English explanation.

Operation	Endpoint	Scope
Canonical Proof (JSON)	GET /v1/proof/{action_id}	audit:read
Human-readable Proof (HTML)	GET /v1/proof/{action_id}/view	audit:read

action_id is the PaymentIntent id. Both routes are tenant-isolated: a cross-tenant id returns 404. The existence of the action is never leaked across tenants.

Get a Proof

GET /v1/proof/{action_id}
Authorization: Bearer <token>

{
  "action_id": "pi_a1b2c3",
  "tenant_id": "acme",
  "agent_id": "ag_payment_v1",
  "behavior_hash": "0x...",
  "outcome": "executed",
  "policy_version": 4,
  "policy_hash": "0xabc...",
  "matched_rule_id": "rule_invoice_above_5k",
  "gate_checks": [
    { "index": 1, "name": "intent_exists_and_approved", "passed": true },
    { "index": 1.5, "name": "agent_behavior_pinned", "passed": true },
    { "index": 5, "name": "source_balance_sufficient", "passed": true },
    { "index": 7, "name": "counterparty_not_sanctioned", "passed": true },
    { "index": 13, "name": "audit_chain_healthy", "passed": true }
  ],
  "evidence": [{ "raw_id": "raw_8231", "parser": "invoice_v2", "confidence": 0.98 }],
  "ledger_snapshot_hash": "0x...",
  "audit_events": ["audit_evt_001", "audit_evt_002"],
  "merkle_root": "0xabc...",
  "merkle_proof": ["0x111...", "0x222..."],
  "chain_anchor": { "tx_hash": "0xdef...", "block": 8829110 },
  "rail_receipt": { "rail": "bank_ach", "provider_id": "..." },
  "human_explanation": "Paid invoice inv_8231 for $7,800.00 to Amazon Web Services on Mercury operating account..."
}

Fields

Field	Description
outcome	allowed | confirmed | rejected | executed | failed | shadow_completed
behavior_hash	The agent's runtime behaviorHash. Must equal the value registered on-chain (§6 check 1.5)
policy_version / policy_hash	The policy version evaluated and its content hash
matched_rule_id	The DSL rule that fired
gate_checks[]	Every numbered + hardening check, in execution order, with passed: boolean and optional reason
evidence[]	The Raw-parsed rows the agent and the gate consulted
ledger_snapshot_hash	Hash of the Ledger state Policy decided against (the snapshot the §6 7.5 check re-validates)
audit_events[]	Every audit event id covering this action
merkle_root / merkle_proof	The Merkle inclusion proof for the audit-chain leaves
chain_anchor	The on-chain anchor for the containing batch. null until the batch lands on Base
rail_receipt	The typed rail receipt (ach / wire / erp / onchain schemas)
human_explanation	One-paragraph plain-English summary, deterministically generated

Verifying a Proof

Three independent paths to the same conclusion:

Method	Description
SDK helper	verifyMerkleProof(...) from @brainfinance/sdk. No Brain account required
On-chain call	BrainAuditAnchor.verify(tenantId, batchIndex, leaf, merkleProof) from any Solidity contract
Public verifier endpoint	POST /v1/audit/verify. Supply event hash, Merkle proof, and claimed root

Human-Readable View

For compliance, investor, or counterparty screens. The same Proof rendered as a single HTML page:

GET /v1/proof/{action_id}/view
Authorization: Bearer <token>

Returns text/html with the same data laid out for human reading. Same tenant-isolation and audit:read scope.

What's Next

Audit API

Underlying events, anchors, exports.

Audit API

The Pre-Execution Gate

What the gate-check rows mean.

The Pre-Execution Gate

Audit and Proof

The conceptual model.

Audit and Proof