APY Earned Check

Note (dated 2026-08-04): a chain composes independent computations performed in an analytical order. No step's output is carried into the next step by the execution model; each step computes from its own declared inputs. This is true of every chain on this site, including chains whose per-step copy below reads as a data handoff.

Check whether a bank paid the APY it disclosed, in two recompute stages: first recompute the period's interest from daily balances under the caller's declared day-count convention, compounding, and rate terms, diffed against the core's reported accruals with a MATCHES, DIVERGES, or INDETERMINATE verdict (ART-661), then recompute the APY earned from a caller-supplied interest figure and the average daily balance and compare it with the disclosed APY inside a caller-declared accuracy band (ART-663), then a session receipt aggregating the run's execution hashes (CRY-05). Day-count convention, compounding, and every rate term are caller-declared inputs; a divergence is an arithmetic finding, never a determination that interest was miscalculated. Not legal advice and not tax advice.

Note: day-count convention, compounding, and every rate term are caller-declared inputs, never inferred by the kernel. A DIVERGES verdict is an arithmetic finding, not a determination that interest was miscalculated or is owed back. The APY stage recomputes from a caller-supplied interest figure, so cite the interest stage's hash alongside it when presenting both runs.

OpenChainGraph · 3 Steps compliance mandate · Reg DD 1030 Hash-Anchored §4 chain_depth:3 Client-Side · Zero PII

Chain Stages · 3 Steps

1 ROOT node

Interest Accrual Recompute art-661-interest-accrual-recompute

Recomputes the period's interest from daily balances under the caller's declared day-count convention, compounding, and rate terms; the recomputation is diffed against the core's reported accruals, with verdict MATCHES, DIVERGES, or INDETERMINATE

MCP Call · compute_interest_accrual_recompute

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "compute_interest_accrual_recompute",
    "arguments": {}
  },
  "id": 1
}

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2 STEP node

APY-Earned Recompute art-663-apy-earned-recompute

Recomputes the APY earned from a caller-supplied interest figure and the average daily balance and compares it with the disclosed APY inside the caller's declared accuracy band, with verdict MATCHES, DIVERGES, or INDETERMINATE

MCP Call · compute_apy_earned_recompute

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "compute_apy_earned_recompute",
    "arguments": {}
  },
  "id": 1
}

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3 TERMINAL · D3 node

Agent-Action Audit-Trail Aggregator cry-05-agent-action-audit-trail-aggregator

Produces session_receipt_root, the Merkle root over the run's execution_hashes (final stage)

MCP Call · aggregate_execution_receipts

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "aggregate_execution_receipts",
    "arguments": {}
  },
  "id": 1
}

Question: My savings statement shows 5.12% APY earned. Did the bank pay the rate it disclosed? Run the AINumbers MCP tool `run_chain` with {"chain":"apy-earned-check"} and read `art-663-apy-earned-recompute.verdict`. Verify: call `verify_execution_hash` (https://mcp.ainumbers.co/mcp) with `claimed_hash` set to `composite_execution_hash` and the full `composite_artifact`. Ledger, for a human re-check: https://ledger.ainumbers.co/ PII rule: send synthetic or anonymised inputs only. The MCP server runs these kernels and logs no payloads. Chain page: https://ainumbers.co/chaingraph/chains/apy-earned-check.html

APY Earned Check

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