OpenChainGraph Suite · ART-309 · insurance evidence

Parametric Index Deriver

Deterministically aggregates a named metric (mean, sum, count, max, or min) across a receipt set into a parametric index value: receipts as an oracle replacement, replay-on-challenge instead of trust-the-feed.

Oracle ReplacementFeeds art-251Zero PII

🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.

Scope

Independent adjacency, no dedicated chain. Feeds the shipped compute_parametric_trigger_payout kernel (art-251), which performs the actual trigger-vs-payout math; this kernel never reimplements that logic. The index is a REPLAYABLE derived value, never a settlement trigger by itself.

Downstream

Feeds art-251 Parametric Trigger Payout Calculator.

Presets

policy_parameters (JSON)

Result

Execution Hash & §4 Artifact

SHA-256 execution hash (JCS canonical, RFC 8785):

Ask your agent

Copy this paragraph into Claude, OpenClaw, or any MCP-aware agent to run this exact tool, with this sample, and verify the artifact.

Run the AINumbers MCP tool `derive_parametric_index_from_receipts`. Task: Deterministically aggregates a named metric (mean, sum, count, max, or min) across a receipt set into a parametric index value: receipts as an oracle replacement, replay-on-challenge instead of trust-the-feed.
Call it with arguments: {"policy_parameters":{"receipts":[{"receipt_hash":"sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","measured_metric":10},{"receipt_hash":"sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb","measured_metric":20},{"receipt_hash":"sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc","measured_metric":30}],"index_def":{"metric":"wind_speed_mph","aggregation":"mean","window":{"from":"2026-08-01","to":"2026-08-31"}}}}
Verify before trusting: call `verify_execution_hash` on mcp.ainumbers.co (https://mcp.ainumbers.co/mcp) with the parameter `claimed_hash` set to the returned `execution_hash`, passing the full artifact the run returned (the object containing `policy_parameters` + `output_payload` + `execution_hash`; equivalently `policy_parameters` + `output_payload` with `claimed_hash`), not the bare hash string.
Return the ledger link https://ledger.ainumbers.co/ so a human can re-verify without contacting us.
PII rule: All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Open the tool with the sample prefilled: https://ainumbers.co/chaingraph/art-309-parametric-index-deriver.html#p=v1.H4sIAAAAAAAA_wHMATP-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