Read limits and coverage-cache

pox5-reader computes its figures by reading pox-5. Every contract-call? into that contract loads it, which costs about 569,000 of read length. A public Hiro node allows 500,000 on /v2/contracts/call-read, so those calls are refused:

{
  "okay": false,
  "cause": "RuntimeCheck(CostBalanceExceeded(ExecutionCost { read_length: 569372, ... }, ExecutionCost { read_length: 500000, ... }))"
}

This is a limit on the read-only HTTP endpoint, not on the chain or on the contract. In a transaction the budget is far larger: the coverage-cache::refresh that produced today's figures used 8.5M of read length and confirmed normally. Contracts calling pox5-reader on-chain, such as coverage-guard, are unaffected.

What is affected

coverage-cache

coverage-cache::refresh calls pox5-reader inside a transaction and stores what it answered. Reading the stored copy touches only that contract, so a public node serves it. The values are the reader's own, so they keep the onchainonchain · Computed by the pox5-reader contract on mainnet from pox-5 state. label, and each one is shown with the burn height of the refresh that recorded it.

refresh is permissionless and takes no arguments. A caller chooses only when a reading is taken, never what it says. The contract holds no funds and can move none.

The keeper

A keeper in the indexer calls pox5-reader::snapshot once per distribution index, and coverage-cache::refresh when a distribution is computed, the cycle rolls over, or the stored reading is about a week old. It runs with its own key, funded for fees only. Anyone else can call either function at any time; the keeper has no privileged position.

Checking it yourself

• node contracts/scripts/verify-mainnet.mjs calls what a public node allows, computes the same figures independently from pox-5, and lists which functions the endpoint refuses.
• node contracts/scripts/verify-at-tip.mjs checks the deployed source against the repo, then runs the full suite against a fork of mainnet pinned at the current chain tip, with every expected value fetched from pox-5 at that same tip. That covers the functions a public node cannot call.
• Or read the stored copy directly:

{
  "value": 16.678,
  "unit": "x",
  "provenance": "onchain",
  "source": "SP2Q3XVGTTA4CW3E2AHFZPAGQ0HM9QPHTTBJTQGJY.pox5-reader::get-coverage-summary (cycle 143, realised so far) via coverage-cache::refresh at burn height 967793",
  "note": "pox5-reader computed this from pox-5 state in a mainnet transaction; coverage-cache stores its answer so the public API can read it"
}

The source names the reader function, the cache refresh and the burn height it ran at.