---
title: "Chain Health Changelog"
canonical: "https://pharos.watch/methodology/chain-health-changelog/"
description: "Chain Health Changelog - Pharos methodology version history."
---

# Chain Health Changelog

## v1.4 - L2BEAT chain-risk environment scoring

**Effective:** 2026-06-12

Matched L2BEAT scaling projects now score the Chain Environment factor from a static L2BEAT stage and risk snapshot before falling back to the legacy Pharos tier model for unmatched chains.

- Added explicit Pharos chain ID to L2BEAT project aliases and a static L2BEAT snapshot sourced from the scaling summary API
- Matched chains derive Chain Environment from L2BEAT stage plus Sequencer Failure, State Validation, Data Availability, Exit Window, and Proposer Failure risk sentiments
- Unmatched chains continue to use the existing tier mapping: tier 1 = 100, tier 2 = 60, tier 3 = 20
- Safety Score chainTier and deploymentModel gain L2BEAT audit helpers only; live Safety Score outputs are unchanged

## v1.3 - Active-only inputs and stale report-card dependency

**Effective:** 2026-06-06

Live Chain Health now uses the same active/non-archived input universe as the daily chain-supply snapshot and degrades its report-card dependency when cached Safety Scores were computed with stale report-card inputs.

- `GET /api/chains` excludes frozen, defunct, and non-active stablecoins before deriving peg rates or aggregating chain supply
- The report-card dependency now reports `degraded` when `report_card_cache.degradedInputs.inputsStale` is true, instead of marking stale-input scores as fresh
- Health scores can remain computed from the cached score map, but response freshness and headers now surface the degraded upstream report-card condition

## v1.2 - Two-bucket backing diversity after active taxonomy cleanup

**Effective:** 2026-04-07

Removed the standalone algorithmic bucket from the active backing taxonomy after reclassifying the remaining reserve-backed cases. Chain Health backing diversity now measures only the live RWA-backed vs crypto-backed split.

- Reclassified FPI, cUSD, and CEUR out of the legacy algorithmic bucket based on their reserve backing
- Active backing filters and taxonomy pages now expose only RWA-backed and crypto-backed cohorts
- Backing diversity now normalizes across the two active backing types, so an even RWA/crypto split scores 100

## v1.1 - Chain environment factor and weight rebalance

**Effective:** 2026-03-16

Added a fifth health factor — Chain Environment — that rates chain infrastructure quality via a resilience tier system. Rebalanced weights to reduce backing diversity influence and give chain quality 20% of the composite.

- New Chain Environment factor (20% weight): tier 1 = 100 (Ethereum), tier 2 = 60 (default), tier 3 = 20 (PulseChain, Harmony, etc.)
- Backing diversity weight reduced from 15% to 10%
- Quality weight reduced from 35% to 30%
- Concentration weight reduced from 25% to 20%
- Peg stability weight reduced from 25% to 20%
- Chains with poor infrastructure penalized — e.g. PulseChain dropped from #1 healthiest to mid-table

Commits: `f6978ec`

## v1.0 - Initial Chain Health Score release

**Effective:** 2026-03-16

Launched per-chain health scoring with four factors: quality (35%), concentration (25%), peg stability (25%), and backing diversity (15%). Exposed via /api/chains and the /chains/ leaderboard.

- Introduced chain health score as a 0–100 composite across four factors
- Quality: supply-weighted average of Pharos Safety Scores (null if < 50% coverage)
- Concentration: HHI-based metric rewarding stablecoin diversity
- Peg stability: supply-weighted peg proximity across all chain stablecoins
- Backing diversity: Shannon entropy across the backing taxonomy active at the time
- Health bands: robust (80–100), healthy (60–79), mixed (40–59), fragile (20–39), concentrated (0–19)
- Added /api/chains endpoint, /chains/ leaderboard page, and /chains/[chain]/ detail pages

Commits: `003eafd`