Two metadata entries are maintained outside the tracked public stablecoin set for historical PSI and depeg continuity:

ust-terra
iron-iron-finance

They live in shared/lib/shadow-stablecoins.ts and are intentionally separated from the tracked stablecoin registry (shared/lib/stablecoins/index.ts, backed by shared/data/stablecoins/*.json).

Purpose

Shadow stablecoins preserve historically important collapse events in systems that would otherwise undercount past systemic stress after an asset is delisted from the public dashboard.

They are used where historical continuity matters:

shared/lib/psi-eligible.ts combines TRACKED_STABLECOINS + SHADOW_STABLECOINS into PSI_ELIGIBLE_STABLECOINS
worker/src/cron/detect-depegs.ts and worker/src/cron/compute-dews.ts use the PSI-eligible set
worker/src/cron/stability-index.ts filters the live cache against PSI_ELIGIBLE_IDS
worker/src/cron/snapshot-supply.ts and worker/src/api/backfill-supply-history.ts use the PSI-eligible registry
worker/src/api/backfill-cg-prices.ts also needs the PSI-eligible registry so replay-critical shadow price gaps can be repaired
worker/src/api/backfill-depegs.ts can backfill shadow assets the same way it backfills tracked assets
shared/lib/stablecoin-id-registry.ts includes shadow entries in canonical ID resolution

Current Inventory

`ust-terra`

llamaId: "3"
detailProvider: "defillama"
geckoId: "terrausd"
Included in the live DefiLlama-ID registry path via REGISTRY_BY_LLAMA_ID
Historical PSI replay and live PSI depeg grouping also canonicalize legacy ust-terra-classic depeg rows onto ust-terra so shadow supply history and collapse-era depegs join back together

`iron-iron-finance`

No DefiLlama stablecoin ID
detailProvider: "coingecko"
geckoId: "iron-stablecoin"
Exists mainly for registry/backfill/history continuity; the source file notes that supply history needs manual DB insertion for the peak-collapse period

Public UI Boundary

Shadow stablecoins are not part of the public tracked-set metadata used for dashboard counts, filters, and table inclusion:

ACTIVE_STABLECOINS.length drives public counts in page metadata and copy
ACTIVE_IDS is the default inclusion set used by src/components/stablecoin-table-logic.ts, and filtered table subsets are built from ACTIVE_STABLECOINS
taxonomy/filter pages derive their selectable universe from tracked metadata, not shadow metadata

Operational consequence:

raw cache-backed surfaces can still contain a shadow asset if the upstream sync emits it
public list/table UX filters those assets back out by tracked ID

Gotchas

Do not add a shadow asset to shared/data/stablecoins/*.json unless it should become publicly tracked everywhere
Do not remove a shadow asset without checking PSI, depeg backfill, and supply-history continuity first
If a shadow asset gains a reliable live source, update both shared/lib/shadow-stablecoins.ts and the paths that depend on PSI_ELIGIBLE_STABLECOINS

File Index

File	Role
`shared/lib/shadow-stablecoins.ts`	Shadow-asset metadata definitions
`shared/lib/psi-eligible.ts`	Tracked + shadow PSI eligibility registry
`shared/lib/stablecoin-id-registry.ts`	Canonical ID / external-ID resolution including shadow entries
`worker/src/cron/stability-index.ts`	PSI computation uses `PSI_ELIGIBLE_IDS`
`worker/src/cron/detect-depegs.ts`	Live depeg detection metadata boundary
`worker/src/cron/compute-dews.ts`	DEWS iteration over PSI-eligible assets
`worker/src/cron/snapshot-supply.ts`	Daily supply snapshot filter includes PSI-eligible assets
`worker/src/api/backfill-supply-history.ts`	Admin supply-history backfill over PSI-eligible assets
`worker/src/api/backfill-cg-prices.ts`	Admin historical price-fill over PSI-eligible assets, including shadows
`worker/src/api/backfill-depegs.ts`	Admin depeg-history backfill over PSI-eligible assets

Shadow Stablecoins