# IMX Rulebook v1.8

**In force from 5 November 2026.** **Administrator:** Radius Technology Systems.
Notice: [`/notices/2026-11-05-imx-v1.8-solana.md`](/notices/2026-11-05-imx-v1.8-solana.md).
v1.8 amends Rulebook v1.7 ([`/methodology-v1.7.md`](/methodology-v1.7.md)); anything not
changed here is unchanged.

## Why v1.8

x402 settles on Solana as well as EVM chains. Rulebook v1.5 listed "EVM only" as a known
limitation. v1.8 removes it.

## §1 Definition (amended)

```
X(d) = EVM x402 payments (v1.7 §1) + Solana x402 payments, on UTC day d, net of §4.1 exclusions
```

A **Solana x402 payment** is an SPL token transfer with a non-zero USD value, of a listed
USD stablecoin, in a transaction whose **fee payer** (first signer) is a registered Solana
facilitator. On Solana the facilitator settles by paying the fee; the payer's signature
authorises the transfer. Excluded, as on EVM:

- transfers to or from a registered facilitator; and
- forwarding legs, where the sender received funds in the same transaction.

Listed stablecoins (by symbol in the source scope): USDC, USDT, USDGO and USD1. BlackRock BUIDL, which also ranks among USD
assets on Solana, is a fund share and is not listed.

## §3 Constituents (amended)

The Solana registry (`src/ingest/solana-facilitators.ts`, v1.0.0) lists 25 fee-payer
addresses for 15 operators. It is taken from the frozen x402 scope of
radius-workshop/agent-payments-intel (2026-08-26). Changes to it follow the same rules as
the EVM registry: dated, reasoned, and chain-linked.

## §4.1 Circular-flow exclusions (Solana)

The same test (circularity ≥ 0.90 with at least 20 payers) is run on Solana with
`scripts/solana-circularity.mjs` (Dune query 9064198, window 2026-08-01 → 2026-11-03).

| Payee | Result | Status |
|---|---|---|
| `2AsjudTyDuVtNLWttP1tJEkUwXLfpTzTHZH8JAGeNfJh` | 47 of 49 payers funded by its payout counterparties (0.96); 46 by `89SeK6…` | **Proposed**, awaiting administrator confirmation; inactive since 2026-10-23 |
| `AQqnMFBwGZEoti85aTVRy8XYpKrho7GaMDx9ZB3CEeKA` | 0.00 across 324 payers | Not excluded. **On watch for concentration** (below) |

Dune has no exchange labels for Solana owners, so funders on Solana are not screened
against exchanges as they are on EVM.

## §1.1 The chain-link

As v1.6 §1.1. On the first day struck under v1.8 the divisor is rescaled so that day prints
the same level as the v1.7 basket.

## Validation

IMX's Solana definition reproduces the independent collection's monthly counts within
0.1% (June 2026: 664,658 vs 664,800; May: 794,102 vs 794,406) and its dollar values within
3%.

## Known limitations of v1.8

- **Concentration.** One payee, `AQqnMF…`, took 97% of Solana x402 payments in
  August–September 2026 (about 400,000 a day, from about 100 payers) and 81% in October
  (about 22,000 a day). It passes the circularity test, so it is counted; the Solana
  component moves largely with it. It is listed on the dashboard's watch list.
- **Registry coverage.** Solana payments by fee payers not in the registry are not counted.
  The figure is a lower bound for Solana x402.