feat(arns): resolve on-demand by default + bundled observer self-references local gateway

CHANGELOG.md

@@ -18,6 +18,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Changed
 
+- **ArNS resolves on-demand (from chain) by default** — the default
+  `ARNS_RESOLVER_PRIORITY_ORDER` is now `on-demand,gateway` (was
+  `gateway,on-demand`). Each gateway resolves ArNS names authoritatively from the
+  ANT record itself, falling back to a trusted-gateway hop only if the on-demand
+  resolver fails. This makes gateways self-sufficient rather than clients of a few
+  trusted gateways (more decentralized) and reads the source of truth instead of
+  another gateway's possibly-stale cached answer. On-demand adds a chain read per
+  cache-miss resolution (cheap on Solana RPC; heavier as an AO CU dryrun) — set
+  `ARNS_RESOLVER_PRIORITY_ORDER=gateway,on-demand` to restore the prior behavior.
+  The bundled observer now references this node's own gateway
+  (`ARNS_ROOT_HOST`) by default, so its reference resolution is authoritative and
+  local.
+
 - **Chunk-post fan-out narrows to the configured threshold** — now that HTTP 303
   counts as a successful (temporary) acceptance (see Fixed), broadcasts stop at
   `CHUNK_POST_MIN_SUCCESS_COUNT` as intended instead of grinding the full peer

docker-compose.yaml

@@ -660,7 +660,14 @@ services:
       - AR_IO_NODE_RELEASE=${AR_IO_NODE_RELEASE:-82-pre}
       - AR_IO_SDK_LOG_LEVEL=${AR_IO_SDK_LOG_LEVEL:-none}
       # Reference Gateway Configuration
-      - REFERENCE_GATEWAY_HOSTS=${REFERENCE_GATEWAY_HOSTS:-}
+      # The bundled observer references THIS node's own gateway by default (its
+      # ARNS_ROOT_HOST), rather than external gateways. Since the gateway now
+      # resolves ArNS on-demand (authoritatively, from chain), self-reference is
+      # both authoritative and more decentralized — the observer forms its own
+      # chain-derived view and the protocol aggregates observers by majority.
+      # Falls back to the observer's own default (turbo/ar-io.net) if neither
+      # REFERENCE_GATEWAY_HOSTS nor ARNS_ROOT_HOST is set.
+      - REFERENCE_GATEWAY_HOSTS=${REFERENCE_GATEWAY_HOSTS:-${ARNS_ROOT_HOST:-}}
       - REFERENCE_GATEWAY_NETWORK_ONLY=${REFERENCE_GATEWAY_NETWORK_ONLY:-}
       - REFERENCE_GATEWAY_NETWORK_FALLBACK=${REFERENCE_GATEWAY_NETWORK_FALLBACK:-}
       - REFERENCE_GATEWAY_CONSENSUS_SIZE=${REFERENCE_GATEWAY_CONSENSUS_SIZE:-}

src/config.ts

@@ -2629,8 +2629,14 @@ export const ARNS_CACHE_MAX_KEYS = +env.varOrDefault(
   '10000',
 );
 
+// Resolve ArNS names authoritatively from chain first (on-demand ANT lookups),
+// falling back to a trusted-gateway hop only if the on-demand resolver fails.
+// This makes each gateway self-sufficient rather than a client of a few trusted
+// gateways (more decentralized) and reads the source of truth (the ANT record)
+// instead of another gateway's possibly-stale cached answer. Operators can revert
+// to the previous behavior with ARNS_RESOLVER_PRIORITY_ORDER=gateway,on-demand.
 export const ARNS_RESOLVER_PRIORITY_ORDER = env
-  .varOrDefault('ARNS_RESOLVER_PRIORITY_ORDER', 'gateway,on-demand')
+  .varOrDefault('ARNS_RESOLVER_PRIORITY_ORDER', 'on-demand,gateway')
   .split(',');
 
 export const ARNS_COMPOSITE_RESOLVER_TIMEOUT_MS = +env.varOrDefault(