Research onboarding Polkadot Bulletin to public indexers/explorers (Subscan, Statescan, …)

[karolk91]

Research what it takes to get the Polkadot Bulletin chain onboarded to public indexers/explorers, and whether Bulletin's storage-chain characteristics need any runtime/RPC changes to index cleanly. Output: a per-target summary (steps, contact, cost, blockers) and a prioritized recommendation.

Targets

• Subscan (subscan.io)
• Statescan (statescan.io, OpenSquare)

Per-target research questions

• Onboarding process, contact, timeline, and cost (Subscan is paid; Statescan is open-source).

Bulletin-specific concerns

• Storage-chain volume: store extrinsics will be inherently larger than usual; can indexers ingest that data volume, and do they store/display the payload or just the extrinsic/CID?

[x3c41a]

TL;DR: Statescan first (testnets), Subscan for production. No runtime/RPC changes needed; both indexers decode via runtime metadata, and neither needs to ingest store payloads (index the Stored event: CID/hash/size).

• Statescan: open source, effectively free. Two one-line config changes in statescan-v2: allowlist Bulletin for unsigned extrinsics (our preimage-authorized store calls are unsigned) and add it to chainsNeedToClean so the 2 MiB payload args get stripped. Contact: GitHub issues / maybe Matrix??
• Subscan: paid, contact api@subscan.io. Pricing is per GB indexed ( around $800 to $3k/mo and above tiers), so the deciding question is whether they exclude store payload bytes; metadata-only, we're a tiny chain (~$500/mo range). Not covered by the existing treasury enterprise subscriptions (refs: https://polkadot.subsquare.io/referenda/1906 and https://polkadot.subsquare.io/referenda/1907).
• Prerequisite: an archive node reachable by the indexer operator (we provide one for Statescan; Subscan usually runs their own as part of the service).

[x3c41a]

Statescan update: turns out OpenSquare already added Bulletin support in May (opensquare-network/statescan-v2#1181) and https://bulletin.statescan.io is live and synced with the production chain.

Two indexer gaps remained for storage traffic:

• unsigned (preimage-authorized) store extrinsics were skipped entirely
• store payload args (up to 2 MiB per call) would have been persisted raw into their DB

Fix proposed in opensquare-network/statescan-v2#1194: index unsigned extrinsics for bulletin-polkadot and strip payload args while keeping Stored event args (CID/content hash).

Next for Statescan: get opensquare-network/statescan-v2#1194 reviewed/merged, and we asked OpenSquare whether they'd host a Paseo Bulletin testnet instance (comment).

Subscan track not started yet (needs an email to api@subscan.io with the payload-exclusion question).

[yakio]

Hi @karolk91 @x3c41a

Thanks for mentioning Subscan. We’re very interested in what Bulletin is building and have already done some initial research and prototyping. We were actually preparing to reach out to your team, so it’s great to see this discussion.

Based on our assessment, the two indexing gaps identified above should not occur with Subscan:

• unsigned (preimage-authorized) store extrinsics were skipped entirely
• store payload args (up to 2 MiB per call) would have been persisted raw into their DB

We therefore do not currently expect Bulletin to require any runtime or RPC changes for Subscan integration.

We also see supporting the standalone Bulletin chain as only the first step. Our goal is to make Bulletin-backed data useful where users actually encounter it. We’re exploring related support directly within Subscan’s Asset Hub experience, including more user-friendly presentation of Bulletin-backed content and potential .dot domain use cases. We already have an initial internal prototype and would be happy to share it and develop the experience further with your team.

For clarity, Subscan’s pricing is transparent:

• Basic Plan: $799/month, including 500 GB/month

• Annual payment discount:

  • Mainnet: 10%
  • Canary network: 25%
  • Testnet: 40%

For Bulletin, we can also discuss keeping the service at Basic Plan pricing for the first three years. Testnets can begin with a fully free three-month trial.

If this direction is interesting, please reach out to us at api@subscan.io. We’d be happy to discuss the Bulletin chain integration, the Asset Hub experience, and .dot-domain-related improvements with your team.