TL;DR
RadiumBlock has notified us they are discontinuing their public RPC for Astar and Shiden. Their nodes were carried in the invulnerable (bond-free) collator set as part of that infrastructure relationship. With the RPC ending, we propose removing both nodes from the invulnerable set: by referendum on Astar and by sudo call on Shiden. RadiumBlock has been informed, has acknowledged the change, and remains welcome to continue as a self-bonded collator at any time.
Background
The invulnerable set is a permissioned, bond-free collator tier the Astar Collective maintains for partners providing material infrastructure to the ecosystem. RadiumBlock was onboarded into it alongside the public RPC endpoints they ran for Astar and Shiden. On 2026-06-01, RadiumBlock informed us they are downsizing their free RPC offering and will discontinue the Astar and Shiden public RPC. With that contribution now ending, the basis for the bond-free invulnerable slots no longer applies.
Action for developers and dApps: RadiumBlock’s public RPC endpoints are being discontinued and will stop serving requests:
- Astar:
https://astar.public.curie.radiumblock.co/ - Shiden:
https://shiden.public.curie.radiumblock.co/
If your application points at either endpoint, migrate to an alternative RPC provider now to avoid disruption. See the Astar network endpoints docs for current options.
RadiumBlock collators being removed from the invulnerable set:
- Astar:
W5UDvLQnfDRCcNS9Aj8pa96c3chgsd83B3wPsmnGZXKeE2R(Subscan) - Shiden:
a58QztZ7M6jrpq5Gf4t7yM5y2syBA17HBKHXNMgGojRLx2x(Subscan)
Proposal
- Astar: remove RadiumBlock’s collator from the invulnerable set via referendum.
- Extrinsic:
CollatorSelection.remove_invulnerable(W5UDvLQnfDRCcNS9Aj8pa96c3chgsd83B3wPsmnGZXKeE2R)
- Extrinsic:
- Shiden: remove RadiumBlock’s collator from the invulnerable set via sudo call.
- Target:
a58QztZ7M6jrpq5Gf4t7yM5y2syBA17HBKHXNMgGojRLx2x
- Target:
- Both are governance/runtime-level changes only; no client upgrade is required.
Rationale
Invulnerable slots are limited and granted on the basis of ecosystem contribution. The bond-free status was extended to RadiumBlock in the context of their broader infrastructure relationship, which included the public RPC. With the RPC discontinued, the standard route for continued collating is self-bonded candidacy, on the same terms as every other permissionless operator (3,200,000 ASTR on Astar, 32,000 SDN on Shiden). This keeps the invulnerable set aligned with active infrastructure contribution while leaving RadiumBlock a clear path to keep collating.
Impact
- No liveness impact is expected; the remaining invulnerable and candidate collators continue block production. Operational monitoring is recommended immediately after each removal.
- RadiumBlock’s public RPC endpoints (
https://astar.public.curie.radiumblock.co/andhttps://shiden.public.curie.radiumblock.co/) are being discontinued; applications relying on them should switch providers. - RadiumBlock can re-enter as a self-bonded collator at any time by reserving the bond and requesting approval, per the collator requirements.
- This change is being made amicably; RadiumBlock has acknowledged it.
Next steps
Astar removal proceeds to referendum a few days after this post to allow for comment. The Shiden removal is executed via sudo call on the same timeline.
We want to thank RadiumBlock for the public RPC service they provided to Astar and Shiden, and for the reliable infrastructure they ran for the ecosystem over the past years. This change is an amicable one. We remain open to continuing our collaboration with RadiumBlock across the Astar ecosystem, and we would be glad to see them continue as a self-bonded collator on Astar and Shiden.
Discussion
- Any objections to the timeline, or reasons to stagger the Astar and Shiden removals?
- Does anyone foresee a liveness concern in the current collator set that would warrant onboarding a replacement before removal?
Gaius_sama 
Astar Foundation & Main Council