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Satellite is the on-chain anchor that other Herodotus services build on.

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Storage Proof API -> Satellite

Storage Proof API manages proof workflows and writes verified historical facts into Satellite. From the app perspective:
  1. You request proof-backed data.
  2. The pipeline verifies data against block commitments.
  3. Verified facts become readable through Satellite contract functions.
This is why on-chain reads can be simple while still cryptographically grounded.

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Data Structure Indexer -> off-chain visibility for Satellite data structures

Data Structure Indexer API is the off-chain companion for accumulator/remapper access. It provides queryable access to data structures and metadata such as:
  • MMR-related roots/peaks/proof data,
  • remapper lookup helpers,
  • and other proof-oriented indexing primitives.
In practice, this is the off-chain indexing and retrieval layer around the same commitment system that Satellite enforces on-chain.

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HDP -> computation on top of committed history

HDP executes proof-backed computation over historical chain data. Its verification model relies on header commitments and proof chains rooted in MMR-backed history. In other words, the blocks and proofs HDP consumes are tied to the same Satellite commitment layer. This linkage is central to HDP soundness:
  • historical facts are validated against committed roots,
  • those roots are anchored in Satellite MMR state,
  • and resulting computations can be authenticated through fact-registry flows.

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Why this matters for trust

Together, these layers separate concerns cleanly:
  • index and fetch off-chain efficiently,
  • verify and anchor on-chain,
  • compute with proof constraints.
That division is what lets Herodotus scale while preserving verifiable correctness across services.