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Version: v1

Midnight Indexer v4.0.0 release notes

For the complete documentation index, see llms.txt
  • Version: v4.0.0
  • Date: 2026-03-17

High-level summary​

This release upgrades the Indexer API to v4 and adds support for Node 0.22 and Ledger 8. It also includes performance, reliability, and internal storage updates.

For compatibility, /api/v3 is currently available as an alias to /api/v4, but v4 should be treated as the target API version.

Audience​

This release note is relevant for developers who:

  • Use the Midnight Indexer via the Indexer API
  • Run and operate the Midnight Indexer

What changed (Summary of updates)​

The updates below summarize the core changes for client integrators and Indexer operators.

  • Upgraded Indexer API from v3 to v4
  • Added /api/v3 alias for /api/v4 for short-term backward compatibility
  • Added support for Node 0.22 and Ledger 8
  • Replaced deterministic session IDs with random per-session tokens (indexer-api)
  • Updated to storage-core v1.1 with layout v2
  • Replaced a window function with a scalar subquery in ledger events query paths
  • Batched ledger_db_nodes inserts to reduce SQL round trips
  • Added lazy loading for ledger state deserialization to avoid recursion depth limit issues

New features​

Below are the new features introduced in this release.

Indexer API v4​

The Indexer API is now v4. This is the recommended API version for all new integrations.

Temporary v3 compatibility alias​

/api/v3 is available as an alias of /api/v4 to support migration windows for existing clients.

Improvements​

  • Replaced deterministic session IDs with random per-session tokens (indexer-api)
  • Batched ledger_db_nodes inserts to reduce SQL round trips
  • Replaced a window function with a scalar subquery in ledger event query logic
  • Added lazy loading for ledger state deserialization to avoid recursion depth limits

Breaking changes​

Below are the breaking changes and required actions for developers.

API version update to v4​

What changed: The primary Indexer API version is now v4.

What breaks: Clients pinned to older API assumptions may fail when they do not align with v4 schema and behavior.

Required actions: Update clients to API v4 and validate schema compatibility. Treat /api/v3 as transitional.

Internal database storage format update​

What changed: Internal database format moved to storage-core v1.1 with layout v2.

What breaks: Existing database state from earlier layout versions is not compatible for in-place reuse.

Required actions: Start from a fresh or empty database when deploying this release.