Release v0.9.0
Arch Network v0.9.0 (2026-09-07)
Compare: v0.8.9...v0.9.0
Date range: 2026-08-31 → 2026-09-07
Stats: 198 files changed, 3074 insertions(+), 26706 deletions(-)
Top impact areas: e2e-tests (49), examples (23), db_utils (17), bitcoin-internal (15), roast (13), program (10), ha (9), db_core (8), runtime (7), sdk (6), validator (5), tpu (5), testing_suite (4), runtime-tests (4), programs (3), local_validator (3), execution (3), docker (3), arch-cli (3), websocket (2)
Highlights
Core storage and consensus underwent a major architectural shift with the retirement of Titan-driven rollback and finality mechanisms in favor of immutable account UTXOs. This change removes over 26,000 lines of code while simplifying state management and eliminating complex rollback logic across the validator, database, and runtime subsystems.
High availability infrastructure improved with Kafka tip migration support during failover scenarios, ensuring continuity during node transitions. Testing infrastructure was enhanced to isolate failover scenarios from epoch boundary interactions.
Runtime capabilities expanded with the addition of instruction introspection syscalls, enabling programs to examine their own execution context. This affects the program SDK, loader, and multiple end-to-end test suites.
Added
- Instruction introspection syscalls allowing programs to query their execution context
- Kafka tip migration capability during high availability failover scenarios
- Immutable account UTXO model replacing prior mutable state tracking
Changed
- Retired Titan-driven rollback and finality system across validator, db_core, db_utils, and bitcoin-internal modules
- Removed rollback-related database columns, functions, and state management logic
- Simplified block confirmation status tracking in db_core
- Updated failover test scenarios to avoid epoch boundary interactions
- Refactored bitcoin-internal sync processor, graph builder, and initialization logic
- Modified account storage structures in structs/src/account_shared_data.rs
- Updated transaction processing in runtime, tpu, and execution modules to support immutable UTXOs
- Revised roast coordinator finality and metrics handling
- Updated high availability journal, store_stream, and service components for failover migration
- Modified arch-cli types and library for UTXO immutability
- Updated example programs (counter, escrow, stake, create-new-account) for new storage model
- Revised e2e-tests including btc-wrap, token-tests, tx-confirmation, syscall-tests, and pda tests
- Updated Cargo.lock files across 49 e2e-test and example programs
Fixed
- Corrected failover scenario behavior by isolating from epoch boundaries before reshaping
Performance and Observability
- Removed rollback-related metrics from roast/src/common/metrics.rs
- Updated ha/src/db/metrics.rs for failover migration observability
RPC and API Changes
- SDK client methods (async_rpc.rs, rpc.rs) updated to reflect immutable UTXO model
- RPC wire format and API stability tests updated in sdk/tests/
- Validator RPC methods and module adjusted for removal of rollback endpoints
- No breaking changes to external RPC interface contract
Breaking Changes
- Titan-driven rollback and finality mechanisms removed; nodes relying on rollback APIs or finality guarantees must adapt to immutable UTXO model
- Database schema changes with removal of rollback-related column families and indices
- Account state management now immutable; programs expecting mutable UTXO semantics will fail
Migration Guidance
Node operators must perform a clean state sync or database rebuild when upgrading to v0.9.0 due to removal of rollback-related database columns and schema changes. Backup existing data before migration. SDK consumers should update to latest SDK version and review changes to processed transaction types and UTXO helper functions. Programs relying on mutable account state or rollback behavior must be redesigned for immutable UTXO semantics.
Documentation
- Updated arch-cli/README.md for UTXO immutability
- Revised validator/Rollback.md to document removal of rollback system
- Updated e2e-tests/cu-tests/README.md
- Modified docker/docker-compose-antithesis.yaml and sidecar reorg.py for testing
- Updated ci/scripts/compute-ebpf-program-state.py
Contributors (v0.8.9 → v0.9.0)
Amine ElQaraoui, Rahul Subramaniyam