HORUS v0.1.8-alpha

HORUS 0.1.8 Release Notes

Release Date: January 2026

Performance & Architecture Improvements

This release focuses on maximizing runtime performance, scalability, and debugging capability by separating concerns and removing overhead from the core scheduler.

Breaking Changes

1. Scheduler API: priority → order

The scheduler builder API has been renamed for clarity:

// Before (0.1.7)
scheduler.add(node,0,true);

// After (0.1.8)
scheduler.add(node).order(0).done();

Why: "Order" better reflects execution sequencing, while "priority" implied preemption (which HORUS doesn't support). Lower numbers execute first.

2. Logging Removed from Core Runtime

Context management and logging have been decoupled from the core scheduler:

• Removed: enable_logging parameter from node registration
• Removed: Built-in NodeContext from scheduler
• Result: Zero logging overhead in hot path (~133ns improvement per tick)

Migration:

// Before (0.1.7)
scheduler.add(node, 0, true);

// After (0.1.8)
scheduler.add(node).order(0).done();

// Use send_logged() explicitly when needed or `horus monitor` or `horus topic echo`
topic.send_logged(msg).ok();  // ~300ns (with logging)
topic.send(msg).ok();          // ~167ns (no logging)

3. Context Separation

Node context (for debugging/monitoring) is now opt-in and managed separately:

// Debugging/monitoring is now external to core runtime
// Use `horus monitor` 

Benefits

Performance

• Faster hot path: Removed context overhead from every tick
• Lower memory: No per-node context allocation by default
• Better cache: Tighter scheduler loop

Scalability

• Cleaner separation: Runtime vs. observability
• Flexible debugging: Add telemetry when needed, not always-on
• Production-ready: Deploy without monitoring tax

Developer Experience

• Explicit logging: send_logged() makes overhead visible
• Simpler defaults: New projects start lean
• Better names: .order() is clearer than .priority()

Migration Guide

1. Rename priority() to order() in all scheduler.add() calls
2. Remove enable_logging() parameters (no longer needed)
3. Use send_logged() only where you need monitoring
4. Use send() for high-frequency hot paths

Template Updates

The horus new templates now reflect these changes:

• Non-macro template includes get_publishers() for topic discovery
• Macro paths fixed for proper module resolution
• Default to send_logged() in examples (easy to optimize later)

Full Changelog

• BREAKING: Rename priority() → order() in scheduler API
• BREAKING: Remove enable_logging from scheduler builder
• BREAKING: Remove automatic NodeContext allocation
• FIX: Non-macro template now implements get_publishers()
• FIX: Macro module paths use absolute ::horus::horus_core::
• PERF: Disable safety monitor by default (prototyping-friendly)
• PERF: Zero logging overhead when using send()

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For questions or issues, visit: https://github.com/softmata/horus/issues