Delibera v10.3.0 — What's New

Status: ✅ Shipped — July 2026 402 unit tests pass (337 Core + 65 Server). Breaking changes — see the migration guide below.

This document covers the three major features and breaking changes in Delibera v10.3.0. For the full changelog, see CHANGELOG.md. For the roadmap, see docs/ROADMAP.md.

Table of contents#

• P-01 — Breaking Changes
• S-01 — Distributed Debates
• S-03 — Result Caching
• Delibera.Server — ASP.NET Core Hosted Service
• Pre-merge Cleanup

P-01 — Breaking Changes#

v10.3.0 removes deprecated APIs that were marked [Obsolete] since v10.1. If you're upgrading from v10.2.x, make the following changes:

WeightedVotingStrategy.ResolveWeight fix#

ResolveWeight now falls back to ballot.Weight instead of the constructor's defaultWeight. Per-ballot weights work as documented.

S-01 — Distributed Debates#

Delibera now supports distributed debate orchestration. The IDebateOrchestrator abstraction decouples debate execution from the transport layer, enabling both in-process and Redis-based deployments.

Core interface#

public interface IDebateOrchestrator
{
    Task<DebateResult> ExecuteAsync(ICouncilBuilder builder, CancellationToken ct = default);
    Task<DebateHandle> EnqueueAsync(string debateId, ICouncilBuilder builder, CancellationToken ct = default);
    Task<DebateHandle?> GetStatusAsync(string debateId, CancellationToken ct = default);
    IAsyncEnumerable<DebateRoundEvent> StreamAsync(string debateId, CancellationToken ct = default);
    Task<bool> CancelAsync(string debateId, CancellationToken ct = default);
}

Local mode (default)#

services.AddDelibera(configuration);
// LocalDebateOrchestrator is registered by default

Redis mode#

services.AddDelibera(configuration);
services.AddRedisDebateOrchestrator(configuration);

Round events are published to Redis Streams so any connected API server can stream them via SSE.

See docs/distributed-debates.md for the full architecture diagram and configuration reference.

S-03 — Result Caching#

Avoid re-running identical debates. The cache key is a SHA-256 hash of the question, members, strategy, and configuration.

Cache Behavior#

Quick Start#

// In-Memory (development)
services.AddDelibera(configuration)
    .UseInMemoryCache(ttl: TimeSpan.FromHours(1));

// File-based
services.AddDelibera(configuration)
    .UseFileCache(directory: "./debate-cache", ttl: TimeSpan.FromDays(7));

// Redis (production)
services.AddRedisDebateOrchestrator(configuration);
services.UseRedisCache(ttl: TimeSpan.FromHours(24));

Per-debate control#

var executor = new CouncilBuilder()
    .WithUserPrompt("What is the best architecture?")
    .AddMember("gpt-4o", provider, "Architect")
    .WithCacheBehavior(CacheBehavior.ReadWrite)
    .Build();

var result = await executor.ExecuteAsync();
Console.WriteLine($"Cache hit: {result.CacheHit}");  // true if served from cache
Console.WriteLine($"Cache key: {result.CacheKey}");   // e.g. "A3F2B8C1D4E5F6A7"
Console.WriteLine($"Cached at: {result.CachedAt}");   // original cache timestamp

See docs/caching.md for the full reference.

Delibera.Server — ASP.NET Core Hosted Service#

A new Delibera.Server project provides a self-hosted ASP.NET Core 10 Minimal API:

• REST API: POST /api/v1/debates (sync), POST /api/v1/debates/async (fire-and-forget), GET /api/v1/debates/{id}, DELETE /api/v1/debates/{id}
• SSE streaming: GET /api/v1/debates/{id}/stream — powered by IDebateOrchestrator.StreamAsync()
• Scenarios: POST /api/v1/scenarios for ad-hoc debates
• OpenAPI: Swagger UI at /openapi

See docs/Server.md for the full API reference.

Pre-merge Cleanup#

• Removed DebateStatus.Paused and DebateOrchestrationStatus.Pending — dead enum values never assigned
• Fixed DebateRecord.Label CS8618 warning (now defaults to string.Empty)
• DebateResponse now includes Label, CacheHit, and CacheKey fields
• SseDebateStreamWriter rewritten to consume IDebateOrchestrator.StreamAsync() instead of DebateRecord.RoundReader
• DebateOrchestrationService rewritten from 200ms polling to event-driven StreamAsync()
• All CS1591/CS1574 XML-doc warnings resolved across Delibera.Core

Performance & Integrity (Phases 1–3)#

Memory leak fixes#

Thread safety#

• DebateRecord.Status and RedisDebateOrchestrator.DebateEntry.Status use volatile int + Volatile.Read/Volatile.Write for cross-thread visibility.
• ProviderFactory.CachingFactory uses ConcurrentDictionary<string, T> + GetOrAdd instead of Dictionary + manual lock.

Async correctness#

• ConfigureAwait(false) added to all await expressions in Delibera.Core and Delibera.Redis (~50+ sites).
• Fire-and-forget CancelAsync in DebateOrchestrationService now uses Task.Run with try/catch + logging.

Allocation optimisations#

• SSE writer — JsonSerializer.SerializeToUtf8Bytes + byte-level writes instead of string-based serialization.
• Cache key generator — SerializeToUtf8Bytes avoids intermediate string allocation.
• ModelContextWindowRegistry — FrozenDictionary/FrozenSet for O(1) lookups; Register invalidates the frozen cache.
• IDebateCache / IDebateStore / IDebateOrchestrator.GetStatusAsync — ValueTask<T> instead of Task<T>; synchronous backends avoid Task allocation.
• Levenshtein distance — single-row DP with Span<int> + stackalloc for strings ≤128 chars.
• TokenCounter — ReaderWriterLockSlim instead of lock for concurrent reads.
• RankedOption — readonly record struct instead of sealed record (avoids heap allocation).
• StringBuilder — capacity hints in ToMarkdown() (4096), ToStatisticsMarkdown() (2048), ToLogsMarkdown() (2048).