redis-scaffold

name	redis-scaffold
description	Generate code patterns for StackExchange.Redis.Extensions — Streams, Geo, VectorSet, Hash, Pub/Sub, Sets, Compression

Redis Scaffold

Generate production-ready code patterns using StackExchange.Redis.Extensions.

When to use

When the user asks to implement:

• Redis Streams consumer group workflow
• GeoSpatial search (nearby locations)
• VectorSet similarity search (RAG, recommendations)
• Hash operations with per-field TTL
• Pub/Sub messaging
• Caching patterns (cache-aside, write-through)
• Bulk operations

Patterns

Cache-Aside Pattern

public class ProductService(IRedisDatabase redis, IProductRepository repo)
{
    public async Task<Product?> GetProductAsync(int id)
    {
        var key = $"product:{id}";
        var cached = await redis.GetAsync<Product>(key);

        if (cached is not null)
            return cached;

        var product = await repo.GetByIdAsync(id);

        if (product is not null)
            await redis.AddAsync(key, product, TimeSpan.FromMinutes(30));

        return product;
    }
}

Consumer Group (Streams)

public class OrderProcessor(IRedisDatabase redis)
{
    public async Task ProcessAsync(CancellationToken ct)
    {
        await redis.StreamCreateConsumerGroupAsync("orders", "processors", "0-0", createStream: true);

        while (!ct.IsCancellationRequested)
        {
            var entries = await redis.StreamReadGroupAsync("orders", "processors", "worker-1", ">", count: 10); // ">" = read only new messages

            foreach (var entry in entries)
            {
                try
                {
                    // Process message
                    await redis.StreamAcknowledgeAsync("orders", "processors", entry.Id.ToString());
                }
                catch
                {
                    // Message stays in PEL for retry
                }
            }

            if (entries.Length == 0)
                await Task.Delay(1000, ct);
        }
    }
}

GeoSpatial Search

public class StoreLocator(IRedisDatabase redis)
{
    public async Task<GeoRadiusResult[]> FindNearbyAsync(double lat, double lon, double radiusKm)
    {
        return await redis.GeoSearchAsync("stores", lon, lat,
            new GeoSearchCircle(radiusKm, GeoUnit.Kilometers),
            count: 20, order: Order.Ascending);
    }

    public async Task AddStoreAsync(string id, double lat, double lon)
    {
        await redis.GeoAddAsync("stores", lon, lat, id);
    }
}

VectorSet Similarity Search (RAG)

public class DocumentSearch(IRedisDatabase redis)
{
    public async Task IndexAsync(string docId, float[] embedding, string title)
    {
        await redis.VectorSetAddAsync("docs",
            VectorSetAddRequest.Member(docId, embedding,
                attributes: $"""{{ "title": "{title}" }}"""));
    }

    public async Task<List<(string Id, double Score)>> SearchAsync(float[] queryVector, int topK = 5)
    {
        using var results = await redis.VectorSetSimilaritySearchAsync("docs",
            VectorSetSimilaritySearchRequest.ByVector(queryVector) with { Count = topK });

        var items = new List<(string, double)>();
        if (results is not null)
            foreach (var r in results.Span)
                items.Add((r.Member!, r.Score));

        return items;
    }
}

Hash with Per-Field TTL

public class SessionStore(IRedisDatabase redis)
{
    public async Task SetSessionDataAsync(string userId, string token, object profile)
    {
        var hashKey = $"user:{userId}";

        // Permanent profile data
        await redis.HashSetAsync(hashKey, "profile", profile);

        // Session token expires in 30 minutes
        await redis.HashSetWithExpiryAsync(hashKey, "token", token, TimeSpan.FromMinutes(30));
    }
}

Pub/Sub with Typed Messages

public class EventBus(IRedisDatabase redis)
{
    public async Task PublishAsync<T>(string channel, T message)
    {
        await redis.PublishAsync(new RedisChannel(channel, RedisChannel.PatternMode.Literal), message);
    }

    public async Task SubscribeAsync<T>(string channel, Func<T?, Task> handler)
    {
        await redis.SubscribeAsync<T>(new RedisChannel(channel, RedisChannel.PatternMode.Literal), handler);
    }
}

Bulk Operations with Expiry

public async Task CacheBulkAsync(IRedisDatabase redis, Dictionary<string, Product> products)
{
    var items = products.Select(p => Tuple.Create($"product:{p.Key}", p.Value)).ToArray();
    await redis.AddAllAsync(items, TimeSpan.FromHours(1));
}

Important Notes

• All values go through ISerializer — strings are JSON-encoded ("hello" → ""hello"")
• For raw Redis operations, use redis.Database directly
• KeyPrefix applies to both keys AND Pub/Sub channels
• VectorSet requires Redis 8.0+
• Hash field expiry requires Redis 7.4+
• Compression wraps ISerializer transparently — all operations benefit automatically
• Lease return types (VectorSet search) must be disposed after use