Lyo.Sftp.Client 1.0.0

Lyo.Sftp.Client

Thin SFTP wrapper over SSH.NET for Lyo hosts and storage adapters (Lyo.IO.Temp.Sftp, Lyo.FileStorage.Sftp). Canonical APIs are *Async (Task + CancellationToken) backed by SSH.NET async methods and await-safe pool/per-client gates. Sync methods remain as thin blockers. Provides connection pooling with leases, POSIX path jail via Lyo.Common.Pathing.PathHelpers, host-key allow lists, optional password/private-key auth, ILogger diagnostics, and sftp.* metrics. Thread-safe for concurrent callers up to MaxPooledClients; do not share one leased Stream across threads.

Features

• Async-first — prefer *Async from hosts/adapters; sync wrappers block on the async implementation (no Task.Run).
• Pooled leases — MaxPooledClients concurrent SSH.NET clients; per-client SemaphoreSlim serializes ops across awaits.
• Thread-safe callers — concurrent use is supported and capped by the pool; one leased stream is not multi-thread safe.
• Path jail — all paths resolve under RootRemoteDirectory with PathStyle.Posix.
• Auth — password and/or PEM / key-file private key; host-key fingerprint allow list (or AcceptAny for tests).
• Observability — ILogger + IMetrics (sftp.connect, sftp.operation, sftp.bytes, sftp.pool, sftp.errors); EnableMetrics opt-out uses NullMetrics.
• DI — AddSftpClient / AddSftpClientFromConfiguration.

Examples

Registration

services.AddSftpClient(o =>
{
    o.Host = "sftp.example.com";
    o.Username = "lyo";
    o.Password = secret;
    o.RootRemoteDirectory = "/data/lyo";
    o.HostKeyPolicy = SftpHostKeyPolicy.FingerprintAllowList;
    o.AllowedHostKeyFingerprints.Add("SHA256:...");
});

Async upload / download

await client.UploadAsync("report.bin", bytes, ct);
var copy = await client.DownloadBytesAsync("report.bin", ct);

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.Common — (direct, lyo)
• Lyo.Exceptions — (direct, lyo)
• Lyo.Metrics — (direct, lyo)
• Microsoft.Extensions.Configuration.Binder 10.0.5 — (direct, microsoft)
• Microsoft.Extensions.DependencyInjection.Abstractions 10.0.5 — (direct, microsoft)
• Microsoft.Extensions.Logging.Abstractions 10.0.5 — (direct, microsoft)
• SSH.NET 2025.1.0 — (direct, third-party)
• Microsoft.Extensions.Options.ConfigurationExtensions 10.0.5 — (transitive, microsoft)
• System.Memory 4.6.3 — (transitive, microsoft, netstandard2.0)
• System.Text.Json 10.0.5 — (transitive, microsoft, netstandard2.0)