Crestapps Core MCP File Resources

CrestApps.Core MCP File Resources - Prompt Templates

Expose Remote Files as MCP Resources

You are a CrestApps.Core expert. Generate code and guidance for FTP and SFTP MCP resource types.

Guidelines

• Reference CrestApps.Core.AI.Mcp.Ftp for FTP and FTPS, and CrestApps.Core.AI.Mcp.Sftp for SFTP.
• Register AddCoreAIFtpMcpResources() or AddCoreAISftpMcpResources() directly on services after AddCoreAIMcpServer(), or use AddFtpResources() and AddSftpResources() on CrestAppsMcpServerBuilder.
• The handlers are FtpResourceTypeHandler for resource type ftp and SftpResourceTypeHandler for resource type sftp.
• Both resource types support a path URI variable. The variable is optional in the type metadata; an omitted value becomes /. Handlers reject null bytes and . or .. path segments, normalize separators, prefix the resulting path with /, and return text content with the configured or detected MIME type.
• Store credentials protected with the matching data-protection purpose. Do not put plaintext secrets in resource metadata.

Register Both Types

builder.Services.AddCrestAppsCore(crestApps => crestApps
    .AddAISuite(ai => ai
        .AddMcpServer(mcpServer => mcpServer
            .AddYesSqlStores()
            .AddFtpResources()
            .AddSftpResources())));

The equivalent direct registration is:

builder.Services
    .AddCoreAIMcpServer()
    .AddCoreAIFtpMcpResources()
    .AddCoreAISftpMcpResources();

Attach FTP Metadata

var protector = dataProtectionProvider.CreateProtector(
    FtpResourceConstants.DataProtectionPurpose);

resource.Put(new FtpConnectionMetadata
{
    Host = "files.example.com",
    Port = 21,
    Username = "reader",
    Password = protector.Protect(password),
    EncryptionMode = "Explicit",
    DataConnectionType = "AutoPassive",
    ConnectTimeout = 30,
    ReadTimeout = 30,
    RetryAttempts = 2,
});

FtpConnectionMetadata also supports ValidateAnyCertificate. Enable it only for development because it disables TLS certificate validation.

Attach SFTP Metadata

var protector = dataProtectionProvider.CreateProtector(
    SftpResourceConstants.DataProtectionPurpose);

resource.Put(new SftpConnectionMetadata
{
    Host = "sftp.example.com",
    Port = 22,
    Username = "reader",
    PrivateKey = protector.Protect(privateKeyPem),
    Passphrase = protector.Protect(passphrase),
    ConnectionTimeout = 30,
    KeepAliveInterval = 30,
});

SftpConnectionMetadata contains proxy fields (ProxyType, ProxyHost, ProxyPort, ProxyUsername, and ProxyPassword), but the current handler does not apply them to its ConnectionInfo. The handler validates Host and requires at least one protected password or private key. It reads protected Password, PrivateKey, and Passphrase; provide Username because the SSH authentication methods use it.

Connection Metadata

Use an McpResource with the matching type and URI, then store the connection model with Put(...). The metadata is read by the handler at resource-read time, not exposed to the MCP client as tool arguments.