var client = new Client() .SetEndpoint("https://.cloud.appwrite.io/v1") .SetProject(Environment.GetEnvironmentVariable("APPWRITE_PROJECT_ID")) .SetKey(Environment.GetEnvironmentVariable("APPWRITE_API_KEY"));


## Code Examples

### User Management

```csharp
var users = new Users(client);

// Create user
var user = await users.Create(ID.Unique(), "user@example.com", null, "password123", "User Name");

// List users
var list = await users.List(new List<string> { Query.Limit(25) });

// Get user
var fetched = await users.Get("[USER_ID]");

// Delete user
await users.Delete("[USER_ID]");

Database Operations

Note: Use TablesDB (not the deprecated Databases class) for all new code. Only use Databases if the existing codebase already relies on it or the user explicitly requests it.

Tip: Prefer named arguments (e.g., databaseId: "...") for all SDK method calls. Only use positional arguments if the existing codebase already uses them or the user explicitly requests it.

var tablesDB = new TablesDB(client);

// Create database
var db = await tablesDB.Create(ID.Unique(), "My Database");

// Create row
var doc = await tablesDB.CreateRow("[DATABASE_ID]", "[TABLE_ID]", ID.Unique(),
    new Dictionary<string, object> { { "title", "Hello World" } });

// Query rows
var results = await tablesDB.ListRows("[DATABASE_ID]", "[TABLE_ID]",
    new List<string> { Query.Equal("title", "Hello World"), Query.Limit(10) });

// Get row
var row = await tablesDB.GetRow("[DATABASE_ID]", "[TABLE_ID]", "[ROW_ID]");

// Update row
await tablesDB.UpdateRow("[DATABASE_ID]", "[TABLE_ID]", "[ROW_ID]",
    new Dictionary<string, object> { { "title", "Updated" } });

// Delete row
await tablesDB.DeleteRow("[DATABASE_ID]", "[TABLE_ID]", "[ROW_ID]");

String Column Types

Note: The legacy string type is deprecated. Use explicit column types for all new columns.

Type	Max characters	Indexing	Storage
`varchar`	16,383	Full index (if size ≤ 768)	Inline in row
`text`	16,383	Prefix only	Off-page
`mediumtext`	4,194,303	Prefix only	Off-page
`longtext`	1,073,741,823	Prefix only	Off-page

varchar is stored inline and counts towards the 64 KB row size limit. Prefer for short, indexed fields like names, slugs, or identifiers.
text, mediumtext, and longtext are stored off-page (only a 20-byte pointer lives in the row), so they don't consume the row size budget. size is not required for these types.

// Create table with explicit string column types
await tablesDB.CreateTable("[DATABASE_ID]", ID.Unique(), "articles",
    new List<object> {
        new { key = "title",    type = "varchar",    size = 255, required = true  },  // inline, fully indexable
        new { key = "summary",  type = "text",                   required = false },  // off-page, prefix index only
        new { key = "body",     type = "mediumtext",             required = false },  // up to ~4 M chars
        new { key = "raw_data", type = "longtext",               required = false },  // up to ~1 B chars
    });

Query Methods

// Filtering
Query.Equal("field", "value")             // == (or pass array for IN)
Query.NotEqual("field", "value")          // !=
Query.LessThan("field", 100)             // <
Query.LessThanEqual("field", 100)        // <=
Query.GreaterThan("field", 100)          // >
Query.GreaterThanEqual("field", 100)     // >=
Query.Between("field", 1, 100)           // 1 <= field <= 100
Query.IsNull("field")                    // is null
Query.IsNotNull("field")                 // is not null
Query.StartsWith("field", "prefix")      // starts with
Query.EndsWith("field", "suffix")        // ends with
Query.Contains("field", "sub")           // contains
Query.Search("field", "keywords")        // full-text search (requires index)

// Sorting
Query.OrderAsc("field")
Query.OrderDesc("field")

// Pagination
Query.Limit(25)                          // max rows (default 25, max 100)
Query.Offset(0)                          // skip N rows
Query.CursorAfter("[ROW_ID]")            // cursor pagination (preferred)
Query.CursorBefore("[ROW_ID]")

// Selection & Logic
Query.Select(new List<string> { "field1", "field2" })
Query.Or(new List<string> { Query.Equal("a", 1), Query.Equal("b", 2) })   // OR
Query.And(new List<string> { Query.GreaterThan("age", 18), Query.LessThan("age", 65) })  // AND (default)

File Storage

var storage = new Storage(client);

// Upload file
var file = await storage.CreateFile("[BUCKET_ID]", ID.Unique(), InputFile.FromPath("/path/to/file.png"));

// List files
var files = await storage.ListFiles("[BUCKET_ID]");

// Delete file
await storage.DeleteFile("[BUCKET_ID]", "[FILE_ID]");

InputFile Factory Methods

using Appwrite.Models;

InputFile.FromPath("/path/to/file.png")                          // from filesystem path
InputFile.FromBytes(byteArray, "file.png", "image/png")          // from byte[]
InputFile.FromStream(stream, "file.png", "image/png", size)      // from Stream (size required)

Teams

var teams = new Teams(client);

// Create team
var team = await teams.Create(ID.Unique(), "Engineering");

// List teams
var list = await teams.List();

// Create membership (invite user by email)
var membership = await teams.CreateMembership(
    teamId: "[TEAM_ID]",
    roles: new List<string> { "editor" },
    email: "user@example.com"
);

// List memberships
var members = await teams.ListMemberships("[TEAM_ID]");

// Update membership roles
await teams.UpdateMembership("[TEAM_ID]", "[MEMBERSHIP_ID]", new List<string> { "admin" });

// Delete team
await teams.Delete("[TEAM_ID]");

Role-based access: Use Role.Team("[TEAM_ID]") for all team members or Role.Team("[TEAM_ID]", "editor") for a specific team role when setting permissions.

Serverless Functions

var functions = new Functions(client);

// Execute function
var execution = await functions.CreateExecution("[FUNCTION_ID]", body: "{\"key\": \"value\"}");

// List executions
var executions = await functions.ListExecutions("[FUNCTION_ID]");

Writing a Function Handler (.NET runtime)

// src/Main.cs — Appwrite Function entry point
using System.Text.Json;

public async Task<RuntimeOutput> Main(RuntimeContext context)
{
    // context.Req.Body        — raw body (string)
    // context.Req.BodyJson    — parsed JSON (JsonElement)
    // context.Req.Headers     — headers (Dictionary)
    // context.Req.Method      — HTTP method
    // context.Req.Path        — URL path
    // context.Req.Query       — query params (Dictionary)

    context.Log($"Processing: {context.Req.Method} {context.Req.Path}");

    if (context.Req.Method == "GET")
        return context.Res.Json(new { message = "Hello from Appwrite Function!" });

    return context.Res.Json(new { success = true });      // JSON
    // context.Res.Text("Hello");                         // plain text
    // context.Res.Empty();                               // 204
    // context.Res.Redirect("https://...");               // 302
}

Server-Side Rendering (SSR) Authentication

SSR apps using .NET frameworks (ASP.NET, Blazor Server, etc.) use the server SDK to handle auth. You need two clients:

Admin client — uses an API key, creates sessions, bypasses rate limits (reusable singleton)
Session client — uses a session cookie, acts on behalf of a user (create per-request, never share)

using Appwrite;
using Appwrite.Services;

// Admin client (reusable)
var adminClient = new Client()
    .SetEndpoint("https://<REGION>.cloud.appwrite.io/v1")
    .SetProject("[PROJECT_ID]")
    .SetKey(Environment.GetEnvironmentVariable("APPWRITE_API_KEY"));

// Session client (create per-request)
var sessionClient = new Client()
    .SetEndpoint("https://<REGION>.cloud.appwrite.io/v1")
    .SetProject("[PROJECT_ID]");

var session = Request.Cookies["a_session_[PROJECT_ID]"];
if (session != null)
{
    sessionClient.SetSession(session);
}

Email/Password Login (ASP.NET Minimal API)

app.MapPost("/login", async (HttpContext ctx, LoginRequest body) =>
{
    var account = new Account(adminClient);
    var session = await account.CreateEmailPasswordSession(body.Email, body.Password);

    // Cookie name must be a_session_<PROJECT_ID>
    ctx.Response.Cookies.Append("a_session_[PROJECT_ID]", session.Secret, new CookieOptions
    {
        HttpOnly = true,
        Secure = true,
        SameSite = SameSiteMode.Strict,
        Path = "/",
    });

    return Results.Ok(new { success = true });
});

Authenticated Requests

app.MapGet("/user", async (HttpContext ctx) =>
{
    var session = ctx.Request.Cookies["a_session_[PROJECT_ID]"];
    if (session == null) return Results.Unauthorized();

    var sessionClient = new Client()
        .SetEndpoint("https://<REGION>.cloud.appwrite.io/v1")
        .SetProject("[PROJECT_ID]")
        .SetSession(session);

    var account = new Account(sessionClient);
    var user = await account.Get();
    return Results.Ok(user);
});

OAuth2 SSR Flow

// Step 1: Redirect to OAuth provider
app.MapGet("/oauth", async () =>
{
    var account = new Account(adminClient);
    var redirectUrl = await account.CreateOAuth2Token(
        provider: OAuthProvider.Github,
        success: "https://example.com/oauth/success",
        failure: "https://example.com/oauth/failure"
    );
    return Results.Redirect(redirectUrl);
});

// Step 2: Handle callback — exchange token for session
app.MapGet("/oauth/success", async (HttpContext ctx, string userId, string secret) =>
{
    var account = new Account(adminClient);
    var session = await account.CreateSession(userId, secret);

    ctx.Response.Cookies.Append("a_session_[PROJECT_ID]", session.Secret, new CookieOptions
    {
        HttpOnly = true, Secure = true, SameSite = SameSiteMode.Strict, Path = "/",
    });

    return Results.Ok(new { success = true });
});

Cookie security: Always use HttpOnly, Secure, and SameSite = SameSiteMode.Strict to prevent XSS. The cookie name must be a_session_<PROJECT_ID>.

Forwarding user agent: Call sessionClient.SetForwardedUserAgent(ctx.Request.Headers["User-Agent"]) to record the end-user's browser info for debugging and security.

Error Handling

using Appwrite;

try
{
    var row = await tablesDB.GetRow("[DATABASE_ID]", "[TABLE_ID]", "[ROW_ID]");
}
catch (AppwriteException e)
{
    Console.WriteLine(e.Message);    // human-readable message
    Console.WriteLine(e.Code);       // HTTP status code (int)
    Console.WriteLine(e.Type);       // error type (e.g. "document_not_found")
    Console.WriteLine(e.Response);   // full response body
}

Common error codes:

Code	Meaning
`401`	Unauthorized — missing or invalid session/API key
`403`	Forbidden — insufficient permissions
`404`	Not found — resource does not exist
`409`	Conflict — duplicate ID or unique constraint
`429`	Rate limited — too many requests

Permissions & Roles (Critical)

Appwrite uses permission strings to control access to resources. Each permission pairs an action (read, update, delete, create, or write which grants create + update + delete) with a role target. By default, no user has access unless permissions are explicitly set at the row/file level or inherited from the table/bucket settings. Permissions are arrays of strings built with the Permission and Role helpers.

using Appwrite;
// Permission and Role are included in the main namespace

Database Row with Permissions

var doc = await tablesDB.CreateRow("[DATABASE_ID]", "[TABLE_ID]", ID.Unique(),
    new Dictionary<string, object> { { "title", "Hello World" } },
    new List<string>
    {
        Permission.Read(Role.User("[USER_ID]")),     // specific user can read
        Permission.Update(Role.User("[USER_ID]")),   // specific user can update
        Permission.Read(Role.Team("[TEAM_ID]")),     // all team members can read
        Permission.Read(Role.Any()),                 // anyone (including guests) can read
    });

File Upload with Permissions

var file = await storage.CreateFile("[BUCKET_ID]", ID.Unique(),
    InputFile.FromPath("/path/to/file.png"),
    new List<string>
    {
        Permission.Read(Role.Any()),
        Permission.Update(Role.User("[USER_ID]")),
        Permission.Delete(Role.User("[USER_ID]")),
    });

When to set permissions: Set row/file-level permissions when you need per-resource access control. If all rows in a table share the same rules, configure permissions at the table/bucket level and leave row permissions empty.

Common mistakes:

Forgetting permissions — the resource becomes inaccessible to all users (including the creator)

Role.Any() with write/update/delete — allows any user, including unauthenticated guests, to modify or remove the resource

Permission.Read(Role.Any()) on sensitive data — makes the resource publicly readable

appwrite-dotnet

Appwrite .NET SDK

Installation

Setting Up the Client