> ## Documentation Index
> Fetch the complete documentation index at: https://docs.firecrawl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# .NET

> Firecrawl .NET SDK is a wrapper around the Firecrawl API to help you easily turn websites into markdown.

## Installation

The official .NET SDK is maintained in the Firecrawl monorepo at [apps/dot-net-sdk](https://github.com/firecrawl/firecrawl/tree/main/apps/dot-net-sdk).

To install the Firecrawl .NET SDK, add the NuGet package:

<Tabs>
  <Tab title=".NET CLI">
    ```bash theme={null}
    dotnet add package firecrawl-sdk
    ```
  </Tab>

  <Tab title="Package Manager">
    ```powershell theme={null}
    Install-Package firecrawl-sdk
    ```
  </Tab>

  <Tab title="PackageReference">
    ```xml theme={null}
    <PackageReference Include="firecrawl-sdk" Version="1.0.0" />
    ```
  </Tab>
</Tabs>

<Note>Requires .NET 8.0 or later.</Note>

## Usage

1. Get an API key from [firecrawl.dev](https://firecrawl.dev)
2. Set the API key as an environment variable named `FIRECRAWL_API_KEY`, or pass it to the `FirecrawlClient` constructor

Here is a quick example using the current SDK API surface:

```csharp theme={null}
using Firecrawl;
using Firecrawl.Models;

var client = new FirecrawlClient("fc-your-api-key");

// Scrape a single page
var doc = await client.ScrapeAsync("https://firecrawl.dev",
    new ScrapeOptions { Formats = new List<object> { "markdown" } });

// Crawl a website
var job = await client.CrawlAsync("https://firecrawl.dev",
    new CrawlOptions { Limit = 5 });

Console.WriteLine(doc.Markdown);
Console.WriteLine($"Crawled pages: {job.Data?.Count ?? 0}");
```

### Scraping a URL

To scrape a single URL, use the `ScrapeAsync` method.

```csharp theme={null}
using Firecrawl.Models;

var doc = await client.ScrapeAsync("https://firecrawl.dev",
    new ScrapeOptions
    {
        Formats = new List<object> { "markdown", "html" },
        OnlyMainContent = true,
        WaitFor = 5000
    });

Console.WriteLine(doc.Markdown);
Console.WriteLine(doc.Metadata?["title"]);
```

#### JSON Extraction

Extract structured JSON with `JsonFormat` via the scrape endpoint:

```csharp theme={null}
using Firecrawl.Models;

var jsonFmt = new JsonFormat
{
    Prompt = "Extract the product name and price",
    Schema = new Dictionary<string, object>
    {
        ["type"] = "object",
        ["properties"] = new Dictionary<string, object>
        {
            ["name"] = new Dictionary<string, object> { ["type"] = "string" },
            ["price"] = new Dictionary<string, object> { ["type"] = "number" }
        }
    }
};

var doc = await client.ScrapeAsync("https://example.com/product",
    new ScrapeOptions
    {
        Formats = new List<object> { jsonFmt }
    });

Console.WriteLine(doc.Json);
```

### Crawling a Website

To crawl a website and wait for completion, use `CrawlAsync`. This method handles polling and pagination automatically.

```csharp theme={null}
using Firecrawl.Models;

var job = await client.CrawlAsync("https://firecrawl.dev",
    new CrawlOptions
    {
        Limit = 50,
        MaxDiscoveryDepth = 3,
        ScrapeOptions = new ScrapeOptions
        {
            Formats = new List<object> { "markdown" }
        }
    });

Console.WriteLine($"Status: {job.Status}");
Console.WriteLine($"Progress: {job.Completed}/{job.Total}");

if (job.Data != null)
{
    foreach (var page in job.Data)
    {
        Console.WriteLine(page.Metadata?["sourceURL"]);
    }
}
```

### Start a Crawl

Start a job without waiting using `StartCrawlAsync`.

```csharp theme={null}
using Firecrawl.Models;

var start = await client.StartCrawlAsync("https://firecrawl.dev",
    new CrawlOptions { Limit = 100 });

Console.WriteLine($"Job ID: {start.Id}");
```

### Checking Crawl Status

Check crawl progress with `GetCrawlStatusAsync`.

```csharp theme={null}
var status = await client.GetCrawlStatusAsync(start.Id!);
Console.WriteLine($"Status: {status.Status}");
Console.WriteLine($"Progress: {status.Completed}/{status.Total}");
```

### Cancelling a Crawl

Cancel a running crawl with `CancelCrawlAsync`.

```csharp theme={null}
var result = await client.CancelCrawlAsync(start.Id!);
Console.WriteLine(result);
```

### Mapping a Website

Discover links on a site using `MapAsync`.

```csharp theme={null}
using Firecrawl.Models;

var data = await client.MapAsync("https://firecrawl.dev",
    new MapOptions
    {
        Limit = 100,
        Search = "blog"
    });

if (data.Links != null)
{
    foreach (var link in data.Links)
    {
        Console.WriteLine(link);
    }
}
```

### Searching the Web

Search with optional search settings using `SearchAsync`.

```csharp theme={null}
using Firecrawl.Models;

var results = await client.SearchAsync("firecrawl web scraping",
    new SearchOptions
    {
        Limit = 10,
        Location = "US"
    });

if (results.Web != null)
{
    foreach (var hit in results.Web)
    {
        Console.WriteLine($"{hit.Title} - {hit.Url}");
    }
}
```

### Batch Scraping

Scrape multiple URLs in parallel using `BatchScrapeAsync`. This method handles polling and pagination automatically.

```csharp theme={null}
using Firecrawl.Models;

var urls = new List<string>
{
    "https://firecrawl.dev",
    "https://firecrawl.dev/blog"
};

var job = await client.BatchScrapeAsync(urls,
    new BatchScrapeOptions
    {
        Options = new ScrapeOptions
        {
            Formats = new List<object> { "markdown" }
        }
    });

if (job.Data != null)
{
    foreach (var doc in job.Data)
    {
        Console.WriteLine(doc.Markdown);
    }
}
```

#### Batch Scrape with Idempotency Key

To ensure duplicate requests are not processed, pass an `IdempotencyKey`:

```csharp theme={null}
var job = await client.BatchScrapeAsync(urls,
    new BatchScrapeOptions
    {
        IdempotencyKey = "my-unique-key",
        Options = new ScrapeOptions
        {
            Formats = new List<object> { "markdown" }
        }
    });
```

### Usage & Metrics

Check concurrency and remaining credits:

```csharp theme={null}
using Firecrawl.Models;

var concurrency = await client.GetConcurrencyAsync();
Console.WriteLine($"Concurrency: {concurrency.Current}/{concurrency.MaxConcurrency}");

var credits = await client.GetCreditUsageAsync();
Console.WriteLine($"Remaining credits: {credits.RemainingCredits}");
```

## Async Support

All methods in the .NET SDK are async by default and return `Task<T>`. They support `CancellationToken` for cooperative cancellation.

```csharp theme={null}
using Firecrawl.Models;

using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(30));

var doc = await client.ScrapeAsync("https://example.com",
    new ScrapeOptions
    {
        Formats = new List<object> { "markdown" }
    },
    cancellationToken: cts.Token);

Console.WriteLine(doc.Markdown);
```

## Configuration

The `FirecrawlClient` constructor supports the following options:

| Option          | Type          | Default                                              | Description                              |
| --------------- | ------------- | ---------------------------------------------------- | ---------------------------------------- |
| `apiKey`        | `string?`     | `FIRECRAWL_API_KEY` env var                          | Your Firecrawl API key                   |
| `apiUrl`        | `string?`     | `https://api.firecrawl.dev` (or `FIRECRAWL_API_URL`) | API base URL                             |
| `timeout`       | `TimeSpan?`   | 5 minutes                                            | HTTP request timeout                     |
| `maxRetries`    | `int`         | `3`                                                  | Automatic retries for transient failures |
| `backoffFactor` | `double`      | `0.5`                                                | Exponential backoff factor in seconds    |
| `httpClient`    | `HttpClient?` | Built from `timeout`                                 | Pre-configured HttpClient instance       |

```csharp theme={null}
using Firecrawl;

var client = new FirecrawlClient(
    apiKey: "fc-your-api-key",
    apiUrl: "https://api.firecrawl.dev",
    timeout: TimeSpan.FromMinutes(5),
    maxRetries: 3,
    backoffFactor: 0.5);
```

### Custom HTTP Client

You can pass a pre-configured `HttpClient` to control connection pooling, proxies, message handlers, and any other `HttpClient` feature. When provided, the `timeout` setting is ignored in favor of the client's own configuration.

```csharp theme={null}
using Firecrawl;

var handler = new HttpClientHandler
{
    Proxy = new WebProxy("http://proxy.example.com:8080"),
    UseProxy = true
};

var httpClient = new HttpClient(handler)
{
    Timeout = TimeSpan.FromSeconds(60)
};

var client = new FirecrawlClient(
    apiKey: "fc-your-api-key",
    httpClient: httpClient);
```

### Environment Variable Configuration

The SDK resolves configuration from environment variables when constructor parameters are omitted:

```csharp theme={null}
// Uses FIRECRAWL_API_KEY and FIRECRAWL_API_URL environment variables
var client = new FirecrawlClient();
```

## Error Handling

The SDK throws specific exceptions under `Firecrawl.Exceptions`.

```csharp theme={null}
using Firecrawl.Exceptions;
using Firecrawl.Models;

try
{
    var doc = await client.ScrapeAsync("https://example.com");
}
catch (AuthenticationException ex)
{
    Console.Error.WriteLine($"Auth failed: {ex.Message}");
}
catch (RateLimitException ex)
{
    Console.Error.WriteLine($"Rate limited: {ex.Message}");
}
catch (JobTimeoutException ex)
{
    Console.Error.WriteLine($"Job {ex.JobId} timed out after {ex.TimeoutSeconds}s");
}
catch (FirecrawlException ex)
{
    Console.Error.WriteLine($"Error {ex.StatusCode}: {ex.Message}");
}
```

The exception hierarchy:

| Exception                 | HTTP Code | When                                                    |
| ------------------------- | --------- | ------------------------------------------------------- |
| `AuthenticationException` | 401       | Invalid or missing API key                              |
| `RateLimitException`      | 429       | Too many requests                                       |
| `JobTimeoutException`     | —         | Async job (crawl/batch scrape) did not complete in time |
| `FirecrawlException`      | varies    | Base exception for all other API errors                 |

Transient failures (408, 409, 502, and other 5xx errors) are retried automatically with exponential backoff before an exception is thrown.

> Are you an AI agent that needs a Firecrawl API key? See [firecrawl.dev/agent-onboarding/SKILL.md](https://www.firecrawl.dev/agent-onboarding/SKILL.md) for automated onboarding instructions.