feat: implement list all files method

src/AnthropicClient/AnthropicApiClient.cs

@@ -397,6 +397,15 @@ public class AnthropicApiClient : IAnthropicApiClient
     return await CreateResultAsync<Page<AnthropicFile>>(response);
   }
 
+  /// <inheritdoc/>
+  public async IAsyncEnumerable<AnthropicResult<Page<AnthropicFile>>> ListAllFilesAsync(int limit = 20, [EnumeratorCancellation] CancellationToken cancellationToken = default)
+  {
+    await foreach (var result in GetAllPagesAsync<AnthropicFile>(FilesEndpoint, limit, cancellationToken))
+    {
+      yield return result;
+    }
+  }
+
   private async IAsyncEnumerable<AnthropicResult<Page<T>>> GetAllPagesAsync<T>(string endpoint, int limit = 20, [EnumeratorCancellation] CancellationToken cancellationToken = default)
   {
     var pagingRequest = new PagingRequest(limit: limit);

src/AnthropicClient/IAnthropicApiClient.cs

@@ -127,4 +127,12 @@ public interface IAnthropicApiClient
   /// <param name="cancellationToken">A token to cancel the asynchronous operation.</param>
   /// <returns>A task that represents the asynchronous operation. The task result contains the response as an <see cref="AnthropicResult{T}"/> where T is <see cref="Page{T}"/> where T is <see cref="AnthropicFile"/>.</returns>
   Task<AnthropicResult<Page<AnthropicFile>>> ListFilesAsync(PagingRequest? request = null, CancellationToken cancellationToken = default);
+
+  /// <summary>
+  /// Lists all files asynchronously, returning every page of results.
+  /// </summary>
+  /// <param name="limit">The maximum number of files to return in each page.</param>
+  /// <param name="cancellationToken">A token to cancel the asynchronous operation.</param>
+  /// <returns>An asynchronous enumerable that yields the response as an <see cref="AnthropicResult{T}"/> where T is <see cref="Page{T}"/> where T is <see cref="AnthropicFile"/>.</returns>
+  IAsyncEnumerable<AnthropicResult<Page<AnthropicFile>>> ListAllFilesAsync(int limit = 20, CancellationToken cancellationToken = default);
 }

tests/AnthropicClient.Tests/EndToEnd/AnthropicApiClientTests.cs

@@ -726,4 +726,22 @@ public class AnthropicApiClientTests(ConfigurationFixture configFixture) : EndTo
     result.Value.Should().BeOfType<Page<AnthropicFile>>();
     result.Value.Data.Should().ContainSingle(f => f.Id == createdFile.Value.Id);
   }
+
+  [Fact]
+  public async Task ListAllFilesAsync_WhenCalled_ItShouldReturnAllFiles()
+  {
+    var httpClient = new HttpClient();
+    httpClient.DefaultRequestHeaders.Add("anthropic-beta", "files-api-2025-04-14");
+    var client = CreateClient(httpClient);
+
+    var fileBytes = await File.ReadAllBytesAsync(TestFileHelper.GetTestFilePath("story.txt"));
+    var createFileRequest = new CreateFileRequest(fileBytes, "story.txt", "text/plain");
+    var createdFile = await client.CreateFileAsync(createFileRequest);
+
+    var responses = await client.ListAllFilesAsync(limit: 1).ToListAsync();
+
+    responses.Should().HaveCountGreaterThan(0);
+    responses.Select(r => r.Value).SelectMany(p => p.Data)
+      .Should().ContainSingle(f => f.Id == createdFile.Value.Id);
+  }
 }

tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs

@@ -2068,4 +2068,103 @@ public class AnthropicApiClientTests : IntegrationTest
       }
     });
   }
+
+  [Fact]
+  public async Task ListAllFilesAsync_WhenCalled_ItShouldReturnAllFiles()
+  {
+    _mockHttpMessageHandler
+      .WhenListFilesRequest()
+      .WithExactQueryString(new Dictionary<string, string>()
+      {
+        { "limit", "20" },
+      })
+      .Respond(
+        HttpStatusCode.OK,
+        "application/json",
+        @"{
+            ""data"": [
+              {
+                ""created_at"": ""2023-11-07T05:31:56Z"",
+                ""downloadable"": false,
+                ""filename"": ""example.txt"",
+                ""id"": ""file_013Zva2CMHLNnXjNJJKqJ2EF"",
+                ""mime_type"": ""text/plain"",
+                ""size_bytes"": 1234,
+                ""type"": ""file""
+              }
+            ],
+            ""has_more"": true,
+            ""first_id"": ""1"",
+            ""last_id"": ""1""
+          }"
+      );
+
+    _mockHttpMessageHandler
+      .WhenListFilesRequest()
+      .WithExactQueryString(new Dictionary<string, string>()
+      {
+        { "after_id", "1" },
+        { "limit", "20" },
+      })
+      .Respond(
+        HttpStatusCode.OK,
+        "application/json",
+        @"{
+            ""data"": [
+              {
+                ""created_at"": ""2023-11-07T05:31:56Z"",
+                ""downloadable"": false,
+                ""filename"": ""example.txt"",
+                ""id"": ""file_013Zva2CMHLNnXjNJJKqJ2EF"",
+                ""mime_type"": ""text/plain"",
+                ""size_bytes"": 1234,
+                ""type"": ""file""
+              }
+            ],
+            ""has_more"": false,
+            ""first_id"": ""2"",
+            ""last_id"": ""2""
+          }"
+      );
+
+    var pageResponses = Client.ListAllFilesAsync();
+    var collectedPages = new List<Page<AnthropicFile>>();
+
+    await foreach (var response in pageResponses)
+    {
+      response.IsSuccess.Should().BeTrue();
+      response.Value.Should().BeOfType<Page<AnthropicFile>>();
+      collectedPages.Add(response.Value);
+    }
+
+    var expectedFile = new AnthropicFile()
+    {
+      CreatedAt = DateTimeOffset.Parse("2023-11-07T05:31:56Z"),
+      Downloadable = false,
+      Name = "example.txt",
+      Id = "file_013Zva2CMHLNnXjNJJKqJ2EF",
+      MimeType = "text/plain",
+      Size = 1234,
+      Type = "file"
+    };
+
+    collectedPages.Should().HaveCount(2);
+    collectedPages.Should().BeEquivalentTo(new List<Page<AnthropicFile>>()
+    {
+      new()
+      {
+        Data = [expectedFile],
+        FirstId = "1",
+        LastId = "1",
+        HasMore = true
+      },
+      new()
+      {
+        Data = [expectedFile],
+        FirstId = "2",
+        LastId = "2",
+        HasMore = false
+      }
+    });
+  }
 }