Files and skills

Swift AI includes focused clients for provider resources that live outside a model request.

Referencing an upload in a message

uploadFile works against any client conforming to FileUploadAPI and tags the result with the provider, so the upload can be dropped straight into a message:

let uploaded = try await uploadFile(
  api: OpenAIFiles(),
  data: pdf,
  filename: "report.pdf",
  mediaType: "application/pdf"
)

let answer = try await generateText(
  model: OpenAIModel("gpt-5"),
  messages: [Message(role: .user, content: [
    .text("Summarize this."),
    .file(uploaded.file(mediaType: "application/pdf"))
  ])]
)

uploaded.file(mediaType:) and uploaded.image() build content parts whose providerReference maps a provider name to its file id (["openai": "file_123"]). A provider that recognizes its own key sends the id — OpenAI as file_id on an input_file / input_image, Anthropic as a file source — and a provider that does not simply ignores the reference, so a reference minted for one provider is never leaked to another.

OpenAI files

let files = OpenAIFiles() // OPENAI_API_KEY
let uploaded = try await files.upload(
  data: pdf,
  filename: "report.pdf",
  purpose: "user_data",
  mediaType: "application/pdf"
)

print(uploaded.id)
try await files.delete(id: uploaded.id)

OpenAIFiles uses https://api.openai.com/v1 by default. The returned UploadedFile contains the provider ID plus filename and size when available. See the OpenAI provider page for model APIs.

Anthropic files

let uploaded = try await AnthropicFiles().upload(
  data: pdf,
  filename: "report.pdf",
  mediaType: "application/pdf"
)

AnthropicFiles reads ANTHROPIC_API_KEY and adds the required Files API beta header. See the Anthropic provider page.

Anthropic skills

Upload a SKILL.md folder as reusable provider-hosted content:

let skill = try await AnthropicSkills().upload(
  files: [
    SkillFile(path: "brand-guide/SKILL.md", data: skillMarkdown),
    SkillFile(path: "brand-guide/references/tone.md", data: toneGuide),
  ],
  displayTitle: "Brand guide"
)

print(skill.id)

Paths are preserved in the multipart upload. AnthropicSkills handles the required Skills API beta header.