# recipe-upload-presigned - Source: `modules/api/src/web/upload.ts` - Capability tags: upload, presigned-url, blob - Applicability: sample-project - Notes: - Reference presigned upload URL generation and validation patterns. ## Reference Code ```typescript import type { Principal } from '@travetto/auth'; import { Authenticated } from '@travetto/auth-web'; import { Inject } from '@travetto/di'; import { Match, Schema } from '@travetto/schema'; import { ContextParam, Controller, Post } from '@travetto/web'; import type { UploadService } from '../services/upload.ts'; /** Request body for obtaining a presigned upload URL */ @Schema() export class UploadRequest { /** MIME type of the file to be uploaded */ @Match(/^(image\/(jpeg|png|webp|gif)|application\/pdf|text\/html|text\/plain)$/) contentType: string; } /** Response containing the presigned URL and the resulting S3 object key */ export type UploadResponse = { /** Presigned S3 PUT URL (expires in 5 minutes) */ uploadUrl: string; /** S3 object key; use this as the imageUrl once the upload is complete */ key: string; /** Public URL of the uploaded file */ imageUrl: string; }; /** Request body for resolving a single artifact key or URL to a presigned read URL */ @Schema() export class ResolveArtifactRequest { key: string; } /** * Controller for generating presigned S3 upload URLs for files */ @Controller('/upload') @Authenticated() export class UploadController { @Inject() uploadService: UploadService; @ContextParam() user: Principal; /** * Generate a presigned S3 PUT URL for a direct file upload. * The client should PUT the file binary directly to `uploadUrl` * with the matching `Content-Type` header, then use `imageUrl` to reference it. */ @Post('/prepareUpload') async postUploadUrl(request: UploadRequest): Promise { return await this.uploadService.prepareUpload(this.user.id, request.contentType); } /** * Exchange a single artifact key or URL for a fresh presigned S3 read URL. */ @Post('/resolveArtifact') async resolveArtifact(request: ResolveArtifactRequest): Promise<{ url: string }> { const url = await this.uploadService.resolveReadUrl(this.user.id, request.key); return { url }; } } ```