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File Upload

RadarOS supports multi-modal inputs over HTTP via file upload. Enable fileUpload in the router options to accept multipart/form-data requests. Uploaded files are converted to content parts (images, audio, documents) and passed to agents.

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Enable File Upload

import { createAgentRouter } from "@radaros/transport";

const router = createAgentRouter({
  agents: { assistant: myAgent },
  fileUpload: true, // Uses defaults
});

// Or with options
const router = createAgentRouter({
  agents: { assistant: myAgent },
  fileUpload: {
    maxFileSize: 50 * 1024 * 1024, // 50MB default
    maxFiles: 10,
    allowedMimeTypes: ["image/png", "image/jpeg", "application/pdf"],
  },
});

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FileUploadOptions

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maxFileSize
number
default:"52428800"
Maximum file size in bytes. Default: 50MB.
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maxFiles
number
default:"10"
Maximum number of files per request.
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allowedMimeTypes
string[]
Whitelist of MIME types. If omitted, all types are allowed (subject to maxFileSize).

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Supported MIME Types

TypeMIME TypesPart Type
Imageimage/png, image/jpeg, image/gif, image/webpimage
Audioaudio/mpeg, audio/mp3, audio/wav, audio/ogg, audio/webm, audio/flac, audio/aac, audio/mp4audio
FileAll othersfile
Images and audio are passed to vision/audio-capable models. Other files are passed as generic file parts.

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Request Format

Send a multipart/form-data request with:
  • input — Text input (string)
  • files — One or more file uploads
curl -X POST http://localhost:3000/api/agents/assistant/run \
  -F "input=What is in this image?" \
  -F "files=@/path/to/image.png"

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buildMultiModalInput

The transport layer uses buildMultiModalInput(body, files) internally to construct the agent input:
  • If no files: returns body.input (string)
  • If files: returns an array of content parts: [{ type: "text", text: "..." }, { type: "image", data: "<base64>", mimeType: "image/png" }, ...]
You can use this helper in custom middleware or handlers: 
import { buildMultiModalInput, createFileUploadMiddleware } from "@radaros/transport";

const upload = createFileUploadMiddleware({ maxFiles: 5 });
app.post("/custom", upload, async (req, res) => {
  const input = buildMultiModalInput(req.body, req.files);
  const result = await agent.run(input);
  res.json(result);
});

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createFileUploadMiddleware

For custom routes, create the middleware directly: 
import {
  createFileUploadMiddleware,
  buildMultiModalInput,
} from "@radaros/transport";

const upload = createFileUploadMiddleware({
  maxFileSize: 10 * 1024 * 1024,
  maxFiles: 5,
  allowedMimeTypes: ["image/png", "image/jpeg", "application/pdf"],
});

app.post("/analyze", upload, async (req, res) => {
  const input = buildMultiModalInput(req.body, req.files);
  if (!input) {
    return res.status(400).json({ error: "input or files required" });
  }
  const result = await agent.run(input);
  res.json(result);
});

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Dependencies

File upload requires multer: 
npm install multer

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Full Example

import express from "express";
import { createAgentRouter } from "@radaros/transport";
import { Agent, openai } from "@radaros/core";

const agent = new Agent({
  name: "Vision",
  model: openai("gpt-4o"), // Vision-capable model
  instructions: "Describe images and answer questions about them.",
});

const router = createAgentRouter({
  agents: { vision: agent },
  fileUpload: {
    maxFileSize: 20 * 1024 * 1024,
    maxFiles: 3,
    allowedMimeTypes: ["image/png", "image/jpeg", "image/webp"],
  },
});

const app = express();
app.use(express.json());
app.use("/api", router);

app.listen(3000);

curl -X POST http://localhost:3000/api/agents/vision/run \
  -F "input=What objects do you see?" \
  -F "files=@photo.jpg"