Streaming Large Payloads with ctx.bodyStream

For scenarios involving large payloads—such as streaming videos, log forwarding, or proxying requests—reading the entire payload into RAM is impractical.

Volten exposes ctx.bodyStream, which returns a Web Standard ReadableStream<Uint8Array>:

import { App } from "volten";
import { Writable } from "node:stream";
import { createWriteStream } from "node:fs";

const app = new App();

app.post("/upload-raw", async (ctx) => {
  const destination = createWriteStream("./uploads/large-file.bin");

  // Pipe Web Standard ReadableStream to Node.js WritableStream
  await ctx.bodyStream.pipeTo(Writable.toWeb(destination));

  return ctx.send("File saved successfully");
});

You can also consume chunks iteratively using for await:

app.post("/process-chunks", async (ctx) => {
  let totalBytes = 0;

  for await (const chunk of ctx.bodyStream) {
    totalBytes += chunk.length;
  }

  return ctx.json({ processedBytes: totalBytes });
});

Memory Protection

If an incoming payload exceeds Node.js's internal string limit (constants.MAX_STRING_LENGTH), ctx.body() rejects the operation to prevent V8 memory crashes and prompts you to use ctx.bodyStream.

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