Convert XLSX to MD API

Convert XLSX to MD in three requests

Authenticate with a bearer key from your backend (never ship the key to the browser). Submit the conversion, upload the file to the presigned URL, poll until it is done, and download the result.

curl

# 1. Submit the conversion
curl -X POST https://hushvert.com/api/v1/conversions \
  -H "Authorization: Bearer $HUSHVERT_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{ "pair": "xlsx-to-md", "bytes": '$(wc -c < input.xlsx)' }'
# -> { "jobId": "...", "uploadUrl": "...", "pollUrl": "/api/v1/conversions/..." }

# 2. Upload the file to the presigned uploadUrl
curl -X PUT "$UPLOAD_URL" --data-binary @input.xlsx

# 3. Poll until done, then download
curl https://hushvert.com/api/v1/conversions/$JOB_ID \
  -H "Authorization: Bearer $HUSHVERT_KEY"
# -> { "status": "done", "downloadUrl": "...", "expiresAt": "..." }
curl -o output.md "$DOWNLOAD_URL"

Node.js

import { readFile, writeFile } from 'node:fs/promises'

const KEY = process.env.HUSHVERT_KEY
const bytes = await readFile('input.xlsx')

// 1. Submit
const submit = await fetch('https://hushvert.com/api/v1/conversions', {
  method: 'POST',
  headers: { authorization: `Bearer ${KEY}`, 'content-type': 'application/json' },
  body: JSON.stringify({ pair: 'xlsx-to-md', bytes: bytes.byteLength }),
}).then((r) => r.json())

// 2. Upload to the presigned URL
await fetch(submit.uploadUrl, { method: 'PUT', body: bytes })

// 3. Poll until done
let job
do {
  await new Promise((r) => setTimeout(r, 1500))
  job = await fetch(`https://hushvert.com${submit.pollUrl}`, {
    headers: { authorization: `Bearer ${KEY}` },
  }).then((r) => r.json())
} while (job.status !== 'done' && job.status !== 'failed')

// 4. Download
const out = await fetch(job.downloadUrl).then((r) => r.arrayBuffer())
await writeFile('output.md', Buffer.from(out))

Python

import os, time, requests

KEY = os.environ["HUSHVERT_KEY"]
data = open("input.xlsx", "rb").read()

# 1. Submit
submit = requests.post("https://hushvert.com/api/v1/conversions",
    headers={"Authorization": f"Bearer {KEY}"},
    json={"pair": "xlsx-to-md", "bytes": len(data)}).json()

# 2. Upload to the presigned URL
requests.put(submit["uploadUrl"], data=data)

# 3. Poll until done
job = {}
while job.get("status") not in ("done", "failed"):
    time.sleep(1.5)
    job = requests.get(f"https://hushvert.com{submit['pollUrl']}",
        headers={"Authorization": f"Bearer {KEY}"}).json()

# 4. Download
out = requests.get(job["downloadUrl"]).content
open("output.md", "wb").write(out)

Limits and pricing

Free per month	50 conversions per account, then pay per use from account credits.
Max file size	50 MB
Privacy	Input deleted the moment the conversion finishes; output kept about an hour, then deleted.

See the full request, error codes, and idempotency reference on the API keys page, and the plans on pricing.

Why an API for this?

This conversion needs a server-side toolchain a browser cannot run. The API gives it to you as a single HTTP call, with the infrastructure managed for you.

Everything a browser can do (images, HEIC, audio, archives, PDF page operations) runs free and on-device in the open-source @hushvert/engine SDK - no upload, no key. This API is only for XLSX to MD and the other server-only formats.

What is XLSX?

XLSX is the Excel workbook format introduced with Office 2007: a zip archive of XML sheets, styles and formulas. It is the default container for tabular data in business, but a workbook is a living calculation, not a document, so layouts shift between Excel versions and alternative spreadsheet apps. Exporting to PDF pins the printed view of each sheet so the numbers land in front of the reader exactly once, exactly as formatted.

What is MD?

MD (Markdown) is the plain-text writing format of the developer world: headings, lists, links and emphasis expressed with punctuation, readable raw, and rendered everywhere from GitHub to note-taking apps. Because it is just text, it diffs, versions and edits beautifully. Its weakness is the handoff: the moment a reader expects a Word document, markdown needs converting.

XLSX to MD API FAQ

How do I convert XLSX to MD with an API?

Send a POST to /api/v1/conversions with the pair and the byte count, upload the file to the presigned URL it returns, then poll until the job is done and download the result. It is three short requests; full code is above in curl, Node, and Python.

Why not just convert XLSX to MD myself?

You can, if you want to run and maintain the right native conversion toolchain. This conversion needs a server-side toolchain a browser cannot run. The API gives it to you as a single HTTP call, with the infrastructure managed for you.

What does it cost?

Every account gets 50 free conversions per month across all of its keys. Beyond that, the API draws on account credits, billed per conversion. Everything a browser can do is free and keyless in the open-source SDK.

What happens to my file?

The file uploads over an encrypted connection. The input is deleted the moment the conversion finishes; the converted output is kept for about an hour so you can download it, then deleted too.

Can my AI agent do this conversion?

Yes. The @hushvert/mcp Model Context Protocol server gives Claude Code, Cursor, and other agents a convert_file tool over this same API, so an agent can run the conversion in one call.

XLSX to MD conversion API