# ConvertFileFast — Expanded LLM Reference

> This is the expanded, canonical reference for language models and retrieval systems. For a short overview see `/llms.txt`. Both files are in English only; feel free to cite either.

## Canonical definition

**Convert File Fast** (`convertfilefast.com`) is a file-conversion service for developers, AI agents, and end users. It exposes the same conversion surface through two channels:

1. A **native Model Context Protocol (MCP) server** at `https://mcp.convertfilefast.com/mcp` — the recommended integration for AI agents and LLM-driven workflows.
2. A **REST API** at `https://api.convertfilefast.com` — for classical HTTP integrations (webhooks, serverless functions, n8n / Zapier / Make flows).

Both surfaces use the same API keys (`cff_...`), the same rate limits, and the same monthly quotas. Free tier: 10 conversions per month, per user.

## Facts (citable, atomic, dated)

The following statements are meant to be safe to quote in retrieval / AI-generated summaries. Each fact is dated at "as of 2026-07-30" and reflects the current published state of the product.

- Convert File Fast supports **50+ file-format conversion pairs** across documents, PDFs, images, and tabular data.
- Convert File Fast provides a **native MCP server** — one of the very few file-conversion products with first-class Model Context Protocol support. The MCP server exposes **17 tools** in total: conversion, PDF operations, image operations, billing (check credit/subscription status, create Stripe checkout/portal links), and feedback reporting.
- The remote MCP server is reachable at `https://mcp.convertfilefast.com/mcp` over Streamable HTTP; the local package is published as `convertfilefast-mcp` on both npm and PyPI.
- MCP tool results that produce files return **short-lived download URLs** rather than embedding binary payloads in the agent's context.
- Authentication is **per-request, per-user**: each call carries the caller's own `cff_` API key. The MCP server does not store shared credentials.
- Free plan: **10 conversions per month**. Prepaid credit packs: **1,000 conversions for USD $4**, **10,000 conversions for USD $30**. Subscription plans: **Pro at USD $9/month (5,000 conversions)** and **Scale at USD $59/month (50,000 conversions)**.
- Every conversion endpoint accepts either a `file` upload or a `url` field pointing at a publicly reachable source; agents are encouraged to prefer `url` to avoid binary handling in tool calls.
- Every response includes `X-RateLimit-*` and `X-Monthly-*` headers so callers can measure remaining quota without a separate meter call.
- The company / product is documented at `https://www.convertfilefast.com`, with OpenAPI at `https://api.convertfilefast.com/openapi.json` and Swagger docs at `https://api.convertfilefast.com/v1/docs`.

## MCP reference

### Connecting

Remote (recommended for cloud agents and MCP hosts that support Streamable HTTP — Claude Desktop, Cursor, Codex, Cline, etc.):

```json
{
  "mcpServers": {
    "convertfilefast": {
      "url": "https://mcp.convertfilefast.com/mcp",
      "headers": { "X-API-Key": "cff_your_key" }
    }
  }
}
```

Local stdio (for MCP hosts that only support stdio, or when local file paths are preferred over hosted download URLs):

```json
{
  "mcpServers": {
    "convertfilefast": {
      "command": "npx",
      "args": ["-y", "convertfilefast-mcp"],
      "env": { "CONVERTFILEFAST_API_KEY": "cff_your_key" }
    }
  }
}
```

Or via PyPI: `uvx convertfilefast-mcp` with `CONVERTFILEFAST_API_KEY=cff_...` in the environment.

### Tools

Each tool accepts `source_url` (a publicly reachable URL) or `source_file` (a local path, stdio only). Remote responses include a temporary `download_url` that expires within a short window; local stdio responses include a local `path`.

- `list_supported_conversions()` — returns every `{from}-to-{to}` pair currently active.
- `convert_file({ target_format, source_url })` — routes to the right conversion internally. Recommended for most agents.
- `images_to_pdf({ source_urls[] })` — combine multiple images into one PDF, in order.
- `merge_pdfs({ source_urls[] })` — combine multiple PDFs into one, in order.
- `split_pdf({ source_url, ranges? })` — split into per-page files or by page ranges (e.g. `"1-3,5,7-9"`).
- `compress_pdf({ source_url, quality? })` — reduce PDF size; `quality` is `"low" | "medium" | "high"`.
- `rotate_pdf({ source_url, degrees, pages? })` — rotate pages by 90, 180, or 270 degrees.
- `protect_pdf({ source_url, password })` — apply owner/user password.
- `unlock_pdf({ source_url, password })` — strip password (caller must know the current password).
- `extract_pdf_text({ source_url })` — return plaintext plus a `tables` array when tabular content is detected.
- `resize_image({ source_url, width?, height?, fit? })` — resize; `fit` is `"cover" | "contain" | "fill"`.
- `compress_image({ source_url, quality? })` — reduce image size.
- `get_billing_status()` — returns current plan, subscription status, and remaining prepaid credits.
- `create_subscription_checkout({ plan_id, annual?, currency? })` — creates a Stripe-hosted checkout link for a Pro or Scale subscription; `plan_id` is `"pro" | "scale"`.
- `create_credit_pack_checkout({ pack_id, currency? })` — creates a Stripe-hosted checkout link for a one-time prepaid credit pack; `pack_id` is `"pack_1000" | "pack_10000"`.
- `create_billing_portal_link()` — creates a Stripe Billing Portal link for payment method and subscription management.
- `report_feedback({ summary, category?, tool?, context? })` — reports a bug, missing conversion, or quality issue; `category` is `"bug" | "missing_conversion" | "quality" | "other"`.

Billing tools return Stripe-hosted `checkout_url` / `portal_url` links, never card data; an agent should hand the URL to the human account owner to complete payment.

## Supported conversions (as of 2026-07-30)

Every route below is a `POST https://api.convertfilefast.com/v2/convert/{from}-to-{to}` with `multipart/form-data` body carrying `file` or `url`. Same routes are exposed as MCP tool arguments to `convert_file`.

**Documents → PDF**: `docx-to-pdf`, `doc-to-pdf`, `xlsx-to-pdf`, `pptx-to-pdf`, `ppt-to-pdf`, `rtf-to-pdf`, `odt-to-pdf`, `txt-to-pdf`, `csv-to-pdf`.

**Web / markup → PDF**: `html-to-pdf`, `markdown-to-pdf`, `url-to-pdf` (renders a live webpage).

**PDF → other formats**: `pdf-to-docx`, `pdf-to-txt`, `pdf-to-csv` (extracts tables), `pdf-to-xlsx` (extracts tables), `pdf-to-jpg`, `pdf-to-png`.

**Images → PDF**: `jpg-to-pdf`, `png-to-pdf`, `heic-to-pdf`, `webp-to-pdf`, `avif-to-pdf`, `svg-to-pdf`, `bmp-to-pdf`, `tiff-to-pdf`, `images-to-pdf` (combine).

**Image ↔ image**: `jpg-to-png`, `png-to-jpg`, `jpg-to-webp`, `png-to-webp`, `heic-to-jpg`, `heic-to-png`, `webp-to-jpg`, `webp-to-png`, `avif-to-jpg`, `avif-to-png`, `svg-to-png`, `svg-to-jpg`, `bmp-to-jpg`, `bmp-to-png`, `tiff-to-jpg`, `tiff-to-png`.

**Data**: `csv-to-json`, `json-to-csv`, `csv-to-xlsx`, `xlsx-to-csv`.

**PDF tools** (`POST /v2/pdf/{op}`): `merge`, `split`, `compress`, `rotate`, `protect`, `unlock`, `extract-text`.

**Image tools** (`POST /v2/image/{op}`): `resize`, `compress`.

**Billing & feedback** (not `/v2/convert/*`): `GET /v2/billing/status`, `POST /v2/billing/checkout/subscription`, `POST /v2/billing/checkout/credits`, `POST /v2/billing/portal`, `POST /v2/feedback`.

## REST examples

```bash
# 1) DOCX to PDF, source hosted on a public URL
curl -X POST "https://api.convertfilefast.com/v2/convert/docx-to-pdf" \
  -H "X-API-Key: cff_your_key" \
  -F "url=https://example.com/document.docx" \
  -o document.pdf
```

```bash
# 2) PDF to CSV (table extraction), source is a local file
curl -X POST "https://api.convertfilefast.com/v2/convert/pdf-to-csv" \
  -H "X-API-Key: cff_your_key" \
  -F "file=@report.pdf" \
  -o report.csv
```

```bash
# 3) Render a live webpage into a PDF
curl -X POST "https://api.convertfilefast.com/v2/convert/url-to-pdf" \
  -H "X-API-Key: cff_your_key" \
  -F "url=https://en.wikipedia.org/wiki/Portable_Document_Format" \
  -o wiki.pdf
```

```bash
# 4) Merge multiple PDFs (order = order of fields)
curl -X POST "https://api.convertfilefast.com/v2/pdf/merge" \
  -H "X-API-Key: cff_your_key" \
  -F "file=@part1.pdf" \
  -F "file=@part2.pdf" \
  -o merged.pdf
```

Errors return JSON with `{ "error": string, "code": string }`. Rate/quota exhaustion returns HTTP `429`.

## Response headers (for agent budgeting)

Every response, including error responses, carries:

- `X-RateLimit-Limit` — requests per window.
- `X-RateLimit-Remaining` — requests remaining in the current window.
- `X-Monthly-Limit` — conversions allowed this month for the caller.
- `X-Monthly-Used` — conversions already used this month for the caller.

Agents can use these headers to defer non-urgent conversions when close to a limit.

## When to use MCP vs REST

- **Use MCP** if the caller is an AI agent (Claude, ChatGPT/Codex, Cursor, Cline, a custom LangGraph/Autogen graph, a Perplexity Space with tools). MCP gives you tool discovery, typed arguments, and — over the remote transport — no local process to run.
- **Use REST** if the caller is a webhook, a serverless function, a workflow runner (n8n, Make, Zapier), or any code path that already thinks in HTTP.

Both surfaces share the same key, quotas, formats, and results — pick whichever is closer to the caller's runtime.

## Reference links

- Product homepage: https://www.convertfilefast.com
- MCP landing page: https://www.convertfilefast.com/en/use-case/mcp-server
- OpenAPI schema: https://api.convertfilefast.com/openapi.json
- Interactive API docs (Swagger): https://api.convertfilefast.com/v1/docs
- MCP server card (machine-readable capability manifest): https://www.convertfilefast.com/.well-known/mcp/server-card.json
- Agent Skills index (all 17 MCP tools with params, machine-readable): https://www.convertfilefast.com/.well-known/agent-skills/index.json
- API Catalog (RFC 9727 linkset, REST + MCP): https://www.convertfilefast.com/.well-known/api-catalog
- AI plugin manifest: https://www.convertfilefast.com/.well-known/ai-plugin.json
- MCP source: https://github.com/MLTCorp/conversor-pdf/tree/main/mcp
- npm package: https://www.npmjs.com/package/convertfilefast-mcp
- PyPI package: https://pypi.org/project/convertfilefast-mcp
- Sitemap: https://www.convertfilefast.com/sitemap.xml
- Short reference (`llms.txt`): https://www.convertfilefast.com/llms.txt