Ffl Mcp – Give Ai A "send File" Capability Via P2p (local First)

ffl-mcp (local-only)

MCP server for ffl. Let AI share anything for you.

Backed by ffl, which turns any file/folder into an HTTPS link.

This MCP server uses the ffl-python binding locally. No file contents are sent to the LLM; the model only triggers local ffl.

This demo shows collaborative debugging: Claude on the left shares a local environment (DB + logs) via P2P link, Claude on the right downloads and diagnoses the error. In this scenario, the two Claudes represent different people working on separate machines.

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Table of Contents

• Installation
  • Windows — GUI Installer
  • Linux / macOS — one-liner
  • Windows — one-liner (PowerShell)
  • uvx (no binary, requires uv)
  • Claude Code cloud sessions
  • Run directly (development)
• MCP Config (manual JSON)
• Tools
  • Sharing
  • Sharing from a Remote Agent
  • Downloading
  • Keygen
  • Session Management
• Notes
• Testing
• WSL2 Users

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Installation

⚡ Short URLs for convenience

• Linux/macOS: curl -fsSL https://fastfilelink.com/mcp/install.sh | bash
• Windows (script): iwr -useb https://fastfilelink.com/mcp/install.ps1 | iex

🔒 fastfilelink.com/mcp/* is a redirect to GitHub. Use the direct GitHub URLs below if you prefer.

Windows — GUI Installer

Download and run ffl-mcp-setup.exe from the latest release.

It registers the server with Claude Desktop, Claude Code, Codex, and Grok Build.

No command line needed — the installer registers ffl-mcp with Claude Desktop and Claude Code automatically.

Linux / macOS — one-liner

curl -fsSL https://raw.githubusercontent.com/nuwainfo/ffl-mcp/refs/heads/main/scripts/Install.sh | bash

Downloads the platform binary from the latest GitHub release and runs ffl-mcp install to register with Claude, Codex, and Grok Build. Falls back to uvx automatically if no binary is available for your platform.

Windows — one-liner (PowerShell)

iwr -useb https://raw.githubusercontent.com/nuwainfo/ffl-mcp/refs/heads/main/scripts/Install.ps1 | iex

Downloads ffl-mcp.exe from the latest GitHub release and registers it with Claude, Codex, and Grok Build.

uvx (no binary, requires uv)

uvx --from git+https://github.com/nuwainfo/ffl-mcp install

Targets can be controlled with --target (default: all):

uvx --from git+https://github.com/nuwainfo/ffl-mcp install --target claude-desktop,claude-code,codex,grok-build

uvx --from git+https://github.com/nuwainfo/ffl-mcp install --print

claude-code uses the Claude Code CLI. codex writes the native ~/.codex/config.toml configuration used by Codex clients. grok-build writes ~/.grok/config.toml, which Grok Build can reload from /mcps.

Legacy target names (claude-cli, codex-cli, codex-desktop, and grok) remain accepted as aliases. The installer first creates a timestamped backup of any config it changes.

For custom config paths, pass the file:

uvx --from git+https://github.com/nuwainfo/ffl-mcp install --config /path/to/claude_desktop_config.json
uvx --from git+https://github.com/nuwainfo/ffl-mcp install --codex-config /path/to/codex/config.toml
uvx --from git+https://github.com/nuwainfo/ffl-mcp install --grok-config /path/to/grok/config.toml

Claude Code cloud sessions

Cloud-hosted Claude Code sessions start in a fresh container. To make ffl-mcp available in every new session, open the cloud environment menu in the session title bar, choose Edit, and add this as the environment Setup script:

claude mcp add ffl -s user -e FFL_USE_STDIN=1 -- uvx --from git+https://github.com/nuwainfo/ffl-mcp ffl-mcp

The setup script runs when each new session starts. In the first new session, run claude mcp list to confirm that the ffl server was registered.

Run directly (development)

Prereq: uv installed.

# optional safety: restrict file sharing to a directory
export ALLOWED_BASE_DIR="$HOME/Downloads"

# optional: use stdin for text/base64 instead of temp files
export FFL_USE_STDIN=1

uvx --from git+https://github.com/nuwainfo/ffl-mcp ffl-mcp

MCP Config (manual JSON)

{
  "mcpServers": {
    "ffl": {
      "command": "uvx",
      "args": ["--from", "git+https://github.com/nuwainfo/ffl-mcp", "ffl-mcp"],
      "env": {
        "ALLOWED_BASE_DIR": "/Users/you/Downloads",
        "FFL_USE_STDIN": "1"
      }
    }
  }
}

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Tools

Sharing

Tool	Input
fflShareText(text, name?, ...)	Plain text
fflShareBase64(dataB64, name?, ...)	Binary data (base64-encoded)
fflShareFile(path, name?, ...)	Single local file or folder
fflShareFiles(paths, name?, ...)	Multiple files (ffl auto-zips them into one download)

Common options for all share tools:

Option	Default	Description
e2ee	False	End-to-end encryption
qrInTerminal	False	Return ASCII QR art (qrCode in response)
authUser / authPassword	—	HTTP Basic Auth to protect the link
maxDownloads	1	Stop serving after N downloads (P2P only)
timeoutSeconds	1800	Inactivity timeout in seconds (P2P only)
recipientAuth	—	pickup (6-digit code), pubkey (RSA), pubkey+pickup, or email (OTP)
pickupCode	auto	Specific pickup code for pickup mode
recipientPublicKey	—	Path to .fflpub file for pubkey mode
recipientEmail	—	Email(s) for email OTP mode, comma-separated
alias	—	Custom link alias e.g. my-release (requires Standard+ account)
receipt	—	Email notification when recipient downloads
receiptConfirm	—	Require recipient confirmation before download; pass a message or ""
forceRelay	False	Disable WebRTC, route all traffic through tunnel
transport	—	Explicitly choose p2p or relay. p2p overrides an automatically detected managed-sandbox relay profile.
preferredTunnel	—	Preferred ffl tunnel, for example default, default:web, cloudflare, ngrok, or bore. A caller-provided value overrides an automatic profile choice.
port	—	Local HTTP server port (auto-detect by default). Useful with fixed tunnels.
invite	False	Open the ffl invite page in a local browser with the generated sharing link.
enableReporting	False	Enable ffl diagnostic error reporting. Disabled by default.
upload	—	Upload to FFL server instead of P2P — e.g. "1 day", "6 hours" (requires Standard+ account)
resumeUpload	False	Resume an interrupted upload
proxy	—	Proxy URL e.g. socks5://127.0.0.1:9050

Additional options for fflShareFile / fflShareFiles:

Option	Default	Description
preview	False	Append ?preview=true to the returned link, so ffl's download page opens straight into its full preview view instead of the normal floating card.
exclude	—	Glob or regex patterns to exclude, comma-separated — e.g. *.pyc,__pycache__ or re:\.env$
pause	—	Pause server upload at a percentage from 1 to 99. Requires upload.
vfs	False	Expose as VFS server (vfs:// URI) — fflShareFile only
preferredTunnel	—	Set preferred tunnel for this and future runs — cloudflare, ngrok, bore, etc.

preview only affects the returned link's query string and works for any share (single file, folder, or multi-file). The preview sidecar routes (/manifest, /file, /thumb — the manifest/thumbnail data behind that preview page) are a separate, always-on mechanism: MCP starts them automatically for folder shares and multi-file shares regardless of preview, and never for single-file shares.

Managed-sandbox policy: In ChatGPT Work, Grok Bot, a cloud-hosted Codex sandbox, or a Claude Code cloud session (Claude Code on the web / claude.ai/code, or a remote session started from the Claude app), use forceRelay=True and preferredTunnel="default:web" immediately. These environments may only allow outbound HTTPS through a proxy, with no usable UDP/ICE or raw TCP tunnels. Do not apply this rule to local Claude Code CLI, local Codex CLI, local Grok Build, or ordinary user machines.

Response fields: sessionId, link, pid, transportDecision, qrCode? (ASCII art when qrInTerminal=True), debugLogPath?. transportDecision reports the selected mode, reason, automatic status, and effective preferredTunnel.

Sharing from a Remote Agent

fflHowToShareFromRemoteAgent() is guidance for a cloud-hosted assistant such as Grok Bot when the user asks it to share a file or folder on the user's own computer. It instructs the assistant to operate on that computer, use an existing ffl/ffl.com when present, or locate the runtime bundled with the installed ffl-mcp or ffl-python package without relying on a fixed internal package path. Local agents such as Claude Code, Codex, and Cursor use fflShareFile directly and do not need this tool.

Downloading

fflDownload(url, outputPath?, resume?, authUser?, authPassword?,
            recipientAuth?, pickupCode?, recipientPrivateKey?, proxy?,
            enableReporting?)
  -> {ok, returncode, outputPath?, transferMode?, transferInfo?, message?, ...}

Downloads from FastFileLink URLs (WebRTC P2P when possible, HTTP fallback) or any HTTP(S) URL (works like wget).

transferMode	Meaning
webrtc_p2p	Direct peer-to-peer over WebRTC (fastest)
p2p_tcp / p2p_quic	Direct peer-to-peer over raw TCP/QUIC
http_fallback	HTTP relay when P2P fails
http_direct	Regular HTTP download (non-FastFileLink URL)

For authenticated links: pass recipientAuth + pickupCode (pickup mode) or recipientPrivateKey (pubkey mode). Set enableReporting=True only when you want to opt into ffl diagnostic error reporting for troubleshooting.

Keygen

fflKeygen(name?) -> {ok, returncode, output}

Generates an RSA keypair for passwordless pubkey recipient auth:

• <name>.fflpub — share with the sender (pass as recipientPublicKey)
• <name>.fflkey — keep private (pass as recipientPrivateKey when downloading)

Session Management

• fflListSessions() — list active share sessions
• fflStopSession(sessionId) — terminate a session
• fflGetSession(sessionId) — get session details
• fflGetSessionEvents(sessionId, limit=50) — retrieve webhook events

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Notes

• FFL_USE_STDIN=1 avoids writing text/base64 payloads to disk.
• Folder and multi-file previews start a local webhook server so FFL can register preview routes.
• FFL_DEBUG=1 saves ffl output to a temp log file; path returned as debugLogPath. Set FFL_DEBUG=/path/to/log.txt to use a fixed path.
• ALLOWED_BASE_DIR restricts fflShareFile/fflShareFiles to a specific directory.
• During installation, ffl-mcp probes example.com and stun.cloudflare.com in parallel for up to 0.5 seconds. If every answer is in the synthetic 198.18.0.0/15 range, it registers FFL_NETWORK_PROFILE=synthetic-dns-198-18; later shares immediately use relay through default:web instead of waiting for P2P. No profile is written for timeouts, failures, mixed answers, or ordinary networks.
• Pass --env FFL_NETWORK_PROFILE=p2p to install to override the install-time result, or use a share tool's transport value p2p for one direct-P2P attempt.

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Testing

# Unit + binary tests (no network needed)
python -m unittest discover -s tests -p "*Test.py" -v

# All tests including share/download round-trips (requires network)
FFL_INTEGRATION_TESTS=1 python -m unittest discover -s tests -p "*Test.py" -v

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