FLUX MCP

FLUX MCP

Bring FLUX into the tools you already use. Generate, edit, vary, and browse FLUX images from any MCP-compatible client.

Install · Showcase · Tools · Examples · Troubleshooting

The FLUX MCP server exposes the full FLUX.2 toolkit — text-to-image, image editing, multi-reference composition, variations, and history — to any client that speaks the Model Context Protocol. Generate options in parallel, edit attached images through prompts, and branch into variations from any result you like. No API code, no keys pasted into the conversation.

• Hosted, remote, OAuth-only. Connect to https://mcp.bfl.ai. Sign in with your BFL account, pick the org to bill — done.
• Every FLUX.2 model. Pro, Max, Klein (4B & 9B), Flex. Your client picks the right one for the task.
• Built for chat. Up to 8 images in parallel per prompt. Edit attached images. Browse and reuse history.
• You pay BFL directly. No middleman, no shared quotas. Current rates: bfl.ai/pricing.

Install

1. Open Settings → Connectors.
2. Click Add custom connector.
3. Name it FLUX, URL https://mcp.bfl.ai.
4. Click Connect, sign in, choose the BFL organization to bill.

claude mcp add --transport http FLUX https://mcp.bfl.ai

A browser opens on first use for OAuth. Tokens refresh automatically.

One-click: Add to Cursor — opens Cursor with the FLUX server pre-filled.

Manual — add to .cursor/mcp.json:

{
  "mcpServers": {
    "FLUX": {
      "url": "https://mcp.bfl.ai"
    }
  }
}

codex mcp add flux --url https://mcp.bfl.ai
codex mcp login flux

Or append to ~/.codex/config.toml:

[mcp_servers.flux]
url = "https://mcp.bfl.ai"

Edit ~/.codeium/windsurf/mcp_config.json (note Windsurf uses serverUrl, not url):

{
  "mcpServers": {
    "FLUX": {
      "serverUrl": "https://mcp.bfl.ai"
    }
  }
}

Reload plugins from the Cascade panel. The first FLUX call opens a browser for sign-in.

For clients that support stdio MCP but don't handle the OAuth flow themselves — for example Hermes (Nous Research) and similar tools that only accept static bearer tokens:

{
  "mcpServers": {
    "FLUX": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://mcp.bfl.ai"]
    }
  }
}

mcp-remote opens a browser for OAuth, caches tokens to ~/.mcp-auth/, and refreshes them automatically.

Showcase

Generate a batch of options in one prompt

"Generate 4 editorial portrait variants — varied lighting, palette, and mood."

Or just one — when a single hero shot is what you need

"A top-down aerial photograph of shallow desert salt pools, intense direct sunlight."

Edit any image directly in chat

"Add a camel on the sand."

Browse and reuse your full generation history

"Show me my recent FLUX generations."

Every generation is saved. Tap any tile to edit, vary, or download. Variations branch off any past image in one click.

Tools

Your client picks which tool to call based on your prompt — you don't need to invoke them by name.

Models

Available on generate_image:

The full catalog and per-model reference-image limits are also exposed as the bfl://models MCP resource.

Example prompts

Try these in your client once FLUX is connected:

Generate 4 editorial portrait variants — varied lighting, palette, and mood.
Use FLUX.2 [pro] at 1440×1792.

A top-down aerial photograph of shallow desert salt pools at golden hour,
intense direct sunlight, #FF6B6B and #F5E6D3 mineral deposits, FLUX.2 [max].

[attach an image]
Add a camel on the sand. Preserve the rest of the composition exactly.

Generate a movie poster with the title "MIRAGE" in 1970s grindhouse type,
high-contrast cyan and orange. Use FLUX.2 [flex].

Show me my recent FLUX generations.

[click Variations on a past image]
4 more like this one, vary the lighting.

Prompt tips

• Front-load the subject. Put the most important object, person, or scene first.
• Describe lighting. "Soft golden hour light" or "overcast diffused studio light" gives the model useful direction.
• Use hex colors. #FF6B6B (coral pink) is more precise than "pinkish red".
• Quote rendered text. Use exact quoted strings for typography, labels, posters, and signs.
• Avoid negative prompts. FLUX responds to what you describe, not a list of what to avoid.
• Iterate from results. Use Variations for alternatives, or Edit to keep refining a generated image.

For the full FLUX prompting playbook, see black-forest-labs/skills.

Troubleshooting

• Claude Desktop / claude.ai: Settings → Connectors, confirm FLUX shows as Connected. If it failed silently, remove and re-add — make sure pop-ups aren't blocked so the OAuth window can open.
• Claude Code: claude mcp list should show the server.
• Codex: codex mcp list should show flux. Start a new Codex session after adding.
• Quick smoke test: ask your client "check my BFL credits".

• Claude.ai / Desktop: Settings → Connectors → toggle FLUX off and on, or click Reconnect.
• Claude Code: /mcp shows status and reauth. Full rebuild:

  claude mcp remove FLUX
  claude mcp add --transport http FLUX https://mcp.bfl.ai
  

• Codex: codex mcp login flux. Full rebuild:

  codex mcp remove flux
  codex mcp add flux --url https://mcp.bfl.ai
  

• mcp-remote clients: rm -rf ~/.mcp-auth and restart the client to force a fresh OAuth.

• Make sure you have a BFL account at bfl.ai.
• Disconnect and reconnect the connector to redo OAuth.
• Check the selected organization has sufficient credits.
• Ask your client to check your BFL credits to verify the balance.

Large batches, FLUX.2 [max], or complex edits take longer than smaller generations. Visual MCP clients update the image view automatically.

Your MCP client needs permission to upload attached images to BFL. If your client blocks outbound HTTPS from its sandbox, allow *.bfl.ai or pass a public image URL instead.

Disconnect the FLUX connector in your client and reconnect it. The OAuth flow will prompt you to select an organization again.

Agent Skills (companion repo)

MCP and Agent Skills solve different problems:

Use both. They complement each other.

Links

• Docs — docs.bfl.ai
• Pricing — bfl.ai/pricing
• Status — status.bfl.ai
• Black Forest Labs — bfl.ai

License

MIT © Black Forest Labs