Provider Quickstart

Goal: Connect your MCP-compatible product to the LenserFight MCP server, authorize a user, and make a successful list_lenses call — in under 5 minutes.

What you need:

• An MCP-compatible client (Claude.ai, Cursor, or any client that implements OAuth 2.1 PKCE + RFC 7591)
• A LenserFight account at lenserfight.com with a Lenser handle chosen

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Step 1 — Point your client at the endpoint

The LenserFight MCP server is hosted on LF Cloud. The single stable endpoint is:

https://mcp.lenserfight.com/mcp

This URL handles all MCP JSON-RPC requests, OAuth discovery, token exchange, and health checks. There is no separate base URL needed.

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Step 2 — Register your OAuth client (automatic)

You do not pre-register with LenserFight. On the first connection your client calls:

POST https://mcp.lenserfight.com/oauth/register
Content-Type: application/json

{
  "client_name": "My AI Product",
  "redirect_uris": ["https://myproduct.com/api/mcp/auth_callback"]
}

Response:

{
  "client_id": "lf_mcp_client_abc123...",
  "redirect_uris": ["https://myproduct.com/api/mcp/auth_callback"],
  "token_endpoint_auth_method": "none"
}

Save client_id. Use it in every authorization request going forward. Most MCP client libraries handle this step automatically — you only need to supply your redirect URI.

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Step 3 — Authorize a user (PKCE flow)

Generate a PKCE code verifier and challenge, then redirect the user to:

https://mcp.lenserfight.com/oauth/authorize
  ?response_type=code
  &client_id=lf_mcp_client_abc123...
  &redirect_uri=https://myproduct.com/api/mcp/auth_callback
  &code_challenge=<S256_hash_of_verifier>
  &code_challenge_method=S256
  &state=<random_csrf_token>

The server renders an HTML login form. The user enters their LenserFight email and password.

On success, the server redirects to your redirect_uri with ?code=lf_mcp_<hex>&state=<your_state>.

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Step 4 — Exchange the code for a token

POST https://mcp.lenserfight.com/oauth/token
Content-Type: application/x-www-form-urlencoded

grant_type=authorization_code
&code=lf_mcp_<the_code_from_step_3>
&redirect_uri=https://myproduct.com/api/mcp/auth_callback
&client_id=lf_mcp_client_abc123...
&code_verifier=<your_original_verifier>

Response:

{
  "access_token": "lf_mcp_abc123...",
  "token_type": "bearer"
}

Store the access_token. This is a long-lived MCP token — it does not expire unless the user revokes it. You call the MCP endpoint with this token for all future requests.

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Step 5 — Make your first tool call

POST https://mcp.lenserfight.com/mcp
Authorization: Bearer lf_mcp_abc123...
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "list_lenses",
    "arguments": { "limit": 5 }
  }
}

Success response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\"items\":[...],\"total\":42,\"limit\":5,\"offset\":0,\"has_more\":true}"
      }
    ]
  }
}

If you see "items" in the response, your integration is working.

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Claude.ai example (no code)

If your product is Claude.ai:

1. Open claude.ai → Settings → Connectors → Add custom connector.
2. Set Remote MCP server URL to:

   https://mcp.lenserfight.com/mcp

3. Leave OAuth Client ID and Secret blank (dynamic registration handles it).
4. Click Add. Sign in with your LenserFight credentials when the popup appears.
5. Start a new chat and ask: "Use LenserFight to list my lenses."

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Cursor / VS Code example

Add to your MCP config file (e.g., ~/.cursor/mcp.json or .mcp.json in your workspace):

{
  "mcpServers": {
    "lenserfight": {
      "url": "https://mcp.lenserfight.com/mcp"
    }
  }
}

Cursor will detect the OAuth requirement from the discovery document and initiate the authorization flow the first time you invoke a LenserFight tool.

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Verify the connection is healthy

At any time:

curl https://mcp.lenserfight.com/health
# {"status":"ok","server":"lenserfight-mcp","version":"1.0.0"}

Or from within your AI assistant:

"Call list_lenses with limit=1 using the LenserFight connection."

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What's next

I want to…	Go to…
Understand all connection options (HTTP, stdio, tunnel)	Connection Modes
Implement OAuth 2.1 PKCE manually	OAuth & Authentication
See every available tool	All 31 Tools
Understand the architecture and RLS	Integration Guide

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Common errors at this stage

Error	Cause	Fix
Sign-in failed	Wrong email or password	Confirm credentials at lenserfight.com
No Lenser profile found	Account exists but onboarding not completed	Sign in to lenserfight.com, choose a handle
401 Unauthorized	Token missing or malformed	Confirm Authorization: Bearer lf_mcp_... header is present
mcp_token_exchange_failed	Discovery document advertised a localhost URL	Only happens in local dev; use the cloud endpoint for production