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Home / Guides / MCP Publisher Guide {#mcp-publisher-guide}

MCP Publisher Guide {#mcp-publisher-guide}

Connect your MCP (Model Context Protocol) server to the Seren marketplace and monetize your tools with micropayments.

What are MCP Publishers? {#what-are-mcp-publishers}

MCP Publishers are a new type of integration that lets you expose an MCP server through Seren's unified marketplace. Instead of building REST APIs, you can:

Publisher Category Taxonomy {#publisher-category-taxonomy}

Seren uses a hierarchical taxonomy for publishers:

Category Subtypes Description
database serendb, neon, supabase Database-as-a-service providers
integration api, mcp External service integrations
compute template, workflow, function Compute resources

MCP publishers use:

Creating an MCP Publisher {#creating-an-mcp-publisher}

Prerequisites {#prerequisites}

  1. An MCP server with HTTP/SSE transport (Streamable HTTP)
  2. A Seren organization with API key
  3. A wallet address for receiving payments

Step 1: Register Your Publisher {#step-1-register}

curl -X POST "https://api.serendb.com/agent/publishers" \
  -H "Authorization: Bearer $SEREN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "My MCP Service",
    "slug": "my-mcp-service",
    "publisher_category": "integration",
    "integration_type": "mcp",
    "mcp_endpoint": "https://mcp.example.com/mcp",
    "description": "AI-powered data analysis tools",
    "wallet_address": "0x...",
    "wallet_network_id": "eip155:8453"
  }'

Step 2: Configure Authentication {#step-2-configure-auth}

MCP publishers support two authentication modes:

Option A: Static API Key

curl -X PUT "https://api.serendb.com/agent/publishers/my-mcp-service" \
  -H "Authorization: Bearer $SEREN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "upstream_api_key": "your-mcp-server-api-key",
    "api_key_header": "Authorization"
  }'

Option B: OAuth Token Exchange

curl -X PUT "https://api.serendb.com/agent/publishers/my-mcp-service" \
  -H "Authorization: Bearer $SEREN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "token_exchange_url": "https://auth.example.com/token",
    "token_exchange_method": "POST",
    "token_exchange_mode": "header",
    "token_cache_ttl_seconds": 3600
  }'

Step 3: Set Pricing {#step-3-set-pricing}

curl -X PUT "https://api.serendb.com/agent/publishers/my-mcp-service/pricing" \
  -H "Authorization: Bearer $SEREN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "price_per_call": "0.01",
    "min_charge": "0.001",
    "prepaid_enabled": true,
    "onchain_enabled": true
  }'

How Agents Use Your MCP Publisher {#how-agents-use-mcp-publishers}

Once registered, AI agents can discover and use your tools:

1. Discover Available Tools {#discover-tools}

Agent: "List tools for the my-mcp-service publisher"

→ Seren calls list_mcp_tools(publisher="my-mcp-service")
→ Returns: [analyze_data, generate_report, ...]

2. Call a Tool {#call-tool}

Agent: "Use my-mcp-service to analyze this dataset"

→ Seren calls call_mcp_tool(
    publisher="my-mcp-service",
    tool_name="analyze_data",
    arguments={"data": [...]}
  )
→ Charges SerenBucks based on pricing
→ Returns tool result

3. Read Resources {#read-resources}

Agent: "Get the latest report from my-mcp-service"

→ Seren calls read_mcp_resource(
    publisher="my-mcp-service",
    uri="reports://latest"
  )

MCP Server Requirements {#mcp-server-requirements}

Your MCP server must:

  1. Use HTTP/SSE transport - Streamable HTTP is required (not stdio)
  2. Support tool listing - Respond to tools/list requests
  3. Handle tool calls - Process tools/call requests and return results
  4. Be publicly accessible - Seren's gateway connects to your endpoint

Supported MCP Capabilities {#supported-capabilities}

Capability Supported Notes
Tools Yes Full support via call_mcp_tool
Resources Yes Full support via read_mcp_resource
Prompts Yes Available via MCP protocol
Sampling No Not supported in v1

Example: FastMCP Server {#example-fastmcp}

Here's a minimal MCP server using FastMCP:

from fastmcp import FastMCP

mcp = FastMCP("My Analysis Service")

@mcp.tool()
def analyze_data(data: list[float]) -> dict:
    """Analyze numerical data and return statistics."""
    return {
        "mean": sum(data) / len(data),
        "count": len(data),
        "min": min(data),
        "max": max(data)
    }

@mcp.resource("reports://latest")
def get_latest_report() -> str:
    """Get the most recent analysis report."""
    return "Latest report content..."

if __name__ == "__main__":
    mcp.run(transport="sse", port=8000)

Deploy this server, then register it as a Seren publisher with:

Pricing Models {#pricing-models}

MCP publishers can use flexible pricing:

Model Description Use Case
Per-call Fixed price per tool invocation Simple tools
Per-tool Different prices per tool Varied complexity
Response-based Price based on response size Data-heavy tools

Configure via update_publisher_pricing with your pricing strategy.

Monitoring & Analytics {#monitoring-analytics}

Track your publisher's usage in the Seren Console:

Troubleshooting {#troubleshooting}

Connection Issues {#connection-issues}

Problem: Seren can't reach your MCP endpoint

Solutions:

  1. Verify mcp_endpoint URL is publicly accessible
  2. Check firewall/security group settings
  3. Ensure HTTPS is properly configured
  4. Test with: curl -v https://your-endpoint/mcp

Authentication Failures {#auth-failures}

Problem: 401/403 errors when agents call tools

Solutions:

  1. Verify upstream_api_key is correct
  2. Check api_key_header matches your server's expected header
  3. For OAuth: verify token_exchange_url returns valid tokens

Tool Not Found {#tool-not-found}

Problem: Agent can't find a specific tool

Solutions:

  1. Verify tool is registered in your MCP server
  2. Check tool name matches exactly (case-sensitive)
  3. Call list_mcp_tools to see available tools

Next Steps {#next-steps}