Solr MCP Server

A Spring AI Model Context Protocol (MCP) server that provides tools for interacting with Apache Solr. Enables AI assistants like Claude to search, index, and manage Solr collections through the MCP protocol.

What's inside

• 🔍 Search Solr collections with filtering, faceting, and pagination
• 📝 Index documents in JSON, CSV, and XML
• 📁 Create collections with configurable shards, replicas, and configsets
• 📊 Manage collections and view statistics
• 🔧 Inspect schema
• 🔌 Transports: STDIO (Claude Desktop) and HTTP (MCP Inspector)
• 🔐 OAuth2 security with Auth0 (HTTP mode only)
• 🐳 Docker images built with Jib

Get started (users)

• Prerequisites: Java 25+, Docker (and Docker Compose), Git
• Start Solr with sample data:

  docker compose up -d
  

• Run the server:
  • STDIO mode (default):
    • Gradle:

      ./gradlew bootRun
      

    • JAR:

      ./gradlew build
      java -jar build/libs/solr-mcp-1.0.0-SNAPSHOT.jar
      

    • Docker:

      docker run -i --rm ghcr.io/apache/solr-mcp:latest
      

  • HTTP mode:
    • Gradle:

      PROFILES=http ./gradlew bootRun
      

    • JAR:

      PROFILES=http java -jar build/libs/solr-mcp-1.0.0-SNAPSHOT.jar
      

    • Docker:

      docker run -p 8080:8080 --rm -e PROFILES=http ghcr.io/apache/solr-mcp:latest
      

For more options (custom SOLR_URL, Linux host networking) see the Deployment Guide: docs/DEPLOYMENT.md

Claude Desktop

Add this to your Claude Desktop config (macOS path shown); then restart Claude.

STDIO mode (default)

Using Docker:

{
  "mcpServers": {
    "solr-mcp": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "ghcr.io/apache/solr-mcp:latest"],
        "env": {
            "SOLR_URL": "http://localhost:8983/solr/"
        }
    }
  }
}

Using JAR:

{
    "mcpServers": {
        "solr-mcp": {
            "command": "java",
            "args": [
                "-jar",
                "/absolute/path/to/solr-mcp-1.0.0-SNAPSHOT.jar"
            ],
            "env": {
                "SOLR_URL": "http://localhost:8983/solr/"
            }
        }
    }
}

HTTP mode

Using Docker:

{
    "mcpServers": {
        "solr-mcp": {
            "command": "docker",
            "args": [
                "run",
                "-p",
                "8080:8080",
                "--rm",
                "ghcr.io/apache/solr-mcp:latest"
            ],
            "env": {
                "PROFILES": "http",
                "SOLR_URL": "http://localhost:8983/solr/"
            }
        }
    }
}

Using JAR:

{
    "mcpServers": {
        "solr-mcp": {
            "command": "java",
            "args": [
                "-jar",
                "/absolute/path/to/solr-mcp-1.0.0-SNAPSHOT.jar"
            ],
            "env": {
                "PROFILES": "http",
                "SOLR_URL": "http://localhost:8983/solr/"
            }
    }
  }
}

Connecting to a running HTTP server

If you already have the MCP server running in HTTP mode (via Gradle, JAR, or Docker), you can connect Claude Desktop to it using mcp-remote:

Running via Gradle:

PROFILES=http ./gradlew bootRun

Running locally (JAR):

PROFILES=http java -jar build/libs/solr-mcp-1.0.0-SNAPSHOT.jar

Running via Docker:

docker run -p 8080:8080 --rm -e PROFILES=http ghcr.io/apache/solr-mcp:latest

Then add to your claude_desktop_config.json:

{
    "mcpServers": {
        "solr-mcp-http": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "http://localhost:8080/mcp"
            ]
        }
    }
}

More configuration options: see the Building Docker images section below.

Claude Code

Add Solr MCP to Claude Code using the CLI or by adding a .mcp.json file to your project root.

STDIO mode (default)

Using Docker (CLI):

claude mcp add --transport stdio solr-mcp -- docker run -i --rm ghcr.io/apache/solr-mcp:latest

Using JAR (CLI):

claude mcp add --transport stdio -e SOLR_URL=http://localhost:8983/solr/ solr-mcp -- java -jar /absolute/path/to/solr-mcp-1.0.0-SNAPSHOT.jar

Or add to your project's .mcp.json:

Using Docker:

{
  "mcpServers": {
    "solr-mcp": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "ghcr.io/apache/solr-mcp:latest"],
      "env": {
        "SOLR_URL": "http://localhost:8983/solr/"
      }
    }
  }
}

Using JAR:

{
  "mcpServers": {
    "solr-mcp": {
      "type": "stdio",
      "command": "java",
      "args": ["-jar", "/absolute/path/to/solr-mcp-1.0.0-SNAPSHOT.jar"],
      "env": {
        "SOLR_URL": "http://localhost:8983/solr/"
      }
    }
  }
}

HTTP mode

Start the server first (pick one):

# Gradle
PROFILES=http ./gradlew bootRun

# JAR
PROFILES=http java -jar build/libs/solr-mcp-1.0.0-SNAPSHOT.jar

# Docker
docker run -p 8080:8080 --rm -e PROFILES=http ghcr.io/apache/solr-mcp:latest

Then add to Claude Code:

claude mcp add --transport http solr-mcp http://localhost:8080/mcp

Or add to .mcp.json:

{
  "mcpServers": {
    "solr-mcp": {
      "type": "http",
      "url": "http://localhost:8080/mcp"
    }
  }
}

Security (OAuth2)

The Solr MCP server supports OAuth2 authentication when running in HTTP mode, providing secure access control for your MCP tools.

Features

• OAuth2 Resource Server: JWT token validation using Auth0 (or any OAuth2 provider)
• HTTP Mode Only: Security is only active when using the http profile
• CORS Support: Enabled for MCP Inspector compatibility
• Machine-to-Machine: Uses Client Credentials flow for service authentication

Quick Setup

1. Configure Auth0 (see detailed guide: security-docs/AUTH0_SETUP.md)

   • Create an Auth0 Application (Machine to Machine)
   • Create an Auth0 API with your audience identifier
   • Note your Domain, Client ID, Client Secret, and Audience

2. Set Environment Variable:

   export OAUTH2_ISSUER_URI=https://your-tenant.auth0.com/
   export PROFILES=http
   

3. Run the Server:

   ./gradlew bootRun
   

4. Get Access Token (using convenience script):

   ./scripts/get-auth0-token.sh --domain your-tenant.auth0.com \
     --client-id YOUR_CLIENT_ID \
     --client-secret YOUR_CLIENT_SECRET \
     --audience https://solr-mcp-api
   

5. Use the Token:

   curl -H "Authorization: Bearer YOUR_TOKEN" \
     http://localhost:8080/mcp
   

For complete setup instructions, see security-docs/AUTH0_SETUP.md

Available MCP tools

Search

Indexing

Collections

Schema

Available MCP Resources

MCP Resources provide a way to expose data that can be read by MCP clients. The Solr MCP Server provides the following resources:

Resource Autocompletion

The solr://{collection}/schema resource supports autocompletion for the {collection} parameter. MCP clients can use the completion API to get a list of available collection names.

Screenshots

• Claude Desktop (STDIO):

  

• MCP Inspector (HTTP):

  

• MCP Inspector (HTTP with OAuth2 - Success):

  

• MCP Inspector (HTTP with OAuth2 - Failure):

  

• MCP Inspector (STDIO):

  

Building Docker images

Three image artifacts cover the full transport × runtime matrix. The JVM image is built with Jib (clean stdout, multi-arch); the native variants are built with Paketo Cloud Native Buildpacks.

Run commands

# STDIO — Jib JVM (default profile is stdio)
docker run -i --rm \
    -e SOLR_URL=http://host.docker.internal:8983/solr/ \
    solr-mcp:latest

# STDIO — native (faster startup, smaller image)
docker run -i --rm \
    -e SOLR_URL=http://host.docker.internal:8983/solr/ \
    solr-mcp:latest-native-stdio

# HTTP — Jib JVM
docker run -p 8080:8080 --rm \
    -e PROFILES=http \
    -e SOLR_URL=http://host.docker.internal:8983/solr/ \
    solr-mcp:latest

# HTTP — native
docker run -p 8080:8080 --rm \
    -e PROFILES=http \
    -e SOLR_URL=http://host.docker.internal:8983/solr/ \
    solr-mcp:latest-native-http

Why three images

• Jib's JVM image is dual-mode because Jib uses a clean java -jar entrypoint with no launcher script. Stdout stays clean for MCP STDIO, and runtime PROFILES=http switches to web mode.
• Paketo's JVM image is unsuitable for stdio — its libjvm helpers (memory calculator, NMT, ca-certificates) write 6 lines to stdout before the JVM, breaking MCP's JSON-RPC stream. Verified end-to-end by DockerImageMcpClientStdioIntegrationTest (Spring AI MCP client times out on initialize()). Filed upstream as paketo-buildpacks/libjvm#482. We use Jib for the JVM image instead.
• Native images must AOT-pin to one profile. Spring AOT bakes spring.main.web-application-type into the binary at AOT time. Activating both profiles picks servlet (http overrides stdio), which forces Tomcat to start regardless of the runtime PROFILES value, breaking stdio. So we ship one native image per transport.

Claude Desktop (native, STDIO)

{
  "mcpServers": {
    "solr-mcp": {
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "SOLR_URL=http://host.docker.internal:8983/solr/",
        "solr-mcp:latest-native"
      ]
    }
  }
}

See docs/specs/graalvm-native-image.md for the native image design and known risks.

Documentation

• Auth0 Setup (OAuth2 configuration)
• GraalVM native image spec

Contributing

We welcome contributions!

• Start here: CONTRIBUTING.md

Support

• Issues: https://github.com/apache/solr-mcp/issues
• Discussions: https://github.com/apache/solr-mcp/discussions

License

Apache License 2.0 — see LICENSE

Acknowledgments

Built with:

• Spring AI MCP — https://spring.io/projects/spring-ai
• Apache Solr — https://solr.apache.org/
• Jib — https://github.com/GoogleContainerTools/jib
• Paketo Cloud Native Buildpacks — https://paketo.io/
• Testcontainers — https://www.testcontainers.org/
• Spring AI MCP Security — https://github.com/spring-ai-community/mcp-security