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Lucidworks MCP (Model Context Protocol) enables agentic search using Claude to search your Fusion data. You configure the connection once, and Claude can immediately search your indexed content.
Self-hosted Fusion users: See Monitor MCP Server usage to set up Grafana dashboards for tracking MCP request volume, latency, and error rates.
Claude can connect to Fusion using MCP

Benefits

Lucidworks MCP server provides these advantages:
  • Self-service integration: Configure Claude to access Fusion data without custom API development.
  • Enterprise security: Leverages Fusion’s existing security controls, including field-level security, role-based access, and audit logging.
  • Multi-pipeline access: Access multiple query pipelines through a single MCP endpoint, enabling Claude to search across different data sources and configurations based on context.
  • Multi-tenant architecture: Support multiple use cases with different data access patterns using query profiles and collection isolation.
  • Query pipeline integration: Claude benefits from your custom query pipelines, ML models, and relevance tuning.
  • Extensible tool framework: Add custom tools programmatically that automatically become available to Claude.

Supported AI clients

Lucidworks MCP works with any MCP-compatible AI client, including these popular clients:
  • Claude Code - Command-line AI agent with built-in MCP support (recommended for easiest setup).
  • Claude Desktop - Desktop application for conversational AI.

MCP server setup

Before you begin

Before configuring MCP access, ensure you have the following:
  • Fusion 5.17 or later deployed with the MCP Server service running
  • A Fusion app configured with indexed content
  • A query profile created for MCP access
  • Claude Code (recommended) or Claude Desktop
The MCP server runs on your Fusion infrastructure at https://FUSION_HOST/mcp.

Set up authentication

Fusion MCP Server supports two authentication methods:
Generate an API key in Fusion with the appropriate permissions for your transport mode.HTTP mode (Claude Code, custom integrations):
STDIO mode (Claude Desktop):
You can replace the wildcards with specific values from your search experience configuration:
To grant access to multiple search experiences, duplicate the permissions for each collection, app, and query profile combination.
Fusion 5.18 and later supports OAuth 2.1 authentication using external identity providers that support the OAuth 2.1 protocol. This enables enterprise single sign-on workflows and provides automatic token lifecycle management.Advantages over API keys:
  • User-specific access control tied to authenticated users
  • Automatic token expiration and refresh (access tokens expire after 30 minutes)
  • Immediate revocation when users are deleted
  • Standard protocol support for all OAuth 2.1-compliant AI clients
Prerequisites:Your external identity provider must support the following:
  • OAuth 2.0 / 2.1 with Authorization Code flow and PKCE (RFC 7636)
  • Authorization Server metadata (RFC 8414)
  • OAuth redirect URIs for callback handling:
    • Azure AD, Keycloak: Support wildcard redirect URIs like http://localhost/callback
    • Okta: Requires specific callback ports (for example, http://localhost:3118/callback)
Configuration steps:
1

Configure JWT realm in Fusion

Create a JWT realm in Fusion with the following configuration:
  • Issuer: Must match the external IDP’s issuer from the Authorization Server metadata
  • JWK Set URL: Must point to the external IDP’s public keys endpoint
See Configure Fusion for JWT for detailed setup instructions.
2

Pre-register OAuth client in your IDP

Create an OAuth client (Single Page Application type) in your external identity provider with the appropriate redirect URI:
  • Azure AD, Keycloak: Use wildcard redirect URI http://localhost/callback
  • Okta: Use specific callback port like http://localhost:3118/callback (or configure multiple ports)
Note the client ID for use in the next step.
Claude Code starts a local server on a random port for OAuth callbacks. IDPs that support wildcard redirect URIs work automatically. For Okta, users can specify a callback port using --callback-port when adding the MCP server.
3

Configure API Gateway environment variables

Set the following environment variables in the API Gateway service:
  • OAUTH_CLIENT_ID: The OAuth client identifier (pre-created in the external IDP) that will be returned to all MCP clients during registration
  • OAUTH_AUTHORIZATION_SERVER_URL: Base URL of the external IDP’s authorization server used to fetch OAuth metadata via /.well-known/oauth-authorization-server
Registration modes:Fusion supports two OAuth registration modes:
  • Dynamic registration: Use when your IDP does not require authorization for its registration endpoint. MCP clients can register directly using the registration_endpoint discovered from /.well-known/oauth-authorization-server.
  • Static registration: Use when your IDP requires authorization for its registration endpoint (such as Okta). Fusion exposes a /oauth2/register endpoint that returns the pre-configured OAUTH_CLIENT_ID to all MCP clients.

Configure the MCP server

In Fusion 5.18 and later, you configure MCP search experiences through the Query Profile panel in the Fusion UI. This is the only supported configuration method for 5.18+. Fusion 5.17 uses a configuration file (configmap) instead.
For any query profile, you can configure an MCP search experience in the Query Profiles panel of the Fusion UI. Repeat these steps for each query profile that you want to make available as an MCP search experience.
1

Open the query profile

In Fusion, navigate to Querying > Query Profiles and select the query profile you want to make available as an MCP search experience.
2

Enable the search experience

Scroll to the MCP Search Experience section and select the Enable for MCP Processing checkbox:
Enable the search experience and fill in the required fields
3

Configure search experience metadata

Fill in the required fields:
  • Name: Display name for this search experience (required)
  • Description: Description that helps Claude understand when to use this search experience (required)
  • Content Field: Optional field name to use as the document description source
The form validates that required fields are populated before allowing you to save.
How document descriptions are determined:When Content Field is specified:
  • If the field contains a value in the Query Profile response, that value is used.
  • If the field is empty, the MCP server falls back to checking default fields like body_t.
When Content Field is empty:
  • The MCP server checks default fields like body_t to generate document descriptions.
4

Save the query profile

Click Save to apply your changes. The search experience is immediately available to MCP clients.
Repeat these steps for each query profile you want to expose as an MCP search experience.
1

Open your Fusion configuration file

Open your Fusion values.yaml configuration file.
2

Add the MCP server configuration

Add the MCP server configuration to the query-pipeline service configuration with at least one search experience, as in this example:
Replace the example values above with your own Fusion configuration. You can configure multiple search experiences that point to different applications and query profiles. Claude automatically selects the appropriate search experience based on the query context and the search experience descriptions.
3

Redeploy Fusion

The MCP server validates the configuration at deployment and requires at least one valid search experience with all required fields populated. If no valid search experiences are configured, the service fails to start with an error message.
Search experience configuration parameters:
query-pipeline.searchExperiences
array
required
List of available search experiences. Each search experience defines how the MCP server routes queries to Fusion applications. You must configure at least one search experience.
query-pipeline.searchExperiences.name
string
required
Display name of the search experience. Claude uses this name to route queries.
query-pipeline.searchExperiences.description
string
required
Description of what this search experience contains. This helps Claude determine which search experience to use for a given query.
A well-crafted description helps provide a seamless experience for users. Make your descriptions as detailed as possible to enable Claude to quickly identify the right search experience for any prompt.
query-pipeline.searchExperiences.application-name
string
required
Fusion application name to query.
query-pipeline.searchExperiences.query-profile
string
required
Fusion query profile to use for queries.
Optional: Tool description configurationYou can also configure custom descriptions for the MCP tools.
mcp-server.tools.search-documents.description
string
Description for the search_documents tool. This parameter is optional and has a safe default that includes critical dependency information.
Only override this if you understand how the tools work together. The default description instructs Claude to first call list_search_experiences to obtain valid search experience names. Incorrect descriptions can break the automatic workflow.
mcp-server.tools.list-search-experiences.description
string
Description for the list_search_experiences tool. This parameter is optional and has a safe default that includes usage examples.
Only override this if you understand how the tools work together. Modifying this incorrectly can prevent Claude from discovering available search experiences properly.

Connect an AI agent

To connect an AI agent to Fusion, you need your Fusion API key for authentication. The key is sent as an HTTP header with each request.
Claude Code connects with a single command.
1

Add the Lucidworks MCP server

Replace the placeholder values with your Fusion host, port, and API key.
If you receive errors when running this command, check your Claude Code version. The --transport and --scope flags require a recent version of Claude Code.
By default, MCP servers are scoped to the current project. To make the server available globally across all projects, add --scope user. To explicitly scope it to the current project, add --scope project.
OAuth with Okta: If using OAuth authentication with Okta, add --callback-port to specify the port configured in your OAuth client:
2

Verify the configuration

You should see fusion listed, with the HTTP transport.
Lucidworks provides an MCP Bundle (.mcpb) file; this is the recommended method. Alternatively, you can configure Claude Desktop manually by editing the JSON configuration file.

Test the connection

After configuring your AI agent, test the connection with these example prompts. These prompts verify that the MCP server is working correctly and that Claude can discover and use the configured search experiences.
1

Retrieve search experiences

Test whether Claude can successfully retrieve the configured search experiences from Fusion.

What search experiences are available?

2

Search by name

Test whether Claude can identify the correct search experience by name and execute a search query.

Search the Product Catalog for wireless headphones

3

Test multi-pipeline access

Test that Claude can automatically route queries to the correct search experience based on context, demonstrating access to multiple query pipelines through a single MCP endpoint.

Find wireless headphones in products, then find the return policy

4

Match natural language queries

Test whether Claude can match natural language queries to search experience descriptions and return relevant results.

What information can I find about benefits and time off policies?

Search with MCP

Lucidworks MCP server provides four tools that work together in a discovery-to-execution pattern. Claude automatically determines which tool to call based on the user’s query.

List search experiences

The list_search_experiences tool discovers available search experiences configured in Fusion. You can use this tool in the following situations:
  • You need to see what search experiences are available.
  • You need to determine which search experience to use for a specific query.
  • You need to help users who don’t know what they can search for.
Claude automatically calls this tool when users ask questions like “What can I search here?” or “What do I find in Fusion?”. The tool returns a list of configured search experiences with their names and descriptions. This tool takes no parameters.

Search documents

The search_documents tool searches for documents and returns relevant results from Fusion collections. Based on user input, it automatically selects a search experience and can optionally filter and sort results. For example, a user can input “Find all reports from the last six months and sort them with the newest ones first” to trigger a query that uses filters to specify the document type and date range and sort to order the results by date, newest to oldest.

Get a document

The get_document tool fetches a specific document by its ID. This is useful when search_documents has already been called and the user inquires about a specific document returned in those results. The tool returns complete details about the document, such as its title, description, URL, similar documents (if MoreLikeThis is implemented), and highlighted fields (if highlighting is implemented).

Get the field schema

The get_schema tool retrieves available fields within a specific search experience and returns schema information with sortable and searchable capability flags. You can use this tool in the following situations:
  • You need to discover what fields exist within a particular search experience.
  • You need to determine which fields can be used for sorting.
  • You need to determine which fields can be used for filtering.
  • You need to display field information to users with human-readable names.
Claude automatically calls this tool before using the sort or filters parameters when searching documents, or when users ask questions like “What fields can I sort by?” or “What can I filter by?”. The tool returns field names with their display values and capability flags. By default, the tool returns only populated fields. Set includeEmptyFields=true to retrieve the complete schema.

How the tools work together

Claude uses these tools in the following order:
  1. When a user asks a question without specifying a search experience, Claude calls list_search_experiences to discover available options.
  2. Claude analyzes the search experiences and matches them to the user’s query intent.
  3. Claude calls search_documents with the appropriate search experience.
  4. Claude returns results to the user.
For example, when a user asks “Find hiking backpacks,” Claude automatically completes the following steps:
  1. Calls list_search_experiences and receives the following data:
  2. Identifies the “Product Catalog” search experience as the one that best matches the prompt.
  3. Calls search_documents with searchExperience: "Product Catalog" and the user’s query.
  4. Returns the product results.
This pattern allows users who know nothing about Fusion’s configuration to simply ask questions and get results without needing to understand the underlying structure.

Example use cases

The following examples demonstrate common MCP integration patterns.
An employee uses Claude to search internal technical documentation:
A Japanese-speaking employee searches in their native language:User query (Japanese):
Fusion processes the Japanese query, applies language-specific tokenization, and returns results with Japanese snippets. Claude displays results in Japanese, maintaining the natural language interaction.
If your query pipeline is configured with highlighting or MoreLikeThis, the MCP server can include those features in its responses:
Example response
A user asks Claude to search across multiple related content types in a single query:User query:
Search experience configuration:The workspace has three search experiences configured:
  • “Customer Support Tickets” - Support cases and resolutions
  • “Product Reviews” - App store reviews and ratings
  • “User Surveys” - Customer satisfaction surveys and NPS data
MCP behavior:Claude recognizes that customer feedback spans multiple sources and automatically searches all three experiences in parallel, then synthesizes the results.Claude output:
This demonstrates how a single query can benefit from searching multiple related content sources, with Claude automatically determining which search experiences are relevant and synthesizing results from all of them.

Example multi-tenant configurations

Lucidworks MCP server supports multi-tenant architectures where different users or use cases access different data subsets.
You can configure separate MCP endpoints with different query profiles:
  • The employee API key accesses a server with search experiences configured for full access to all collections.
  • The contractor API key accesses a server with search experiences limited to public documentation and shared resources.
You can support both public (unauthenticated) and authenticated access patterns:
This approach enables use cases like showroom kiosks (public read-only access with search experiences configured for public documents) and internal employee tools (authenticated with search experiences configured for full access and security trimming) using the same Fusion instance.

Troubleshooting

If you cannot connect to the MCP server, verify the following:
  1. Verify the endpoint is accessible:
    The protocol version in this example (2025-11-25) may differ from your installed version. See the MCP schema specification for the current version.
    If the endpoint is accessible, it returns output similar to the example below. Any other result means that the endpoint is not accessible.
}
  1. Check the URL path is exactly /mcp (no trailing slash, not /api/mcp).
  2. Test with verbose logging:
  1. Regenerate the API key in Fusion Admin (the key may be expired or revoked).
  2. Verify the header format is exactly x-api-key: API_KEY (case-sensitive).
  3. Test the key directly against Fusion’s API:
  1. Verify the query profile exists in the specified Fusion app.
  2. Check the profile name is an exact match (case-sensitive).
  3. Ensure the API key’s role has permission to execute queries on this profile.
The x-api-key header is required for authentication:
Run this command to verify your configuration:
The response should show your MCP URL:
If searches complete successfully but return no results, try these steps.
  1. Verify the Fusion app contains indexed content:
  2. Check that the query profile has access to the expected collections.
  3. Test the same query directly in Fusion’s Query Workbench to confirm results exist.
  4. Review security trimming rules that might filter out documents for the API key’s role.
If MCP searches are slow, try these steps.
  1. Check the query profile’s pipeline stages for expensive operations.
  2. Review the query complexity (complex filter queries can impact performance).
  3. Monitor Fusion’s query logs for slow queries.
  4. Consider optimizing ML model execution or caching strategies.
  5. Verify network latency between Claude and the Fusion instance.
If the Lucidworks MCP server fails to start with an error message about search experiences, follow these steps.Symptom:
Solution:
  1. Add at least one search experience with all required fields to values.yaml:
  2. Restart the server.
  3. Verify startup logs show: Found 1 valid search experience(s): [Company Knowledge]
If list_search_experiences returns fewer search experiences than you configured, follow these steps.Solution:
  1. Check server startup logs for: INFO - Found N valid search experience(s): [names]
  2. Compare logged names with your configuration.
  3. Verify all required fields are populated (name, description, application-name, query-profile).
  4. Fix configuration and restart.
If your search query returns an error message about the search experience not being configured, verify the search experience name.Symptom:
Solution:
  1. Call list_search_experiences to get exact names.
  2. Use the exact name (case-sensitive).
Common mistakes:
  • ❌ “engineering docs” (wrong case)
  • ✅ “Engineering Docs” (exact match)
If you receive a generic error message about being unable to process the request, verify your Fusion configuration and connectivity.Symptom:
Solution:Follow these troubleshooting steps:
  1. Verify Fusion is running and accessible.
  2. Check that application-name exists in Fusion (case-sensitive).
  3. Verify query-profile exists and is enabled in Fusion.
  4. Check authentication and network connectivity.
  5. Review MCP server logs for detailed error messages.
If your search completes successfully but returns no documents, verify your data and query configuration.Symptom:
Solution:Follow these troubleshooting steps:
  1. Verify documents are indexed in Fusion (check Collections in Fusion UI).
  2. Try omitting the query parameter to return all documents (defaults to *:*):
  3. Try a broader query.
  4. Test the same query directly in Fusion’s Query Workbench.
  5. Verify application-name points to the correct Fusion application.
  6. Check query profile settings for permission filters.