feat: Add first-class resource template support#12
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This commit implements comprehensive resource template support in fast-mcp-scala,
enabling URI templates with parameters like "users://{userId}" to work seamlessly.
Key changes:
- Add ResourceArgument and template validation to ResourceManager
- Implement getTemplateHandler() and listTemplateDefinitions() methods
- Add javaTemplateResourceReadHandler using Java SDK's DefaultMcpUriTemplateManager
- Update ResourceDefinition with isTemplate flag and toJava union type
- Enhance ResourceProcessor macro to detect and handle URI placeholders
- Add @ResourceParam annotation support for template parameters
- Update examples to demonstrate template usage (user://{userId})
- Fix resource/template separation in listResources() vs listResourceTemplates()
- Register templates as resources for handler routing while maintaining separate discovery
Technical improvements:
- Leverage Java SDK's built-in URI template matching instead of reimplementing
- Avoid duplicate template registration in discovery endpoints
- Properly validate template placeholders match method parameters
- Update to mcp-sdk 0.10.0 for enhanced template support
This enables MCP clients to discover and use templated resources with proper
parameter extraction and validation.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
The MCP SDK 0.10.0 changed the JsonSchema constructor to require 6 parameters instead of 4. Updated test expectations to match the SDK's behavior when parsing JSON schema strings (sets additionalProperties to null rather than false). 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
- FastMcpServer: add type ascription for McpServer.AsyncSpecification to satisfy Scala 3 inference - Tests: add NoopLoggableSession and update MockServerExchange to pass a McpLoggableSession - Tests: include ClientCapabilities.Elicitation per new SDK constructor - TypesConversionTest: allow null or empty arguments per SDK normalization - Enable local maven repo in quickstart and sbt; bump mcpSdk to 0.11.3 - ToolDefinition.toJava: use Tool.Builder() API (SDK change)
- Do not register templates under resources(); use resourceTemplates() only
- Add robust classification: treat any URI containing '{' or '}' as a template
- Keep static resources strictly separate from templates
- Prepares for SDK upgrade to new template+handler API
- Register template read handlers via resources(...) so readResource works - Do not advertise templates by default; add settings.exposeTemplatesEndpoint to opt in - On unresolved template URIs (with braces), return clear error instead of placeholder text - Add meta hints to template resources (fastmcp_is_template, fastmcp_template_params) - Modernize builders: use Annotations for Content and Resource.builder for static resources - Switch tool registration to toolCall(...) with CallToolRequest handler This balances correctness (template reads work) with cleaner discovery until SDK adds a template+handler API.
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Once modelcontextprotocol/java-sdk#528 is merged, resource templates will no longer also be listed as resources. This is a known issue with the java MCP SDK. |
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This commit implements comprehensive resource template support in fast-mcp-scala, enabling URI templates with parameters like "users://{userId}" to work seamlessly.
Key changes:
Technical improvements:
This enables MCP clients to discover and use templated resources with proper parameter extraction and validation.
🤖 Generated with Claude Code