v0.5.0

Added

• Protocol specification version "2025-11-25" support (#184)
• icons parameter support (#205)
• websiteUrl parameter in serverInfo (#188)
• description parameter in serverInfo (#201)
• additionalProperties support for schema validation (#198)
• "Draft" protocol version to supported versions (#179)
• stateless mode for high availability (#101)
• Exception messages for tool call errors (#194)
• Elicitation skeleton (#178)
• prompts/list and prompts/get support to client (#163)
• Accept header validation for HTTP client transport (#207)
• Ruby 2.7 - Ruby 3.1 support (#206)

Changed

• Make tool names stricter (#204)

Fixed

• Symlink path comparison in schema validation (#193)
• Duplicate tool names across namespaces now raise an error (#199)
• Tool error handling to follow MCP spec (#165)
• XSS vulnerability in json_rpc_handler (#175)

v0.4.0

Added

• Client resources support with resources/list and resources/read methods (#160)
• _meta field support for Tool schema (#124)
• _meta field support for Prompt
• title field support for prompt arguments
• call_tool_raw method to client for accessing full tool responses (#149)
• Structured content support in tool responses (#147)
• AGENTS.md development guidance documentation (#134)
• Dependabot configuration for automated dependency updates (#138)

Changed

• Set default content to empty array instead of nil (#150)
• Improved prompt spec compliance (#153)
• Allow output schema to be array of objects (#144)
• Return 202 response code for accepted JSON-RPC notifications (#114)
• Added validation to MCP::Configuration setters (#145)
• Updated metaschema URI format for cross-OS compatibility

Fixed

• Client tools functionality and test coverage (#166)
• Client resources test for empty responses (#162)
• Documentation typos and incorrect examples (#157, #146)
• Removed redundant transport requires (#154)
• Cleaned up unused block parameters and magic comments

v0.3.0

Added

• Tool output schema support with comprehensive validation (#122)
• HTTP client transport layer for MCP clients (#28)
• Tool annotations validation for protocol compatibility (#122)
• Server instructions support (#87)
• Title support in server info (#119)
• Default values for tool annotation hints (#118)
• Notifications/initialized method implementation (#84)

Changed

• Make default protocol version the latest specification version (#83)
• Protocol version validation to ensure valid values (#80)
• Improved tool handling for tools with no arguments (#85, #86)
• Better error handling and response API (#109)

Fixed

• JSON-RPC notification format in Streamable HTTP transport (#91)
• Errors when title is not specified (#126)
• Tools with missing arguments handling (#86)
• Namespacing issues in README examples (#89)

v0.2.0

Added

• Custom methods support via define_custom_method (#75)
• Streamable HTTP transport implementation (#33)
• Tool argument validation against schemas (#43)

Changed

• Server context is now optional for Tools and Prompts (#54)
• Improved capability handling and removed automatic capability determination (#61, #63)
• Refactored architecture in preparation for client support (#27)

Fixed

• Input schema validation for schemas without required fields (#73)
• Error handling when sending notifications (#70)

v0.1.0

Initial release