ruby-sdk/CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

[0.8.0] - 2026-03-03

Added

• Content::EmbeddedResource class for embedded resource content type (#244)
• Content::Audio class for audio content type (#243)
• $ref support in Tool::Schema for protocol version 2025-11-25 (#242)
• MCP conformance test suite (#248)

Fixed

• Handle Errno::ECONNRESET in SSE stream operations (#249)
• Fix default handler return values to comply with MCP spec (#247)
• Fix Prompt#validate_arguments! crash when arguments are nil (#246)
• Return 202 Accepted for SSE responses per MCP spec (#245)
• Fix Content::Image#to_h to return mimeType (camelCase) per MCP spec (#241)

[0.7.1] - 2026-02-21

Fixed

• Fix Resource::Contents#to_h to use correct property names per MCP spec (#235)
• Return JSON-RPC protocol errors for unknown tool calls (#231)
• Fix logging/setLevel to return empty hash per MCP specification (#230)

[0.7.0] - 2026-02-14

Added

• logging support (#103)
• Protocol version negotiation to server initialization (#223)
• Tool arguments to instrumentation data (#218)
• Client info to instrumentation callback (#221)
• resource_templates to MCP::Client (#225)

Changed

• Extract MCP::Annotations into a dedicated file (#224)

Fixed

• Resource::Embedded not setting @resource in initialize (#220)

[0.6.0] - 2026-01-16

Changed

• Update licensing to Apache 2.0 for new contributions (#213)

Fixed

• Omit icons from responses when empty or nil to reduce context window usage (#212)

[0.5.0] - 2026-01-11

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)

[0.4.0] - 2025-10-15

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

[0.3.0] - 2025-09-14

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)

[0.2.0] - 2025-07-15

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)

[0.1.0] - 2025-05-30

Initial release in collaboration with Shopify