Changelog

All notable changes to this project are documented in this file.

0.14.1 (2025-08-14)

Bug Fixes

• remove the default mcp path for streamable http (#226) (7163ce3)

0.14.0 (2025-08-06)

Features

• propagating opts from client.base (#223) (c47a54b)

0.13.4 (2025-08-05)

Reverts

• revert cache impl (#221) (cf94019)

0.13.3 (2025-08-04)

Bug Fixes

• otp to v27.3.4.1 (#219) (2ba5896)

0.13.2 (2025-08-04)

Bug Fixes

• just use elixir v1.19 locally (#217) (b8963a7)

0.13.1 (2025-08-04)

Features

• add independently configurable logs (#113) (bb0be27)
• add internal client/transport state inspect on cli/mix tasks (#61) (83550ee)
• allow customize server registry impl (#94) (f3ac087)
• allow json schema fields on tools/prompts definition (#99) (0345f12)
• allow multiple client <> transport pairs (#24) (933876d)
• allow redact patterns on server assigns/data (#190) (07af99f)
• allow sse graceful shutdown and handle sse streaming reconnection (#25) (008725d)
• basic client interface API (fd3412d)
• batch operations on server-side (#125) (28eea7c)
• better dsl for embedded nested fields on server components (#199) (097f5fd)
• centralized state management (#31) (76c0ab1)
• client request cancelation (#35) (ace2c3b)
• client sampling capability (#170) (da617a6)
• client support new mcp spec (#83) (73d14f7)
• create client operation struct (#56) (083bda6)
• enable log disabling (#78) (fa1453f)
• extensive guides and documentation (b39ccca)
• http/sse transport (#7) (690a57f)
• implement termination cleanup on Hermes.Client (#43) (d7bbf5d)
• improve cli experience with help cmd and sse conn info (#37) (0122af2)
• improve cli experience with help cmd and sse conn info (#37) (7a9d4e7)
• improve interactive mix tasks for testing mcp servers (#34) (53779a9)
• improve log handling on core lib and interactive/cli (#68) (7717f37)
• improve sse uri path handling (#36) (7ed2ea8)
• improve sse uri path handling (#36) (f044d7d)
• inject user and transport data on mcp server frame (#106) (feb2ce3)
• legacy sse server transport (#102) (4a71088)
• low level genservy mcp server implementation (stdio + stremable http) (#77) (e6606b4)
• mcp domain model (#28) (f8c877b)
• mcp high level server components definition (#91) (007f41d)
• mcp server handlers refactored (#92) (e213e04)
• missing notifications handlers (#129) (34d5934)
• mvp higher level mcp server definition (#84) (a5fec1c)
• new server response contents for tools/resources with annotations (2025-06-18) (#195) (9b65308)
• pretty print tool arguments on list_tools (#57) (03f8781)
• progress notifications (#26) (a3245a0)
• propagating headers on requests (#214) (a740aa4)
• resources templates (#193) (1457e59)
• roadmap and protocol update proposal (#53) (52cbf10)
• roots/list and completion features (#178) (d22a6bd)
• rpc and mcp specific message parsing (#5) (531b416)
• runtime server components, simplified api (#153) (8af35d6)
• server components cursor pagination (#177) (a95eba7)
• server-side sampling capability (#173) (c09e7f3)
• sse: support custom base and sse paths for client (#19) (787bc2d)
• sse: unit tests... (#20) (4941fd4)
• standard error resposne (#32) (52602dd)
• stateful client interface (#6) (6b97987)
• structured server-client logging support (#27) (4e1dfa7)
• support batch operations on client side (#101) (fadf28d)
• telemetry (#54) (c52734e)
• tools annotations (#127) (c83e8f1)
• tools output schema feature (2025-06-18) (#194) (8088a49)
• websocket transport (#70) (cee3945)

Bug Fixes

• allow configuring server request timeout (#182) (e79fe2f)
• allow empty capabilities on incoming JSON-RPC messages (#105) (f0ad4cf), closes #96
• allow enum specific type on json-schema (#121) (23c9ce2), closes #114
• allow registering a name for the client supervisor (#117) (d356511)
• allow users to control external process messages (#149) (8fef4eb)
• client reinitialization from interactive cli (#55) (cb6b167)
• client should send both sse/json headers on POST requests (#134) (e906b7f)
• correctly allows macro-based/callback-based server implementations (#131) (d7bfc75)
• correctly encode prompt/resource (#155) (4249b13)
• correctly escape quoted expressions (#119) (0c469c5), closes #118
• correctly handle mcp requests on phoenix apps (#88) (09f4235), closes #86
• correctly parse dates when default values are passed (58f6368)
• correctly parse peri numeric contrainsts to json-schema (#160) (808c2c0)
• correctly set supported versions for different transports (#205) (30435e1)
• default implementation for server handle_notification (#135) (c958041)
• do not allow duplicate server components and more convenient API (#180) (bc71df8)
• do not handle domain errors (#33) (20dde00)
• do not handle domain errors (#33) (c15b260)
• fixed erts version to avoid release error (80780d2)
• handle SSE ping and reconnect events from server (#65) (dccdca3)
• hermes should respect mix releases startup (#109) (f42d476)
• include formatter on hex release (#139) (d91b244)
• include frame helpers on module-based component (#163) (15ba2c7)
• interactive http tasks should accept custom headers (#159) (c2fe91e)
• loggin should respect the logger config (#157) (0fbf6a6)
• make gun/websocket optional (#76) (8f55057)
• more genserver mcp server callbacks, plug based startup and documentation (#152) (9c26b1c)
• nested timeout (#71) (c7ffa71)
• normalize transport api (#146) (8a30a34), closes #145
• remove assign redact feature, simplify server state inspect (#206) (a4d9ae9)
• remove last uses of hard-coded Hermes.Server.Registry (cc0ffd9)
• server behaviour with optional callbacks (#151) (91aa191)
• server can now send notifications correctly (#166) (33f32de)
• server session expiration on idle (configurable) (#143) (d9f7164)
• sse endpoint uri merging (#64) (2fa7869)
• use mix.lock as cache key (#58) (6a3134a)

Miscellaneous Chores

• add llms summary about the library (#175) (ed0e608)
• allow different kind of components have the same name (#181) (d5ba6f5)
• deprecate sse transport (#187) (1932fbc)
• deps: bump the npm_and_yarn group across 1 directory with 2 updates (#198) (5e21aac)
• readme (bed6ff7)
• release 0.10.0 (#124) (8db7a92)
• release 0.10.1 (#133) (2caf67b)
• release 0.10.2 (#136) (580d96a)
• release 0.10.3 (#140) (2bf9890)
• release 0.10.4 (#144) (ae22d44)
• release 0.10.5 (#147) (fe8f374)
• release 0.11.0 (#150) (615e9ac)
• release 0.11.1 (#158) (e0c63f4)
• release 0.11.2 (#161) (2520588)
• release 0.11.3 (#167) (1ff0786)
• release 0.12.0 (#171) (c378929)
• release 0.12.1 (#184) (9f5f751)
• release 0.13.0 (#191) (cfaaa9d)
• release 0.5.0 (#80) (feac95b)
• release 0.6.0 (#89) (5f44c37)
• release 0.7.0 (#100) (c9efd80)
• release 0.8.0 (#104) (cc535dd)
• release 0.8.1 (#110) (9fca055)
• release 0.8.2 (#112) (5dc7d40)
• release 0.9.0 (#116) (73ac1ed)
• release 0.9.1 (#120) (a490789)
• release please correct version on readme (#128) (d0125c6)
• release please should include all files (#108) (d0a25b9)
• simplify genserver naming handling, and bidirectional communication client <> transport (#38) (5288ceb)
• streamable http on hermes cli (standalone) (#203) (2f41337)
• upcate automatic version (#98) (0c08233)
• update documentation, simplify, more storytelling (#168) (ccdddc1)
• update peri (#126) (7292615)

Code Refactoring

• base mcp server implementation correctly uses streamable http (#85) (29060fd)
• cleaner peri integration (#137) (43226cc), closes #123
• do not hangle on transport process (#185) (e6ba926)
• handle_sampling callback, use frame as entrypoint for notifications (#176) (1e88711)
• higher-level client implementation (#111) (5de2162)
• improve runtime components schema def (#154) (96ff2a9)
• interactive tasks now support JSON file input (#172) (9465266)
• remove batch messaging feature (#183) (99458c0)
• tests (#93) (ca31feb)

0.13.0 (2025-07-18)

Features

• allow redact patterns on server assigns/data (#190) (07af99f)
• better dsl for embedded nested fields on server components (#199) (097f5fd)
• new server response contents for tools/resources with annotations (2025-06-18) (#195) (9b65308)
• resources templates (#193) (1457e59)
• tools output schema feature (2025-06-18) (#194) (8088a49)

Miscellaneous Chores

• deprecate sse transport (#187) (1932fbc)
• deps: bump the npm_and_yarn group across 1 directory with 2 updates (#198) (5e21aac)
• readme (bed6ff7)

0.12.1 (2025-07-14)

Code Refactoring

• do not hangle on transport process (#185) (e6ba926)
• remove batch messaging feature (#183) (99458c0)

0.12.0 (2025-07-11)

Features

• client sampling capability (#170) (da617a6)
• roots/list and completion features (#178) (d22a6bd)
• server components cursor pagination (#177) (a95eba7)
• server-side sampling capability (#173) (c09e7f3)

Bug Fixes

• allow configuring server request timeout (#182) (e79fe2f)
• do not allow duplicate server components and more convenient API (#180) (bc71df8)

Miscellaneous Chores

• add llms summary about the library (#175) (ed0e608)
• allow different kind of components have the same name (#181) (d5ba6f5)

Code Refactoring

• handle_sampling callback, use frame as entrypoint for notifications (#176) (1e88711)
• interactive tasks now support JSON file input (#172) (9465266)

0.11.3 (2025-07-02)

Bug Fixes

• correctly parse dates when default values are passed (58f6368)
• include frame helpers on module-based component (#163) (15ba2c7)
• server can now send notifications correctly (#166) (33f32de)

Miscellaneous Chores

• update documentation, simplify, more storytelling (#168) (ccdddc1)

0.11.2 (2025-06-30)

Bug Fixes

• correctly parse peri numeric contrainsts to json-schema (#160) (808c2c0)
• interactive http tasks should accept custom headers (#159) (c2fe91e)

0.11.1 (2025-06-30)

Bug Fixes

• loggin should respect the logger config (#157) (0fbf6a6)

0.11.0 (2025-06-30)

Features

• runtime server components, simplified api (#153) (8af35d6)

Bug Fixes

• allow users to control external process messages (#149) (8fef4eb)
• correctly encode prompt/resource (#155) (4249b13)
• more genserver mcp server callbacks, plug based startup and documentation (#152) (9c26b1c)
• server behaviour with optional callbacks (#151) (91aa191)

Code Refactoring

• improve runtime components schema def (#154) (96ff2a9)

0.10.5 (2025-06-25)

Bug Fixes

• normalize transport api (#146) (8a30a34), closes #145

0.10.4 (2025-06-24)

Bug Fixes

• server session expiration on idle (configurable) (#143) (d9f7164)

0.10.3 (2025-06-23)

Bug Fixes

• include formatter on hex release (#139) (d91b244)

0.10.2 (2025-06-23)

Bug Fixes

• default implementation for server handle_notification (#135) (c958041)

Code Refactoring

• cleaner peri integration (#137) (43226cc), closes #123

0.10.1 (2025-06-21)

Bug Fixes

• client should send both sse/json headers on POST requests (#134) (e906b7f)
• correctly allows macro-based/callback-based server implementations (#131) (d7bfc75)
• remove last uses of hard-coded Hermes.Server.Registry (cc0ffd9)

0.10.0 (2025-06-18)

Features

• batch operations on server-side (#125) (28eea7c)
• missing notifications handlers (#129) (34d5934)
• support batch operations on client side (#101) (fadf28d)
• tools annotations (#127) (c83e8f1)

Miscellaneous Chores

• release please correct version on readme (#128) (d0125c6)
• update peri (#126) (7292615)

0.9.1 (2025-06-13)

Bug Fixes

• allow enum specific type on json-schema (#121) (23c9ce2), closes #114
• correctly escape quoted expressions (#119) (0c469c5), closes #118

0.9.0 (2025-06-12)

Features

• add independently configurable logs (#113) (bb0be27)

Bug Fixes

• allow registering a name for the client supervisor (#117) (d356511)

0.8.2 (2025-06-11)

Code Refactoring

• higher-level client implementation (#111) (5de2162)

0.8.1 (2025-06-10)

Bug Fixes

• hermes should respect mix releases startup (#109) (f42d476)

0.8.0 (2025-06-10)

Features

• inject user and transport data on mcp server frame (#106) (feb2ce3)
• legacy sse server transport (#102) (4a71088)

Bug Fixes

• allow empty capabilities on incoming JSON-RPC messages (#105) (f0ad4cf), closes #96

Miscellaneous Chores

• release please should include all files (#108) (d0a25b9)

0.7.0 (2025-06-09)

Features

• allow json schema fields on tools/prompts definition (#99) (0345f12)

0.6.0 (2025-06-09)

Features

• allow customize server registry impl (#94) (f3ac087)
• mcp high level server components definition (#91) (007f41d)
• mcp server handlers refactored (#92) (e213e04)

Bug Fixes

• correctly handle mcp requests on phoenix apps (#88) (09f4235), closes #86

Miscellaneous Chores

• upcate automatic version (#98) (0c08233)

Code Refactoring

• tests (#93) (ca31feb)

0.5.0 (2025-06-05)

Features

• client support new mcp spec (#83) (73d14f7)
• enable log disabling (#78) (fa1453f)
• low level genservy mcp server implementation (stdio + stremable http) (#77) (e6606b4)
• mvp higher level mcp server definition (#84) (a5fec1c)

Code Refactoring

• base mcp server implementation correctly uses streamable http (#85) (29060fd)

0.4.0 - 2025-05-06

Added

• Implemented WebSocket transport (#70)
• Emit telemetry events (#54)
• Implement client feature completion request (#72)
• Implement client feature roots, server requests (#73)

0.3.12 - 2025-04-24

Fixed

• Correctly handles "nested" timeouts (genserver vs MCP) (#71)

0.3.11 - 2025-04-17

Added

• Improved core library logging and added verbosity level on interactive/CLI (#68)

0.3.10 - 2025-04-17

Fixed

• Handle SSE ping and reconnect events from server (#65)

0.3.9 - 2025-04-15

Fixed

• Improved and simplified SSE endpoint event URI merging (#64)

Added

• Added internal client/transport state inspection on CLI/mix tasks (#61)

0.3.8 - 2025-04-10

Added

• Created Operation struct to standardize client API calls (#56)
• Fixed ERTS version to avoid release errors

Fixed

• Resolved client timeout confusion by standardizing timeout handling (#42)

0.3.7 - 2025-04-01

Fixed

• Client reinitialization from interactive CLI (#55)

0.3.6 - 2025-03-28

Added

• New roadmap and protocol update proposal (#53)
• Added documentation for the 2025-03-26 protocol update

0.3.5 - 2025-03-25

Documentation

• Added Roadmap to README (#47)

0.3.4 - 2025-03-20

Added

• help command and flag on the interactive CLI (#37)
• improve SSE connection status on interactive task/cli (#37)

0.3.3 - 2025-03-20

Added

• Client request cancellation support (#35)
• Improved URI path handling for SSE transport (#36)
• Enhanced interactive mix tasks for testing MCP servers (#34)

0.3.2 - 2025-03-19

Added

• Ship static binaries to use hermes-mcp as standalone application

0.3.1 - 2025-03-19

Added

• Ship interactive mix tasks stdio.interactive and sse.interactive to test MCP servers

0.3.0 - 2025-03-18

Added

• Structured server-client logging support (#27)
• Progress notification tracking (#26)
• MCP domain model implementation (#28)
• Comprehensive SSE unit tests (#20)
• Centralized state management (#31)
• Standardized error response handling (#32)

Fixed

• Improved domain error handling (#33)

0.2.3 - 2025-03-12

Added

• Enhanced SSE transport with graceful shutdown capabilities (#25)
• Improved SSE streaming with automatic reconnection handling (#25)

0.2.2 - 2025-03-05

Added

• Support for multiple concurrent client <> transport pairs (#24)
• Improved client resource management

0.2.1 - 2025-02-28

Added

• Support for custom base and SSE paths in HTTP/SSE client (#19)
• Enhanced configuration options for SSE endpoints

0.2.0 - 2025-02-27

Added

• Implemented HTTP/SSE transport (#7)
  • Support for server-sent events communication
  • HTTP client integration for MCP protocol
  • Streaming response handling

Documentation

• Extensive guides and documentation improvements

0.1.0 - 2025-02-26

Added

• Implemented STDIO transport (#1) for MCP communication

  • Support for bidirectional communication via standard I/O
  • Automatic process monitoring and recovery
  • Environment variable handling for cross-platform support
  • Integration test utilities in Mix tasks

• Created stateful client interface (#6)

  • Robust GenServer implementation for MCP client
  • Automatic initialization and protocol handshake
  • Synchronous-feeling API over asynchronous transport
  • Support for all MCP operations (ping, resources, prompts, tools)
  • Proper error handling and logging
  • Capability negotiation and management

• Developed JSON-RPC message parsing (#5)

  • Schema-based validation of MCP messages
  • Support for requests, responses, notifications, and errors
  • Comprehensive test suite for message handling
  • Encoding/decoding functions with proper validation

• Established core architecture and client API

  • MCP protocol implementation following specification
  • Client struct for maintaining connection state
  • Request/response correlation with unique IDs
  • Initial transport abstraction layer

Documentation

• Added detailed RFC document describing the library architecture
• Enhanced README with project overview and installation instructions