PH68212: INCORRECT TRANSPORT TYPE USED CICS MODEL CONTEXT PROTOCOL (MCP) SERVER

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The CICS Model Context Protocol (MCP) server incorrectly
  uses SSE MCP Transport type, rather than Streamable HTTP. This
  should be Streamable HTTP (SHTTP) to better support a range of
  MCP clients.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Updates to the CICS Model Context       *
  *                      Protocol (MCP) Server:                  *
  *                      - MCP transport type is SSE and needs   *
  *                      to be changed to Streamable HTTP        *
  *                      (SHTTP)                                 *
  *                                                              *
  *                      - All tools are incorrectly being       *
  *                      reported for all toolboxes, rather      *
  *                      than the expected filtered list.        *
  *                                                              *
  *                      - Links on MCP server welcome page may  *
  *                      appear broken.                          *
  *                                                              *
  *                      - Improved error handling and reporting *
  *                      when invoking MCP supplied tools.       *
  *                                                              *
  *                      - Additional logging and serviceability *
  *                      messages.                               *
  *                                                              *
  *                      - Improvements to tool for CICSplex     *
  *                      system groups.                          *
  ****************************************************************
  The following changes have been identified in the MCP server and
  tools to be addressed in this APAR:
  
  - The transportation type used between the MCP server provided
  and MCP clients is currently HTTP SSE (Server-Sent Events) ,
  however to improve compatibility between clients and later
  protocol specifications this should be Streamable HTTP (SHTTP).
  
  - The toolboxes provided by the CICS MCP server to scope
  collections of tools incorrectly lists all tools available
  in the sever to all the toolboxes. The toolboxes should only
  contain a scoped list of tools applicable to the toolbox
  description, except for the allTools toolbox.
  
  - The MCP server supplies a welcome page. This lists the
  supplied toolboxes and links to use for MCP client connections.
  These may include incorrect URLs for each toolbox, resulting
  in clients being unable to connect to the toolbox and MCP
  server.
  
  - When errors occur within the execution of an MCP tool, the
  errors are inconsistently reported back to the calling MCP
  client. This can result in empty results being returned without
  an error.
  
  - The MCP server and tools have limited logging to determine
  the state of the MCP server and tools. This limits ability
  to observe the state and identify issues, as such these will
  be improved for users and serviceability.
  
  - The supplied tool to obtain details on CICSplex system groups
  needs improvements to better return information about the
  topology information.
  

Problem conclusion

• The CICS MCP server and supplied tools has been improved to
  address these issues.
  
  - SSE type transport has been replaced with Streamable HTTP
  for MCP client connections.
  
  - Toolboxes have been corrected to ensure an appropriate
  filtered lists of tools are returned.
  
  - The welcome page has been corrected to ensure the correct
  URLs are returned to use with an MCP client.
  
  - The MCP tools supplied have been improved to ensure if an
  error occurs during an MCP tool execution, an error response is
  returned to the MCP client, as per the protocol specification.
  
  - Additional messages are produced during MCP server
  initialisation and tool execution to better show the state
  of the MCP server.
  
  - The CICSplex system group tool supplied has been improved to
  better show the topology state information for these resources.
  
  ----------------------------------------------------------------
  
  This APAR includes the following additional open source
  (third-party) components previously not shipped with IBM CICS
  Transaction Server for z/OS 6.3, which are distributed under
  their respective license terms:
  
  Apache-2.0 license terms
  (see https://spdx.org/licenses/Apache-2.0.html):
  itu, jackson-dataformat-yaml, json-schema-validator, snakeyaml
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UO06400

Modules/Macros

• DFJ@H531 DFJ@H532 DFJ@H533 DFJ@H583
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R600 PSY UO06400

     UP26/01/08 I 1000

Fix is available

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