Add support for protocol version 2025 06 18 (#54)

* Add basic support for 2025-06-18 header

* Remove json-rpc batch support

* Extend _meta and ajson slash in key support

* Add title to more entries

* Annotations, meta, output schema, structured outpu

* Update documentation for 2025-06-18

* Update demos 

* Update changelog

Author: wommel0

README.md

@@ -4,9 +4,13 @@
 
 ## Overview
 
-ABAP implementation of the [Model Context Protocol](https://modelcontextprotocol.io/introduction) based on version [2025-03-26](https://modelcontextprotocol.io/specification/2025-03-26). \
+ABAP implementation of the [Model Context Protocol](https://modelcontextprotocol.io/introduction) based on version [2025-06-18](https://modelcontextprotocol.io/specification/2025-06-18). \
 **Note** that this is only a server implementation as I currently see no realistic way to support SSE streaming which is mandatory for the client.
 
+Supported protocol versions: 2025-03-28, 2025-06-18
+
+Note that old protocol versions might be dropped after a while especially if they increaase maintenance effort.
+
 ## Documentation
 
 See [Overview](docs/Overview.md) in docs folder.
@@ -35,12 +39,13 @@ Not implemented:
 
 - Sampling - considered for the future, open an issue if you have a use case that would benefit from it
 - Completions - questionable from a performance point of view with ABAP
+- Elicitation - without SSE I see no proper way to implement this
 - Roots - likely irrelevant for ABAP
 - Further notifications not relevant without SSE: Cancellation, Ping, Progress, Logging
 
 ## Authorization
 
-Implement the standard [Authorization](https://modelcontextprotocol.io/specification/2025-03-26/basic/authorization) in ABAP via custom code is not feasible, we have to rely on ABAP features. \
+Implement the standard [Authorization](https://modelcontextprotocol.io/specification/2025-06-18/basic/authorization) in ABAP via custom code is not feasible, we have to rely on ABAP features. \
 An overview of likely options is outlined in [Authentication Documentation](./docs/Authentication.md).
 
 ## Autentication
@@ -66,4 +71,4 @@ Feel free to:
 
 ## GenAI Notice
 
-Part of the coding was generated using AI, mostly with Sonnet 3.7 and GitHub Copilot. Detailed documentation is largely AI generated - only high-level reviewed.
+Part of the coding was generated using AI, mostly with Sonnet 3.7/4 and GitHub Copilot. Detailed documentation is largely AI generated - only high-level reviewed.

changelog.txt

@@ -1,3 +1,8 @@
+2025-06-22 v0.2
+-----------------
+
+ + Support for 2025-06-18 protocol version
+
 2025-05-26 v0.1
 -----------------
 

docs/FAQ.md

@@ -13,3 +13,7 @@ This class is not fully downwards compatible, exclude the sub-package OAuth or d
 ## Syntax error after pull from branch 702
 
 Somehow abapgit sometimes does not recognize changes, probably due to the unusual coding structure after downport. Make sure to update all code and not just changed if this issue happens. If this does not solve it and you confirmed there is a real error in the code by checking GitHub sources (if possible) feel free to open an issue with details. Due to me not having a system < 7.50 it might be challenging to fix but I will have a look and do my best.
+
+## Accessing _meta data
+
+As per the specification there will be prefixes and therefore slashed in the keys of _meta data. You can use JSON Pointer notation to access those, e.g. "prefix/keyname" would be "prefix~1keyname", basicall replacing slash with ~1. This works for retrieving and setting those values.

docs/Overview.md

@@ -250,7 +250,7 @@ Interface defining all required MCP server methods. The main methods include:
 
 ### Schema Builder
 
-`ZCL_MCP_SCHEMA_BUILDER` creates JSON Schema definitions for tool input validation with a fluent, chainable API:
+`ZCL_MCP_SCHEMA_BUILDER` creates JSON Schema definitions for tool input validation and output schemas with a fluent, chainable API:
 
 ```abap
 DATA(schema) = NEW zcl_mcp_schema_builder( ).