April 7th, 2026 - SLIM WG Meeting Notes

[NickG44]

SLIM Working Group Call Summary April 7th, 2026

Attendees: (10)

Nick Gill
Luca Muscariello
Sam Betts
Amit Kumar
Elaine Powers
Cody Hartsook
Michele Papalini
Benjamin Torress
Mark Marton
Sandor Magyari

Key Topics & Outcomes

1. SLIM v1.4 Planning & Priority Use Cases

Multi-Cluster Demo: the immediate engineering priority is adding authentication and configuration features to support a multi-cluster use cases This involves using SLIM to securely traverse networks.
Benchmarking: The team is actively benchmarking SLIM (messages per second, agent churn, group creation) and has identified specific bottlenecks that will be resolved in the v1.4 release.

2. A2A Integration & Backward Compatibility Demo

Sam demonstrated the A2A v1.0 integration for both Golang and Python.
The demo highlighted seamless backward compatibility and version negotiation between v1.0 and v0.3.0. The transport layer successfully translates v1 types to v0.3 on the wire, allowing old servers to talk to new clients and vice versa.
Note: An upcoming breaking change in SlimRPC (related to multicast RPC subscriptions) was flagged for future awareness.

3. Rust SDK, SlimRPC, & Protocol Bindings

A newly published A2A SDK in Rust that includes native SlimRPC support. It currently features CSIT multi-language testing against Go and C# (with JS, Java, and Python planned next).
A formal proposal has been submitted to add SlimRPC as an experimental custom protocol binding for A2A. Once accepted, it will get a dedicated repository under the A2A project.

4. WebAssembly, WebSockets, & MLS Compatibility

Amit successfully compiled the SLIM data plane in WebAssembly, enabling point-to-point and multicast communication directly within the browser via WebSockets.
Current Blocker: A cipher suite incompatibility exists when mixing browser nodes (using Web Crypto, which defaults to P256) and native nodes (using Curve25519) with MLS enabled. The team discussed implementing cipher suite negotiation to find a lowest common denominator to resolve this.

5. Shadi CLI & Agent Discovery

Integration of the A2A SDK into the "shady" CLI is planned for early May, following the completion of the Splunk/Dell use case.
Discussions continue around standardizing agent discovery using the "AI Catalog/AI Card" to unify MCP, Agent Skills, and A2A locators (including SLIM channels).

Next Steps & Action Items

Authentication/Multi-Cluster: Complete the authentication and configuration improvements for the Splunk/Dell multi-cluster demo.
A2A Protocol Binding: Review and accept the proposal for the SlimRPC custom protocol binding to establish its new repository.
MLS Cipher Negotiation: Amit to open an issue/PR to address the MLS cipher suite incompatibility (Curve25519 vs. P256) between browser and native participants.
CSIT Expansion: Expand the Rust SDK's CSIT multi-language testing to include JavaScript, Java, and Python.
CLI Integration: Resume work on Shady CLI and standard IO/WebSocket transports in early May.