stacklok / toolhive / 19304282141

51%

Build Type

push

github

Committed by web-flow

Commit Message

Implement lazy per-session capability discovery (#2539)

* Create vMCP-specific VMCPSession type to track routing tables for sessions

Create VMCPSession type that extends StreamableSession with per-session
routing table storage. This enables capability caching per-session.

The VMCPSession type embeds StreamableSession to keep compatibility and
inherit the same session behaviour, but adds a routingTable field
protected by a mutex.

The new type adds GetRoutingTable/SetRoutingTable to access and set the
routing table in a thread-safe way.

When capabilities will be later discovered when the SDK registers a new
session, the routing table will be stored in the vMCPSession and later
retrieved by the vMCP middleware.

* Add context helpers and capability discovery manager

Adds helpers to retrieve capabilities from context and add them to ctx
as well as a discovery manager. The discovery manager is now a simple
passthrough to the aggregator, but will be extended in the future to add
a caching layer.

* Add discovery middleware

Adds a new middleware for capability discovery. The middleware has two branches:

1. Initialize request (no session ID):
    1. Auth middleware extracts user identity
    2. Discovery middleware performs capability aggregation with user context
    3. Discovered capabilities injected into request context
    4. Later: SDK's OnRegisterSession hook stores routing table in VMCPSession to be readable by subsequent requests not sharing ctx

2. Subsequent requests (has session ID):
    1. Discovery middleware retrieves session from session manager
    2. Extracts routing table from VMCPSession
    3. Reconstructs AggregatedCapabilities from cached routing table
    4. Injects into request context for router/handlers to use

This eliminates expensive discovery operations on every request while
maintaining per-user capability isolation. Each session gets its own
routing table based on the user's discovered capabilities at
initialization ti... (continued)

Run Details

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10 existing lines in 4 files now uncovered.

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