Files
coder/agent/x/agentmcp/mcphttpclient.go
T
Michael Suchacz 7720e283f5 feat(agent/x/agentmcp): migrate workspace agent MCP client to official Go SDK (#28059)
## Stack Context

PR 4 of 6 in a stack that migrates every Coder MCP surface from the
archived `github.com/mark3labs/mcp-go` library to the official
`github.com/modelcontextprotocol/go-sdk` v1.7.0.

Stack: #28056 -> #28057 -> #28058 -> #28059 -> #28060 -> #28061

## Why

The workspace agent MCP manager now stores `*mcp.ClientSession` per
configured server.

- stdio servers use `mcp.CommandTransport` with an `exec.Cmd` built from
Coder's `agentexec.Execer`, preserving environment enrichment; the
command uses the manager's parent context so a stdio subprocess outlives
the connect handshake and stops when the session closes.
- HTTP and SSE servers use header-injecting HTTP clients.
- Binary tool content is re-encoded to base64 for the agent API because
the official SDK decodes it into raw bytes.
- The reload test now triggers config diffs via an environment variable
because the official SDK drops connections on non-protocol stdout output
(flags like `-test.v` made the fake server chatty).

> Mux created this PR on Mike's behalf.
2026-08-13 10:29:13 +00:00

53 lines
1.4 KiB
Go

package agentmcp
import (
"flag"
"net/http"
)
func httpClientWithHeaders(headers map[string]string) *http.Client {
base := http.DefaultTransport
if isolated := mcpHTTPClient(); isolated != nil {
base = isolated.Transport
}
if len(headers) == 0 {
return &http.Client{Transport: base}
}
return &http.Client{Transport: &headerRoundTripper{
base: base,
headers: headers,
}}
}
type headerRoundTripper struct {
base http.RoundTripper
headers map[string]string
}
func (h *headerRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
clone := req.Clone(req.Context())
for k, v := range h.headers {
clone.Header.Set(k, v)
}
return h.base.RoundTrip(clone)
}
// mcpHTTPClient returns an isolated *http.Client when running
// inside tests, or nil for production. During tests,
// httptest.Server.Close() calls
// http.DefaultTransport.CloseIdleConnections(), which disrupts
// any MCP client sharing that transport. When DefaultTransport
// is a *http.Transport it is cloned; otherwise a minimal
// transport with ProxyFromEnvironment is created as a fallback.
func mcpHTTPClient() *http.Client {
if flag.Lookup("test.v") == nil {
return nil
}
if dt, ok := http.DefaultTransport.(*http.Transport); ok {
return &http.Client{Transport: dt.Clone()}
}
return &http.Client{Transport: &http.Transport{
Proxy: http.ProxyFromEnvironment,
}}
}