Function connectOne

coderd/x/chatd/mcpclient/mcpclient.go:172–280

connectOne establishes a connection to a single MCP server, discovers its tools, and wraps each one as an AgentTool with the server slug prefix applied.

(
	ctx context.Context,
	logger slog.Logger,
	cfg database.MCPServerConfig,
	tokensByConfigID map[uuid.UUID]database.MCPServerUserToken,
	userID uuid.UUID,
	oidcSrc UserOIDCTokenSource,
	coderHeaders map[string]string,
)

// discovers its tools, and wraps each one as an AgentTool with
// the server slug prefix applied.
func connectOne(
	ctx context.Context,
	logger slog.Logger,
	cfg database.MCPServerConfig,
	tokensByConfigID map[uuid.UUID]database.MCPServerUserToken,
	userID uuid.UUID,
	oidcSrc UserOIDCTokenSource,
	coderHeaders map[string]string,
) ([]fantasy.AgentTool, *client.Client, error) {
	headers := buildAuthHeaders(ctx, logger, cfg, tokensByConfigID, userID, oidcSrc)

	// When opted-in, merge Coder identity headers BEFORE the
	// transport is created so any auth header already set above
	// wins on a conflict. Conflict detection uses
	// http.CanonicalHeaderKey because the upstream transport applies
	// http.Header.Set, which canonicalizes keys; without that, an
	// admin-configured header that differs only in case from a Coder
	// identity header would land in the request map twice and the
	// surviving value would be non-deterministic.
	if cfg.ForwardCoderHeaders {
		canonicalAuth := make(map[string]struct{}, len(headers))
		for k := range headers {
			canonicalAuth[http.CanonicalHeaderKey(k)] = struct{}{}
		}
		for k, v := range coderHeaders {
			if _, exists := canonicalAuth[http.CanonicalHeaderKey(k)]; exists {
				continue
			}
			headers[k] = v
		}
	}

	tr, err := createTransport(cfg, headers)
	if err != nil {
		return nil, nil, xerrors.Errorf(
			"create transport: %w", err,
		)
	}

	mcpClient := client.NewClient(tr)

	// The timeout covers the entire connect+init+list sequence,
	// not each phase individually.
	connectCtx, cancel := context.WithTimeout(
		ctx, connectTimeout,
	)
	defer cancel()

	if err := mcpClient.Start(connectCtx); err != nil {
		_ = mcpClient.Close()
		return nil, nil, xerrors.Errorf(
			"start transport: %w", err,
		)
	}

	_, err = mcpClient.Initialize(
		connectCtx,
		mcp.InitializeRequest{