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#### Requirements
@sap/cds-lsp is a NodeJS module. As such it requires NodeJS installed on the client machine. Minimum version is 22.15.1

#### Start-up

##### Installation via npm

1) Create an empty folder and cd into it
2) Execute npm i @sap/cds-lsp to download the language server and all its dependencies

This will create a sub-folder node_modules with all required npm modules.
It will also create a platform specific shell script to start the language server.
It is located in the node_modules/.bin sub-folder and is called cds-lsp.

For a _stdio_ connection use node_modules/.bin/cds-lsp --stdio.
For other connection channels see below

##### Custom Installation

##### TL;DR
1. install @sap/cds-lsp from _npmjs.org_ into subfolder cds-lsp

``
#!/bin/bash
componentName=cds-lsp
fullName="@sap/$componentName"

echo '=== Getting latest download URL'
url=$(npm view $fullName | sed -n 's/.tarball.\(https.\)$/\1/p')
echo "=== Downloading $url"
curl -O $url
filename=$(echo $url | sed -n 's/.\/\(.\)$/\1/p')
echo "=== Extracting $filename"
tar xfv $filename
mv package $componentName
echo "=== Removing $filename"
rm $filename
cd $componentName
echo "=== Installing dependencies"
npm i
`

2. start the server using _stdio_
`
#!/bin/bash
main=$(cat cds-lsp/package.json | sed -n 's/."main"."\(.\)"./\1/p')
node "cds-lsp/$main" --stdio
`


----
##### Details

1) Get the download URL for the tarball with npm view @sap/cds-lsp. E.g.

`
/home/user$ npm view @sap/cds-lsp
@sap/cds-lsp@6.2.2 | SEE LICENSE IN LICENSE | deps: 9 | versions: 33
Language server for CDS
https://cap.cloud.sap/

keywords: CAP, CDS, LSP, SAP, language, editor

bin: cds-lsp, format-cds

dist
.tarball: https://registry.npmjs.org/@sap/cds-lsp/-/cds-lsp-6.2.2.tgz
...
`

2) Download the tarball e.g. curl -O https://registry.npmjs.org/@sap/cds-lsp/-/cds-lsp-6.2.2.tgz
3) Extract the TGZ file e.g. tar -xf cds-lsp-6.2.2.tgz
4) Enter package folder: cd package
5) Execute npm i to install the dependencies.
6) Check the main entry in package.json. This is the start script e.g.

`
/home/user/package$ grep "main" package.json
"main": "dist/main.js",
`

7) The simplest form to start the language server using stdio (see Connection channels below) e.g.

`
/home/user/package$ node dist/main.js --stdio
`

8) The server is started and waits for a client to connect

##### Connection channels

@sap/cds-lsp can communicate to a client via one of three different connection channels (see the documentation of the client plug-in for details which channels are supported)
- stdio: the language server listens on stdin for requests and sends responses to stdout
- node-ipc (if the client runs with NodeJS): add --node-ipc as a command-line argument
- sockets: add --socket= as a command-line argument

For details see the similar json-language-server integration docs.

#### Syntax Highlighting
For performance reasons, syntax highlighting is not done via the language server protocol.
A TextMate grammar aside of the language server provides this.
@sap/cds-lsp comes with a TextMate grammar file included for the CDS language.
Additionally @sap/cds-lsp supports semantic highlighting. This is a feature of the language server protocol and is supported by some IDEs.

While specific client extensions usually integrate this by default, a generic integration requires to configure this separately.
Some IDEs have TextMate support built-in. Others require another plug-in, a TextMate client.
Refer to the corresponding documentation how to configure a custom TextMate grammar file. CDS source files have the .cds` file extension.