Merge pull request #695 from LIT-Protocol/docs/improve-get-session-sigs-jsdoc

doc(getSessionSigs): improve jsDocs

Author: Ansonhkg

packages/lit-node-client-nodejs/src/lib/lit-node-client-nodejs.ts

@@ -2066,18 +2066,25 @@ export class LitNodeClientNodeJs
   };
 
   /**
-   * Get session signatures for a set of [Lit resources](https://v6-api-doc-lit-js-sdk.vercel.app/interfaces/types_src.ILitResource.html#resource).
+   *
+   * Retrieves or generates sessionSigs (think access token) for accessing Lit Network resources.
    *
    * How this function works on a high level:
    * 1. Generate or retrieve [session keys](https://v6-api-doc-lit-js-sdk.vercel.app/interfaces/types_src.SessionKeyPair.html) (a public and private key pair)
    * 2. Generate or retrieve the [`AuthSig`](https://v6-api-doc-lit-js-sdk.vercel.app/interfaces/types_src.AuthSig.html) that specifies the session [abilities](https://v6-api-doc-lit-js-sdk.vercel.app/enums/auth_helpers_src.LitAbility.html)
    * 3. Sign the specific resources with the session key
    *
+   * The process follows these steps:
+   * 1. Retrieves or generates a session key pair (Ed25519) for the user's device. The session key is either fetched from local storage or newly created if not found. The key does not expire.
+   * 2. Generates an authentication signature (`authSig`) by signing an ERC-5573 “Sign-in with Ethereum” message, which includes resource ability requests, capabilities, expiration, the user's device session public key, and a nonce. The `authSig` is retrieved from local storage, and if it has expired, the user will be prompted to re-sign.
+   * 3. Uses the session private key to sign the session public key along with the resource ability requests, capabilities, issuedAt, and expiration details. This creates a device-generated signature.
+   * 4. Constructs the session signatures (`sessionSigs`) by including the device-generated signature and the original message. The `sessionSigs` provide access to Lit Network features such as `executeJs` and `pkpSign`.
+   *
+   * See Sequence Diagram: https://www.plantuml.com/plantuml/uml/VPH1RnCn48Nl_XLFlT1Av00eGkm15QKLWY8K9K9SO-rEar4sjcLFalBl6NjJAuaMRl5utfjlPjQvJsAZx7UziQtuY5-9eWaQufQ3TOAR77cJy407Rka6zlNdHTRouUbIzSEtjiTIBUswg5v_NwMnuAVlA9KKFPN3I0x9qSSj7bqNF3iPykl9c4o9oUSJMuElv2XQ8IHAYRt3bluWM8wuVUpUJwVlFjsP8JUh5B_1DyV2AYdD6DjhLsTQTaYd3W3ad28SGWqM997fG5ZrB9DJqOaALuRwH1TMpik8tIYze-E8OrPKU5I6cMqtem2kCqOhr4vdaRAvtSjcoMkTo68scKu_Vi1EPMfrP_xVtj7sFMaHNg-6GVqk0MW0z18uKdVULTvDWtdqko28b7KktvUB2hKOBd1asU2QgDfTzrj7T4bLPdv6TR0zLwPQKkkZpIRTY4CTMbrBpg_VKuXyi49beUAHqIlirOUrL2zq9JPPdpRR5OMLVQGoGlLcjyRyQNv6MHz4W_fG42W--xWhUfNyOxiLL1USS6lRLeyAkYLNjrkVJuClm_qp5I8Lq0krUw7lwIt2DgY9oiozrjA_Yhy0
    *
    * Note: When generating session signatures for different PKPs or auth methods,
    * be sure to call disconnectWeb3 to clear auth signatures stored in local storage
    *
-   *
    * @param { GetSessionSigsProps } params
    *
    * An example of how this function is used can be found in the Lit developer-guides-code repository [here](https://github.com/LIT-Protocol/developer-guides-code/tree/master/session-signatures/getSessionSigs).