add: README

programs/gpl_session/README.md

@@ -0,0 +1,52 @@
+ GPL Session
+==============
+
+Manage sessions in your Solana Anchor Programs.
+
+
+# Installation
+
+```bash
+cargo add gpl-session --features no-entrypoint
+```
+
+# Usage
+
+1. Import the dependencies
+
+```rust
+use gpl_session::{SessionError, SessionToken, session_auth_or, Session};
+```
+
+2. Derive the `Session` trait on your instruction struct
+
+```rust
+#[derive(Accounts, Session)]
+pub struct Instruction<'info> {
+    .....
+    pub user: Account<'info, User>,
+
+    #[session(
+        signer = authority,
+        authority = user.authority.key()
+    )]
+    pub session_token: Option<Account<'info, SessionToken>>,
+
+    #[account(mut)]
+    pub authority: Signer<'info>,
+    .....
+}
+```
+
+3. Add the `session_auth_or` macro to your instruction handler with fallback logic on who the instruction should validate the signer when sessions are not present and an appropirate ErrorCode. If you've used `require*!` macros in anchor_lang you already know how this works.
+
+```rust
+#[session_auth_or(
+    ctx.accounts.user.authority.key() == ctx.accounts.authority.key(),
+    ErrorCode
+)]
+pub fn ix_handler(ctx: Context<Instruction>,) -> Result<()> {
+.....
+}
+
+```