diff --git a/test-cli/src/cmd/mod.rs b/test-cli/src/cmd/mod.rs
index d93c6fe..73c28e7 100644
--- a/test-cli/src/cmd/mod.rs
+++ b/test-cli/src/cmd/mod.rs
@@ -9,6 +9,7 @@ use crate::Cli;
 pub mod create_order;
 pub mod initialize;
 pub mod settle;
+pub mod solver;
 
 /// Shared context threaded through every subcommand.
 pub struct Context {
diff --git a/test-cli/src/cmd/solver.rs b/test-cli/src/cmd/solver.rs
new file mode 100644
index 0000000..12e2d5f
--- /dev/null
+++ b/test-cli/src/cmd/solver.rs
@@ -0,0 +1,91 @@
+use anyhow::Context as _;
+use clap::{Args as ClapArgs, Parser, Subcommand};
+use cow_settlement_client::{
+    cow_settlement_interface::{pda::state::find_state_pda, Pubkey},
+    instructions::AddSolver,
+};
+use solana_sdk::{
+    signature::{read_keypair_file, Signer},
+    transaction::Transaction,
+};
+
+use crate::helpers::print_summary;
+
+use super::Context;
+
+#[derive(Parser)]
+pub struct SolverArgs {
+    #[command(subcommand)]
+    command: SolverCommand,
+}
+
+#[derive(Subcommand)]
+enum SolverCommand {
+    #[command(about = "Authorize a solver to settle orders")]
+    Add(AddArgs),
+}
+
+#[derive(ClapArgs)]
+pub struct AddArgs {
+    /// Address of the solver to authorize
+    solver: Pubkey,
+
+    /// Path to the manager keypair, which authorizes the change and must sign
+    /// it (defaults to the payer keypair, which always funds the state PDA's
+    /// growth)
+    #[arg(long)]
+    manager: Option<String>,
+}
+
+pub fn run(ctx: Context, args: SolverArgs) -> anyhow::Result<()> {
+    match args.command {
+        SolverCommand::Add(args) => add(ctx, args),
+    }
+}
+
+fn add(ctx: Context, args: AddArgs) -> anyhow::Result<()> {
+    let payer = ctx.payer.pubkey();
+    // Without `--manager` the payer manages the program, so reuse the keypair
+    // the context already holds instead of reading a file again.
+    let from_file = args
+        .manager
+        .map(|path| {
+            read_keypair_file(&path)
+                .map_err(|e| anyhow::anyhow!("failed to read manager keypair from {path}: {e}"))
+        })
+        .transpose()?;
+    let manager = from_file.as_ref().unwrap_or(&ctx.payer);
+    let manager_pubkey = manager.pubkey();
+
+    let ix = AddSolver {
+        program_id: ctx.program_id,
+        manager: manager_pubkey,
+        payer,
+        solver: args.solver,
+    };
+
+    let blockhash = ctx
+        .rpc
+        .get_latest_blockhash()
+        .context("failed to fetch blockhash")?;
+    let tx = Transaction::new_signed_with_payer(
+        &[ix.into()],
+        Some(&payer),
+        &[&ctx.payer, manager],
+        blockhash,
+    );
+    let sig = ctx
+        .rpc
+        .send_and_confirm_transaction(&tx)
+        .context("transaction failed")?;
+
+    let (state_pda, _) = find_state_pda(&ctx.program_id);
+    print_summary(&[
+        ("signature", &sig),
+        ("added solver", &args.solver),
+        ("manager", &manager_pubkey),
+        ("statePda", &state_pda),
+    ]);
+
+    Ok(())
+}
diff --git a/test-cli/src/main.rs b/test-cli/src/main.rs
index 352c309..e045a95 100644
--- a/test-cli/src/main.rs
+++ b/test-cli/src/main.rs
@@ -73,6 +73,8 @@ enum Commands {
     Buy(cmd::create_order::BuyOrSellArgs),
     #[command(about = "Settle one or more orders")]
     Settle(cmd::settle::SettleArgs),
+    #[command(about = "Manage the program's solvers (e.g. `cow solver add <address>`)")]
+    Solver(cmd::solver::SolverArgs),
 }
 
 fn main() -> anyhow::Result<()> {
@@ -83,5 +85,6 @@ fn main() -> anyhow::Result<()> {
         Commands::Sell(args) => cmd::create_order::run_sell(ctx, args),
         Commands::Buy(args) => cmd::create_order::run_buy(ctx, args),
         Commands::Settle(args) => cmd::settle::run(ctx, args),
+        Commands::Solver(args) => cmd::solver::run(ctx, args),
     }
 }