How do I set up a Noble Dollar (USDN) swap pool for local ymax testing?

[dckc]

I can do a swap on the Noble grand testnet...

nobled tx swap on grand-1 testnet

$ nobled --node 'https://noble-testnet-rpc.polkachu.com:443' tx swap swap 266666uusdc '{"pool_id":0,"denom_to":"uusdn"}' 263999uusdn '--chain-id=grand-1' '--from=trader1' '--keyring-backend=test' --yes '--fees=25000uusdc' '--gas=auto' '--gas-adjustment=1.3' -o json
[16:08:37.958] [0] ✔ (done in 951ms)
{
  txhash: '64689B18834BF0C57EA9E6727905011B655FAD2C3AF67E01B4AB9EC9E5DB2595',
  url: 'https://www.mintscan.io/noble-testnet/tx/64689B18834BF0C57EA9E6727905011B655FAD2C3AF67E01B4AB9EC9E5DB2595'
}

But when I try on my local node (set up using starship) I get error computing swap routes plan: pool 0 does not exists.

When I look at the noble grand-1 testnet, I see pool 0 with USDC/USDN liquidity:

nobled query swap pool 0

$ nobled query --node https://noble-testnet-rpc.polkachu.com:443 swap pool 0 -o json | jq .

{
  "pool": {
    "address": "noble1nj5skf28jfps7hqwcp484zwj6kt9aejdt3ghxv",
    "algorithm": "STABLESWAP",
    "pair": "uusdc",
    "details": {
      "type": "/noble.swap.stableswap.v1.Pool",
      "value": {
        "protocol_fee_percentage": "50",
        "rewards_fee": "2500000",
        "initial_a": "800",
        "future_a": "800",
        "initial_a_time": "1740153360",
        "rate_multipliers": [
          {
            "denom": "uusdc",
            "amount": "1000000000000000000"
          },
          {
            "denom": "uusdn",
            "amount": "1000000000000000000"
          }
        ],
        "total_shares": "10929071011.790794276857608692",
        "initial_rewards_time": "2025-02-21T18:01:58.138804404Z"
      }
    },
    "liquidity": [
      {
        "denom": "uusdc",
        "amount": "6389833131"
      },
      {
        "denom": "uusdn",
        "amount": "6389132685"
      }
    ],
    "protocol_fees": [
      {
        "denom": "uusdc",
        "amount": "3540755"
      },
      {
        "denom": "uusdn",
        "amount": "2963426"
      }
    ],
    "reward_fees": [
      {
        "denom": "uusdc",
        "amount": "3540753"
      },
      {
        "denom": "uusdn",
        "amount": "2963424"
      }
    ]
  }
}

But I have no pools on my local setup:

$ nobled --node=http://localhost:26654 query swap pools
{}

[dckc]

Part I: Create the Pool using nobled tx authority execute

The update to our system is

• feat(multichain): Add Noble Swap Pool Creation in Multichain for Ymax #11514
  from
• create working noble pool in multichain-testing #11513

What we learned that went into that was...

At genesis, use an address whose key you know for the authority owner:

.app_state.authority.owner

echo "Configure owner for authority module…"
jq --arg addr "$GENESIS_ADDR" '
  .app_state.authority = {
    "owner": $addr
  }
' $CHAIN_DIR/config/genesis.json \
  > /tmp/genesis.json && mv /tmp/genesis.json $CHAIN_DIR/config/genesis.json

Then generate and sign, but don't broadcast, the create-pool transaction:

generate create-pool

# nobled tx swap stableswap create-pool uusdc 0 5 1 100 100  1000000000000000000uusdc 1000000000000000000uusdn  --chain-id noblelocal --generate-only --from noble13am065qmk680w86wya4u9refhnssqwcvgs0sfk |jq . >,create-pool.json

The help text might suggest one argument for rate_multipliers...

Usage:
  nobled tx swap stableswap create-pool [pair] [protocol_fee_percentage] [rewards_fee] [initial_a] [future_a] [future_a_time] [rate_multipliers] [flags]

But {ProtoField: "rate_multipliers", Varargs: true} in module.go tells us that it's separate shell arguments.

Finally, use authority execute:

authority execute

# nobled tx authority execute ,create-pool.json --from genesis --chain-id noblelocal --keyring-backend test  --gas auto --gas-adjustment 1.4
gas estimate: 130880
{"body":{"messages":[{"@type":"/noble.authority.v1.MsgExecute","signer":"noble1qjtcxl86z0zua2egcsz4ncff2gzlcndz22lqv2","messages":[{"@type":"/noble.swap.stableswap.v1.MsgCreatePool","signer":"noble13am065qmk680w86wya4u9refhnssqwcvgs0sfk","pair":"uusdc","protocol_fee_percentage":"0","rewards_fee":"5","initial_a":"1","future_a":"100","future_a_time":"100","rate_multipliers":[{"denom":"uusdc","amount":"1000000000000000000"},{"denom":"uusdn","amount":"1000000000000000000"}]}]}],"memo":"","timeout_height":"0","extension_options":[],"non_critical_extension_options":[]},"auth_info":{"signer_infos":[],"fee":{"amount":[],"gas_limit":"130880","payer":"","granter":""},"tip":null},"signatures":[]}
confirm transaction before signing and broadcasting [y/N]: y
{"height":"0","txhash":"576B23273B1D41223AA1571387B989A3320AFD9C4DB7CCAC96B33B1D98DABD8B","codespace":"","code":0,"data":"","raw_log":"","logs":[],"info":"","gas_wanted":"0","gas_used":"0","tx":null,"timestamp":"","events":[]}

Now we have a pool!

query pools wins

noblelocal-genesis-0:/opt# nobled query swap pools
{
  "pools": [
    {
      "address": "noble1nj5skf28jfps7hqwcp484zwj6kt9aejdt3ghxv",
      "algorithm": "STABLESWAP",
      "pair": "uusdc",
      "details": {
        "type": "/noble.swap.stableswap.v1.Pool",
        "value": {
          "rewards_fee": "5",
          "initial_a": "1",
          "future_a": "100",
          "initial_a_time": "1750353613",
          "future_a_time": "100",
          "rate_multipliers": [
            {
              "denom": "uusdc",
              "amount": "1000000000000000000"
            },
            {
              "denom": "uusdn",
              "amount": "1000000000000000000"
            }
          ],
          "total_shares": "0.000000000000000000",
          "initial_rewards_time": "0001-01-01T00:00:00Z"
        }
      },
      "liquidity": [],
      "protocol_fees": [],
      "reward_fees": []
    }
  ]
}

Next challenge: liquidity

At this point, when we tried to swap, we got Error: rpc error: ... error computing swap routes plan: pool liquidity must be positive.

More on that in comments to follow...

[dckc]

After spending way too much time with an LLM to figure this out, I asked it to summarize with a bit of style...

---

Creating a USDN Whale on Noble (Star Wars Edition)

How I stopped worrying and learned to mint a galactic hoard of uusdn.

---

🚀 The Successful Strategy (A New Hope)

After much experimentation, the working solution to create a USDN whale was to use Starship's native balances: config syntax in the config.yaml chain definition:

balances:
  # USDN whale
  - address: noble16fskzhlguwkq35f5hmvnxg6urug46fhmn9frwu
    amount: 100000000000000uusdn

This configuration directly inserts the balance into the genesis file during Starship's provisioning step. It is clean, declarative, and survives all script overrides.

---

❌ What Didn't Work (The Phantom Errors)

⚡ add-genesis-account in shell script

$CHAIN_BIN add-genesis-account $ADDR 1000000000000uusdn

This seemed like the obvious path, but it silently failed or was overridden. Likely reasons:

• The nobled binary in Noble v10+ wraps all genesis ops under a genesis subcommand.
  • Correct form: $CHAIN_BIN genesis add-genesis-account ...
• Even when correct, Starship likely re-generates or overwrites genesis in later stages.

💥 Validator Self-Destruct

Adding a balance to a malformed validator gentx account triggered this panic:

invalid coin denomination: got uusdc, expected stake

Why? Because the gentx had:

"delegator_address": ""

Adding funds to any account made the staking module try to validate the broken gentx, leading to a full-blown crash on InitGenesis.

⌛ Sed and bond_denom

Attempts to patch the genesis file with:

sed -i -e "s/\"stake\"/\"uusdc\"/g" genesis.json

...did not fix the gentx, which still used uusdc without a corresponding bond denom setting or valid address.

Even jq-based patches to .app_state.staking.params.bond_denom were ineffective because the validator tx was simply malformed.

---

✨ Lessons from the Galaxy

• ✅ Use Starship's balances: config. It's the native, supported way to mint large balances.
• 🖕 Don't try to out-script Starship. Your script is not the final say in genesis state.
• ⚡ Beware of broken gentx files. A validator with no delegator_address is a ticking thermal detonator.
• 💡 Don't assume your add-genesis-account worked unless you verify with jq or query the resulting chain.

---

🚐 For the Next Rebel Engineer

If you ever need a whale:

1. Generate the key with nobled keys add whale --keyring-backend=test
2. Add its address under balances: in config.yaml
3. Let Starship do the heavy lifting
4. Confirm post-boot with:

   nobled query bank balances <whale-address> -o text

And may your balances be as deep as a Sarlaac pit.

—Dan, signing off from Noble Base Echo

[dckc]

Episode VII: A New Pool — Adding Liquidity to a Noble Swap Pool (USDN)

✅ What Worked in This Episode

To successfully add liquidity to a STABLESWAP pool on Noble:

1. Ensure pool exists: (See Episode VI: Making a USDN Whale for setup) You should see an entry via:

   nobled query swap pools
   

   which shows a pool with correct rate multipliers for uusdc and uusdn.

2. Use separate arguments for each coin in the CLI command (not a comma-separated coin string!). This is because the command uses Varargs for the amount field:

   nobled tx swap stableswap add-liquidity 0 5 21000000uusdc 21000000uusdn \
     --from whale \
     --node 'http://localhost:26654' \
     --chain-id noblelocal \
     --keyring-backend test \
     --broadcast-mode block \
     --gas auto \
     --gas-adjustment 1.4 \
     --yes -o json

3. Verify liquidity was added:

   nobled query swap pool 0 | jq .pool.liquidity

   should show:

   [
     { "denom": "uusdc", "amount": "21000000" },
     { "denom": "uusdn", "amount": "21000000" }
   ]

4. Confirm functional liquidity via a real swap:

   nobled tx swap swap 123uusdc '{"pool_id":0,"denom_to":"uusdn"}' 121uusdn \
     --from trader1 \
     --node 'http://localhost:26654' \
     --chain-id noblelocal \
     --keyring-backend test \
     --gas auto \
     --gas-adjustment 1.4 \
     --yes -o json

   Then verify the resulting balances:

   nobled query bank balances noble18qlqfelxhe7tszqqprm2eqdpzt9s6ry025y3j5 -o text

   Example output:

   balances:
   - amount: "9999999877"
     denom: uusdc
   - amount: "122"
     denom: uusdn
   

⚠️ Dark Side Encounters: Failure Modes and Lessons

• 💥 Gotcha # 1: If you try amount as '21000000uusdc,21000000uusdn', you'll hit:

  Error: invalid argument "21000000uusdc,21000000uusdn" for "--2" flag
  

  The CLI expects separate args for each coin!

• 🤯 Gotcha # 2: If the pool is empty, any swap will fail with:

  error computing swap routes plan: pool liquidity must be positive
  

• 🧃 Lesson: Pool liquidity isn’t real until it's queried and used. Swapping is the ultimate test.

---

🌌 "Once more the whales will rule the pool... and we shall have liquidity! The swap must flow."

[dckc]

The answer is above in 3 parts:

1. Create the Pool using nobled tx authority execute
2. Creating a USDN Whale on Noble
3. Adding Liquidity to a Noble Swap Pool (USDN)