polydesk

Polydesk: a paper-trading desk for Polymarket, built for Hermes Agent

Polydesk lets Hermes trade Polymarket prediction markets on paper, against the live order
book. Your agent can research a market, quote a trade, show you the real cost and
slippage, and execute only after you confirm. It tracks P&L and settles positions when markets
resolve. The bankroll can be backed 1:1 by testnet USDC in your Base Sepolia wallet
(Coinbase's L2 testnet), so it pairs with Base tooling like basekit.

No keys. No signing. No real orders. No real money. Not financial advice.

Why it's more than a prompt

Real fills, real slippage. Every order walks the live CLOB book level by level, so a
$500 buy in a thin market gets the price it would actually get, not the headline odds.
Quote, then confirm. A trade first returns a single-use ticket that expires in 5 minutes.
At execution it's re-priced against a fresh book and rejected if the price moved against you.
Risk limits. Max per-trade size, max % of equity in one outcome, a max-slippage sweep
guard, cash checks, and a liquidity check. Rejections explain exactly why.
Persistent ledger. SQLite in the plugin's own data folder. Mark-to-mid portfolio,
liquidation value, realized and unrealized P&L, full activity log.
Auto-settlement. When a market resolves, winning shares pay $1 and losing shares pay $0.
Testnet-backed bankroll. Link a Base Sepolia address (public address only) and deposit up
to its on-chain testnet USDC balance.

Tools

| Tool | What it does |
|---|---|
| polydesk_markets | Search open markets, list trending ones, or read one market's outcomes and live order book |
| polydesk_trade | Quote → ticket → confirm → fill against the live book (buy by USD, sell by shares or all) |
| polydesk_portfolio | Cash, positions marked to market, P&L, return, bankroll backing; settles resolved markets |
| polydesk_history | Buys, sells, settlements and deposits |
| polydesk_wallet | status / link / deposit for a Base Sepolia wallet |

Slash command: /desk (portfolio), /desk history, /desk reset confirm.
A bundled polydesk skill teaches the agent the confirm-before-execute workflow.

Try it

hermes plugins install clatsonhacks/hermes-polydesk
hermes plugins enable polydesk
hermes
> What are the odds the Fed cuts in December? Put $50 on whichever side you think is underpriced.
> /desk

To back the bankroll with testnet funds, get Base Sepolia USDC at https://faucet.circle.com, then:

> Link my testnet wallet 0xYourAddress and deposit 10 USDC

Settings

Settings are under plugins.entries.polydesk.settings, or in the Desktop plugin form.

| Key | Default | |
|---|---|---|
| demo_bankroll | 1000 | Unbacked paper cash on first use (0 = testnet-backed only) |
| max_trade_usd | 250 | Per-trade cap |
| max_position_pct | 25 | Max % of equity in one outcome |
| max_slippage | 0.03 | Max sweep from best price, and max adverse re-price at execution |
| auto_execute | false | Skip the confirmation ticket (for scheduled strategies) |
| rpc_url | https://sepolia.base.org | Base Sepolia JSON-RPC (chain id is verified) |
| wallet_address | "" | Optional default testnet address |

Disclosure

Network: HTTPS GET to gamma-api.polymarket.com and clob.polymarket.com only (the client
refuses any other host). JSON-RPC eth_chainId, eth_getBalance and eth_call (USDC balanceOf)
to sepolia.base.org or your configured rpc_url, only when you use polydesk_wallet. The
wallet address you link is sent to that RPC.
Storage: a SQLite ledger at <HERMES_HOME>/plugin-data/polydesk/desk.db. It reads nothing
else on disk.
No credentials, private keys, signing, transactions, shell commands, background processes,
telemetry, self-updating code or binaries. Standard library only.

Development

python -m pytest tests -q        # offline tests, Polymarket and the RPC are mocked
hermes plugins validate . --install-deps

MIT licensed.

README from the reviewed commit 190d38e; it updates when the author re-pins.

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