This server does not currently have a deployable release on Glama. Follow the repository's setup instructions to install and configure it for your MCP client, including any required credentials and local dependencies.
An MCP server for your own Polymarket US account. It is an official Roost server: Roost downloads the release file from this repository, checks its SHA-256, and runs it on your hub with your own key. Your key stays on your hub. It never goes to Roost.
Polymarket US is the CFTC-regulated exchange at api.polymarket.us. This is not the international Polymarket (Polygon CLOB).
Make a key. Open the Polymarket US app, make an account, and finish identity verification. Then open polymarket.us/developer, sign in the same way as in the app, and click to create a key. Copy the Key ID and the Secret key. The secret key is shown only once.
In Roost, open Marketplace, find Polymarket US (it has the By Roost chip), and click Set up.
Paste the Key ID and the Secret key. Keep Largest order (USD) at 50, or change it.
Click Connect. Roost downloads the server, checks it, starts it, and checks the key with get_balances. A key that Polymarket US refuses is not saved.
The money tools are on, as other tools are, and they follow each bot's access: a bot with "Ask first" asks you, and a bot with Full access does not. The switch Ask every time on the app page (off by default) makes each money tool ask you before each call, also for a bot with Full access and in saved automations. To stop one tool, turn it off on the app page.
Related MCP server: QuantRisk
Tool | What it does | Key |
| Search events and markets by words | No |
| One market by its slug | No |
| The order book and stats of a market | No |
| YES and NO prices over time | No |
| Cash balance and buying power | Yes |
| Positions by market slug | Yes |
| Trades, resolutions, deposits, withdrawals | Yes |
| Open orders | Yes |
| One order by its ID | Yes |
| Check an order and its expected cost. Sends no order | Yes |
These place, change, or cancel live orders with real money.
Tool | What it does |
| Place a LIMIT or MARKET order |
| Change the price, quantity, or time in force of an open order |
| Cancel one open order |
| Cancel every open order, or every open order in one market |
| Close the whole position in one market at the market price |
Orders that this server sends carry MANUAL_ORDER_INDICATOR_AUTOMATIC, so Polymarket US can see that a program sent them.
Largest order. An order whose estimated notional is over the largest order is refused here and never sent. At the largest order is allowed.
LIMIT (and modify_order with a price and a quantity): price × quantity.
MARKET: the price that you give, else the best ask for a buy and the best bid for a sell. With neither, the order is refused.
close_position: |net position| × the best bid (long) or the best ask (short). When that cannot be estimated, the close goes on.
Prices are for the YES side, from 0 to 1 USD.
Orders a minute. At most 10 orders (place, modify, close) in one minute. A cancel is never limited.
Rate limit. Polymarket US allows 25 requests a second for each address. The server keeps 40 ms between requests. A read that gets a 429 waits 1 second, then 2 seconds, and tries again. An order that gets a 429 is not sent again.
Rule 5.2(i) of the Polymarket US Rulebook asks automated trading systems for "order throttles, price collars, and kill switches". The largest order and the orders a minute limit are the throttles. cancel_all_orders is the kill switch, and turning a money tool off in Roost stops it at once. There is no price collar yet: the server only checks that a price is above 0 and below 1.
A failed call returns isError: true and structuredContent.error with class and message:
Class | Meaning |
| The key is missing, refused, or the hub clock is off ("Check the clock of the hub.") |
| The input or the order is wrong, or Polymarket US refused it (with its message) |
| A check of this server refused it, such as the largest order |
| Polymarket US did not answer or was slow. Try again |
| Too many requests or orders. Wait, then try again |
| Anything else |
No message, result, or log carries the secret key.
Roost sets these when it starts the server. You need them only to run it by hand.
Variable | Default | Purpose |
| none | The Key ID |
| none | The Secret key (base64) |
|
| The largest order in USD |
|
| Orders in one minute |
With no key, only the four public tools work.
bun install
bun test # against a fake Polymarket US; no network, no real key
bun run typecheck
bun run build # dist/roost-mcp-polymarket-us.js, one file, no install step
bun run drift # compare the vendor's public OpenAPI files with openapi/The server has no runtime dependencies. @modelcontextprotocol/sdk is only for the stdio test.
Set version in package.json (for example 0.1.0), then push the tag v0.1.0.
The Release workflow tests, builds, and publishes roost-mcp-polymarket-us.js and roost-mcp-polymarket-us.js.sha256 as release assets.
In the Roost repository, set the Polymarket US row of app-catalog.json to the new tag and the SHA-256 from the .sha256 file. Each hub downloads the new file the next time it starts the server.
The vendor's API can change. The Vendor API drift workflow runs each Monday and fails when the public OpenAPI files differ from openapi/. Read the changelog, fix the tools, then run bun scripts/drift.ts --write. SOURCE.md lists each vendor page and the date it was read.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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This server cannot be deployed
Live prices, perps, prediction markets and a paper trading desk over one MCP.
Keyless prediction-market data across 12 venues plus paper-trading of crypto spot, futures, and PM.
Markets, strategies with a measured record and your own account, for any AI. Read-only.
Place and inspect orders on your own exchange accounts from an MCP-connected agent.
