blockrunai/blockrun-mcp/polymarket-trading

Polymarket Trading (blockrun_polymarket)

Real-money trading on Polymarket's CLOB V2 (Polygon), signed locally by the user's BlockRun wallet key. Data discovery stays on `blockrun_markets` — this tool only trades.

Mental model

• Signer = the BlockRun wallet key (~/.blockrun/.session by default; a

BLOCKRUN_WALLET_KEY env var or an existing agent wallet.json takes precedence). Never leaves the machine. setup prints the actual signer address — back up the key behind it, wherever it lives (key file or env-var value).

• Deposit wallet = a Polygon vault contract derived from that key

(POLY_1271). It holds the betting funds in pUSD and only honors the signer's EIP-712 signatures. Deploy/approve/redeem are gasless (relayer).

• Money separation: bets spend pUSD on Polygon; x402 API fees spend USDC on

Base. The budget ledger does NOT cover bets — confirm:true + caps do.

• Zero setup: no Polymarket account, no API keys, no gas token. On first

setup the MCP bootstraps a builder key from the user's OWN wallet, then derives + deploys the vault (all gasless). Geoblock is handled by default — CLOB traffic routes through BlockRun's Finland egress out of the box.

Golden rules for agents

1. **Never pass confirm:true unless the user explicitly approved that exact

trade.** Call once WITHOUT confirm → show the dry-run preview → ask → re-call with confirm:true.

1. Per-order cap POLYMARKET_MAX_BET_USD (default $25) and optional session cap

are enforced server-side; don't try to split orders to sneak past them. The optional POLYMARKET_MAX_FUND_USD bounds a single fund call the same way. A withdraw preview marks any to_address that is not the user's own agent wallet as CUSTOM — show the user that line verbatim before confirming.

1. On ANY error, read the message — it says exactly what to do next (fund,

approve, region, re-run setup). Don't retry blindly.

End-to-end flow

# 0. No Polymarket account or API keys needed — the MCP bootstraps everything
#    from the user's own wallet on first setup. (Geoblock is already handled:
#    CLOB traffic routes through BlockRun's Finland egress by default. Set
#    POLYMARKET_CLOB_HOST only to use your own egress, or to hit Polymarket
#    directly from a permitted region.)
 
# 1. Provision + inspect (idempotent, safe to re-run any time)
blockrun_polymarket action:"setup"
# → deposit wallet address + funding instructions + region status
 
# 2. Fund the vault from the user's Base USDC — gasless x402, one call ($0.01 fee,
#    non-custodial). pUSD credit is ASYNC (minutes) — re-run setup to watch it. Min $2.
blockrun_polymarket action:"fund" amount_usd:5             # dry-run preview
blockrun_polymarket action:"fund" amount_usd:5 confirm:true
 
# 3. Sign the one-time gasless approval batch (after user consent)
blockrun_polymarket action:"setup" confirm:true
 
# 4. Find a market, then resolve the selected condition (paid data)
blockrun_markets path:"markets/search" params:{q:"Bitcoin",status:"open",venue:"polymarket",limit:"20"}
blockrun_markets path:"polymarket/markets/keyset" params:{condition_id:"0x...",status:"open",limit:"5"}
 
# 5. Preview, then place
blockrun_polymarket_read action:"preview" side:"buy" token_id:"..." amount_usd:5 order_type:"FOK"
blockrun_polymarket action:"buy" token_id:"..." amount_usd:5 order_type:"FOK" confirm:true
#   or limit: price:0.45 size:10 (GTC; order_type:"GTD" + expires_at for expiry)
#   or via condition: condition_id:"0x..." outcome:"Yes"
 
# 6. Manage
blockrun_polymarket_read action:"orders"                # open orders
blockrun_polymarket action:"cancel" order_id:"..."      # or all:true
blockrun_polymarket_read action:"positions"             # holdings + PnL + redeemable
 
# 7. Claim winnings after resolution (gasless)
blockrun_polymarket action:"redeem" condition_id:"0x..."             # preview
blockrun_polymarket action:"redeem" condition_id:"0x..." confirm:true
 
# 8. Cash out — pUSD → native USDC on Base, back to the user's agent wallet
blockrun_polymarket action:"withdraw"                                # dry-run (full balance)
blockrun_polymarket action:"withdraw" confirm:true                   # (partial: amount_usd:5)

Order semantics

• Prices are probabilities 0–1, auto-rounded to the market's tick grid.
• A market-order preview states worst fill ≤ X (buy) / ≥ X (sell); the

order is signed at that bound, so quote it to the user as the price limit.

• Market buy = amount_usd (dollars). Market sell = size (shares).
• Limit orders: price + size; default GTC; post_only:true for maker-only.
• FOK fails whole-or-nothing; FAK fills what it can. On "FOK not filled", offer

FAK or a limit at the shown book price.

Regions / geoblock

Order placement is IP-geoblocked (US/UK/EU + many regions). Handled by default — CLOB traffic routes through BlockRun's Finland egress, so setup reports ✅ Region: order placement permitted out of the box; you don't need to do anything. A user can override by pointing POLYMARKET_CLOB_HOST at their own relay (or at Polymarket directly, from a permitted region), optionally reached through their own proxy via POLYMARKET_CLOB_PROXY / HTTPS_PROXY (POLYMARKET_CLOB_PROXY wins if both are set). A proxy alone does NOT change the Polymarket-facing egress — CLOB traffic still exits from BlockRun's Finland relay unless POLYMARKET_CLOB_HOST is also repointed. Respecting Polymarket's ToS for the user's jurisdiction is the user's responsibility — never suggest evading it.

Troubleshooting

• "No deposit wallet configured" → run action:"setup".
• No manual creds are ever needed — the MCP bootstraps its builder key from the

user's own wallet on first setup. (Advanced: POLYMARKET_SIG_TYPE=0 = plain EOA mode; needs POL gas + pUSD in the EOA. The CLOB may reject plain-EOA makers on order placement — treat it as a diagnostic fallback, not a guaranteed trading mode.)

• Balance/allowance errors on a buy → the buy path auto-refreshes the CLOB's

balance cache and retries once; if it still fails, the vault genuinely lacks pUSD or approvals — fund it, then action:"setup" confirm:true.

• A neg-risk market buy (multi-outcome "winner" markets) fails though setup

shows ready → a deposit wallet created before the pUSD→NegRisk Adapter approval was added needs ONE more action:"setup" confirm:true to grant it (setup reads approvals on-chain every run, so it detects and signs the missing one).

• A redeem reverts → same self-heal: wallets set up before 2026-07 lack the

collateral-adapter approvals redeem now pulls tokens through — one action:"setup" confirm:true grants them.

• 403 → region issue; see setup's region line.
• "order signer address has to be the address of the API KEY" → auto-recovered

once (creds re-derived); if persistent, setup, then as a last resort POLYMARKET_SIG_TYPE=0 (upstream clob-client-v2 issue #65; see the EOA-mode caveat above).