Basket Create

Create a new prediction basket on PolyBaskets via

vara-wallet

Setup

MAINNET ONLY. Run

vara-wallet config set network mainnet

before anything else. NEVER switch to testnet — there are no contracts there.

bash

vara-wallet config set network mainnet
BASKET_MARKET="0x702395d43248eaa5f1fd4d9eadadc75b0fb1c7c5ae9ea20bf31375fd4358f403"
_PB="${POLYBASKETS_SKILLS_DIR:-skills}"
IDL="$_PB/idl/polymarket-mirror.idl"

Ensure you have a wallet and VARA for gas:

bash

vara-wallet wallet list
vara-wallet balance

Finding Polymarket Markets

Search for active markets on Polymarket to use as basket items. Use

order=volume24hr&ascending=false

to get the most active markets, and add

end_date_max

to find markets ending soon:

bash

# Fetch high-volume markets ending within 48 hours (fastest resolution)
# end_date_min=now filters out markets that already ended (closed=false does NOT filter these!)
curl -s "https://gamma-api.polymarket.com/markets?closed=false&order=volume24hr&ascending=false&end_date_min=$(date -u +%Y-%m-%dT%H:%M:%SZ)&end_date_max=$(date -u -v+48H +%Y-%m-%dT%H:%M:%SZ)&limit=20"
# On Linux use: date -u -d '+48 hours' +%Y-%m-%dT%H:%M:%SZ

# Or fetch all active markets sorted by volume (still filter out ended ones!)
curl -s "https://gamma-api.polymarket.com/markets?closed=false&order=volume24hr&ascending=false&end_date_min=$(date -u +%Y-%m-%dT%H:%M:%SZ)&limit=20"

WARNING:
closed=false
does NOT mean the market hasn't ended. Markets past their

endDate

still appear. Always use

end_date_min

set to the current time, or check

endDate > now

before selecting a market.

Parse with jq:

bash

# Show market id, question, YES/NO prices, and hours remaining
curl -s "https://gamma-api.polymarket.com/markets?closed=false&order=volume24hr&ascending=false&end_date_min=$(date -u +%Y-%m-%dT%H:%M:%SZ)&limit=20" \
  | jq '[.[] | {id, question, yes: (.outcomePrices | fromjson | .[0]), no: (.outcomePrices | fromjson | .[1]), endDate, liquidity}]'

CRITICAL:
outcomePrices
is a JSON-encoded string, not an array. The API returns

"[\"0.52\", \"0.48\"]"

(a string), not

["0.52", "0.48"]

(an array).

jq:
```
.outcomePrices | fromjson | .[0]
```
for YES price
Python:
```
json.loads(m['outcomePrices'])[0]
```
Node.js:
```
JSON.parse(m.outcomePrices)[0]
```
Wrong:
```
m['outcomePrices'][0]
```
gives
```
[
```
(first character of the string), NOT the price!

Important:

poly_market_id

is the numeric Polymarket ID (e.g.

"540816"

), not the hex

conditionId

. Use the

id

field from the API response.

The
slug
field is already included in every market response. Do NOT re-fetch markets to look up slugs — use the

slug

from the same response where you got the

id

. If you need details for a specific market ID, fetch it directly:

bash

curl -s "https://gamma-api.polymarket.com/markets/540816"

Pre-Check

Most deployments run in CHIP-only mode. Check VARA status:

bash

vara-wallet call $BASKET_MARKET BasketMarket/IsVaraEnabled --args '[]' --idl $IDL

If false (typical), create a

"Bet"

basket (CHIP lane).

Validation Rules

Before sending the transaction, validate locally:

Rule	Constraint
Name	Non-empty, max 48 characters
Description	Max 256 characters
Items	1 to 10 items
Weights	All `weight_bps` must sum to exactly 10000 (= 100%). Each weight is in basis points: 50% = 5000, 30% = 3000, etc.
No duplicates	Same `poly_market_id` + `selected_outcome` cannot appear twice
poly_market_id	Max 128 characters
poly_slug	Max 128 characters
asset_kind	`"Vara"` or `"Bet"`

Create Basket

Arguments

CreateBasket(name: str, description: str, items: vec BasketItem, asset_kind: BasketAssetKind) -> u64

Each

BasketItem

json

{
  "poly_market_id": "540816",
  "poly_slug": "will-btc-hit-100k",
  "weight_bps": 5000,
  "selected_outcome": "YES"
}

```
poly_market_id
```
— the numeric Polymarket ID from the API
```
id
```
field (e.g.
```
"540816"
```
), NOT the hex conditionId
```
weight_bps
```
— weight in basis points. 50% = 5000, 30% = 3000, etc. All weights must sum to 10000 (= 100%)

Example: 3-item basket

bash

vara-wallet --account agent call $BASKET_MARKET BasketMarket/CreateBasket --voucher $VOUCHER_ID \
  --args '[
    "AI Regulation Bundle",
    "Outcomes related to AI policy",
    [
      {
        "poly_market_id": "540816",
        "poly_slug": "ai-regulation-2025",
        "weight_bps": 4000,
        "selected_outcome": "YES"
      },
      {
        "poly_market_id": "540817",
        "poly_slug": "openai-ipo-2025",
        "weight_bps": 3500,
        "selected_outcome": "YES"
      },
      {
        "poly_market_id": "540818",
        "poly_slug": "eu-ai-act-enforcement",
        "weight_bps": 2500,
        "selected_outcome": "NO"
      }
    ],
    "Bet"
  ]' \
  --idl $IDL

Weights: 40% + 35% + 25% = 100% (4000 + 3500 + 2500 = 10000 bps).

Parse Result

The call returns a

u64

basket ID:

bash

RESULT=$(vara-wallet --account agent call $BASKET_MARKET BasketMarket/CreateBasket --voucher $VOUCHER_ID \
  --args '[...]' --idl $IDL)
BASKET_ID=$(echo $RESULT | jq -r '.result // .ok // .')
echo "Created basket: $BASKET_ID"

After Creation

Verify:

vara-wallet call $BASKET_MARKET BasketMarket/GetBasket --args "[$BASKET_ID]" --idl $IDL

Place a bet: see
```
../basket-bet/SKILL.md
```
Share the basket ID for others to bet on

Common Errors

Error	Cause	Fix
`InvalidWeights`	Weights don't sum to 100%	Adjust weight_bps so they sum to 10000 (= 100%)
`NoItems`	Empty items array	Add at least 1 item
`TooManyItems`	More than 10 items	Remove items
`DuplicateBasketItem`	Same market+outcome twice	Remove duplicate
`VaraDisabled`	VARA mode off	Use `"Bet"` asset_kind instead
`NameTooLong`	Name > 48 chars	Shorten name

See

../references/error-codes.md

for all error variants.

basket-create

NPX Install

Tags

SKILL.md Content

Basket Create

Setup

Finding Polymarket Markets

Pre-Check

Validation Rules

Create Basket

Arguments

Example: 3-item basket

Parse Result

After Creation

Common Errors