How to Build a CS2 Trade-Up Calculator

cs2.sh provides the three pricing inputs a CS2 trade-up calculator needs: item metadata from the schema, exact-float BUFF input buckets, and current bids for valuing possible outputs.

The API does not return a finished contract or outcome-probability table. A calculator must supply and validate the game rules, then use cs2.sh to resolve and price the resulting items.

1. Resolve inputs and possible outputs#

GET /v1/schema is keyed by exact market_hash_name. Skin records can include rarity, collections, containers, available wears, native float_range, StatTrak and Souvenir flags, def_index, and paint_index.

Use those fields to verify item identity and map each modeled output to the correct wear row. Doppler, Gamma Doppler, and Case Hardened variants appear both under their base item's variants list and as linked standalone rows.

2. Cost inputs at their actual float range#

GET /v1/market/buff/latest splits each item into base, float, fade, and float_fade buckets. Every bucket has a stable bucket_id and its own ask, avg_ask, bid, ask_volume, and bid_volume.

Match an exact input float where float.min is inclusive and float.max is exclusive. The matched bucket's ask is a more relevant acquisition floor than the exterior-wide base ask, especially near a low-float boundary. Variants carry their own bucket arrays.

3. Value outputs at a chosen exit quote#

Read current prices from GET /v1/prices/latest. For an immediate-sale model, use positive, fresh bid values from the chosen cash sources and calculate the probability-weighted output value. For an acquisition-value model, use ask and label it separately.

Source field coverage differs. BUFF, Youpin, and Steam include bid_volume; CSFloat and C5Game provide bids without bid volume; Skinport has no bid. Keep missing sources out of the calculation rather than replacing them with zero.

Applicable endpoints#

Pricing limits#

• A BUFF bucket ask is the lowest listing in that range. ask_volume counts all listings in the range, not quantity at the floor, so it cannot price a multi-unit fill by itself.
• A highest bid is an observed buy order, not a completed sale. Fees and trade restrictions remain external to the response.
• Exact float, paint seed, and stickers are not priced at the individual asset level. BUFF ranges provide narrower market buckets, not a quote for a unique inventory item.
• A crossed source pair can reflect asynchronous collection. Exclude that source's bid from exit value when its positive ask is lower.

The BUFF float-range history guide covers bucket selection in more detail.