Which agent should I use? Decide size first.

Agent choice is reversible. A lost link is not.

Most agent comparisons rank service quality, and every ranking disagrees with the next one. Fees change. Warehouses change. The agent people recommended last season is not the one they recommend now.

One thing does not change: the store link. Weidian item 7800400500 is that item at every agent. If you save the store link, switching agent costs you one click. If you save the agent link, switching costs you the whole list.

So decide in this order. First the item and the size. Then the agent.

Three things you can check yourself

• Link format. Some agents take the whole store URL. Others want only the numeric item id plus a platform token. This decides whether a link you paste opens the item or dumps you on a homepage.
• Marketplace coverage. Not every agent handles Weidian, Taobao, Tmall, and 1688. Check the one your seller uses.
• The login wall. Several agents show the item only after you sign in. A bounce to a register page is their rule, not a broken link.

Shipping price, warehouse speed, and QC quality matter too. Nobody can verify those for you from a web page, and any guide that claims to is guessing.

What each agent wants

These are the formats Credenza builds. Each was checked against a real item.

• Superbuy — takes the full store URL. Covers Weidian, Taobao, Tmall, and 1688.
• AllChinaBuy — Superbuy's sister site, same full-URL format, same four marketplaces.
• Sugargoo — takes the full store URL. Item pages need a Sugargoo login, so a logged-out click bounces to register.
• Kakobuy — takes the full store URL. Covers all four marketplaces.
• Hoobuy and Oopbuy — want the item id plus a numeric platform code in the path.
• CNFans, Mulebuy, and Joyagoo — want the item id plus a platform name.
• Fansbuy — Weidian only, id in the path plus the URL as a parameter.

CSSBuy is retired in Credenza. They refuse purchasing-agent service to US customers and offer forwarding only. Links stored against them still open — they fall back to the store page.

Credenza does not pick the agent. It keeps the choice cheap.

• Every card stores the canonical store link, never the agent wrap.
• Your preferred agent lives in Profile → Default agent. Change it once and every Buy button follows.
• Credenza builds the agent link at the moment you press Buy, from the format above.
• If it cannot build one — wrong marketplace, missing id — Buy opens the store page instead. It never strands you on a dead URL.
• The size recommendation comes from the seller's chart and your body profile, so it survives the agent switch too.

Size first, agent second

• Save the store link on a card.
• Paste the seller's size chart. Credenza reads it against your body profile.
• Decide yes or no on the item, with the size in front of you.
• Only then press Buy, and only for the items that survived.

This order matters because agent carts have no memory of why you added something. A cart of eleven items tells you nothing about which three you were sure of.

Some Buy links carry a referral code

Buy links may include a referral code. Credenza may earn a commission on agent shipping fees. A referral never changes your item price. Your stored links always stay canonical, so you can leave at any time and take the list with you.

Credenza does not rank agents by what pays best. The list above is ordered by link format, and it names the agent that pays nothing — CNFans stopped its referral programme — alongside the ones that do.

When this guide does not help

If you have one item and you already know your size, open the agent directly. A planner earns its place at five items and more, when the list is long enough that you cannot hold it in your head.

Credenza also cannot tell you which agent ships fastest to your country, or which handles a claim best. Ask the community for that. Ask the chart for your size.