Now accepting sellers

Sell your spare API capacity

List unused API keys. Buyers pay per request — no accounts, no contracts. Earn from capacity you already have.

terminallive
$ curl openai.cn2.ai/v1/chat/completions \
-H "Authorization: MPP ..." \
-d '{"model":"gpt-4o","messages":[...]}'
HTTP/2 200 OK
Payment-Receipt: MPP receipt=...abc
{ "choices": [{ "message": { "content": "Hello!" }}] }
$0.003 · 142ms · paid via Tempo
50+
Providers
4,200+
Keys listed
58M+
Requests routed
<50ms
Routing overhead
99.97%
Uptime
How it works

Two sides, one marketplace

Seller
1
Add your API key
Paste your key, set a floor price, and choose which routes to expose.
2
We verify liveness
A lightweight health check confirms your key works. Takes under 2 seconds.
3
Start earning
Buyers pay per request via MPP. You earn automatically — payouts in USDC, Stripe, Lightning, or wire.
Buyer
1
Replace the base URL
Point your client to openai.cn2.ai instead of api.openai.com.
2
Pay per request
MPP handles payment in the same HTTP request. No API key management, no accounts required.
3
Automatic failover
If a key fails, cn2 retries on another seller's key. You never see the error.
Request flow

One request, paid and routed

Step 1
Request arrives
Buyer sends request to openai.cn2.ai
HTTP 402
Step 2
Payment required
cn2 responds with HTTP 402 and an MPP payment challenge
mppx SDK
Step 3
Pay inline
Client SDK attaches payment credential to the retry request
Step 4
Route to key
cn2 selects the cheapest eligible key and proxies to the upstream provider
200 OK
Step 5
Response + receipt
Upstream response returned to buyer with a payment receipt header
Pricing

Start free, scale as you earn

Free
$0/month
  • Unlimited key listings
  • 10% platform fee
  • Standard pool only
  • Email support
  • Webhook notifications
Pro
$29/month
  • Everything in Free
  • 5% platform fee
  • Premium pool access
  • Priority support
  • Advanced analytics
  • Custom webhook events
Enterprise
Custom
  • Everything in Pro
  • Custom fee structure
  • Dedicated account manager
  • SLA guarantee
  • Volume discounts

Start earning from your spare keys

List your first key in under a minute. Earnings start the moment a buyer sends a request.