Rails at a glance
x402
Endpoint style:
/{network}/*MPP (Tempo)
Endpoint style:
/mpp/*MPP (Solana)
Endpoint style:
/mpp-solana/*Protocol differences
| Topic | x402 | MPP |
|---|---|---|
| Challenge header | Payment-Required + accepts[] | WWW-Authenticate: Payment ... |
| Retry header | PAYMENT-SIGNATURE | Authorization: Payment ... |
| Typical success signal | JSON paid: true | Payment-Receipt header + JSON |
| Discovery source | /.well-known/x402 | OpenAPI (/openapi*.json) |
Naming differences to watch
| x402 | MPP |
|---|---|
reposts | xreposts |
comments | xcomments |
bookmarks | xbookmarks |
dex | dex-rocket |
Amount defaults and requirements
- x402 social quick routes often allow omitted
amountand default to40. - MPP social routes usually require explicit
amount(or equivalent winners alias). - Many quick social actions are priced per slot (commonly
$0.025, with some follower/member flows at$0.04).
x402 flow
- Call paid
/{network}/...endpoint without payment. - Receive
402with requirements. - Sign challenge data and retry with
PAYMENT-SIGNATURE. - Store returned
jobIdandsecretwhen present.
MPP flow
- Call
/mpp/...or/mpp-solana/...withoutAuthorization. - Receive
402with payment challenge inWWW-Authenticate. - Build payment credential from challenge.
- Retry with
Authorization: Payment .... - Store
Payment-Receipt.
Choosing the right rail
- Choose x402 when
- Choose MPP when
- You already use x402 clients (
@x402/fetch). - Your workload is mostly on
/{network}endpoint families. - You want simple challenge -> signature -> retry behavior.
Practical rail selection
| Situation | Recommended choice | Why |
|---|---|---|
| First-time WURK integrator | x402 on Solana | Fastest path to first paid success |
| Existing Payment credential stack | MPP Tempo | Native auth model for MPP clients |
| Solana MPP-native infra | MPP Solana | Strong alignment with Solana MPP tooling |
Runtime availability
- x402 routes are generally available with the x402 server rail.
- MPP Tempo routes depend on MPP Tempo enablement.
- MPP Solana routes depend on MPP Solana enablement.
- OpenAPI documents can be reachable even when specific runtime rails are disabled.
Canonical references
https://wurkapi.fun/.well-known/x402https://wurkapi.fun/openapi-x402.jsonhttps://wurkapi.fun/openapi.jsonhttps://wurkapi.fun/openapi-mpp-solana.jsonhttps://wurkapi.fun/skill.md
