> STAKR.space. Content reviewed 2026-09-28. Paid RPC is not available.

＋ INFRASTRUCTURE EXPLAINED

# Four roles.  
Four kinds of evidence.

A validator, a restaking operator, a prover and an RPC endpoint are different resources. The presence of one does not establish that the others are available.

## Compare the roles.

Infrastructure roles and what to verify
| Role | What to inspect | Directory examples |
| --- | --- | --- |
| Validator staking | Network, validator identity, current commission and participation | Solana, Cosmos Hub, Monad |
| Restaking / shared security | Operator, vault or service relationship and applicable conditions | Symbiotic, EigenLayer |
| Proving / confidential compute | Protocol-specific operator or prover record and environment | Fermah, Marlin, Interfold, Octra devnet |
| RPC access | Endpoint, chain identity, supported methods, limits and availability | Paid gateway not connected |

## Why a validator listing is not an RPC offer.

A validator participates in a network’s operation. RPC is an interface for making network requests. A published validator address does not specify an RPC hostname, method policy, archive capability or rate limit. Those must be documented separately.

## Where MPP and x402 fit.

MPP and x402 are payment protocols that can be used to authorize access to a resource. They do not determine which blockchain the RPC serves. Settlement details and the requested RPC network are separate configuration choices.

The [Agent RPC page](https://stakr.space/rpc/) illustrates the request, payment challenge, authorization and response. It does not contact an upstream node or charge a wallet.

## Choose the evidence relevant to the task.

For delegation, inspect the validator. For proving, inspect the prover. For an agent’s API call, inspect the endpoint specification and payment conditions once published. Start with the [directory](https://stakr.space/networks/), which links the available source for each role.

## Sources & review

*   [Solana: agentic payments and protocol comparison ↗](https://solana.com/docs/payments/agentic-payments)
*   [MPP documentation ↗](https://mpp.dev/)
*   [x402 documentation ↗](https://docs.x402.org/)

By [STAKR.space](https://stakr.space/about/) · Reviewed 28 September 2026

ON THIS PAGE

[Compare the roles.](#section-1)[Why a validator listing is not an RPC offer.](#section-2)[Where MPP and x402 fit.](#section-3)[Choose the evidence relevant to the task.](#section-4)

[Browse network profiles ↗](https://stakr.space/networks/)  
[All guides & resources ↗](https://stakr.space/resources/)