Pricing
Discovery, scoring, and browsing are always free. When your agent runs a capability through Rhumb, you pay per call — and you can check the exact price before committing. No subscriptions, no seat fees, no minimums.
Default path
Default path: discover a Service, choose a Capability, estimate the call, then execute through Layer 2 with a governed API key or wallet-prefunded API key. Use x402 only when zero-signup per-call matters. Use Layer 1 only when you must pin the provider. Use Layer 3 only when a published recipe already exists.
What you are paying for
The main paid surface today is Layer 2 capability routing: discover a Service, choose a Capability, estimate the call, then execute.
Default repeat-traffic rails
For repeat traffic, default to governed API key or wallet-prefund. Both end up executing with X-Rhumb-Key.
When to use x402
Use x402 per-call when zero-signup, request-level payment authorization is the point — not as the default repeat-throughput path.
Canonical onboarding map: /docs#resolve-mental-model
Choose your path
Discovery is always free. Execution depends on how you want authorization and payment to work: account API key, wallet-prefunded balance, zero-signup x402 per-call, or BYOK passthrough.
Scores, comparisons, read endpoints, and MCP discovery. No signup, no key, no wallet.
Rhumb handles routing, failover, and billing behind one key. Best default for apps and production agents.
Use USDC on Base when the agent should pay directly and the payment proof should authorize each request.
Authenticate wallet once, top up balance via x402, then execute repeat calls with X-Rhumb-Key.
Route through Rhumb with your own provider credentials when you need direct vendor control or enterprise boundaries.
Rhumb supports three ways to fund execution traffic: account billing with API keys,
wallet-prefunded balance, or x402 per-call settlement. All roads still end at
POST /v1/capabilities/{capability_id}/execute.
| Rail | Auth | Best fit |
|---|---|---|
| Governed API key | X-Rhumb-Key | Apps and teams with dashboard-based billing controls. |
| Wallet-prefunded balance | X-Rhumb-Key | Wallet-first agents that want reusable balance for repeat calls. |
| x402 per-call | X-Payment | Zero-signup and strict request-level payment authorization. |
Pick the right rail
Buyers do not need a protocol lecture first. Ask three questions: do you want the default production path, do you need wallet identity, and do you need each request to carry its own payment authorization?
Common buyer paths
If you are unsure which rail fits, find the path that sounds like you and start there.
Start with governed API key unless you have a strong reason not to.
Use wallet-prefund when wallet identity matters but repeat traffic matters more than zero-signup purity.
Use x402 when payment authorization on each request is the product requirement.
$0
Browse services, read scores, search the directory, check comparisons, and call any read-only endpoint. No signup required. No limits.
Rhumb handles credentials, routing, failover, and billing. You get pre-call cost estimates, smart provider selection, and fail-closed execution safety. Pay per call, no commitments.
For teams that need procurement support, security review coordination, or a direct conversation about rollout and controls.
Usage
1 call = 1 API call to a third-party service routed through Rhumb. Scoring, searching, and browsing are always free. You're only charged when Rhumb makes an API call on your behalf.
| Example | Counts as | Notes |
|---|---|---|
| Send an email via Resend | 1 call | Rhumb makes one third-party API call on your behalf. |
| Search for a service on Rhumb | 0 calls | Discovery is never charged. |
| Get an AN Score for a service | 0 calls | Scoring is always free. |
| Execute a 3-step capability chain | 3 calls | Each provider API call counts separately. |
| Failed call (provider error) | 0 calls | Provider errors are not charged. |
A call is one API call to a third-party service routed through Rhumb. Searching, scoring, and browsing are always free, and failed provider calls are not charged. See the examples above .
Start with the governed API key unless you specifically need wallet identity or per-request payment authorization. It is the default production path because it gives you one stable execution header, pre-call estimates, and simpler repeat-traffic operations. See the examples above .
API key and wallet-prefund both execute with X-Rhumb-Key. API key is account-first billing; wallet-prefund is wallet-first funding that tops up reusable balance and currently uses the standard x402 authorization settlement path during top-up verification. x402 direct per-call execute is payment-as-auth using X-Payment, but today the repeatable public execute path expects legacy tx-hash proof rather than wrapped authorization payloads. See the examples above .
No. Most buyers should not start with crypto. If you are using the governed API-key path or BYOK, you do not need wallet setup. Wallet-prefund and x402 are wallet-first rails for teams that explicitly want those payment properties. See the examples above .
The canonical machine-readable source remains public. Resolve the pricing contract, then call the estimate endpoint for exact per-call numbers before you run anything.
Contract
curl https://api.rhumb.dev/v1/pricingEstimate
curl "https://api.rhumb.dev/v1/capabilities/{capability_id}/execute/estimate"For wallet-first flows (x402 per-call and wallet-prefunded balance), see our Agent Payments guide.