Rhumb

Index ranks. Resolve routes. Rhumb is an agent gateway for external tools: Index scores and compares services; Resolve routes supported capability calls through governed execution rails with receipts.

🌐 rhumb.dev · ⚡ Quickstart · 🧭 Resolve · 💵 Pricing · 📊 Leaderboard · 📖 Methodology · 🔑 Trust

For agents: See llms.txt for machine-readable documentation and agent-capabilities.json for structured capability metadata.

Start in 30 seconds

MCP (recommended)

npx -y --package rhumb-mcp@latest rhumb-mcp

Zero config. Discovery tools work immediately — no signup, no governed API key.

For execution, pass your governed API key:

RHUMB_API_KEY=your_key npx -y --package rhumb-mcp@latest rhumb-mcp

Get a governed API key →

API (read-only, no auth)

curl "https://api.rhumb.dev/v1/services/stripe/score"

# See supported execution routes before you execute
curl "https://api.rhumb.dev/v1/capabilities/email.send/resolve"

All read endpoints are public, including Resolve readiness checks. Estimate and execute require an authenticated payment path.

What Rhumb does

Use Rhumb Index when an agent needs to discover and evaluate services. Use Rhumb Resolve when the task is on a supported capability path and you want governed execution with an explicit receipt.

Agents need external tools. Choosing the right one is hard — not because of feature lists, but because of:

• auth and signup friction
• provisioning reality vs. marketing claims
• schema instability
• failure recovery when no human is watching
• hidden costs and rate limits

Rhumb makes those constraints visible before you commit.

Best fit today

Rhumb is strongest today for research, extraction, generation, and narrow enrichment.

Treat broader multi-system business automation as future scope, not the current callable promise. Use Layer 2 capabilities for real work now, and treat Layer 3 as beta with an intentionally sparse public catalog.

Rhumb Index — Discover & Evaluate

999 scored services across 149 capability domains. Each gets an AN Score (0–10) measuring execution quality, access readiness, and agent autonomy support.

• find_services — Search indexed Services by what you need them to do
• get_score — Get the full AN Score breakdown for a Service: execution quality, access readiness, autonomy level, tier label, and freshness
• get_alternatives — Find alternative Services, ranked by AN Score
• get_failure_modes — Get known failure patterns, impact severity, and workarounds for a service
• discover_capabilities — Browse Capabilities by domain or search text
• resolve_capability — Given a Capability ID, and optionally a credential mode, returns ranked providers with health status, cost per call, auth methods, endpoint patterns, execute guidance, and machine-readable recovery fields like recovery_hint.resolve_url, recovery_hint.credential_modes_url, and, when applicable, recovery_hint.alternate_execute_hint or recovery_hint.setup_handoff, plus typo recovery when the capability ID is wrong

Discovery breadth is wider than current execution coverage. The index is broader than what Rhumb can execute today.

Rhumb Resolve — Execute

435 capability definitions across 28 callable providers today. Resolve chooses the best-fit supported provider for the call using AN Score, availability / circuit state, estimated cost, latency proxy, credential mode, and explicit policy constraints.

• execute_capability — Call a Capability through Rhumb Resolve
• resolve_capability — Given a Capability ID, and optionally a credential mode, returns ranked providers with health status, cost per call, auth methods, endpoint patterns, execute guidance, and machine-readable recovery fields like recovery_hint.resolve_url, recovery_hint.credential_modes_url, and, when applicable, recovery_hint.alternate_execute_hint or recovery_hint.setup_handoff, plus typo recovery when the capability ID is wrong
• estimate_capability — Estimate the active execution rail, cost, and health before a Capability call; anonymous direct system-of-record paths also preserve machine-readable execute_readiness handoffs
• get_receipt — Retrieve an execution receipt by ID
• Budget enforcement, credential management, and execution telemetry included

Best current fit: research, extraction, generation, and narrow enrichment. Treat general business-agent automation and broad multi-system orchestration as future scope, not the current callable promise.

Repository visibility map

Three credential paths

Payment paths

• Governed API key — sign up, get a key, prepaid credits
• x402 / USDC — no signup, pay per call on-chain

Resolve mental model

• Service = vendor Rhumb evaluates and compares
• Capability = executable action like email.send
• Recipe = deterministic multi-step workflow on top of capabilities (beta, sparse public catalog)
• Layer 2 is the default path — start with governed API key or wallet-prefund on X-Rhumb-Key, discover a Service, choose a Capability, estimate, then execute
• Start with managed superpowers first — bring BYOK or Agent Vault only when the workflow touches your own systems
• Default auth for repeat traffic = governed API key or wallet-prefund on X-Rhumb-Key
• Bring BYOK or Agent Vault only when provider control is the point
• Use x402 when zero-signup per-call payment matters more than repeat throughput

Canonical onboarding map: https://rhumb.dev/docs#resolve-mental-model

MCP tools

rhumb-mcp exposes 21 tools:

Discovery

• find_services — Search indexed Services by what you need them to do
• get_score — Get the full AN Score breakdown for a Service: execution quality, access readiness, autonomy level, tier label, and freshness
• get_alternatives — Find alternative Services, ranked by AN Score
• get_failure_modes — Get known failure patterns, impact severity, and workarounds for a service
• discover_capabilities — Browse Capabilities by domain or search text
• resolve_capability — Given a Capability ID, and optionally a credential mode, returns ranked providers with health status, cost per call, auth methods, endpoint patterns, execute guidance, and machine-readable recovery fields like recovery_hint.resolve_url, recovery_hint.credential_modes_url, and, when applicable, recovery_hint.alternate_execute_hint or recovery_hint.setup_handoff, plus typo recovery when the capability ID is wrong

Execution

• execute_capability — Call a Capability through Rhumb Resolve
• estimate_capability — Estimate the active execution rail, cost, and health before a Capability call; anonymous direct system-of-record paths also preserve machine-readable execute_readiness handoffs
• credential_ceremony — Get step-by-step instructions to obtain API credentials for a Service
• check_credentials — Inspect live credential-mode readiness, globally or for a specific Capability
• rhumb_list_recipes — List the current published Rhumb Layer 3 recipe catalog
• rhumb_get_recipe — Get the full published definition for a Rhumb recipe, including input/output schemas and step topology
• rhumb_recipe_execute — Execute a published Rhumb Layer 3 recipe once one is live in the public catalog
• get_receipt — Retrieve an execution receipt by ID

Billing

• budget — Check or set your call spending limit
• spend — Get your spending breakdown for a billing period: total USD spent, call count, average cost per call, broken down by Capability and by provider
• check_balance — Check your current Rhumb credit balance in USD
• get_payment_url — Get a checkout URL to add credits to your Rhumb balance
• get_ledger — Get your billing history: charges (debits), top-ups (credits), and auto-reload events