Axiom Relay MCP Server

Axiom by Elevated AI

The economic layer for agents that isn't also a payment rail. Axiom is the neutral economic control and evidence layer for autonomous software. It evaluates an agent's economic intent against operator policy, compares eligible providers and payment routes, validates the proposed execution, and preserves evidence for actions authorized and signed externally.

Axiom owns no payment rail and takes no custody of principal. That is the point rather than a caveat: a stack that operates a rail is structurally incentivised to prefer its own, so provider-independent evaluation is only defensible from somewhere that owns none.

Two capabilities, one product:

Axiom never holds customer funds, never signs a customer transaction, and stores no customer key. It returns unsigned transactions; the agent or its authorized operator signs and submits them. In both capabilities the caller is the signer.

Canonical site: https://axiom.elevatedai.io · API origin: axiom-relay.reference-seller.workers.dev

These are deliberately separate. The canonical site mirrors every machine contract over GET and serves no execution route, so documents reference it while requests execute against the runtime.

Built by Elevated AI. See the public changelog for completed integration updates.

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Why this exists

Most x402 tooling assumes the agent already knows the provider's URL. In practice it doesn't — and roughly 13% of advertised x402 providers do not answer a valid challenge when actually called (measured across the live Coinbase Bazaar catalogue). Axiom absorbs that problem.

intent -> discover candidates -> validate -> rank -> pay -> return result

Pricing

The fee is a percentage below ~$16.67 and flat above it, so a $25 purchase and a $250 purchase both cost $0.50.

Non-custodial by construction

The buyer signs two independent authorisations: one payable directly to the seller, one payable to Axiom. Axiom relays the seller's authorisation without modification and cannot alter its amount or destination.

• Seller funds never enter an Axiom-controlled address.
• Axiom holds no signing key at all — it cannot move your money.
• Exactly one routing fee per completed purchase, charged only on success.
• Fallback advances only on positive evidence the previous seller was not paid; an ambiguous settlement halts the chain rather than risk a double payment.

Quickstart

npm install axiom-relay

import { Axiom } from 'axiom-relay';
import { x402Client } from '@x402/core/client';
import { registerExactEvmScheme } from '@x402/evm/exact/client';
import { privateKeyToAccount } from 'viem/accounts';

const signer = new x402Client();
registerExactEvmScheme(signer, { signer: privateKeyToAccount(process.env.KEY) });

const axiom = new Axiom({ baseUrl: 'https://axiom-relay.reference-seller.workers.dev' });

const { route, result } = await axiom.buy(signer, 'crypto price', {
  network: 'eip155:8453',
});

console.log(route.selectionReason);
console.log(result.downstream.body);

Or with plain HTTP:

curl -sX POST https://axiom-relay.reference-seller.workers.dev/v1/route \
  -H 'content-type: application/json' \
  -d '{"capability":"crypto price","requirements":{"network":"eip155:8453"}}'

How routing decides

Axiom evaluates eligible service routes using factors such as cost, observed reliability, execution conditions, and applicable policy constraints. Responses include user-relevant reasons so integrators can evaluate the result.

Internal weights, thresholds, selection rules, and detailed fallback logic are part of the hosted Axiom service and are not published.

Interfaces

The same decisioning and evidence surface is reachable through every interface below. None of them is the product; the product is the decision and the evidence, and each interface reaches the same one -- there is no interface-specific routing, pricing or validation path.

Machine integration

MCP

{
  "mcpServers": {
    "axiom": { "type": "http", "url": "https://axiom-relay.reference-seller.workers.dev/mcp" }
  }
}

Tools: find_paid_resource, quote_paid_resource, purchase_paid_resource, check_provider. The MCP layer is a thin adapter over the HTTP API — it contains no payment logic, so the safety properties are identical.

Not live

Stated explicitly, because a reader is more likely to assume a capability exists than to assume it does not:

• KyberSwap execution. Kyber is under shadow evaluation and a prepared canary only. It is not an enabled execution provider, it executes nothing, and KYBERSWAP_ROUTING_ENABLED is false in production.
• Machine Economic Receipt (MER). A draft, unpublished and unlicensed for external use. Not enabled, not issuing, and no signing key exists.
• Any verification programme. No audited status, no certification, no revocation policy. Nothing Axiom publishes describes anything as "verified".

Examples

See examples/: raw TypeScript, MCP, OpenAI tools, Claude Agent Skills, LangChain, Cloudflare Agents, WebMCP, and a generic x402 client.

Live first-party reference implementations:

• Axiom Marketplace
• Route Explorer
• Swap Agent
• Service Buyer
• WebMCP integration and 19-tool manifest

Two behaviours worth knowing

Waived fee. When feePolicy is fee_waived_micropayment, axiomFee is 0 and payTo is null. Do not sign a fee leg — there is nothing to authorise.

Free-route quota. free_route_quota_exhausted (HTTP 429) means the purchase is valid and the provider healthy, but Axiom's free-routing allocation is spent. The response carries resetsAt. Purchases whose fee is collectible are never quota-limited.

Security model

• x402 v2, exact scheme, USDC on Base.
• Destination URLs are validated against SSRF: loopback, RFC1918, link-local, cloud metadata, IPv4-mapped and NAT64 embeddings, embedded credentials and non-web ports are refused, and every redirect hop is revalidated independently.
• Replay protection claims each EIP-3009 authorisation nonce atomically.
• A discovered provider is an untrusted claim: schema-checked, SSRF-validated and probed for a live challenge before it can be selected.

Status

Live on Base mainnet with real settlements. Base Sepolia also supported for testing. Current state is always readable at /health.

Licence

MIT

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Axiom Crypto Beta

Describe a swap. Axiom queries execution providers, normalises every fee and gas cost, ranks routes on what you would actually receive, validates the calldata against what you asked for, and hands back transactions your wallet signs.

Axiom never takes custody and never signs.

What it supports today

These are operational safety limits, not product limits. Axiom Crypto is Beta and currently live, and uses LI.FI as the enabled execution provider -- the only one. Limits rise through the published capacity tiers; see /v1/crypto/capacity for the current tier and its graduation gates.

That endpoint reports capacity, not reliability. It exposes no reliability score, and Axiom operates no verification programme -- there is no audited status, no certification and no revocation policy, so nothing here is described as "verified".

Fees are disclosed separately, always

Execution providers often report one aggregate fee line. LI.FI's is 25 bps of its own plus Axiom's 15. Axiom splits them and attributes each to its recipient, because presenting a provider's fee as Axiom revenue would misstate both what you pay Axiom and what Axiom earns:

"costDisclosure": {
  "providerFee":  { "amount": "5000", "token": "USDC", "bps": 25 },
  "axiomFee":     { "amount": "3000", "token": "USDC", "bps": 15 },
  "networkGas":   { "amount": "...",  "token": "ETH" },
  "slippage":     { "toleranceBps": 50, "guaranteedOutput": "...", "worstCaseBps": 50 },
  "priceImpactBps": null,
  "expectedOutput":   { "amount": "...", "token": "WETH" },
  "netAfterAllCosts": { "amount": "...", "token": "WETH" },
  "totalEffectiveCostBps": 87,
  "note": "providerFee is charged by the execution provider and is not Axiom revenue."
}

priceImpactBps is null rather than 0 when a provider does not report it. An unreported impact is unknown, not absent.

Quote a route

curl -sX POST https://axiom-relay.reference-seller.workers.dev/v1/crypto/quote \
  -H 'content-type: application/json' \
  -d '{
    "fromChain": 8453,
    "sellToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "buyToken":  "0x4200000000000000000000000000000000000006",
    "sellAmount": "2000000",
    "taker": "<your wallet>",
    "slippageBps": 100
  }'

You get back selected, costDisclosure, selectionReason, savingsVsRunnerUp, alternatives, and transactions — an exact-amount approval followed by the swap. Sign them in order from the taker wallet.

Analyse without receiving calldata

POST /v1/crypto/analyze answers the same question and deliberately withholds the means to act: identical economics, transactions: null, plus a recommendation. Useful when an agent wants the cost of a trade without being handed the ability to make it.

What Axiom will refuse

Route validation checks the provider's answer against what was asked, not against what the provider claims it did:

• calldata built for a different chain
• a sell amount that is not the one quoted
• native value attached to an ERC-20 sale
• an approval whose spender is not the route's allowance target
• unlimited approvals — exact-amount only, unless an operator opts in
• a floor implying wider slippage than you specified
• a stale quote
• a token that is not allowlisted
• a route whose simulation fails

Signing model

intent → quote → inspect route → sign transaction → submit

Axiom performs the first three. Your wallet performs the last two. There is no execution endpoint, because execution is signing, and Axiom cannot sign.

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Licensing

This repository is Axiom's client and integration layer — the typed SDK, framework adapters, protocol descriptors and examples. It is MIT licensed, and you are free to embed it anywhere, including commercially.

The Axiom hosted service is a separate proprietary work. It is not distributed here, and using or forking this SDK does not grant rights to it, imply partnership, or imply endorsement. The production service runs at https://axiom.elevatedai.io.

The MIT licence applies to the source code in this repository. It does not grant rights to use the project's names, logos, or branding.

Copyright (c) 2026 Elevated AI / N3RD Labs LLC. See LICENSE and NOTICE.