x402 · agent-native API

Your AI agent has a wallet.
That's the only key it needs.

MadeOnSol speaks HTTP 402. Your agent calls our endpoint, gets a payment challenge, signs a $0.005–$0.02 USDC payment from its own wallet, retries — and the data is yours. One request, one transaction, agent-native. No signup, no API key, no monthly minimum.

Build an agent in 20 lines Live discovery endpoint

USDC on Solana mainnet · Facilitator-sponsored fees · Failed payments don't charge

The economics

What the protocol costs, what it ships, and what it doesn't require.

$0.005
Cheapest call: ~1s
Settle time: 7
Endpoints live: 0
Signup steps

Why agents love it

Built for software, not for sign-up forms.

Agent-native auth

Your AI agent's Solana wallet IS the identity. No OAuth, no client secrets, no rotation, no human in the loop. Drop into LangChain, CrewAI, ElizaOS, Solana Agent Kit, or your own runtime.

Pay only what you use

$0.005 to $0.02 per call, settled in USDC on Solana mainnet. No monthly minimum, no overage tiers, no auto-renew. Your agent stops calling, your spend stops. Period.

Same data as Ultra

x402 responses match the exact shape of our paid REST API — same KOL coverage, same tx signatures, full precision. No downgrade for paying per call.

Cost anchor

One dollar of USDC pays for a day of agent calls.

$1 in your agent's wallet covers up to 200 KOL-feed calls or 100 deployer-alert checks or 50 coordination queries. A subscription tier with the same data costs you $49/mo — with x402 you spend $1.50 in a month of constant polling.

calls / $1 at $0.02 each

coordination · pairs

200

calls / $1 at $0.005 each

feed · leaderboard

100

calls / $1 at $0.01 each

hot · trending · alerts

The flow

One request, one transaction.

1Step

Agent calls endpoint

Plain HTTP GET. No auth header.

2Step

Server returns 402

Response carries a PAYMENT-REQUIRED header with amount, recipient, asset (USDC), Solana network.

3Step

Agent signs payment

SDK builds a USDC transfer, signs with the agent's keypair, base64-encodes the payload as PAYMENT-SIGNATURE.

4Step

Server settles + returns data

Facilitator verifies + settles on-chain in ~1s. Server returns the data + PAYMENT-RESPONSE proof.

Payment goes to88xSdWeuGxWLXGe7sWk2baMEfaaB9iJ9vuU5MjQCycVUon Solana mainnet. Facilitator:PayAI. Failed payments don't charge.

Catalog

7 endpoints. Discoverable as JSON.

Endpoint	What you get	Price
KOL Trade Feed `/kol/feed`	Real-time trade events from 1,000+ tracked Solana KOL wallets, MC-stamped at trade time.	$0.005
KOL Leaderboard `/kol/leaderboard`	Ranked KOLs by PnL, winrate, profit factor, ROI, consistency. 7d / 30d / 90d / 180d windows.	$0.005
Hot KOL Tokens `/kol/tokens/hot`	Tokens with accelerating KOL interest — acceleration scoring, not raw flow.	$0.01
Trending KOL Tokens `/kol/tokens/trending`	Tokens by KOL buy volume. Capital-flow signal: where smart money is right now.	$0.01
KOL Coordination `/kol/coordination`	Multi-KOL clusters on a single token with peak-density windows, exit detection, 0-100 score.	$0.02
KOL Affinity Matrix `/kol/pairs`	Pairs of KOLs that frequently co-trade the same tokens within tight time windows.	$0.02
Deployer Alerts `/deployer-hunter/alerts`	Real-time launches from tier-graded Pump.fun deployers with KOL buy cross-reference.	$0.01

All endpoints share the response shape of their paid REST counterparts. Discovery endpoint: /api/x402 returns this catalog as JSON.

Try it

Call your first paid endpoint.

The SDK handles the 402 challenge, signs the USDC transfer from your agent's wallet, and retries — one call from your code.

# Discover the catalog (free, no payment)
curl -s https://madeonsol.com/api/x402 | jq

# Hit a paid endpoint — first call returns 402 with the payment challenge
curl -i https://madeonsol.com/api/x402/kol/feed?limit=5

When to use which

x402 vs. API key

x402 isn't a replacement for the subscription API — it's a different billing model for a different workload.

Use case / property	x402per-call	API keyPro · Ultra
Autonomous AI agent (LangChain, ElizaOS, CrewAI, Agent Kit)
Per-call pricing · no monthly minimum
Account / signup required
Predictable monthly cost at high volume
Webhooks · WebSocket streaming · copy-trade rules
DEX firehose (all-DEX trade stream)
Wallet-tracker watchlist
Wallet IS the identity (no API key to rotate)

Long-running app for human users? Get an API key. Autonomous agent that pays per data point? You're in the right place.

SDKs

Install once. Forget the protocol.

TypeScript · npmopen →

$ npm install madeonsol-x402

Pass privateKey at construction; every call auto-handles the 402 challenge. Works in Node, Bun, Deno, and edge runtimes.

Python · PyPIopen →

$ pip install madeonsol-x402

Drop-in for LangChain and CrewAI agent toolkits. Sync + async methods. Same per-call billing, same response shapes.

FAQ

Protocol questions

What is x402, really?+

x402 is an HTTP-native payment protocol. Servers return 402 Payment Required with a payment challenge; clients (your agent) sign a USDC transfer on Solana, retry the request with a PAYMENT-SIGNATURE header, and the server hands back the data. No accounts, no API keys, no OAuth — just HTTP and a wallet.

Who's the facilitator and what does it do?+

We use PayAI (payai.network) as the x402 facilitator. The facilitator verifies and settles the USDC payment on-chain before we return data. Settlement is final in ~1 second; failed payments don't return data and don't charge the agent. Fees are sponsored by the facilitator so your agent doesn't need SOL for tx costs — only USDC for the call price.

Same data as the paid API?+

Yes. x402 responses share the exact same shape as the equivalent /api/v1 endpoints. Real wallet addresses, real tx signatures, full precision. No downgrade for paying per call.

When should I use x402 vs an API key?+

Autonomous AI agent paying its own way per call → x402. Long-running app or human-facing dashboard → API key (Pro $49/mo or Ultra $149/mo). x402 has no monthly minimum, no signup, and works with the agent's existing Solana wallet as identity. API key tiers include webhooks, WebSocket streaming, copy-trade rules — features that don't fit a per-call model.

What does an agent actually need to install?+

TypeScript: npm i madeonsol-x402, pass a base58 secret key at construction. Python: pip install madeonsol-x402, same. The SDKs auto-handle the 402 challenge → sign → retry loop. Works inside LangChain tools, CrewAI agents, ElizaOS plugins, Solana Agent Kit, or your own framework. The agent just needs a Solana wallet with a few USDC.

How do I fund the agent's wallet?+

Send USDC (mainnet, mint EPjFWd…wyTDt1v) to the agent's Solana address. $5 of USDC is enough for 1,000 calls at the $0.005 tier. No SOL needed — the facilitator sponsors transaction fees.

Can I see the discovery catalog without paying?+

Yes. GET /api/x402 is free and returns the full endpoint catalog as JSON — paths, prices, schemas, descriptions. Use it for agent self-configuration.

What about rate limits?+

x402 endpoints don't have account-level rate limits — your throughput is bounded by the facilitator's settlement throughput (~1 call/sec sustained per wallet is fine). For burst patterns, queue calls in your agent. If you need 100+ calls/sec sustained, the Ultra API key tier with WebSocket streams is the right tool.

Ready to wire your agent

One SDK install. One USDC top-up. Ship.

Read the tutorial Discovery endpoint

No signup · USDC on Solana mainnet · Failed payments don't charge

Your AI agent has a wallet.
That's the only key it needs.

USDC on Solana mainnet · Facilitator-sponsored fees · Failed payments don't charge

Endpoint

What you get

Price

KOL Trade Feed

/kol/feed

Real-time trade events from 1,000+ tracked Solana KOL wallets, MC-stamped at trade time.

$0.005

KOL Leaderboard

/kol/leaderboard

Ranked KOLs by PnL, winrate, profit factor, ROI, consistency. 7d / 30d / 90d / 180d windows.

$0.005

Hot KOL Tokens

/kol/tokens/hot

Tokens with accelerating KOL interest — acceleration scoring, not raw flow.

$0.01

Trending KOL Tokens

/kol/tokens/trending

Tokens by KOL buy volume. Capital-flow signal: where smart money is right now.

$0.01

KOL Coordination

/kol/coordination

Multi-KOL clusters on a single token with peak-density windows, exit detection, 0-100 score.

$0.02

KOL Affinity Matrix

/kol/pairs

Pairs of KOLs that frequently co-trade the same tokens within tight time windows.

$0.02

Deployer Alerts

/deployer-hunter/alerts

Real-time launches from tier-graded Pump.fun deployers with KOL buy cross-reference.

$0.01

# Discover the catalog (free, no payment) curl -s https://madeonsol.com/api/x402 | jq # Hit a paid endpoint — first call returns 402 with the payment challenge curl -i https://madeonsol.com/api/x402/kol/feed?limit=5

Use case / property

x402per-call

API keyPro · Ultra

Autonomous AI agent (LangChain, ElizaOS, CrewAI, Agent Kit)

Per-call pricing · no monthly minimum

Account / signup required

Predictable monthly cost at high volume

Webhooks · WebSocket streaming · copy-trade rules

DEX firehose (all-DEX trade stream)

Wallet-tracker watchlist

Wallet IS the identity (no API key to rotate)

Your AI agent has a wallet.That's the only key it needs.

Built for software, not for sign-up forms.

Agent-native auth

Pay only what you use

Same data as Ultra

One dollar of USDC pays for a day of agent calls.

One request, one transaction.

Agent calls endpoint

Server returns 402

Agent signs payment

Server settles + returns data

7 endpoints. Discoverable as JSON.

Call your first paid endpoint.

x402 vs. API key

Install once. Forget the protocol.

Protocol questions

One SDK install. One USDC top-up. Ship.

Your AI agent has a wallet.That's the only key it needs.

Built for software, not for sign-up forms.

Agent-native auth

Pay only what you use

Same data as Ultra

One dollar of USDC pays for a day of agent calls.

One request, one transaction.

Agent calls endpoint

Server returns 402

Agent signs payment

Server settles + returns data

7 endpoints. Discoverable as JSON.

Call your first paid endpoint.

x402 vs. API key

Install once. Forget the protocol.

Protocol questions

One SDK install. One USDC top-up. Ship.

Your AI agent has a wallet.
That's the only key it needs.

Your AI agent has a wallet.
That's the only key it needs.