Pricing for agents

Public endpoints

These endpoints stay reachable without payment regardless of x402 state. They expose discovery data, live pricing, or wallet-side tool discovery that must be available before an agent can decide what to call.

• /api/manifest: Endpoint manifest. Full inventory of callable paths and x402 config. Query this first.
• /api/pricing: Pricing catalog. Every fee on this page in machine-readable JSON, with live USD figures.
• /api/owned-mints: Owned-mints lookup. List mints a wallet holds mint or freeze authority of. Not gated because it powers wallet-side tool discovery.

x402 per-call pricing

Every gated API path returns HTTP 402 with a challenge body unless the caller proves a payment in the X-Payment header. The same flat price applies to every endpoint in x402.gatedPaths on the manifest, including the MCP endpoint.

Volume economics

Monthly x402 cost at four traffic levels, using 30-day months and the live SOL/USD figure above. These numbers are for gated API calls only; transaction-producing endpoints can also include the tool's normal on-chain operation fee.

MCP server

The Streamable HTTP MCP endpoint at /api/mcp is x402-gated like any other read. Each MCP call counts as one x402 call.

→ MCP client configuration

Transaction-producing calls

The build endpoints (every tool that returns an unsigned transaction) also embed a flat lamport fee inside the transaction itself. That fee is separate from the x402 per-call price and applies once the wallet submits the signed tx. See user-facing pricing for the per-op breakdown.

Frequently asked

How does x402 actually work?

First call to a gated path returns HTTP 402 with a challenge body (recipient address, amount, optional nonce). The agent sends a Solana SystemProgram.transfer to the recipient, waits for confirmation, then retries the original request with X-Payment: <base58 signature>. The server verifies the on-chain payment matches the challenge, records the signature to prevent replay, and proxies the original call. End to end: two transactions plus the data call.

When is per-call pricing a good fit?

It is best for agents that need simple metered access without a custom commercial agreement. Each gated call carries the same flat x402 price, and the monthly table above lets you budget from an expected calls-per-day number.

How do I integrate via MCP?

Point your MCP client at /api/mcp (Streamable HTTP transport, both POST and GET). The endpoint is x402-gated; send a valid x402 payment in the X-Payment header lets the MCP traffic flow. Each MCP request counts as one gated call. See /agents for the full client config.

Are there rate limits beyond x402?

Yes, a politeness per-IP limiter sits in front of every endpoint. It's much higher than typical agent traffic for normal paid callers, but it exists to stop accidental loops. The exact value is operator-set; check the response's rate-limit header if you hit one. The real budget control is the per-upstream rate budget (Helius, Jupiter, …); when those are exhausted the gated endpoint returns a 503 degraded status, not a 429.

How do replay-prevention nonces work?

When SOLKNIFE_X402_REQUIRE_NONCE=true, the challenge body includes a server-issued nonce, and the payment transaction MUST carry an SPL Memo instruction with that nonce as its data. The server HMAC-verifies the nonce and enforces a TTL (default 10 min). Makes replay impossible across process restarts past the TTL window. Phase 1 agents that pay without a memo continue to work when this flag is off (the default).

Machine-readable

Both pages render from the same source:

• /api/pricing : every fee, with live USD figures
• /api/manifest : endpoint inventory + x402 config

Build pricing decisions from the JSON; treat this page as the rendered view of it.