k402

Agent-payable APIs on Kaspa: LLMs, chain data, covenants, zk proofs — pay per call, no API key

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What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    Agent-payable APIs on Kaspa: LLMs, chain data, covenants, zk proofs — pay per call, no API key

    How to connect

    How to connect k402 to Claude

    The server address to paste into Claude settings:

    https://x402-compute.68cxgfyr0.workers.dev/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect k402 to ChatGPT

    The server address to paste into ChatGPT settings:

    https://x402-compute.68cxgfyr0.workers.dev/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect k402 to Cursor

    The server address to paste into Cursor settings:

    https://x402-compute.68cxgfyr0.workers.dev/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (36)

    Raw names from tools/list. Only developers need these.

    catalogList every service this gateway sells (text tools, Kaspa chain data, LLM tiers) with live prices in KAS and USD. Free. Start here to see what's available and what calls cost.
    open_sessionOpen a prepaid payment session: returns a session key and a personal Kaspa MAINNET deposit address. Send KAS to the address from any wallet (min 0.25 KAS); confirmed deposits become spendable balance within seconds and every paid tool call meters against it. Free. The session is saved locally so subsequent calls use it automatically.
    use_sessionAttach an existing k402 session key (from a previous open_session) so paid calls meter against its balance — use after reconnecting to the hosted endpoint, or to carry one funded session across clients. Returns the session's current balance. Free.
    session_statusCheck the current payment session: deposit address, deposited / spent / remaining KAS. Free.
    registry_searchDiscover providers in the k402 service exchange — an open marketplace of agent-payable services, each settled trustlessly over a Kaspa payment channel directly with the provider (no custodian). Filter by capability (e.g. 'summarize', 'llm:reason', 'zk-prove'), max USD price, and minimum reputation (settled KAS volume, chain-verified). Results are ranked reputation-first. Free. Returns each provider's endpoint, payee pubkey, price, channel terms, and reputation.
    registry_providerFull detail on one provider in the service exchange by its payee pubkey: every service it lists, its chain-verified reputation (settled KAS volume + settlement count), and its payee address. Free.
    channel_configParameters for opening a kaspa-channel — a covenant-enforced payment channel that settles per-call vouchers on Kaspa L1 with NO custodian (the trustless alternative to a prepaid session). Returns the payee pubkey, min/max channel size, required expiry lead, and maxfee. Free. Opening a channel means funding the channel covenant on-chain (payer holds the key), then paying per call with signed vouchers — use the `k402` Python client (`pip install k402`, k402.channel) to build the covenant and sign vouchers, since that flow needs your Kaspa key. Returns {error} if this gateway hasn't enabled the (experimental) channel rail.
    channel_statusStatus of a kaspa-channel by its channel id (covenant id): funded value, amount spent via vouchers, remaining, expiry, and whether it has been closed on-chain. Free.
    payment_optionsWhich coins and schemes this gateway accepts for payment. Free. Ways to pay any paid tool: a prepaid KAS session (open_session — simplest, no per-call step); per-call in any listed coin (pay the offer a 402 returns, then pay_per_call); or, where the experimental 'kaspa-channel' scheme is offered, a covenant payment channel that settles per-call vouchers on L1 with no custodian (see channel_config). Coins may include Kaspa, Pearl, BTC, LTC, DOGE, BCH, DASH, and EVM assets (ETC, ETH, USDC, USDT).
    pay_per_callComplete a PER-CALL coin payment. After a paid tool returns a 402 with pay_per_call_offers, pay one offer on-chain from your own wallet, then call this with the 402's `endpoint` and `request_body`, the chosen offer's `scheme` and `payment_id`, and your payment `txid`. The gateway verifies the payment landed and returns the tool's real result. (Alternative to a prepaid session — use this when you'd rather pay each call directly in a specific coin.)
    summarizeSummarize text or a public URL in at most max_words. Paid (~$0.001 in KAS).
    extractExtract structured data from text as JSON guaranteed to match your JSON schema (schema-constrained decoding, not best-effort). Paid (~$0.0015 in KAS).
    rewriteRewrite text per an instruction (tone, format, length...). Paid (~$0.001 in KAS).
    classifyClassify text into one (or multiple, if multi=true) of 2-32 labels; the result is constrained to your label set. Paid (~$0.0003 in KAS).
    read_urlFetch a public web page and return its title + clean markdown; distill=true adds key-fact bullets. Useful when you have no web access of your own. Paid (~$0.0012 in KAS).
    embed_textEmbed up to 64 texts (768-dim vectors, nomic-embed-text). Paid (~$0.0003 in KAS).
    search_indexStore documents [{id, text, meta?}] in a named server-side collection for semantic search. Use an unguessable collection name and keep it secret. Paid (~$0.0015 in KAS).
    search_querySemantic-search a collection you indexed earlier; returns top-k matches with scores. Paid (~$0.0003 in KAS).
    kaspa_balanceBalance of any Kaspa MAINNET address, straight from a node (no indexer, no API key). Paid (~$0.00015 in KAS).
    kaspa_utxosUTXO set of a Kaspa mainnet address, including scriptPublicKey and covenant_id where set. Paid (~$0.0003 in KAS).
    kaspa_tx_statusMempool status of a Kaspa transaction. Absent from mempool means accepted-or-unknown — confirm acceptance by checking one of its outputs with kaspa_utxos. Paid (~$0.00015).
    kaspa_fee_estimateCurrent Kaspa mainnet feerate buckets (sompi per gram of tx mass). Paid (~$0.00015).
    kaspa_networkKaspa mainnet status: DAA score, block count, difficulty, node sync state. Paid (~$0.00015 in KAS).
    generateRun a prompt on a GPU model tier: 'chat' (fast 7B, ~$0.0015), 'llama' (budget 8B, ~$0.0008), 'reason' (35B, ~$0.004), 'think' (deep chain-of-thought 35B MoE, ~$0.004), 'code' (coder model, ~$0.0025), or 'kaspa-expert' (RAG-grounded, current Kaspa knowledge, ~$0.0015). Returns the completion text.
    covenant_compileCompile a Silverscript covenant to script hex, ABI, hardened template hash, and its P2SH address on each network. constructor_args is the silverc ctor JSON (e.g. [{"kind":"int","data":7}]). Paid (~$0.002). NOTE: 'compiles' ≠ proven on-chain.
    covenant_addressDerive the covenant P2SH address for a compiled script on 'mainnet' or 'testnet-10'. Paid (~$0.0003).
    covenant_utxosLive UTXO set locked under a covenant address (covenant state inspection), from the node. Optionally filter by covenant_id. Paid (~$0.0003).
    covenant_buildAssemble a covenant spend tx. Each input: {txid, index, entry, compute_budget?, and either sigscript:{source,decl,args,is_leader?} to build a covenant sigscript server-side, or omit sigscript for a P2PK input you sign locally}. Each output: {amount, address|script_public_key_hex, covenant?:{authorizing_input,covenant_id}}. Returns the tx, a broadcast-ready rpc_transaction, fee accounting, and (if fully authorized) a pre-verify. We never sign. Paid (~$0.001).
    covenant_checkLocal txscript pre-verify of a signed covenant tx BEFORE broadcast — catches script failures that would otherwise cost you a broadcast. 'entries' are the spent UTXOs (covenant_utxos output plugs in directly). Returns {all_ok, inputs:[{index, ok, error?}]}. Paid (~$0.0005).
    covenant_broadcastBroadcast a signed covenant tx (RpcTransaction JSON from covenant_build). MAINNET moves real KAS — run covenant_check first. Paid (~$0.0003).
    prove_guest_uploadUpload a RISC Zero program binary (the .bin risc0-build emits, base64) once; returns its content-addressed image_id (also the verification key), reusable across proofs. Paid (~$0.01).
    prove_preflightExecute a guest WITHOUT proving: exact cycle count + a signed price quote {total_cycles, price_kas, quote_id, quote_expires}. Run this first — proving cost scales with cycles by orders of magnitude. Paid (~$0.002).
    prove_submitQueue a proving job -> {job_id, cost_kas}. Pass quote_id (from prove_preflight; charged the quote) or max_kas (skip preflight; priced on actual cycles, refuses if over the cap). Then poll job_status and fetch job_result. Paid: the proof's cycle-based price (dynamic).
    job_statusPoll a proving job: queued/running/done/failed, queue position, cost. Free.
    job_resultFetch a finished proving job's result {image_id, total_cycles, journal_b64, receipt_b64}. 404 until done; results kept 24h. Free.
    attest_verifyVerify a RISC Zero receipt against an image_id -> {valid, journal_b64}. Anyone can check an attestation without trusting the prover. Paid (~$0.0002).