K402 MCP server

• attest_verifyFree

  Verify a RISC Zero receipt against an image_id -> {valid, journal_b64}. Anyone can check an attestation without trusting the prover. Paid (~$0.0002).

• catalogFree

  List 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.

• channel_configFree

  Parameters 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_statusFree

  Status 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.

• classifyFree

  Classify 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).

• covenant_addressFree

  Derive the covenant P2SH address for a compiled script on 'mainnet' or 'testnet-10'. Paid (~$0.0003).

• covenant_broadcastFree

  Broadcast a signed covenant tx (RpcTransaction JSON from covenant_build). MAINNET moves real KAS — run covenant_check first. Paid (~$0.0003).

• covenant_buildFree

  Assemble 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_checkFree

  Local 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_compileFree

  Compile 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_utxosFree

  Live UTXO set locked under a covenant address (covenant state inspection), from the node. Optionally filter by covenant_id. Paid (~$0.0003).

• embed_textFree

  Embed up to 64 texts (768-dim vectors, nomic-embed-text). Paid (~$0.0003 in KAS).

• extractFree

  Extract structured data from text as JSON guaranteed to match your JSON schema (schema-constrained decoding, not best-effort). Paid (~$0.0015 in KAS).

• generatewrite actionFree

  Run 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.

• job_resultFree

  Fetch a finished proving job's result {image_id, total_cycles, journal_b64, receipt_b64}. 404 until done; results kept 24h. Free.

• job_statusFree

  Poll a proving job: queued/running/done/failed, queue position, cost. Free.

• kaspa_balanceFree

  Balance of any Kaspa MAINNET address, straight from a node (no indexer, no API key). Paid (~$0.00015 in KAS).

• kaspa_fee_estimateFree

  Current Kaspa mainnet feerate buckets (sompi per gram of tx mass). Paid (~$0.00015).

• kaspa_networkFree

  Kaspa mainnet status: DAA score, block count, difficulty, node sync state. Paid (~$0.00015 in KAS).

• kaspa_tx_statusFree

  Mempool 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_utxosFree

  UTXO set of a Kaspa mainnet address, including scriptPublicKey and covenant_id where set. Paid (~$0.0003 in KAS).

• open_sessionFree

  Open 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.

• pay_per_callwrite actionFree

  Complete 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.)

• payment_optionsFree

  Which 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).

• prove_guest_uploadwrite actionFree

  Upload 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_preflightwrite actionFree

  Execute 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_submitwrite actionFree

  Queue 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).

• read_urlFree

  Fetch 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).

• registry_providerFree

  Full 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.

• registry_searchFree

  Discover 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.

• rewriteFree

  Rewrite text per an instruction (tone, format, length...). Paid (~$0.001 in KAS).

• search_indexFree

  Store 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_queryFree

  Semantic-search a collection you indexed earlier; returns top-k matches with scores. Paid (~$0.0003 in KAS).

• session_statusFree

  Check the current payment session: deposit address, deposited / spent / remaining KAS. Free.

• summarizeFree

  Summarize text or a public URL in at most max_words. Paid (~$0.001 in KAS).

• use_sessionFree

  Attach 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.

• Code scan3 source files scanned25/25
• Live reliabilityremote reachable in 900ms20/20
• Tool poisoning36 tool descriptions checked15/15
• Auth qualityopen endpoint exposes 5 write-action tools with no auth3/15
• Maintenancelast push 70 days ago12/15
• Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10

Safety score

83/100

higher than 68% of 4,460 AI and agents servers

Tools

36

the typical AI and agents server has 6

Tools that change things

14%

typical: 0%. Fewer write tools means less an agent can break

Uptime

100%

of our recent checks; the typical remote AI and agents server answers 100%

Response time

443 ms

faster than 31% of 2,331 AI and agents servers

GitHub stars

1

more than 50% of 2,711 AI and agents servers

K402: common questions

Is K402 MCP server safe?

Mostly: it is graded B (83/100). Read the K402 safety report

How do I install K402?

It runs remotely at x402-compute.68cxgfyr0.workers.dev. Add it to Claude Code, Cursor, VS Code or Claude Desktop with the snippets above, or call it through the mcp.market gateway without installing anything.

Does K402 need an API key?

No secret keys are declared. It reads 2 settings from the environment.

Is K402 maintained?

The last commit was 109 days ago (2026-07-18). The latest release is v0.7.0.

Is K402 up?

100% of our last 28 checks got an answer. We check remote servers about four times a day.

What can I use instead of K402?

Servers from other publishers that do the same job: Ausca MCP server, Spotifyscraper MCP server and Mnemoverse Memory MCP server.

How does K402 compare with other AI and agents MCP servers?

safety score 83/100 (higher than 68% of 4,460 AI and agents servers); tools 36 (the typical AI and agents server has 6); tools that change things 14% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.