@bsvkey/inference-mcp

An MCP server that lets any agent buy Claude & Grok inference metered per token, settled in BSV, through the hosted gateway at inference.bsvkey.com. Zero dependencies (Node ≥ 18, uses global fetch). It's a thin HTTP client — it never holds your keys or runs models; every call is billed through the gateway.

Tools: list_models, infer, channel_balance, open_channel, x402_infer, xrp_infer.

Two ways to pay: a prepaid channel (infer, fund once, draw down per token) or per call via x402 (x402_infer — no channel; the agent pays each request in BSV with its own key). x402_infer needs a funded WIF (wif arg or BSVKEY_WIF) and the optional @bsvkey/x402-bsv-client + @bsv/sdk packages (installed with this one).

Pay per call in XRP with xrp_infer: the tool gets a quote in XRP (priced from the XRP Ledger's own XRP/RLUSD market), signs one XRP Payment for exactly that locally, and the gateway checks it before broadcasting, waits for validation (a few seconds), and returns the answer, the settlement tx, and a signed receipt. It needs a funded XRP seed (xrpSeed arg or BSVKEY_XRP_SEED; create one at xrp.bsvkey.com/wallet) and the optional xrpl package (installed with this one; it needs Node 20.19+ or 22.12+). The account keeps a 1 XRP reserve that can't be spent.

Verifiable metering. Each infer call returns a signed usage receipt, and the tool auto-verifies it offline (with the optional packages installed): the result includes receiptVerified and meterVerified (true, false + receiptCheck, or null). It recovers the broker key (pinned from GET /v1/receipt-key); binds the receipt to the channel you called (from your API key, not the receipt's self-report); checks a monotonic sequence (no replay/gap) and running totals within the funded amount; recomputes the charge from the published rate (you can never be overcharged); and recomputes the token count from the exact bytes of your messages and the completion, under the pinned bsvkey-meter/1 tokenizer. So the channel payment is on-chain and both the meter and the charge are auditable, without trusting the broker's word.

Four things an unattended client should know:

• Fails closed. If the pinned-key endpoint is unreachable, receiptVerified is null (unknown), never true — a down pin weakens the check to unknown, not to trusted.
• Supply your funded amount. Set BSVKEY_FUNDED_SATS (or pass fundedSats) to the amount you funded on-chain. The receipt's own fundedSats is the broker's assertion; when you supply yours, a receipt claiming a different amount is rejected and totals are checked against what you actually paid.
• Persist across restarts. Sequence continuity is in-memory by default (a replay before the first receipt this process sees would be invisible). Set BSVKEY_RECEIPT_STATE to a file path to persist per-channel seq/totals so replays are caught across restarts.
• The receipt is the ledger. The GET /v1/channels/:id balance endpoint can lag the signed receipt by ~20s; trust the receipt, treat the endpoint as a cache.

Spec: https://inference.bsvkey.com/usage-receipts.md

Quick start

1. Fund a channel once at https://inference.bsvkey.com (BRC-100 wallet, or load a key in-page). Copy the key it returns: channelId:channelSecret.
2. Add the MCP server to your agent host (below), with that key in BSVKEY_API_KEY.
3. Ask your agent to run inference — it calls infer and pays per token.

list_models and open_channel work with no key; infer and channel_balance need a funded channel key.

Install

Published on npm as @bsvkey/inference-mcp.

Claude Code

claude mcp add bsvkey-inference \
  --env BSVKEY_API_KEY=channelId:channelSecret \
  -- npx -y @bsvkey/inference-mcp

Claude Desktop / Codex / any MCP host (JSON config)

{
  "mcpServers": {
    "bsvkey-inference": {
      "command": "npx",
      "args": ["-y", "@bsvkey/inference-mcp"],
      "env": { "BSVKEY_API_KEY": "channelId:channelSecret" }
    }
  }
}

No npm? Grab the single-file server directly (https://inference.bsvkey.com/mcp/server.js) and use "command": "node", "args": ["server.js"].

Configuration (env)

Var	Default	Meaning
BSVKEY_BASE_URL	https://inference.bsvkey.com/v1	Gateway base URL (set to a self-hosted deployment if you run your own).
BSVKEY_API_KEY	—	channelId:channelSecret for a funded channel. Optional; can also be passed per call as apiKey.
BSVKEY_FUNDED_SATS	—	The amount you funded your channel with on-chain. When set, receipts are verified against it instead of the broker-signed fundedSats. Optional; per-call fundedSats.
BSVKEY_XRP_SEED	none	An XRP wallet seed for xrp_infer. Optional; can also be passed per call as xrpSeed. Never leaves this process.
BSVKEY_RECEIPT_STATE	—	Path to a JSON file for persisting per-channel receipt continuity (seq + totals) across restarts. Optional; in-memory only if unset.

Errors

A failed tool call returns isError: true with text in one fixed shape, so an agent can branch on the code without parsing prose:

error: <code> (<http status>): <message> [extra=value, ...]

Code	Status	Tool	What it means	What to do
no_channel_key		infer, channel_balance	No apiKey and no BSVKEY_API_KEY	Open a channel at the site (see open_channel)
invalid_channel	401 / 404	infer, channel_balance	Channel not found, wrong secret, or closed	Open a new channel
insufficient_balance	402	infer	The channel can't cover the worst case for this call; extras give requiredSats and balanceSats	Top up at the site, or lower maxTokens / turn off webSearch
invalid_request	400	infer, x402_infer	Unknown model or policy, a model whose provider isn't enabled, or bad input	Call list_models
upstream_failed	502	infer	The model provider failed	Nothing is charged; retry or pick another model
no_wif		x402_infer	No wif and no BSVKEY_WIF	Pass a funded key
verifier_missing		x402_infer	@bsvkey/x402-bsv-client / @bsv/sdk not installed	npm i @bsvkey/x402-bsv-client @bsv/sdk
payment_failed	402	x402_infer	The payment didn't settle (e.g. the key's address is unfunded); extras give the reason	Fund the address; nothing was spent
upstream_failed	502	x402_infer	The payment settled but the provider then failed; extras give settlementTxid	No automatic refund: email embryospace@gmail.com with the txid
no_xrp_seed		xrp_infer	No xrpSeed and no BSVKEY_XRP_SEED	Pass a funded XRP seed
xrpl_missing		xrp_infer	The xrpl package isn't installed	npm i xrpl
node_too_old		xrp_infer	Node is older than 20.19 / 22.12, which the xrpl package needs	Upgrade Node (the other tools run on Node 18+)
insufficient_xrp		xrp_infer	The wallet isn't activated, or can't cover the quote above its 1 XRP reserve	Fund it; nothing was spent
payment_failed	402	xrp_infer	The payment was refused before broadcast, or didn't settle; extras give the reason	Nothing was spent unless a settlement tx is included
upstream_failed	502	xrp_infer	The payment settled but the provider then failed; extras give the settlement tx	No automatic refund: email embryospace@gmail.com with the tx

On a prepaid channel nothing is charged on any error. A successful infer can still report receiptVerified: false (the signed receipt didn't check out; see receiptCheck) or null (couldn't check: verifier missing, or the receipt-key endpoint was down).

Thinking models (claude-sonnet-5, claude-opus-5, claude-opus-5-5, claude-fable-5-1) bill their hidden reasoning as output, and maxTokens is raised to at least 1024 for them.

Verify it's wired (no key needed)

printf '%s\n' \
  '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' \
  '{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}' \
  '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"list_models","arguments":{}}}' \
  | node server.js

Marketplace listing blurb

BSV Inference — Pay-per-token Claude & Grok, settled in BSV. Prepay a channel once, then meter every token with no subscription, account, or card. OpenAI- compatible, optional live web search, on-chain settlement. MCP + portable SKILL.md.

Publishing (operator)

• Live on npm under the @bsvkey org (owner: interence). First publish: v1.0.0.
• To ship an update: bump version in package.json, then npm publish --access public (2FA/security-key prompt applies).
• Canonical source: https://github.com/BSVKey/inference-mcp
• To list on a skills marketplace (e.g. bopen.ai), submit SKILL.md + this README.