FabTally Guard — MCP server
De-risk-a-dollar verification checks an AI agent runs before a costly action. Fronts the Guard HTTP API at https://guard.fabtally.com. Holds no private key.
Tools (all paid; a call with no payment returns the decoded x402 402 challenge)
| Tool | Price | What it does |
|---|---|---|
deps_check | $0.003 | Vet a package before installing — OSV.dev CVEs, typosquat similarity, deprecation/yank, SPDX license, age/download signals + a plain-English risk verdict. Args: ecosystem (npm|pypi|crates), name, version?. |
x402_preflight | $0.002 | Verify another x402 endpoint before paying it — valid x402 v2 402 challenge? price/asset/network/payTo consistent with its /.well-known/x402? TLS/reachability/openapi? + the parsed price. Args: url. |
json_repair | $0.002 | Coerce near-miss LLM JSON to a JSON-Schema-conformant object (fences/commas/quotes/keys/literals/brackets, then type-coerce, defaults, drop extras) — or precise per-field errors. Args: json (string), schema. |
url_read | $0.004 | Fetch a public url → clean Markdown + token estimate for RAG. Respects robots.txt, public pages only, nothing stored. Args: url. |
Every tool also accepts an optional x_payment (base64 x402 payload) that is
forwarded as the X-PAYMENT header to settle the call and return the real result.
Humans can instead prepay by card and use an X-FabTally-Key credit key against
the HTTP API.
Transports
- stdio (portable):
npx fabtally-guard-mcp(bin:fabtally-guard-mcp) - streamable-http (hosted):
https://guard.fabtally.com/mcp
Config: FABTALLY_GUARD_BASE (default https://guard.fabtally.com).
Read-only, keyless, stateless, descriptive. Operated by Sunstone Soft (fabtally.com). Not a security guarantee.