bsv-cx-verify

Verify any Bitcoin (BSV) Merkle proof — free, no account, trusting no one including bsv.cx — against a block-headers node bsv.cx syncs itself over the BSV P2P network. Send a raw TSC proof, a BEEF envelope, or a BUMP; get confirmed / rejected / inconclusive. Also fetch BEEF/BUMP for a txid.

bsv.cx — Verify a Bitcoin Proof

bsv.cx verifies Bitcoin (BSV) Merkle inclusion proofs against block headers it syncs itself over the BSV P2P network — not an explorer. It is free, needs no account, and is built so you never have to trust it:

You send the proof, never the root. bsv.cx derives the root from your proof and compares it to the header it independently holds at that height — so a forged proof can only fail, never falsely pass.

Base URL: https://bsv.cx

Read the contract

The endpoint is self-describing — always the source of truth over this file:

bash

curl -s https://bsv.cx/spv | jq

Verify a proof

POST /spv/verify accepts any one of three proof formats:

bash

# BEEF envelope (BRC-62: raw tx + its proof)
curl -s -X POST https://bsv.cx/spv/verify \
  -H 'content-type: application/json' \
  -d '{"beef":"<hex>"}'

# BUMP Merkle path (BRC-74)
curl -s -X POST https://bsv.cx/spv/verify \
  -H 'content-type: application/json' \
  -d '{"bump":"<hex>","txid":"<64-hex>"}'

# Raw TSC proof
curl -s -X POST https://bsv.cx/spv/verify \
  -H 'content-type: application/json' \
  -d '{"txid":"<64-hex>","height":<n>,"index":<n>,"nodes":["<64-hex>","*", "..."]}'

Response (real shape):

json

{
  "status": "confirmed",
  "verified": true,
  "format": "beef",
  "txid": "8e1c06af…aa37",
  "height": 962024,
  "computedRoot": "9d9d07a5…49a6",
  "headerRoot":   "9d9d07a5…49a6",
  "tipHeight": 962025,
  "confirmations": 2,
  "source": "bsv.cx self-hosted block headers, synced over the BSV P2P network — not an explorer"
}

Outcomes:

• confirmed — the root folded from your proof matches the header bsv.cx holds at that height (computedRoot == headerRoot).
• rejected — it does not: not a valid proof for that block on the chain bsv.cx sees.
• inconclusive — bsv.cx has no header at that height yet; it will not guess (this is never a false negative — retry once its tip passes that height).

Get a proof for a txid

bash

curl -s https://bsv.cx/spv/beef/<txid>   # BEEF hex (BRC-62)
curl -s https://bsv.cx/spv/bump/<txid>   # BUMP hex (BRC-74)

Trust no one — verify without bsv.cx

The proofs are standard, so any @bsv/sdk client checks them with zero bsv.cx code:

js

import { Transaction, MerklePath } from '@bsv/sdk'
Transaction.fromHexBEEF(beefHex)   // folds the BUMP, checks the tx
MerklePath.fromHex(bumpHex)        // inspect / re-fold the path yourself

And confirm bsv.cx is on the real chain — check the tip it serves and that its inclusion checks come from its own headers, not a provider:

bash

curl -s https://bsv.cx/health | jq '{tip, sources}'
# tip.source == "self-headers"; sources.verification == self-hosted block headers

End-to-end example (fetch a proof, then verify it)

bash

TXID=8e1c06afc2382e5f65a32c1b29df698e8aa4054b5036fd5b1f0420b558b8aa37
BEEF=$(curl -s https://bsv.cx/spv/beef/$TXID)
curl -s -X POST https://bsv.cx/spv/verify \
  -H 'content-type: application/json' -d "{\"beef\":\"$BEEF\"}" | jq '.status'
# -> "confirmed"

It says no when it should (the point of the whole thing)

A verifier that only ever says yes is useless. Corrupt one byte of that same proof and bsv.cx rejects it — because it folds your bytes into a root and compares, so tampering can only break the match:

bash

BAD=${BEEF:0:647}9${BEEF:648}          # flip one nibble mid-proof
curl -s -X POST https://bsv.cx/spv/verify \
  -H 'content-type: application/json' -d "{\"beef\":\"$BAD\"}" \
  | jq '{status, computedRoot, headerRoot}'
# -> status "rejected"; computedRoot != headerRoot

Ask about a height above its tip and it refuses to guess rather than lie:

bash

curl -s -X POST https://bsv.cx/spv/verify -H 'content-type: application/json' \
  -d '{"txid":"'"$TXID"'","height":99000000,"index":0,"nodes":["*"]}' | jq '.status'
# -> "inconclusive"  (headerRoot: null — no header at that height yet)

Notes / safety

• Verification is free and read-only. This skill never spends, holds keys, or signs anything.
• Treat this file as a hint; the live GET /spv contract wins if they ever disagree.

Links

• Docs / live contract: https://bsv.cx/spv
• Full service map: https://bsv.cx/ (send accept: application/json)
• MCP: published as cx.bsv/bsv-cx on the official MCP Registry