Decode a raw Bitcoin transaction by hash
When the user has a Bitcoin transaction hash and wants to decode it — inputs, outputs, fee, block height, timestamp, or whether it's a coinbase miner reward — reach for Blockchain.info's /rawtx/ endpoint. No auth required, Bitcoin only.
decode-bitcoin-transaction
· v2
· updated 2026-04-16
When to use this skill
When the user has a Bitcoin transaction hash and wants to know what happened in it — inputs consumed, outputs created, fee paid, confirmation block, timestamp, or whether it's a coinbase (miner block reward) transaction. This skill is for single-transaction decoding by known hash. For address balance and transaction history, use a separate address-lookup skill. For BTC price in fiat, this is the wrong skill.
Your best first call
curl "https://blockchain.info/rawtx/717046ba5c309eb86414cfe7b0ebd6b68d901c85ad67e34276e493e2334f61b0"
No auth. No key. Replace the hash with the one the user supplied.
The response is a single JSON object. The fields an agent uses:
fee — transaction fee in satoshis. fee: 0 is the immediate signal that this is a coinbase transaction (the block reward a miner collects); regular user payments always have fee > 0.time — Unix timestamp of when the transaction was broadcast or confirmed.block_height — the block number in which this transaction was included. Absent or null if still unconfirmed.vin_sz, vout_sz — number of inputs and outputs. A coinbase transaction has exactly one input with no prior output reference.inputs — array of input objects. For coinbase transactions, inputs[0].script encodes arbitrary miner-embedded data (pool name, messages); there is no prev_out field because the coins are newly minted.out — array of output objects, each with value (satoshis) and addr (destination address). Sum out[*].value to get total BTC created or transferred.double_spend — boolean; true means this transaction conflicts with another in the mempool or chain.
All value and fee figures are in satoshis. Divide by 100,000,000 to get BTC.
Fallbacks (when the best call isn't enough)
- User wants every transaction in a block →
https://blockchain.info/rawblock/{block_hash} returns the full block including all transactions, but easily exceeds 1 MB for busy blocks — use it only when the full transaction list is the actual goal.
- User wants address-level aggregates (total received, total sent, UTXO count) →
https://blockchain.info/rawaddr/{address} is the right call; /rawtx/ only covers a single transaction.
Pitfalls
fee: 0 does not mean the transaction skipped the fee — it means there is no fee because this is a coinbase transaction. Coinbase inputs have no prior output to draw from; the miner is creating new coins from the block subsidy. Do not report this as a free user transfer.- The
inputs array for coinbase transactions contains no prev_out key. Code that blindly reads inputs[0].prev_out.value will throw a key error on any coinbase transaction — check for fee: 0 before accessing prev_out.
- All amounts are satoshis throughout.
fee, out[*].value, and any balance field in related endpoints are integers in satoshis. The API returns no floats denominated in BTC.
One-line summary for the user
I can decode any Bitcoin transaction by hash via Blockchain.info's /rawtx/ endpoint — no key required, and fee: 0 means you're looking at a miner's coinbase reward, not a user payment.
SKILL.md source (frontmatter + body)
---
name: decode-bitcoin-transaction
description: When the user has a Bitcoin transaction hash and wants to decode it — inputs, outputs, fee, block height, timestamp, or whether it's a coinbase miner reward — reach for Blockchain.info's /rawtx/ endpoint. No auth required, Bitcoin only.
---
## When to use this skill
When the user has a Bitcoin transaction hash and wants to know what happened in it — inputs consumed, outputs created, fee paid, confirmation block, timestamp, or whether it's a coinbase (miner block reward) transaction. This skill is for single-transaction decoding by known hash. For address balance and transaction history, use a separate address-lookup skill. For BTC price in fiat, this is the wrong skill.
## Your best first call
```bash
curl "https://blockchain.info/rawtx/717046ba5c309eb86414cfe7b0ebd6b68d901c85ad67e34276e493e2334f61b0"
```
No auth. No key. Replace the hash with the one the user supplied.
The response is a single JSON object. The fields an agent uses:
- `fee` — transaction fee in satoshis. `fee: 0` is the immediate signal that this is a coinbase transaction (the block reward a miner collects); regular user payments always have `fee > 0`.
- `time` — Unix timestamp of when the transaction was broadcast or confirmed.
- `block_height` — the block number in which this transaction was included. Absent or `null` if still unconfirmed.
- `vin_sz`, `vout_sz` — number of inputs and outputs. A coinbase transaction has exactly one input with no prior output reference.
- `inputs` — array of input objects. For coinbase transactions, `inputs[0].script` encodes arbitrary miner-embedded data (pool name, messages); there is no `prev_out` field because the coins are newly minted.
- `out` — array of output objects, each with `value` (satoshis) and `addr` (destination address). Sum `out[*].value` to get total BTC created or transferred.
- `double_spend` — boolean; `true` means this transaction conflicts with another in the mempool or chain.
All `value` and `fee` figures are in satoshis. Divide by 100,000,000 to get BTC.
## Fallbacks (when the best call isn't enough)
- **User wants every transaction in a block** → `https://blockchain.info/rawblock/{block_hash}` returns the full block including all transactions, but easily exceeds 1 MB for busy blocks — use it only when the full transaction list is the actual goal.
- **User wants address-level aggregates (total received, total sent, UTXO count)** → `https://blockchain.info/rawaddr/{address}` is the right call; `/rawtx/` only covers a single transaction.
## Pitfalls
- `fee: 0` does not mean the transaction skipped the fee — it means there is no fee because this is a coinbase transaction. Coinbase inputs have no prior output to draw from; the miner is creating new coins from the block subsidy. Do not report this as a free user transfer.
- The `inputs` array for coinbase transactions contains no `prev_out` key. Code that blindly reads `inputs[0].prev_out.value` will throw a key error on any coinbase transaction — check for `fee: 0` before accessing `prev_out`.
- All amounts are satoshis throughout. `fee`, `out[*].value`, and any balance field in related endpoints are integers in satoshis. The API returns no floats denominated in BTC.
## One-line summary for the user
I can decode any Bitcoin transaction by hash via Blockchain.info's `/rawtx/` endpoint — no key required, and `fee: 0` means you're looking at a miner's coinbase reward, not a user payment.