Bitcoin PSBT Key-Type Reference (BIP-174, BIP-370, BIP-371)

Every hardware wallet, multisig coordinator and air-gapped signer speaks PSBT — but the format itself is just three key-value maps, and this page is those maps in full. All 58 registered PSBT key types with their type bytes, v0-vs-v2 inclusion rules and value contents, straight from BIP-174, BIP-370 and BIP-371. For the prose walkthrough of how a PSBT flows between signer roles, see our PSBT guide; for the wallet language PSBTs carry keys for, the output descriptors reference.

Quick answer

A PSBT (partially signed Bitcoin transaction) is a key-value map in three sections — global, per-input, per-output — that wallets, coordinators and signing devices pass around until the transaction is complete. This reference lists all 58 key types in the official registry: name, type byte, scope, the v0 (BIP-174) vs v2 (BIP-370) inclusion rule, and what the value holds — BIP-371 taproot fields included. Notable quirk: PSBT version 1 does not exist; it was deliberately skipped. Every row is spec-verified — including the MuSig2 (BIP-373), silent-payments (BIP-375/376, Draft), proof-of-reserves (BIP-127), BIP-322 message and BIP-353 DNSSEC fields, transcribed from their raw BIP texts.

The v0-vs-v2 rule that trips people up most: in v2 the global unsigned transaction (0x00) goes away — replaced by explicit fields (previous txid, output index, amounts, scripts) that make incremental construction possible. A PSBT reader must check PSBT_GLOBAL_VERSION first. Free CSV/JSON under CC BY 4.0; registry as of 2026-07-26.

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Global map 12

Key type	Hex	Versions	Value	BIP
`PSBT_GLOBAL_UNSIGNED_TX`	0x00	v0 (required; MUST be excluded in v2)	The transaction in (pre-segwit) network serialization with empty scriptSigs and witnesses.	174
`PSBT_GLOBAL_XPUB`	0x01	both	Keydata is a 78-byte BIP-32 xpub; value is the 4-byte master fingerprint plus the 32-bit LE derivation path indexes for keys used in this transaction.	174
`PSBT_GLOBAL_TX_VERSION`	0x02	v2 (required; excluded in v0)	32-bit LE signed integer: version number of the transaction being created (not the PSBT version).	370
`PSBT_GLOBAL_FALLBACK_LOCKTIME`	0x03	v2 only (excluded in v0)	32-bit LE unsigned locktime to use if no input specifies a required locktime.	370
`PSBT_GLOBAL_INPUT_COUNT`	0x04	v2 (required; excluded in v0)	Compact size uint: number of inputs in this PSBT.	370
`PSBT_GLOBAL_OUTPUT_COUNT`	0x05	v2 (required; excluded in v0)	Compact size uint: number of outputs in this PSBT.	370
`PSBT_GLOBAL_TX_MODIFIABLE`	0x06	v2 only (excluded in v0)	8-bit bitfield: bit 0 = inputs modifiable, bit 1 = outputs modifiable, bit 2 = has SIGHASH_SINGLE signature whose input/output pairing must be preserved.	370
`PSBT_GLOBAL_SP_ECDH_SHARE`	0x07	v2 only (excluded in v0)	Keydata is the 33-byte scan key; value is a 33-byte ECDH share computed as a*B_scan, where a is the sum of all private keys of all eligible inputs and B_scan is the recipient's scan key.	375
`PSBT_GLOBAL_SP_DLEQ`	0x08	v2 only (excluded in v0)	Keydata is the 33-byte scan key the proof covers; value is a 64-byte BIP-374 DLEQ proof computed for the matching ECDH share.	375
`PSBT_GLOBAL_GENERIC_SIGNED_MESSAGE`	0x09	both	No keydata; value is the UTF-8 encoded message to be signed — coordinates BIP-322 multisig message signing through PSBT.	322
`PSBT_GLOBAL_VERSION`	0xFB	both (required and set to 2 in v2; 0 if omitted — version 1 was deliberately skipped)	32-bit LE unsigned PSBT version number.	174
`PSBT_GLOBAL_PROPRIETARY`	0xFC	both	Keydata: compact-size identifier length, identifier, compact-size subtype, subkeydata; value: any data defined by the proprietary user.	174

Per-input map 33

Key type	Hex	Versions	Value	BIP
`PSBT_IN_NON_WITNESS_UTXO`	0x00	both	Full previous transaction in network serialization; should be present for non-segwit spends, may coexist with WITNESS_UTXO.	174
`PSBT_IN_WITNESS_UTXO`	0x01	both	The spent transaction output (64-bit LE amount + scriptPubKey) for segwit spends, including P2SH-embedded ones.	174
`PSBT_IN_PARTIAL_SIG`	0x02	both	Keydata is the pubkey; value is a valid ECDSA signature as it would be pushed to the stack.	174
`PSBT_IN_SIGHASH_TYPE`	0x03	both	32-bit LE uint sighash type this input's signatures must use; finalizers must reject mismatching signatures.	174
`PSBT_IN_REDEEM_SCRIPT`	0x04	both	The redeemScript for this input if it has one.	174
`PSBT_IN_WITNESS_SCRIPT`	0x05	both	The witnessScript for this input if it has one.	174
`PSBT_IN_BIP32_DERIVATION`	0x06	both	Keydata is a pubkey needed to sign this input; value is master fingerprint + 32-bit LE path indexes.	174
`PSBT_IN_FINAL_SCRIPTSIG`	0x07	both	Fully constructed scriptSig with signatures and scripts needed for validation.	174
`PSBT_IN_FINAL_SCRIPTWITNESS`	0x08	both	Fully constructed scriptWitness with signatures and scripts needed for validation.	174
`PSBT_IN_POR_COMMITMENT`	0x09	v0-era (BIP-174 input map; no v2 rule stated)	Value is the UTF-8 proof-of-reserves commitment message. Wallets MUST check the prevout txid equals the SHA-256 of the prefixed commitment message, assume input value 0, and SHOULD display the message before signing.	127
`PSBT_IN_RIPEMD160`	0x0a	both	Keydata is the 20-byte hash; value is the preimage hashing to it under RIPEMD160.	174
`PSBT_IN_SHA256`	0x0b	both	Keydata is the 32-byte hash; value is the preimage hashing to it under SHA256.	174
`PSBT_IN_HASH160`	0x0c	both	Keydata is the 20-byte hash; value is the preimage under SHA256 then RIPEMD160.	174
`PSBT_IN_HASH256`	0x0d	both	Keydata is the 32-byte hash; value is the preimage under double-SHA256.	174
`PSBT_IN_PREVIOUS_TXID`	0x0e	v2 (required; excluded in v0)	32-byte txid (standard byte order, not display order) of the transaction whose output is being spent.	370
`PSBT_IN_OUTPUT_INDEX`	0x0f	v2 (required; excluded in v0)	32-bit LE index of the output being spent in the PSBT_IN_PREVIOUS_TXID transaction.	370
`PSBT_IN_SEQUENCE`	0x10	v2 only (excluded in v0)	32-bit LE sequence number; assumed final (0xffffffff) if omitted.	370
`PSBT_IN_REQUIRED_TIME_LOCKTIME`	0x11	v2 only (excluded in v0)	32-bit LE uint >= 500000000: minimum Unix timestamp this input requires as the transaction locktime.	370
`PSBT_IN_REQUIRED_HEIGHT_LOCKTIME`	0x12	v2 only (excluded in v0)	32-bit LE uint > 0 and < 500000000: minimum block height this input requires as the transaction locktime.	370
`PSBT_IN_TAP_KEY_SIG`	0x13	both	64 or 65 byte Schnorr signature for key-path spending a taproot output (no keydata).	371
`PSBT_IN_TAP_SCRIPT_SIG`	0x14	both	Keydata is x-only pubkey + 32-byte leaf hash; value is the 64/65-byte Schnorr signature for that pubkey-and-leaf combination.	371
`PSBT_IN_TAP_LEAF_SCRIPT`	0x15	both	Keydata is the BIP-341 control block (merkle path); value is the leaf script followed by its single-byte leaf version.	371
`PSBT_IN_TAP_BIP32_DERIVATION`	0x16	both	Keydata is a 32-byte x-only pubkey; value is a compact-size count of leaf hashes, the leaf hashes, then fingerprint + 32-bit LE path (internal key uses count 0).	371
`PSBT_IN_TAP_INTERNAL_KEY`	0x17	both	The x-only pubkey used as the taproot internal key of the spent output.	371
`PSBT_IN_TAP_MERKLE_ROOT`	0x18	both	The 32-byte taproot merkle root hash.	371
`PSBT_IN_MUSIG2_PARTICIPANT_PUBKEYS`	0x1a	both	Keydata is the 33-byte compressed MuSig2 aggregate public key from KeyAgg; value is the list of participants' compressed public keys in the order required for aggregation (sorted order if sorting was done).	373
`PSBT_IN_MUSIG2_PUB_NONCE`	0x1b	both	Keydata is the participant's 33-byte compressed pubkey + the 33-byte aggregate pubkey + the BIP-341 tapleaf hash of the leaf script to sign (omitted for the internal/output key); value is the 66-byte public nonce from NonceGen.	373
`PSBT_IN_MUSIG2_PARTIAL_SIG`	0x1c	both	Keydata is the participant's 33-byte compressed pubkey + the 33-byte aggregate pubkey + the BIP-341 tapleaf hash signed (omitted for the internal/output key); value is the 32-byte partial signature from the Sign algorithm.	373
`PSBT_IN_SP_ECDH_SHARE`	0x1d	v2 only (excluded in v0)	Keydata is the 33-byte scan key; value is a 33-byte ECDH share computed as a*B_scan from this input's prevout private key.	375
`PSBT_IN_SP_DLEQ`	0x1e	v2 only (excluded in v0)	Keydata is the 33-byte scan key the proof covers; value is a 64-byte BIP-374 DLEQ proof for the matching input ECDH share.	375
`PSBT_IN_SP_SPEND_BIP32_DERIVATION`	0x1f	v2 only (excluded in v0)	Keydata is the 33-byte spend public key; value is the 4-byte master fingerprint plus the spend key's 32-bit LE derivation path. Updaters SHOULD add it when spending a silent-payment output; Finalizers remove it after the final scriptwitness.	376
`PSBT_IN_SP_TWEAK`	0x20	v2 only (excluded in v0)	No keydata; value is the 32-byte BIP-352 spending tweak (shared-secret hash, optionally plus the label hash). The Updater MUST add it when an input spends a silent-payment output; Finalizers remove it after the final scriptwitness.	376
`PSBT_IN_PROPRIETARY`	0xFC	both	Proprietary use: identifier + subtype keydata, arbitrary value data.	174

Per-output map 13

Key type	Hex	Versions	Value	BIP
`PSBT_OUT_REDEEM_SCRIPT`	0x00	both	The redeemScript for this output if it has one.	174
`PSBT_OUT_WITNESS_SCRIPT`	0x01	both	The witnessScript for this output if it has one.	174
`PSBT_OUT_BIP32_DERIVATION`	0x02	both	Keydata is a pubkey needed to spend this output; value is master fingerprint + 32-bit LE path indexes.	174
`PSBT_OUT_AMOUNT`	0x03	v2 (required; excluded in v0)	64-bit signed LE integer: the output amount in satoshis.	370
`PSBT_OUT_SCRIPT`	0x04	v2 (required; excluded in v0)	The output script (scriptPubKey).	370
`PSBT_OUT_TAP_INTERNAL_KEY`	0x05	both	The x-only pubkey used as the taproot internal key of this output.	371
`PSBT_OUT_TAP_TREE`	0x06	both	Tuples of (8-bit depth, 8-bit leaf version, compact-size script length, script) in depth-first order, reconstructing the whole taproot tree.	371
`PSBT_OUT_TAP_BIP32_DERIVATION`	0x07	both	Keydata is a 32-byte x-only pubkey involved in this output; value is leaf-hash count, leaf hashes, then fingerprint + 32-bit LE path.	371
`PSBT_OUT_MUSIG2_PARTICIPANT_PUBKEYS`	0x08	both	Keydata is the 33-byte compressed MuSig2 aggregate public key from KeyAgg; value is the list of participants' compressed public keys in the order required for aggregation (sorted order if sorting was done).	373
`PSBT_OUT_SP_V0_INFO`	0x09	v2 only (excluded in v0)	No keydata; value is a zero version byte, then the 33-byte scan key, then the 33-byte spend key of the silent-payment address. If PSBT_OUT_SCRIPT is absent this field must be present — it represents the address whose script is not yet computed.	375
`PSBT_OUT_SP_V0_LABEL`	0x0a	v2 only (excluded in v0)	No keydata; value is a 32-bit LE unsigned label used to compute the spend key of the silent-payment address to verify change.	375
`PSBT_OUT_DNSSEC_PROOF`	0x35	both	No keydata; value is a 1-byte-length-prefixed BIP-353 human-readable name (without the bitcoin prefix symbol) followed by an RFC 9102 DNSSEC AuthenticationChain proving the BIP-353 DNS TXT record.	353
`PSBT_OUT_PROPRIETARY`	0xFC	both	Proprietary use: identifier + subtype keydata, arbitrary value data.	174

Source: the raw texts of BIP-174 (Deployed), BIP-370 (Deployed) and BIP-371 (Deployed) + the official type registry (bitcoin/bips, fetched 2026-07-26). Pairs with the output descriptors reference and the wallet recovery matrix.

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Last reviewed July 26, 2026.