diff --git a/bitcoin/Cargo.toml b/bitcoin/Cargo.toml
index 3ebe7dad..adbfe092 100644
--- a/bitcoin/Cargo.toml
+++ b/bitcoin/Cargo.toml
@@ -9,7 +9,7 @@ documentation = "https://docs.rs/bitcoin/"
 description = "General purpose library for using and interoperating with Bitcoin and other cryptocurrencies."
 keywords = [ "crypto", "bitcoin" ]
 readme = "README.md"
-exclude = ["test_data/"]
+exclude = ["tests/"]
 edition = "2018"
 
 # Please don't forget to add relevant features to docs.rs below
diff --git a/bitcoin/examples/ecdsa-psbt.rs b/bitcoin/examples/ecdsa-psbt.rs
index 1effe001..1b256723 100644
--- a/bitcoin/examples/ecdsa-psbt.rs
+++ b/bitcoin/examples/ecdsa-psbt.rs
@@ -234,6 +234,7 @@ impl WatchOnly {
     }
 
     /// Finalizes the PSBT, in BIP174 parlance this is the 'Finalizer'.
+    /// This is just an example. For a production-ready PSBT Finalizer, use [rust-miniscript](https://docs.rs/miniscript/latest/miniscript/psbt/trait.PsbtExt.html#tymethod.finalize)
     fn finalize_psbt(&self, mut psbt: Psbt) -> Result<Psbt> {
         use bitcoin::util::psbt::serialize::Serialize;
 
diff --git a/bitcoin/src/bip158.rs b/bitcoin/src/bip158.rs
index 7692d5a2..9e7bacff 100644
--- a/bitcoin/src/bip158.rs
+++ b/bitcoin/src/bip158.rs
@@ -564,7 +564,7 @@ mod test {
     #[test]
     fn test_blockfilters() {
         // test vectors from: https://github.com/jimpo/bitcoin/blob/c7efb652f3543b001b4dd22186a354605b14f47e/src/test/data/blockfilters.json
-        let data = include_str!("../test_data/blockfilters.json");
+        let data = include_str!("../tests/data/blockfilters.json");
 
         let testdata = serde_json::from_str::<Value>(data).unwrap().as_array().unwrap().clone();
         for t in testdata.iter().skip(1) {
diff --git a/bitcoin/src/blockdata/block.rs b/bitcoin/src/blockdata/block.rs
index 1fa7bc1b..9ab112a8 100644
--- a/bitcoin/src/blockdata/block.rs
+++ b/bitcoin/src/blockdata/block.rs
@@ -460,7 +460,7 @@ mod tests {
     // Check testnet block 000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b
     #[test]
     fn segwit_block_test() {
-        let segwit_block = include_bytes!("../../test_data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw").to_vec();
+        let segwit_block = include_bytes!("../../tests/data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw").to_vec();
 
         let decode: Result<Block, _> = deserialize(&segwit_block);
 
@@ -564,7 +564,7 @@ mod benches {
 
     #[bench]
     pub fn bench_stream_reader(bh: &mut Bencher) {
-        let big_block = include_bytes!("../../test_data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
+        let big_block = include_bytes!("../../tests/data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
         assert_eq!(big_block.len(), 1_381_836);
         let big_block = black_box(big_block);
 
@@ -577,7 +577,7 @@ mod benches {
 
     #[bench]
     pub fn bench_block_serialize(bh: &mut Bencher) {
-        let raw_block = include_bytes!("../../test_data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
+        let raw_block = include_bytes!("../../tests/data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
 
         let block: Block = deserialize(&raw_block[..]).unwrap();
 
@@ -592,7 +592,7 @@ mod benches {
 
     #[bench]
     pub fn bench_block_serialize_logic(bh: &mut Bencher) {
-        let raw_block = include_bytes!("../../test_data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
+        let raw_block = include_bytes!("../../tests/data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
 
         let block: Block = deserialize(&raw_block[..]).unwrap();
 
@@ -604,7 +604,7 @@ mod benches {
 
     #[bench]
     pub fn bench_block_deserialize(bh: &mut Bencher) {
-        let raw_block = include_bytes!("../../test_data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
+        let raw_block = include_bytes!("../../tests/data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw");
 
         bh.iter(|| {
             let block: Block = deserialize(&raw_block[..]).unwrap();
diff --git a/bitcoin/src/blockdata/opcodes.rs b/bitcoin/src/blockdata/opcodes.rs
index 7b37d663..c5605aec 100644
--- a/bitcoin/src/blockdata/opcodes.rs
+++ b/bitcoin/src/blockdata/opcodes.rs
@@ -755,6 +755,8 @@ impl serde::Serialize for All {
     }
 }
 
+/// Push an empty array onto the stack.
+pub static OP_0: All = OP_PUSHBYTES_0;
 /// Empty stack is also FALSE.
 pub static OP_FALSE: All = OP_PUSHBYTES_0;
 /// Number 1 is also TRUE.
diff --git a/bitcoin/src/network/message.rs b/bitcoin/src/network/message.rs
index 5e1b0ee1..6de93622 100644
--- a/bitcoin/src/network/message.rs
+++ b/bitcoin/src/network/message.rs
@@ -497,7 +497,7 @@ mod test {
         // TODO: Impl Rand traits here to easily generate random values.
         let version_msg: VersionMessage = deserialize(&Vec::from_hex("721101000100000000000000e6e0845300000000010000000000000000000000000000000000ffff0000000000000100000000000000fd87d87eeb4364f22cf54dca59412db7208d47d920cffce83ee8102f5361746f7368693a302e392e39392f2c9f040001").unwrap()).unwrap();
         let tx: Transaction = deserialize(&Vec::from_hex("0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000").unwrap()).unwrap();
-        let block: Block = deserialize(&include_bytes!("../../test_data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw")[..]).unwrap();
+        let block: Block = deserialize(&include_bytes!("../../tests/data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw")[..]).unwrap();
         let header: BlockHeader = deserialize(&Vec::from_hex("010000004ddccd549d28f385ab457e98d1b11ce80bfea2c5ab93015ade4973e400000000bf4473e53794beae34e64fccc471dace6ae544180816f89591894e0f417a914cd74d6e49ffff001d323b3a7b").unwrap()).unwrap();
         let script: Script = deserialize(&Vec::from_hex("1976a91431a420903c05a0a7de2de40c9f02ebedbacdc17288ac").unwrap()).unwrap();
         let merkle_block: MerkleBlock = deserialize(&Vec::from_hex("0100000079cda856b143d9db2c1caff01d1aecc8630d30625d10e8b4b8b0000000000000b50cc069d6a3e33e3ff84a5c41d9d3febe7c770fdcc96b2c3ff60abe184f196367291b4d4c86041b8fa45d630100000001b50cc069d6a3e33e3ff84a5c41d9d3febe7c770fdcc96b2c3ff60abe184f19630101").unwrap()).unwrap();
diff --git a/bitcoin/src/sighash.rs b/bitcoin/src/sighash.rs
index 3b3fe380..582e2811 100644
--- a/bitcoin/src/sighash.rs
+++ b/bitcoin/src/sighash.rs
@@ -1127,7 +1127,7 @@ mod tests {
         // These test vectors were stolen from libbtc, which is Copyright 2014 Jonas Schnelli MIT
         // They were transformed by replacing {...} with run_test_sighash(...), then the ones containing
         // OP_CODESEPARATOR in their pubkeys were removed
-        let data = include_str!("../test_data/legacy_sighash.json");
+        let data = include_str!("../tests/data/legacy_sighash.json");
 
         let testdata = serde_json::from_str::<Value>(data).unwrap().as_array().unwrap().clone();
         for t in testdata.iter().skip(1) {
@@ -1479,7 +1479,7 @@ mod tests {
     }
 
     fn bip_341_read_json() -> serde_json::Value {
-        let json_str = include_str!("../test_data/bip341_tests.json");
+        let json_str = include_str!("../tests/data/bip341_tests.json");
         serde_json::from_str(json_str).expect("JSON was not well-formatted")
     }
 
diff --git a/bitcoin/src/util/hash.rs b/bitcoin/src/util/hash.rs
index 3f492e4d..79f75c77 100644
--- a/bitcoin/src/util/hash.rs
+++ b/bitcoin/src/util/hash.rs
@@ -108,7 +108,7 @@ mod tests {
     #[test]
     fn both_merkle_root_functions_return_the_same_result() {
         // testnet block 000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b
-        let segwit_block = include_bytes!("../../test_data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw");
+        let segwit_block = include_bytes!("../../tests/data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw");
         let block: Block = deserialize(&segwit_block[..]).expect("Failed to deserialize block");
         assert!(block.check_merkle_root()); // Sanity check.
 
diff --git a/bitcoin/src/util/psbt/mod.rs b/bitcoin/src/util/psbt/mod.rs
index b103968f..304e641d 100644
--- a/bitcoin/src/util/psbt/mod.rs
+++ b/bitcoin/src/util/psbt/mod.rs
@@ -1664,9 +1664,9 @@ mod tests {
     // PSBTs taken from BIP 174 test vectors.
     #[test]
     fn combine_psbts() {
-        let mut psbt1 = hex_psbt!(include_str!("../../../test_data/psbt1.hex")).unwrap();
-        let psbt2 = hex_psbt!(include_str!("../../../test_data/psbt2.hex")).unwrap();
-        let psbt_combined = hex_psbt!(include_str!("../../../test_data/psbt2.hex")).unwrap();
+        let mut psbt1 = hex_psbt!(include_str!("../../../tests/data/psbt1.hex")).unwrap();
+        let psbt2 = hex_psbt!(include_str!("../../../tests/data/psbt2.hex")).unwrap();
+        let psbt_combined = hex_psbt!(include_str!("../../../tests/data/psbt2.hex")).unwrap();
 
         psbt1.combine(psbt2).expect("psbt combine to succeed");
         assert_eq!(psbt1, psbt_combined);
@@ -1674,8 +1674,8 @@ mod tests {
 
     #[test]
     fn combine_psbts_commutative() {
-        let mut psbt1 = hex_psbt!(include_str!("../../../test_data/psbt1.hex")).unwrap();
-        let mut psbt2 = hex_psbt!(include_str!("../../../test_data/psbt2.hex")).unwrap();
+        let mut psbt1 = hex_psbt!(include_str!("../../../tests/data/psbt1.hex")).unwrap();
+        let mut psbt2 = hex_psbt!(include_str!("../../../tests/data/psbt2.hex")).unwrap();
 
         let psbt1_clone = psbt1.clone();
         let psbt2_clone = psbt2.clone();
diff --git a/bitcoin/src/util/taproot.rs b/bitcoin/src/util/taproot.rs
index c41f9883..096c71e9 100644
--- a/bitcoin/src/util/taproot.rs
+++ b/bitcoin/src/util/taproot.rs
@@ -1438,7 +1438,7 @@ mod test {
     }
 
     fn bip_341_read_json() -> serde_json::Value {
-        let json_str = include_str!("../../test_data/bip341_tests.json");
+        let json_str = include_str!("../../tests/data/bip341_tests.json");
         serde_json::from_str(json_str).expect("JSON was not well-formatted")
     }
 }
diff --git a/bitcoin/tests/data/README.md b/bitcoin/tests/data/README.md
new file mode 100644
index 00000000..70ed7a4e
--- /dev/null
+++ b/bitcoin/tests/data/README.md
@@ -0,0 +1,4 @@
+Test vector data
+================
+
+This file contains data (hex strings) taken from BIP test vectors.
diff --git a/bitcoin/test_data/bip341_tests.json b/bitcoin/tests/data/bip341_tests.json
similarity index 100%
rename from bitcoin/test_data/bip341_tests.json
rename to bitcoin/tests/data/bip341_tests.json
diff --git a/bitcoin/test_data/blockfilters.json b/bitcoin/tests/data/blockfilters.json
similarity index 100%
rename from bitcoin/test_data/blockfilters.json
rename to bitcoin/tests/data/blockfilters.json
diff --git a/bitcoin/test_data/psbt2.hex b/bitcoin/tests/data/combine_psbt_hex
similarity index 100%
rename from bitcoin/test_data/psbt2.hex
rename to bitcoin/tests/data/combine_psbt_hex
diff --git a/bitcoin/tests/data/create_psbt_hex b/bitcoin/tests/data/create_psbt_hex
new file mode 100644
index 00000000..b5ef8d5e
--- /dev/null
+++ b/bitcoin/tests/data/create_psbt_hex
@@ -0,0 +1 @@
+70736274ff01009a020000000258e87a21b56daf0c23be8e7070456c336f7cbaa5c8757924f545887bb2abdd750000000000ffffffff838d0427d0ec650a68aa46bb0b098aea4422c071b2ca78352a077959d07cea1d0100000000ffffffff0270aaf00800000000160014d85c2b71d0060b09c9886aeb815e50991dda124d00e1f5050000000016001400aea9a2e5f0f876a588df5546e8742d1d87008f000000000000000000
\ No newline at end of file
diff --git a/bitcoin/tests/data/extract_tx_hex b/bitcoin/tests/data/extract_tx_hex
new file mode 100644
index 00000000..41c22961
--- /dev/null
+++ b/bitcoin/tests/data/extract_tx_hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/bitcoin/tests/data/finalize_psbt_hex b/bitcoin/tests/data/finalize_psbt_hex
new file mode 100644
index 00000000..2866b82b
--- /dev/null
+++ b/bitcoin/tests/data/finalize_psbt_hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/bitcoin/test_data/legacy_sighash.json b/bitcoin/tests/data/legacy_sighash.json
similarity index 100%
rename from bitcoin/test_data/legacy_sighash.json
rename to bitcoin/tests/data/legacy_sighash.json
diff --git a/bitcoin/tests/data/lex_combine_psbt_hex b/bitcoin/tests/data/lex_combine_psbt_hex
new file mode 100644
index 00000000..9ee710b6
--- /dev/null
+++ b/bitcoin/tests/data/lex_combine_psbt_hex
@@ -0,0 +1 @@
+70736274ff01003f0200000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000ffffffff010000000000000000036a0100000000000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f00
\ No newline at end of file
diff --git a/bitcoin/tests/data/lex_psbt_1_hex b/bitcoin/tests/data/lex_psbt_1_hex
new file mode 100644
index 00000000..a125c529
--- /dev/null
+++ b/bitcoin/tests/data/lex_psbt_1_hex
@@ -0,0 +1 @@
+70736274ff01003f0200000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000ffffffff010000000000000000036a0100000000000af00102030405060708090f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f00
\ No newline at end of file
diff --git a/bitcoin/tests/data/lex_psbt_2_hex b/bitcoin/tests/data/lex_psbt_2_hex
new file mode 100644
index 00000000..766c7eee
--- /dev/null
+++ b/bitcoin/tests/data/lex_psbt_2_hex
@@ -0,0 +1 @@
+70736274ff01003f0200000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000ffffffff010000000000000000036a0100000000000af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708100f0102030405060708090a0b0c0d0e0f00
\ No newline at end of file
diff --git a/bitcoin/test_data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw b/bitcoin/tests/data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw
similarity index 100%
rename from bitcoin/test_data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw
rename to bitcoin/tests/data/mainnet_block_000000000000000000000c835b2adcaedc20fdf6ee440009c249452c726dafae.raw
diff --git a/bitcoin/tests/data/previous_tx_0_hex b/bitcoin/tests/data/previous_tx_0_hex
new file mode 100644
index 00000000..ce208945
--- /dev/null
+++ b/bitcoin/tests/data/previous_tx_0_hex
@@ -0,0 +1 @@
+0200000000010158e87a21b56daf0c23be8e7070456c336f7cbaa5c8757924f545887bb2abdd7501000000171600145f275f436b09a8cc9a2eb2a2f528485c68a56323feffffff02d8231f1b0100000017a914aed962d6654f9a2b36608eb9d64d2b260db4f1118700c2eb0b0000000017a914b7f5faf40e3d40a5a459b1db3535f2b72fa921e88702483045022100a22edcc6e5bc511af4cc4ae0de0fcd75c7e04d8c1c3a8aa9d820ed4b967384ec02200642963597b9b1bc22c75e9f3e117284a962188bf5e8a74c895089046a20ad770121035509a48eb623e10aace8bfd0212fdb8a8e5af3c94b0b133b95e114cab89e4f7965000000
\ No newline at end of file
diff --git a/bitcoin/tests/data/previous_tx_1_hex b/bitcoin/tests/data/previous_tx_1_hex
new file mode 100644
index 00000000..9297523e
--- /dev/null
+++ b/bitcoin/tests/data/previous_tx_1_hex
@@ -0,0 +1 @@
+0200000001aad73931018bd25f84ae400b68848be09db706eac2ac18298babee71ab656f8b0000000048473044022058f6fc7c6a33e1b31548d481c826c015bd30135aad42cd67790dab66d2ad243b02204a1ced2604c6735b6393e5b41691dd78b00f0c5942fb9f751856faa938157dba01feffffff0280f0fa020000000017a9140fb9463421696b82c833af241c78c17ddbde493487d0f20a270100000017a91429ca74f8a08f81999428185c97b5d852e4063f618765000000
\ No newline at end of file
diff --git a/bitcoin/test_data/psbt1.hex b/bitcoin/tests/data/psbt1.hex
similarity index 100%
rename from bitcoin/test_data/psbt1.hex
rename to bitcoin/tests/data/psbt1.hex
diff --git a/bitcoin/test_data/psbt_combined.hex b/bitcoin/tests/data/psbt2.hex
similarity index 100%
rename from bitcoin/test_data/psbt_combined.hex
rename to bitcoin/tests/data/psbt2.hex
diff --git a/bitcoin/tests/data/psbt_combined.hex b/bitcoin/tests/data/psbt_combined.hex
new file mode 100644
index 00000000..47f38701
--- /dev/null
+++ b/bitcoin/tests/data/psbt_combined.hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/bitcoin/tests/data/sign_1_psbt_hex b/bitcoin/tests/data/sign_1_psbt_hex
new file mode 100644
index 00000000..3bcb9179
--- /dev/null
+++ b/bitcoin/tests/data/sign_1_psbt_hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/bitcoin/tests/data/sign_2_psbt_hex b/bitcoin/tests/data/sign_2_psbt_hex
new file mode 100644
index 00000000..70231338
--- /dev/null
+++ b/bitcoin/tests/data/sign_2_psbt_hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/bitcoin/test_data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw b/bitcoin/tests/data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw
similarity index 100%
rename from bitcoin/test_data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw
rename to bitcoin/tests/data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw
diff --git a/bitcoin/tests/data/update_1_psbt_hex b/bitcoin/tests/data/update_1_psbt_hex
new file mode 100644
index 00000000..705d70d0
--- /dev/null
+++ b/bitcoin/tests/data/update_1_psbt_hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/bitcoin/tests/data/update_2_psbt_hex b/bitcoin/tests/data/update_2_psbt_hex
new file mode 100644
index 00000000..31fbd54f
--- /dev/null
+++ b/bitcoin/tests/data/update_2_psbt_hex
@@ -0,0 +1 @@
+70736274ff01009a020000000258e87a21b56daf0c23be8e7070456c336f7cbaa5c8757924f545887bb2abdd750000000000ffffffff838d0427d0ec650a68aa46bb0b098aea4422c071b2ca78352a077959d07cea1d0100000000ffffffff0270aaf00800000000160014d85c2b71d0060b09c9886aeb815e50991dda124d00e1f5050000000016001400aea9a2e5f0f876a588df5546e8742d1d87008f00000000000100bb0200000001aad73931018bd25f84ae400b68848be09db706eac2ac18298babee71ab656f8b0000000048473044022058f6fc7c6a33e1b31548d481c826c015bd30135aad42cd67790dab66d2ad243b02204a1ced2604c6735b6393e5b41691dd78b00f0c5942fb9f751856faa938157dba01feffffff0280f0fa020000000017a9140fb9463421696b82c833af241c78c17ddbde493487d0f20a270100000017a91429ca74f8a08f81999428185c97b5d852e4063f618765000000010304010000000104475221029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f2102dab61ff49a14db6a7d02b0cd1fbb78fc4b18312b5b4e54dae4dba2fbfef536d752ae2206029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f10d90c6a4f000000800000008000000080220602dab61ff49a14db6a7d02b0cd1fbb78fc4b18312b5b4e54dae4dba2fbfef536d710d90c6a4f0000008000000080010000800001012000c2eb0b0000000017a914b7f5faf40e3d40a5a459b1db3535f2b72fa921e8870103040100000001042200208c2353173743b595dfb4a07b72ba8e42e3797da74e87fe7d9d7497e3b2028903010547522103089dc10c7ac6db54f91329af617333db388cead0c231f723379d1b99030b02dc21023add904f3d6dcf59ddb906b0dee23529b7ffb9ed50e5e86151926860221f0e7352ae2206023add904f3d6dcf59ddb906b0dee23529b7ffb9ed50e5e86151926860221f0e7310d90c6a4f000000800000008003000080220603089dc10c7ac6db54f91329af617333db388cead0c231f723379d1b99030b02dc10d90c6a4f00000080000000800200008000220203a9a4c37f5996d3aa25dbac6b570af0650394492942460b354753ed9eeca5877110d90c6a4f000000800000008004000080002202027f6399757d2eff55a136ad02c684b1838b6556e5f1b6b34282a94b6b5005109610d90c6a4f00000080000000800500008000
\ No newline at end of file
diff --git a/bitcoin/tests/psbt.rs b/bitcoin/tests/psbt.rs
new file mode 100644
index 00000000..c00598b4
--- /dev/null
+++ b/bitcoin/tests/psbt.rs
@@ -0,0 +1,467 @@
+//! Tests PSBT integration vectors from BIP 174
+//! defined at <https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki#test-vectors>
+
+use std::collections::BTreeMap;
+use std::str::FromStr;
+
+use bitcoin::bip32::{ExtendedPrivKey, ExtendedPubKey, Fingerprint, IntoDerivationPath, KeySource};
+use bitcoin::blockdata::opcodes::OP_0;
+use bitcoin::blockdata::script;
+use bitcoin::consensus::encode::{deserialize, serialize_hex};
+use bitcoin::hashes::hex::FromHex;
+use bitcoin::psbt::{Psbt, PsbtSighashType};
+use bitcoin::secp256k1::{self, Secp256k1};
+use bitcoin::{
+    absolute, Amount, Denomination, Network, OutPoint, PrivateKey, PublicKey, Script, Sequence,
+    Transaction, TxIn, TxOut, Txid, Witness,
+};
+
+const NETWORK: Network = Network::Testnet;
+
+macro_rules! hex_script {
+    ($s:expr) => {
+        <Script as FromStr>::from_str($s).unwrap()
+    };
+}
+
+macro_rules! hex_psbt {
+    ($s:expr) => {
+        deserialize::<Psbt>(&<Vec<u8> as FromHex>::from_hex($s).unwrap())
+    };
+}
+
+#[test]
+fn bip174_psbt_workflow() {
+    let secp = Secp256k1::new();
+
+    //
+    // Step 0: Create the extended private key from the test vector data.
+    //
+
+    let ext_priv = build_extended_private_key();
+    let ext_pub = ExtendedPubKey::from_priv(&secp, &ext_priv);
+    let parent_fingerprint = ext_pub.fingerprint();
+
+    //
+    // Step 1: The creator.
+    //
+
+    let tx = create_transaction();
+    let psbt = create_psbt(tx);
+
+    //
+    // Step 2: The first updater.
+    //
+
+    let psbt = update_psbt(psbt, parent_fingerprint);
+
+    //
+    // Step 3: The second updater.
+    //
+
+    let psbt = update_psbt_with_sighash_all(psbt);
+
+    //
+    // Step 4: The first signer.
+    //
+
+    // Strings from BIP 174 test vector.
+    let test_vector = vec![
+        ("cP53pDbR5WtAD8dYAW9hhTjuvvTVaEiQBdrz9XPrgLBeRFiyCbQr", "m/0h/0h/0h"), // from_priv, into_derivation_path?
+        ("cR6SXDoyfQrcp4piaiHE97Rsgta9mNhGTen9XeonVgwsh4iSgw6d", "m/0h/0h/2h"),
+    ];
+
+    // We pass the keys to the signer after doing verification to make explicit
+    // that signer is only using these two keys.
+    let keys = parse_and_verify_keys(&ext_priv, &test_vector);
+    let psbt_1 = signer_one_sign(psbt.clone(), keys);
+
+    //
+    // Step 5: The second signer.
+    //
+
+    // Strings from BIP 174 test vector.
+    let test_vector = vec![
+        ("cT7J9YpCwY3AVRFSjN6ukeEeWY6mhpbJPxRaDaP5QTdygQRxP9Au", "m/0h/0h/1h"),
+        ("cNBc3SWUip9PPm1GjRoLEJT6T41iNzCYtD7qro84FMnM5zEqeJsE", "m/0h/0h/3h"),
+    ];
+
+    let keys = parse_and_verify_keys(&ext_priv, &test_vector);
+    let psbt_2 = signer_two_sign(psbt, keys);
+
+    //
+    // Step 6: Combiner the two signed PSBTs.
+    //
+
+    let combined = combine(psbt_1, psbt_2);
+
+    //
+    // Step 7: Finalize the PSBT.
+    //
+
+    let finalized = finalize(combined);
+
+    //
+    // Step 8: Extract the transaction.
+    //
+
+    let _tx = extract_transaction(finalized);
+
+    //
+    // Step 9: Test lexicographical PSBT combiner.
+    //
+    // Combine would be done earlier, at Step 6, in typical workflow.
+    // We define it here to reflect the order of test vectors in BIP 174.
+    //
+
+    combine_lexicographically();
+}
+
+/// Attempts to build an extended private key from seed and also directly from a string.
+fn build_extended_private_key() -> ExtendedPrivKey {
+    // Strings from BIP 174 test vector.
+    let extended_private_key = "tprv8ZgxMBicQKsPd9TeAdPADNnSyH9SSUUbTVeFszDE23Ki6TBB5nCefAdHkK8Fm3qMQR6sHwA56zqRmKmxnHk37JkiFzvncDqoKmPWubu7hDF";
+    let seed = "cUkG8i1RFfWGWy5ziR11zJ5V4U4W3viSFCfyJmZnvQaUsd1xuF3T";
+
+    let xpriv = ExtendedPrivKey::from_str(extended_private_key).unwrap();
+
+    let sk = PrivateKey::from_wif(seed).unwrap();
+    let seeded = ExtendedPrivKey::new_master(NETWORK, &sk.inner.secret_bytes()).unwrap();
+    assert_eq!(xpriv, seeded);
+
+    xpriv
+}
+
+/// Creates the initial transaction, called by the PSBT Creator.
+fn create_transaction() -> Transaction {
+    // Strings from BIP 174 test vector.
+    let output_0 = TvOutput {
+        amount: "1.49990000",
+        script_pubkey: "0014d85c2b71d0060b09c9886aeb815e50991dda124d",
+    };
+    let output_1 = TvOutput {
+        amount: "1.00000000",
+        script_pubkey: "001400aea9a2e5f0f876a588df5546e8742d1d87008f",
+    };
+    let input_0 = TvInput {
+        txid: "75ddabb27b8845f5247975c8a5ba7c6f336c4570708ebe230caf6db5217ae858",
+        index: 0,
+    };
+    let input_1 = TvInput {
+        txid: "1dea7cd05979072a3578cab271c02244ea8a090bbb46aa680a65ecd027048d83",
+        index: 1,
+    };
+    struct TvOutput {
+        amount: &'static str,
+        script_pubkey: &'static str,
+    }
+    struct TvInput {
+        txid: &'static str,
+        index: u32,
+    }
+
+    Transaction {
+        version: 2,
+        lock_time: absolute::PackedLockTime::ZERO,
+        input: vec![
+            TxIn {
+                previous_output: OutPoint {
+                    txid: Txid::from_hex(input_0.txid).expect("failed to parse txid"),
+                    vout: input_0.index,
+                },
+                script_sig: Script::new(),
+                sequence: Sequence::MAX, // Disable nSequence.
+                witness: Witness::default(),
+            },
+            TxIn {
+                previous_output: OutPoint {
+                    txid: Txid::from_hex(input_1.txid).expect("failed to parse txid"),
+                    vout: input_1.index,
+                },
+                script_sig: Script::new(),
+                sequence: Sequence::MAX,
+                witness: Witness::default(),
+            },
+        ],
+        output: vec![
+            TxOut {
+                value: Amount::from_str_in(output_0.amount, Denomination::Bitcoin)
+                    .expect("failed to parse amount")
+                    .to_sat(),
+                script_pubkey: Script::from_str(output_0.script_pubkey)
+                    .expect("failed to parse script"),
+            },
+            TxOut {
+                value: Amount::from_str_in(output_1.amount, Denomination::Bitcoin)
+                    .expect("failed to parse amount")
+                    .to_sat(),
+                script_pubkey: Script::from_str(output_1.script_pubkey)
+                    .expect("failed to parse script"),
+            },
+        ],
+    }
+}
+
+/// Creates the initial PSBT, called by the Creator. Verifies against BIP 174 test vector.
+fn create_psbt(tx: Transaction) -> Psbt {
+    // String from BIP 174 test vector.
+    let expected_psbt_hex = include_str!("data/create_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let psbt = Psbt::from_unsigned_tx(tx).unwrap();
+
+    assert_eq!(psbt, expected_psbt);
+    psbt
+}
+
+/// Updates `psbt` according to the BIP, returns the newly updated PSBT. Verifies against BIP 174 test vector.
+fn update_psbt(mut psbt: Psbt, fingerprint: Fingerprint) -> Psbt {
+    // Strings from BIP 174 test vector.
+    let previous_tx_0 = include_str!("data/previous_tx_0_hex");
+    let previous_tx_1 = include_str!("data/previous_tx_1_hex");
+
+    let redeem_script_0 = "5221029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f2102dab61ff49a14db6a7d02b0cd1fbb78fc4b18312b5b4e54dae4dba2fbfef536d752ae";
+    let redeem_script_1 = "00208c2353173743b595dfb4a07b72ba8e42e3797da74e87fe7d9d7497e3b2028903";
+    let witness_script = "522103089dc10c7ac6db54f91329af617333db388cead0c231f723379d1b99030b02dc21023add904f3d6dcf59ddb906b0dee23529b7ffb9ed50e5e86151926860221f0e7352ae";
+
+    // Public key and its derivation path (these are the child pubkeys for our `ExtendedPrivKey`,
+    // can be verified by deriving the key using this derivation path).
+    let pk_path = vec![
+        ("029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f", "m/0h/0h/0h"),
+        ("02dab61ff49a14db6a7d02b0cd1fbb78fc4b18312b5b4e54dae4dba2fbfef536d7", "m/0h/0h/1h"),
+        ("03089dc10c7ac6db54f91329af617333db388cead0c231f723379d1b99030b02dc", "m/0h/0h/2h"),
+        ("023add904f3d6dcf59ddb906b0dee23529b7ffb9ed50e5e86151926860221f0e73", "m/0h/0h/3h"),
+        ("03a9a4c37f5996d3aa25dbac6b570af0650394492942460b354753ed9eeca58771", "m/0h/0h/4h"),
+        ("027f6399757d2eff55a136ad02c684b1838b6556e5f1b6b34282a94b6b50051096", "m/0h/0h/5h"),
+    ];
+
+    let expected_psbt_hex = include_str!("data/update_1_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let mut input_0 = psbt.inputs[0].clone();
+
+    let v = Vec::from_hex(previous_tx_1).unwrap();
+    let tx: Transaction = deserialize(&v).unwrap();
+    input_0.non_witness_utxo = Some(tx);
+    input_0.redeem_script = Some(hex_script!(redeem_script_0));
+    input_0.bip32_derivation = bip32_derivation(fingerprint, &pk_path, vec![0, 1]);
+
+    let mut input_1 = psbt.inputs[1].clone();
+
+    let v = Vec::from_hex(previous_tx_0).unwrap();
+    let tx: Transaction = deserialize(&v).unwrap();
+    input_1.witness_utxo = Some(tx.output[1].clone());
+
+    input_1.redeem_script = Some(hex_script!(redeem_script_1));
+    input_1.witness_script = Some(hex_script!(witness_script));
+    input_1.bip32_derivation = bip32_derivation(fingerprint, &pk_path, vec![2, 3]);
+
+    psbt.inputs = vec![input_0, input_1];
+
+    let mut output_0 = psbt.outputs[0].clone();
+    output_0.bip32_derivation = bip32_derivation(fingerprint, &pk_path, vec![4]);
+
+    let mut output_1 = psbt.outputs[1].clone();
+    output_1.bip32_derivation = bip32_derivation(fingerprint, &pk_path, vec![5]);
+
+    psbt.outputs = vec![output_0, output_1];
+
+    assert_eq!(psbt, expected_psbt);
+    psbt
+}
+
+/// `pk_path` holds tuples of `(public_key, derivation_path)`. `indecies` is used to access the
+/// `pk_path` vector. `fingerprint` is from the parent extended public key.
+fn bip32_derivation(
+    fingerprint: Fingerprint,
+    pk_path: &[(&str, &str)],
+    indecies: Vec<usize>,
+) -> BTreeMap<secp256k1::PublicKey, KeySource> {
+    let mut tree = BTreeMap::new();
+    for i in indecies {
+        let pk = pk_path[i].0;
+        let path = pk_path[i].1;
+
+        let pk = PublicKey::from_str(pk).unwrap();
+        let path = path.into_derivation_path().unwrap();
+
+        tree.insert(pk.inner, (fingerprint, path));
+    }
+    tree
+}
+
+/// Does the second update according to the BIP, returns the newly updated PSBT. Verifies against BIP 174 test vector.
+fn update_psbt_with_sighash_all(mut psbt: Psbt) -> Psbt {
+    let expected_psbt_hex = include_str!("data/update_2_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let ty = PsbtSighashType::from_str("SIGHASH_ALL").unwrap();
+
+    let mut input_0 = psbt.inputs[0].clone();
+    input_0.sighash_type = Some(ty);
+    let mut input_1 = psbt.inputs[1].clone();
+    input_1.sighash_type = Some(ty);
+
+    psbt.inputs = vec![input_0, input_1];
+
+    assert_eq!(psbt, expected_psbt);
+    psbt
+}
+
+/// Verifies the keys in the test vector are valid for the extended private key and derivation path.
+fn parse_and_verify_keys(
+    ext_priv: &ExtendedPrivKey,
+    sk_path: &[(&str, &str)],
+) -> BTreeMap<PublicKey, PrivateKey> {
+    let secp = &Secp256k1::new();
+
+    let mut key_map = BTreeMap::new();
+    for (secret_key, derivation_path) in sk_path.iter() {
+        let wif_priv = PrivateKey::from_wif(secret_key).expect("failed to parse key");
+
+        let path =
+            derivation_path.into_derivation_path().expect("failed to convert derivation path");
+        let derived_priv =
+            ext_priv.derive_priv(secp, &path).expect("failed to derive ext priv key").to_priv();
+        assert_eq!(wif_priv, derived_priv);
+        let derived_pub = derived_priv.public_key(secp);
+        key_map.insert(derived_pub, derived_priv);
+    }
+    key_map
+}
+
+/// Does the first signing according to the BIP, returns the signed PSBT. Verifies against BIP 174 test vector.
+fn signer_one_sign(psbt: Psbt, key_map: BTreeMap<bitcoin::PublicKey, PrivateKey>) -> Psbt {
+    let expected_psbt_hex = include_str!("data/sign_1_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let psbt = sign(psbt, key_map);
+
+    assert_eq!(psbt, expected_psbt);
+    psbt
+}
+
+/// Does the second signing according to the BIP, returns the signed PSBT. Verifies against BIP 174 test vector.
+fn signer_two_sign(psbt: Psbt, key_map: BTreeMap<bitcoin::PublicKey, PrivateKey>) -> Psbt {
+    let expected_psbt_hex = include_str!("data/sign_2_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let psbt = sign(psbt, key_map);
+
+    assert_eq!(psbt, expected_psbt);
+    psbt
+}
+
+/// Does the combine according to the BIP, returns the combined PSBT. Verifies against BIP 174 test vector.
+fn combine(mut this: Psbt, that: Psbt) -> Psbt {
+    let expected_psbt_hex = include_str!("data/combine_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    this.combine(that).expect("failed to combine PSBTs");
+
+    assert_eq!(this, expected_psbt);
+    this
+}
+
+/// Does the finalize step according to the BIP, returns the combined PSBT. Verifies against BIP 174
+/// test vector.
+fn finalize(psbt: Psbt) -> Psbt {
+    let expected_psbt_hex = include_str!("data/finalize_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let psbt = finalize_psbt(psbt);
+
+    assert_eq!(psbt, expected_psbt);
+    psbt
+}
+
+/// Does the transaction extractor step according to the BIP, returns the combined PSBT. Verifies
+/// against BIP 174 test vector.
+fn extract_transaction(psbt: Psbt) -> Transaction {
+    let expected_tx_hex = include_str!("data/extract_tx_hex");
+
+    let tx = psbt.extract_tx();
+
+    let got = serialize_hex(&tx);
+    assert_eq!(got, expected_tx_hex);
+
+    tx
+}
+
+/// Combines two PSBTs lexicographically according to the BIP. Verifies against BIP 174 test vector.
+fn combine_lexicographically() {
+    let psbt_1_hex = include_str!("data/lex_psbt_1_hex");
+    let psbt_2_hex = include_str!("data/lex_psbt_2_hex");
+
+    let expected_psbt_hex = include_str!("data/lex_combine_psbt_hex");
+    let expected_psbt = hex_psbt!(expected_psbt_hex).unwrap();
+
+    let v = Vec::from_hex(psbt_1_hex).unwrap();
+    let mut psbt_1: Psbt = deserialize(&v).expect("failed to deserialize psbt 1");
+
+    let v = Vec::from_hex(psbt_2_hex).unwrap();
+    let psbt_2: Psbt = deserialize(&v).expect("failed to deserialize psbt 2");
+
+    psbt_1.combine(psbt_2).expect("failed to combine PSBTs");
+
+    assert_eq!(psbt_1, expected_psbt);
+}
+
+/// Signs `psbt` with `keys` if required.
+fn sign(mut psbt: Psbt, keys: BTreeMap<bitcoin::PublicKey, PrivateKey>) -> Psbt {
+    let secp = Secp256k1::new();
+    psbt.sign(&keys, &secp).unwrap();
+    psbt
+}
+
+/// Finalizes a PSBT accord to the Input Finalizer role described in BIP 174.
+/// This is just a test. For a production-ready PSBT Finalizer, use [rust-miniscript](https://docs.rs/miniscript/latest/miniscript/psbt/trait.PsbtExt.html#tymethod.finalize)
+fn finalize_psbt(mut psbt: Psbt) -> Psbt {
+    use bitcoin::util::psbt::serialize::Serialize;
+
+    // Input 0: legacy UTXO
+
+    let sigs: Vec<_> = psbt.inputs[0].partial_sigs.values().collect();
+    let script_sig = script::Builder::new()
+        .push_opcode(OP_0) // OP_CHECKMULTISIG bug pops +1 value when evaluating so push OP_0.
+        .push_slice(&sigs[0].serialize())
+        .push_slice(&sigs[1].serialize())
+        .push_slice(&psbt.inputs[0].redeem_script.clone().unwrap().serialize())
+        .into_script();
+
+    psbt.inputs[0].final_script_sig = Some(script_sig);
+
+    psbt.inputs[0].partial_sigs = BTreeMap::new();
+    psbt.inputs[0].sighash_type = None;
+    psbt.inputs[0].redeem_script = None;
+    psbt.inputs[0].bip32_derivation = BTreeMap::new();
+
+    // Input 1: SegWit UTXO
+
+    let script_sig = script::Builder::new()
+        .push_slice(&psbt.inputs[1].redeem_script.clone().unwrap().serialize())
+        .into_script();
+
+    psbt.inputs[1].final_script_sig = Some(script_sig);
+
+    let script_witness = {
+        let sigs: Vec<_> = psbt.inputs[1].partial_sigs.values().collect();
+        let mut script_witness = Witness::new();
+        script_witness.push([]); // Push 0x00 to the stack.
+        script_witness.push(&sigs[1].serialize());
+        script_witness.push(&sigs[0].serialize());
+        script_witness.push(&psbt.inputs[1].witness_script.clone().unwrap().serialize());
+
+        script_witness
+    };
+
+    psbt.inputs[1].final_script_witness = Some(script_witness);
+
+    psbt.inputs[1].partial_sigs = BTreeMap::new();
+    psbt.inputs[1].sighash_type = None;
+    psbt.inputs[1].redeem_script = None;
+    psbt.inputs[1].witness_script = None;
+    psbt.inputs[1].bip32_derivation = BTreeMap::new();
+
+    psbt
+}