diff --git a/Pipfile b/Pipfile
index e0edea9..35bcb73 100644
--- a/Pipfile
+++ b/Pipfile
@@ -28,6 +28,7 @@ stripe = "*"
 matplotlib = "*"
 requests = "*"
 python-dotenv = "*"
+bitpay = "*"
 
 [dev-packages]
 
diff --git a/Pipfile.lock b/Pipfile.lock
index 25156ce..3db94ca 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "4f61804f9405ff8f66e41739aeac24a2577f7b64f7d08b93459b568528c4f494"
+            "sha256": "51691e6158d1c309027d595bc4d26079c368f983223f7a567688dd5a98c865fa"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -24,6 +24,13 @@
             "index": "pypi",
             "version": "==2.4.1"
         },
+        "bitpay": {
+            "hashes": [
+                "sha256:3da21326e5a7e98fae93f7fe4c1b046993cf1d8fba60a6c5049cc15f30026b75"
+            ],
+            "index": "pypi",
+            "version": "==2.6.1910"
+        },
         "blinker": {
             "hashes": [
                 "sha256:471aee25f3992bd325afa3772f1063dbdbbca947a041b8b89466dc00d606f8b6"
@@ -60,6 +67,13 @@
             ],
             "version": "==0.10.0"
         },
+        "ecdsa": {
+            "hashes": [
+                "sha256:867ec9cf6df0b03addc8ef66b56359643cb5d0c1dc329df76ba7ecfe256c8061",
+                "sha256:8f12ac317f8a1318efa75757ef0a651abe12e51fc1af8838fb91079445227277"
+            ],
+            "version": "==0.15"
+        },
         "flask": {
             "hashes": [
                 "sha256:4efa1ae2d7c9865af48986de8aeb8504bf32c7f3d6fdc9353d34b21f4b127060",
diff --git a/README.md b/README.md
index bedff50..4f94cb4 100644
--- a/README.md
+++ b/README.md
@@ -45,9 +45,8 @@ Run the app
 FLASK_APP=capsulflask flask run
 ```
 
-Run the app in gunicorn locally
+Run the app in gunicorn
 ```
-pip install gunicorn
 .venv/bin/gunicorn --bind 127.0.0.1:5000 capsulflask:app
 ```
 
@@ -61,3 +60,61 @@ For example, the script named `02_up_xyz.sql` should contain code that migrates
 **IMPORTANT: if you need to make changes to the schema, make a NEW schema version. DO NOT EDIT the existing schema versions.**
 
 In general, for safety, schema version upgrades should not delete data. Schema version downgrades will simply throw an error and exit for now. 
+
+
+## how to setup btcpay server
+
+Generate a private key and the accompanying bitpay SIN for the bitpay API client. 
+
+  I used this code as an example: https://github.com/bitpay/bitpay-python/blob/master/bitpay/key_utils.py#L6
+
+```
+$ python ./readme/generate_btcpay_keys.py
+```
+
+It should output something looking like this:
+
+```
+-----BEGIN EC PRIVATE KEY-----
+EXAMPLEIArx/EXAMPLEKH23EXAMPLEsYXEXAMPLE5qdEXAMPLEcFHoAcEXAMPLEK
+oUQDQgAEnWs47PT8+ihhzyvXX6/yYMAWWODluRTR2Ix6ZY7Z+MV7v0W1maJzqeqq
+NQ+cpBvPDbyrDk9+Uf/sEaRCma094g==
+-----END EC PRIVATE KEY-----
+
+
+EXAMPLEwzAEXAMPLEEXAMPLEURD7EXAMPLE
+```
+
+In order to register the key with the btcpay server, you have to first generate a pairing token using the btcpay server interface.
+This requires your btcpay server account to have access to the capsul store. Ask Cass about this.
+
+Navigate to `Manage store: Access Tokens` at: `https://btcpay.cyberia.club/stores/<store-id>/Tokens`
+
+![](readme/btcpay_sin_pairing.jpg)
+
+
+Finally, send an http request to the btcpay server to complete the pairing:
+
+```
+curl -H "Content-Type: application/json" https://btcpay.cyberia.club/tokens -d "{'id': 'EXAMPLEwzAEXAMPLEEXAMPLEURD7EXAMPLE', 'pairingCode': 'XXXXXXX'}"
+```
+
+It should respond with a token: 
+
+```
+{"data":[{"policies":[],"pairingCode":"XXXXXXX","pairingExpiration":1589473817597,"dateCreated":1589472917597,"facade":"merchant","token":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","label":"capsulflask"}]}
+```
+
+And you should see the token in the btcpay server UI:
+
+![](readme/paired.jpg)
+
+Now simply set your BTCPAY_PRIVATE_KEY private key in `.env`
+
+```
+BTCPAY_PRIVATE_KEY='-----BEGIN EC PRIVATE KEY-----
+EXAMPLEIArx/EXAMPLEKH23EXAMPLEsYXEXAMPLE5qdEXAMPLEcFHoAcEXAMPLEK
+oUQDQgAEnWs47PT8+ihhzyvXX6/yYMAWWODluRTR2Ix6ZY7Z+MV7v0W1maJzqeqq
+NQ+cpBvPDbyrDk9+Uf/sEaRCma094g==
+-----END EC PRIVATE KEY-----'
+```
\ No newline at end of file
diff --git a/capsulflask/__init__.py b/capsulflask/__init__.py
index 0503997..8cd5c03 100644
--- a/capsulflask/__init__.py
+++ b/capsulflask/__init__.py
@@ -28,8 +28,10 @@ app.config.from_mapping(
 
   STRIPE_API_VERSION=os.environ.get("STRIPE_API_VERSION", default="2020-03-02"),
   STRIPE_SECRET_KEY=os.environ.get("STRIPE_SECRET_KEY", default=""),
-  STRIPE_PUBLISHABLE_KEY=os.environ.get("STRIPE_PUBLISHABLE_KEY", default="")
+  STRIPE_PUBLISHABLE_KEY=os.environ.get("STRIPE_PUBLISHABLE_KEY", default=""),
   #STRIPE_WEBHOOK_SECRET=os.environ.get("STRIPE_WEBHOOK_SECRET", default="")
+
+  BTCPAY_PRIVATE_KEY=os.environ.get("BTCPAY_PRIVATE_KEY", default="")
 )
 
 stripe.api_key = app.config['STRIPE_SECRET_KEY']
diff --git a/readme/btcpay_sin_pairing.jpg b/readme/btcpay_sin_pairing.jpg
new file mode 100644
index 0000000..26ef8e3
Binary files /dev/null and b/readme/btcpay_sin_pairing.jpg differ
diff --git a/readme/generate_btcpay_keys.py b/readme/generate_btcpay_keys.py
new file mode 100644
index 0000000..8c18d1b
--- /dev/null
+++ b/readme/generate_btcpay_keys.py
@@ -0,0 +1,47 @@
+from ecdsa import SigningKey, SECP256k1, VerifyingKey
+import binascii
+import hashlib
+
+def sha_digest(hexastring):
+  return hashlib.sha256(binascii.unhexlify(hexastring)).hexdigest()
+
+def base58encode(hexastring):
+  chars = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
+  int_val = int(hexastring, 16)
+  encoded =  encode58("", int_val, chars)
+  return encoded
+
+def encode58(string, int_val, chars):
+  if int_val == 0:
+    return string
+  else:
+    new_val, rem = divmod(int_val, 58) 
+    new_string = (chars[rem]) + string
+    return encode58(new_string, new_val, chars)
+
+sk = SigningKey.generate(curve=SECP256k1)
+pem = sk.to_pem()
+pem = pem.decode("utf-8")
+
+print("")
+print(pem)
+print("")
+
+public_key = SigningKey.from_pem(pem).get_verifying_key().to_string()
+public_key_hex = binascii.hexlify(public_key)
+checksum_int = int(public_key_hex, 16)
+if(checksum_int % 2 == 0):
+  prefix = "02"
+else:
+  prefix = "03"
+public_key_compressed = prefix + public_key_hex[0:64].decode("utf-8")
+hash_of_public_key = sha_digest(public_key_compressed)
+ripe_hash_of_public_key = hashlib.new("ripemd160")
+ripe_hash_of_public_key.update(binascii.unhexlify(hash_of_public_key))
+version_hash = "0F02"+ripe_hash_of_public_key.hexdigest()
+version_checksum = sha_digest(sha_digest(version_hash))[0:8]
+btcpay_sin = base58encode(version_hash+version_checksum)
+
+print("")
+print(btcpay_sin)
+print("")
diff --git a/readme/paired.jpg b/readme/paired.jpg
new file mode 100644
index 0000000..9d16bee
Binary files /dev/null and b/readme/paired.jpg differ