Develop Reference

ValueError: Method eth_maxPriorityFeePerGas not supported, web3.py with ganache

I'm running the following code with web3.py:
transaction = SimpleStorage.constructor().buildTransaction(
{"chainId": chain_id, "from": my_address, "nonce": nonce}
)
And I am running into the following error:
Traceback (most recent call last):
File "/Users/patrick/code/web3_py_simple_storage/deploy.py", line 64, in <module>
transaction = SimpleStorage.constructor().buildTransaction(
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/eth_utils/decorators.py", line 18, in _wrapper
return self.method(obj, *args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/contract.py", line 684, in buildTransaction
return fill_transaction_defaults(self.web3, built_transaction)
File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/_utils/transactions.py", line 121, in fill_transaction_defaults
default_val = default_getter(web3, transaction)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/_utils/transactions.py", line 71, in <lambda>
web3.eth.max_priority_fee + (2 * web3.eth.get_block('latest')['baseFeePerGas'])
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/eth.py", line 549, in max_priority_fee
return self._max_priority_fee()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/module.py", line 57, in caller
result = w3.manager.request_blocking(method_str,
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/manager.py", line 198, in request_blocking
return self.formatted_response(response,
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/manager.py", line 171, in formatted_response
raise ValueError(response["error"])
ValueError: {'message': 'Method eth_maxPriorityFeePerGas not supported.', 'code': -32000, 'data': {'stack': 'Error: Method eth_maxPriorityFeePerGas not supported.\n at GethApiDouble.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/geth_api_double.js:70:16)\n at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n at GethDefaults.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/gethdefaults.js:15:12)\n at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n at SubscriptionSubprovider.FilterSubprovider.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/subproviders/filters.js:89:7)\n at SubscriptionSubprovider.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/subproviders/subscriptions.js:137:49)\n at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n at DelayedBlockFilter.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/delayedblockfilter.js:31:3)\n at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n at RequestFunnel.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/requestfunnel.js:32:12)\n at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n at Web3ProviderEngine._handleAsync (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:123:3)\n at Timeout._onTimeout (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:107:12)\n at listOnTimeout (internal/timers.js:531:17)\n at processTimers (internal/timers.js:475:7)', 'name': 'Error'}}
How do I fix this?

This is an issue from a new edition of web3.py.
You need to add gasPrice to your transaction, like so:
transaction = SimpleStorage.constructor().buildTransaction(
{"chainId": chain_id, "gasPrice": w3.eth.gas_price, "from": my_address, "nonce": nonce}
)
This is due to EIP1559 changing, and web3.py updating for the change.

Python Web3 Ganache - Traceback error on BuildTransaction

I am going through the freeCodeCamp course on YouTube and have caught an error regarding when I run. As I am trying to build a transaction into Ganache. I see in Ganache logs that there is activity as well. First time posting, so let me know what other information should I provide!
The course: Solidity, Blockchain, and Smart Contract Course – Beginner to Expert Python Tutorial
transaction = SimpleStorage.constructor().buildTransaction(
{"chainId": chain_id, "from": my_address, "nonce": nonce}
)
The error that the terminal returns:
Traceback (most recent call last):
File "C:\Users\Justin\demos\web3_py_simple_storage\deploy.py",
line 60, in <module>
transaction = SimpleStorage.constructor().buildTransaction(
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\eth_utils\decorators.py", line 18, in _wrapper
return self.method(obj, *args, **kwargs)
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\contract.py", line 684, in buildTransaction
return fill_transaction_defaults(self.web3, built_transaction)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\_utils\transactions.py", line 121, in fill_transaction_defaults
default_val = default_getter(web3, transaction)
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\_utils\transactions.py", line 67, in <lambda>
'gas': lambda web3, tx: web3.eth.estimate_gas(tx),
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\eth.py", line 759, in estimate_gas
return self._estimate_gas(transaction, block_identifier)
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\module.py", line 57, in caller
result = w3.manager.request_blocking(method_str,
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\manager.py", line 197, in request_blocking
response = self._make_request(method, params)
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\manager.py", line 150, in _make_request
return request_func(method, params)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\formatting.py", line 76, in apply_formatters
response = make_request(method, params)
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\gas_price_strategy.py", line 90,
in middleware
return make_request(method, params)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\formatting.py", line 74, in apply_formatters
response = make_request(method, formatted_params)
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\attrdict.py", line 33, in middleware
response = make_request(method, params)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\formatting.py", line 74, in apply_formatters
response = make_request(method, formatted_params)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\formatting.py", line 73, in apply_formatters
formatted_params = formatter(params)
File "cytoolz\functoolz.pyx", line 503, in cytoolz.functoolz.Compose.__call__
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\eth_utils\decorators.py", line 91, in wrapper
return ReturnType(result) # type: ignore
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\eth_utils\applicators.py", line 22, in apply_formatter_at_index
yield formatter(item)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\eth_utils\functional.py", line 45, in inner
return callback(fn(*args, **kwargs))
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\eth_utils\applicators.py", line 84, in apply_formatters_to_dict
yield key, formatters[key](item)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\eth_utils\applicators.py", line 72, in apply_formatter_if
return formatter(value)
File "cytoolz\functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
File "C:\Users\Justin\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\web3\middleware\validation.py", line 57, in validate_chain_id
raise ValidationError(
web3.exceptions.ValidationError: The transaction declared chain ID 5777, but the connected node is on 1337
The Full Code that I used is below:
from solcx import compile_standard, install_solc
import json
from web3 import Web3
with open("./SimpleStorage.sol", "r") as file:
simple_storage_file = file.read()
# Compile Our Solidity
print("Installing...")
install_solc("0.6.0")
compiled_sol = compile_standard(
{
"language": "Solidity",
"sources": {"SimpleStorage.sol": {"content": simple_storage_file}},
"settings": {
"outputSelection": {
"*": {
"*": [
"abi",
"metadata",
"evm.bytecode",
"evm.bytecode.sourceMap",
]
}
}
},
},
solc_version="0.6.0",
)
with open("compiled_code.json", "w") as file:
json.dump(compiled_sol, file)
# get bytecode
bytecode = compiled_sol["contracts"]["SimpleStorage.sol"]["SimpleStorage"]["evm"][
"bytecode"
]["object"]
# get abi
abi = compiled_sol["contracts"]["SimpleStorage.sol"]["SimpleStorage"]["abi"]
# for connecting to ganache
w3 = Web3(Web3.HTTPProvider("http://127.0.0.1:7545"))
chain_id = 5777
my_address = "0xf2580f5ddfFb89e69A12a7CbCa8CA175Df4cBe08"
private_key = "0x937073896304af4297e6bbb3a3c623689d48388aa8595058752fafb522b31a13"
# Create the contract in python
SimpleStorage = w3.eth.contract(abi=abi, bytecode=bytecode)
print(SimpleStorage)
# Get the latest transaction
nonce = w3.eth.getTransactionCount(my_address)
print(nonce)
# 1. Build a transaction
# 2. Sign a transaction
# 3. Send a transaction
transaction = SimpleStorage.constructor().buildTransaction(
{"chainId": chain_id, "from": my_address, "nonce": nonce}
)
print(transaction)

As of 5.25.0 of web3.py, we now need to add gasPrice to our transactions with a local Ganache chain. Adding "gasPrice": w3.eth.gas_price should fix your issue in the transactions.
Full Example:
transaction = SimpleStorage.constructor().buildTransaction(
{
"chainId": chain_id,
"gasPrice": w3.eth.gas_price,
"from": my_address,
"nonce": nonce,
}
)

Use the following line in .buildTransaction:
transaction = SimpleStorage.constructor().buildTransaction(
{'from': address, 'nonce':nonce, 'chainId':chain_id,'gas': 1728712,
'gasPrice': w3.toWei('21', 'gwei')})
And change the chain_id = 1337.

The transaction declared chain ID 5777, but the connected node is on 1337.
You have to change your chain_id:
chain_id = 5777❌
But use the one below
chain_id = 1337✔

I was having this exact same problem. Including "gasPrice": w3.eth.gas_price, solved it originally, but it came back.
After some tweaking, I found that casting chain_id (because I was getting that from .env as well) as an int solved my problems.
So the full code looked like this:
transaction = SimpleStorage.constructor().buildTransaction(
{
"chainId": int(chain_id),
"gasPrice": w3.eth.gas_price,
"from": my_address,
"nonce": nonce,
}
)

Creating a subscription through Stripe-payments

I threw this together earlier today:
import stripe
stripe.api_key = "sk_test_key"
stripe.Token.create(
card={
"number": '4242424242424242',
"exp_month": 12,
"exp_year": 2018,
"cvc": '123'
},
)
stripe.Customer.create(
description="test test test",
source="tok_visa"
)
stripe.Customer.list(limit=1)
stripe.Subscription.create(
customer="id",
items=[
{
"plan": "1",
},
],
)
Running this returns with this
read-only#bash: Traceback (most recent call last):
File "main.py", line 28, in <module> "plan": "1",
File "/tmp/stripe/api_resources/subscription.py", line 33, in create return super(Subscription, cls).create(**params)
File "/tmp/stripe/api_resources/abstract/createable_api_resource.py", line 17, in create response, api_key = requestor.request('post', url, params, headers)
File "/tmp/stripe/api_requestor.py", line 152, in request resp = self.interpret_response(rbody, rcode, rheaders)
File "/tmp/stripe/api_requestor.py", line 359, in interpret_response self.handle_error_response(rbody, rcode, resp, rheaders)
File "/tmp/stripe/api_requestor.py", line 177, in handle_error_response raise err
stripe.error.InvalidRequestError: Request req_ZmLk0oWGjmrkut: No such customer: id
This seems to be an error or I'm just putting the wrong value in "customer"
Any ideas on on what to do?

Elastic Search - Failed to parse query

I am using python-elasticsearch client - elasticsearch.py and elastic search fails to parse query when I try to update a document using update_by_query method.
My update body is as follows:
{
'script': {
'inline': 'ctx._source.viewers += info',
'params': {
'info': {
'time': datetime.datetime(2017, 3, 7, 18, 8, 50),
'viewer': 'abc#xyz.com'
}
}
}
}
Elastic Search is called as follows::
update = es.update_by_query(index=index_el,
doc_type='1',
q='delivery_reference_id:' + str(cam_id) +'',
body=doc)
A sample value for cam_id is:
CAM_10_DATA_4_2017-03-07 18:02:07
Internally, the following query is formed::
http://127.0.0.1:9200/user_tracker/1/_update_by_query?q=delivery_reference_id%3ACAM_10_DATA_4_2017-03-07+18%3A02%3A07
The error received is as follows:
TransportError(400, 'search_phase_execution_exception', 'Failed to parse query [delivery_reference_id:CAM_10_DATA_4_2017-03-07 18:02:07]')
The full error log is as follows:
Traceback (most recent call last):
File "C:\Users\catch\AppData\Roaming\Python\Python34\site-packages\django\core\handlers\exception.py", line 42, in inner
response = get_response(request)
File "C:\Users\catch\AppData\Roaming\Python\Python34\site-packages\django\core\handlers\base.py", line 187, in _get_response
response = self.process_exception_by_middleware(e, request)
File "C:\Users\catch\AppData\Roaming\Python\Python34\site-packages\django\core\handlers\base.py", line 185, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\catch\AppData\Roaming\Python\Python34\site-packages\django\views\decorators\csrf.py", line 58, in wrapped_view
return view_func(*args, **kwargs)
File "C:\Users\catch\AppData\Roaming\Python\Python34\site-packages\django\views\generic\base.py", line 68, in view
return self.dispatch(request, *args, **kwargs)
File "C:\Python34\lib\site-packages\rest_framework\views.py", line 483, in dispatch
response = self.handle_exception(exc)
File "C:\Python34\lib\site-packages\rest_framework\views.py", line 443, in handle_exception
self.raise_uncaught_exception(exc)
File "C:\Python34\lib\site-packages\rest_framework\views.py", line 480, in dispatch
response = handler(request, *args, **kwargs)
File "C:\Users\catch\PycharmProjects\myproject\myproj\apis\views.py", line 516, in get
viewer=viewer_email)
File "C:\Users\catch\PycharmProjects\myproject\myproj\apis\views.py", line 541, in update_track_info
doc=doc)
File "C:\Users\catch\PycharmProjects\myproject\myproj\apis\views.py", line 553, in es_update
body=doc)
File "C:\Python34\lib\site-packages\elasticsearch\client\utils.py", line 73, in _wrapped
return func(*args, params=params, **kwargs)
File "C:\Python34\lib\site-packages\elasticsearch\client\__init__.py", line 680, in update_by_query
doc_type, '_update_by_query'), params=params, body=body)
File "C:\Python34\lib\site-packages\elasticsearch\transport.py", line 318, in perform_request
status, headers, data = connection.perform_request(method, url, params, body, ignore=ignore, timeout=timeout)
File "C:\Python34\lib\site-packages\elasticsearch\connection\http_urllib3.py", line 128, in perform_request
self._raise_error(response.status, raw_data)
File "C:\Python34\lib\site-packages\elasticsearch\connection\base.py", line 122, in _raise_error
raise HTTP_EXCEPTIONS.get(status_code, TransportError)(status_code, error_message, additional_info)
elasticsearch.exceptions.RequestError: TransportError(400, 'search_phase_execution_exception', 'Failed to parse query [delivery_reference_id:CAM_10_DATA_4_2017-03-07 18:02:07]')
Would be nice if someone figured it out. Let me know if more info is needed.
Appreciate it. Thanks in advance.

I think your query syntax is not up to date. I had good results with the following syntax:
{
"query": {
"bool": {
"must": [
{ "match": { "MYFIELD": "myoldvalue" } }
]
}
},
"script": {
"inline": "ctx._source.MYFIELD = \"mynewvalue\"",
"lang": "painless"
}
}
HTH :)

bulk update failing when document has attachments?

I am performing the following operation:
Prepare some documents: docs = [ doc1, doc2, ... ]. The documents have maybe attachments
I POST to _bulk_docs the list of documents
I get an Exception > Problems updating list of documents (length = 1): (500, ('badarg', '58'))
My bulk_docs is (in this case just one):
[ { '_attachments': { 'image.png': { 'content_type': 'image/png',
'data': 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAM8AAADkCAIAAACwiOf9AAAAA3NCSVQICAjb4U/gAAAgAElEQVR4nO...'}},
'_id': '08b8fc66-cd90-47a1-9053-4f6fefabdfe3',
'_rev': '15-ff3d0e8baa56e5ad2fac4937264fb3f6',
'docmeta': { 'created': '2013-10-01 14:48:24.311257',
'updated': [ '2013-10-01 14:48:24.394157',
'2013-12-11 08:19:47.271812',
'2013-12-11 08:25:05.662546',
'2013-12-11 10:38:56.116145']},
'org_id': 45345,
'outputs_id': None,
'properties': { 'auto-t2s': False,
'content_type': 'image/png',
'lang': 'es',
'name': 'dfasdfasdf',
'text': 'erwerwerwrwerwr'},
'subtype': 'voicemail-st',
'tags': ['RRR-ccc-dtjkqx'],
'type': 'recording'}]
This is the detailed exception:
Traceback (most recent call last):
File "portal_support_ut.py", line 470, in test_UpdateDoc
self.ps.UpdateDoc(self.org_id, what, doc_id, new_data)
File "/home/gonvaled/projects/new-wavilon-portal/python_modules/wav/ps/complex_ops.py", line 349, in UpdateDoc
success, doc = database.UpdateDoc(doc_id, new_data)
File "/home/gonvaled/projects/new-wavilon-portal/python_modules/wav/cdb/core/updater.py", line 38, in UpdateDoc
res = self.SaveDoc(doc_id, doc)
File "/home/gonvaled/projects/new-wavilon-portal/python_modules/wav/cdb/core/saver.py", line 88, in SaveDoc
else : self.bulk_append(doc, flush, update_revision)
File "/home/gonvaled/projects/new-wavilon-portal/python_modules/wav/cdb/core/bulker.py", line 257, in bulk_append
if force_send or flush or not self.timer.use_timer : self.BulkSend(show_progress=True)
File "/home/gonvaled/projects/new-wavilon-portal/python_modules/wav/cdb/core/bulker.py", line 144, in BulkSend
results = self.UpdateDocuments(self.bulk)
File "/home/gonvaled/projects/new-wavilon-portal/python_modules/wav/cdb/core/bulker.py", line 67, in UpdateDocuments
results = self.db.update(bulkdocs)
File "/home/gonvaled/.virtualenvs/python2.7.3-wavilon1/local/lib/python2.7/site-packages/couchdb/client.py", line 764, in update
_, _, data = self.resource.post_json('_bulk_docs', body=content)
File "/home/gonvaled/.virtualenvs/python2.7.3-wavilon1/local/lib/python2.7/site-packages/couchdb/http.py", line 527, in post_json
**params)
File "/home/gonvaled/.virtualenvs/python2.7.3-wavilon1/local/lib/python2.7/site-packages/couchdb/http.py", line 546, in _request_json
headers=headers, **params)
File "/home/gonvaled/.virtualenvs/python2.7.3-wavilon1/local/lib/python2.7/site-packages/couchdb/http.py", line 542, in _request
credentials=self.credentials)
File "/home/gonvaled/.virtualenvs/python2.7.3-wavilon1/local/lib/python2.7/site-packages/couchdb/http.py", line 398, in request
raise ServerError((status, error))
ServerError: (500, ('badarg', '58'))
What does that badarg mean? Is it possible to send attachments when doing _bulk_docs?

The solution is to remove the data:image/png;base64, prefix before sending the attachment to coudhdb.
For a python alternative, see here.

This was answered in our mailing list, repeating the answer here for completeness.
The data field was malformed in two ways;
'data': 'data:image/png;base64,iVBORw0KGgoAA....'
The 'data:image/png;base64,' prefix is wrong, and the base64 part was malformed (CouchDB obviously needs to decode it to store it).