> ## Documentation Index
> Fetch the complete documentation index at: https://docs.parmanasystems.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Python SDK Quickstart
> Get Parmana running end-to-end with the Python SDK: build a transaction, execute it, and read back a signed proof.
This walks through the same flow as the top-level [Quickstart](/quickstart),
with more explanation at each step and a focus on the SDK's own ergonomics. If
you just want the fastest path to a working local server, use
[Quickstart](/quickstart) instead. This page assumes you're already inside a
local clone of [the Parmana
repo](https://github.com/pavancharak/AgentLabsBuildathon) with a server you
can point at.
## Prerequisites
* **Python 3.8+** (`python --version`)
* **Node.js** (to run the Parmana server locally, `node --version`)
* A local clone of the Parmana repo, with `npm install` already run in it
From the repo root, override storage to run with no external dependency:
```bash theme={null}
NODE_ENV=test \
PARMANA_STORAGE=memory \
PARMANA_POLICY_DIR=/absolute/path/to/policies \
npm run dev
```
Confirm it's up:
```bash theme={null}
curl http://localhost:3000/health
# {"status":"UP"}
```
With `NODE_ENV=test`, a generic, credential-free test connector (`test-fixture`) registers
automatically, no external credentials needed for this walkthrough. See [Quickstart](/quickstart)
for what each flag does and how to generate a local Gateway keypair if you haven't already.
```bash theme={null}
pip install parmana
```
Real PyPI package. See [Python SDK](/sdks/python) for the current published version and what's
inside it (generated models, a typed error taxonomy, a real bearer-key `requests.Session()`).
```python theme={null}
from parmana import ParmanaClient
client = ParmanaClient(endpoint="http://localhost:3000", api_key="my-secret-api-key")
```
The committed `.env` in the repo ships one demo caller key for local development:
`callerId: "demo"`, raw key `my-secret-api-key`. `api_key` is optional only against a server
started with `PARMANA_AUTH_DISABLED=true`. Every real deployment requires one, and an
omitted/wrong key raises `AuthenticationError`, not a silent failure.
`create_business_transaction()` derives every id pair the server checks for internal consistency
(see [why that matters](/sdks/python#create_business_transaction-no-more-hand-synced-ids)), so
there's nothing to hand-assemble and get wrong:
```python theme={null}
from parmana import PolicyReference, create_business_transaction
transaction = create_business_transaction(
principal_id="python-sdk-quickstart",
purpose="Quickstart demo",
action="test:fixture-execute",
target="vendor://payments",
parameters={"amount": 1000, "currency": "USD"},
policy=PolicyReference(name="vendor-payment", version="2.0.0", schema_version="1.0.0"),
signals={
"vendorVerified": True,
"invoiceVerified": True,
"paymentApproved": True,
"sufficientFunds": True,
"paymentAmount": 1000,
"riskScore": 5,
# vendor-payment@2.0.0 declares boundSignals: { "vendorId": "target" }.
# This must exactly equal `target` above, checked before policy evaluation
# ever runs, or the request is rejected as a binding-tamper attempt.
"vendorId": "vendor://payments",
},
)
print(transaction.business_transaction_id)
```
`test:fixture-execute` is a generic, credential-free capability built for exactly this kind of
walkthrough. It's unrelated to any real connector, and only registers when the server runs with
`NODE_ENV=test`.
One call runs the policy decision and, if approved, the connector. There's no separate
"authorize" step:
```python theme={null}
from parmana import ExecutionRejectedError
try:
trust_record = client.execution.execute(transaction)
print(f"Approved: {trust_record.trust_record_hash}")
except ExecutionRejectedError as exc:
print(f"Denied: {exc}")
```
If the policy denies the transaction, `execute()` raises `ExecutionRejectedError` with the
policy's own reason in the message. It never returns a "REJECTED" status you'd have to check for.
`trust_record` is a real, signed `ExecutionTrustRecord`:
```python theme={null}
print(f"Trust Record ID: {trust_record.trust_record_id}")
print(f"Trust Record Hash: {trust_record.trust_record_hash}")
print(f"Signature Algorithm: {trust_record.signature.algorithm}")
print(f"Decision: {trust_record.executions[0].decision.outcome}")
print(f"Connector evidence: {trust_record.executions[0].evidence}")
```
This same call, run for real against a local server, is captured verbatim in
[Quickstart's "Real output" step](/quickstart). Expect the same shape (a fresh hash each run,
since the transaction and timestamp differ). See [Execution Trust
Records](/concepts/execution-trust-records) for the complete field-by-field shape, and [Verify
independently](/guides/verify-independently) to check the signature yourself instead of trusting
this output.
## Full script
```python theme={null}
from parmana import (
ExecutionRejectedError,
ParmanaClient,
PolicyReference,
create_business_transaction,
)
client = ParmanaClient(endpoint="http://localhost:3000", api_key="my-secret-api-key")
transaction = create_business_transaction(
principal_id="python-sdk-quickstart",
purpose="Quickstart demo",
action="test:fixture-execute",
target="vendor://payments",
parameters={"amount": 1000, "currency": "USD"},
policy=PolicyReference(name="vendor-payment", version="2.0.0", schema_version="1.0.0"),
signals={
"vendorVerified": True,
"invoiceVerified": True,
"paymentApproved": True,
"sufficientFunds": True,
"paymentAmount": 1000,
"riskScore": 5,
"vendorId": "vendor://payments",
},
)
try:
trust_record = client.execution.execute(transaction)
print(f"Trust Record Hash: {trust_record.trust_record_hash}")
print(f"Decision: {trust_record.executions[0].decision.outcome}")
except ExecutionRejectedError as exc:
print(f"Denied: {exc}")
```
The same, already-tested version of this script lives at `python/examples/quickstart/run.py`;
`python/tests/test_quickstart_example.py` runs it against a real, freshly-spawned server on every
test run, so it's verified to work, not just syntax-checked.
## Troubleshooting
**`ConnectionError` / connection refused on `localhost:3000`**
The server isn't running, or isn't listening on the port you're pointing at. Confirm with
`curl http://localhost:3000/health`.
**`AuthenticationError` (401)**
Either no `api_key` was passed against a server that requires one, or the key is wrong. Confirm
the demo key matches what's in the repo's committed `.env`, or that `PARMANA_AUTH_DISABLED=true`
is actually set if you intended to skip auth.
**`ExecutionRejectedError`**
The named policy denied the transaction. The exception message is the policy's own reason. Check
that every signal the policy references is present in `signals`, and that any `boundSignals`
field (like `vendorId` above) exactly matches its bound intent field.
**`ValidationError` (400), often "X must equal Y"**
A hand-built transaction had two of the three cross-checked id pairs out of sync. Use
`create_business_transaction()` instead of constructing the object by hand. It makes this class
of mistake structurally impossible.
## Next
The concepts behind what you just ran: transactions, decisions, proofs.
Wire this into LangChain, CrewAI, FastAPI, and async agent code.
Error handling, audit logging, and a deployment checklist.
The same flow against a real connector and real infrastructure, not the
local test fixture.