The v2 SDK migration (#5273, #6564) shipped five breaking changes in both
SDKs but got the release mechanics wrong in three separate ways, and left
one of the two rewrites unable to complete a single successful call.
Versions. packages/ts-sdk/package.json read 0.1.3 -- a patch digit added
inside an unrelated compatibility commit, never deliberated. npm expands
^0.1.2 to >=0.1.2 <0.2.0, so every existing consumer would have picked the
break up on a lockfile refresh: AsyncExecutionResult.jobId renamed to
runId, executionId dropped from that interface, a failed sync run now
throwing instead of resolving {success:false}, the request body reshaped,
and the endpoint moved to /api/v2 with no fallback. 0.2.0 excludes every
existing range, so the upgrade becomes opt-in. packages/python-sdk carries
the identical break and was never bumped at all, so its publish job would
have skipped green at the "version already exists" gate and left the repo
and PyPI silently divergent; it moves 0.1.2 -> 0.2.0 in lockstep, along
with the __version__ string in simstudio/__init__.py, which tracks
pyproject and would otherwise have started lying. setup.py is left at
0.1.1: it is unchanged from main and demonstrably unread (0.1.2 published
from pyproject while setup.py already said 0.1.1). It wants deleting, in
its own commit.
A 404 fallback was considered and rejected. The legacy 202 body's statusUrl
points at /api/jobs/{jobId}, so mapping jobId onto runId would hand the
caller an id that getWorkflowRun cannot resolve against that same old
server -- a successful execute followed by an inexplicable failure on the
next call is a worse contract than a clean 404. Both READMEs instead state
the minimum server version and name the endpoint to check for.
Cancelled runs. packages/python-sdk computed success as status != 'failed',
so a run cancelled out of band reported success=True. The TypeScript SDK
uses a closed whitelist and reports False, and before the migration both
SDKs read the server's own value, which was False -- so this was a Python
regression, not merely an inconsistency. Fixed by mirroring the whitelist.
The v2 contract enumerates exactly completed|failed|paused|cancelled, so
narrowing the blacklist to a whitelist cannot drop a live value, and a
status added later now defaults to "not successful" rather than silently
reporting True. WorkflowExecutionResult gains a status field because
Python, unlike TypeScript, does not throw on 'failed' -- so success=False
alone is ambiguous there in a way it is not in the TypeScript SDK, which
is why status is not added to both.
Rate-limit header. Found while auditing the two SDKs for further
divergence, and the reason the Python bump could not have shipped as it
stood: every authenticated v2 response now carries X-RateLimit-Reset as an
ISO 8601 timestamp (recorded by v2RateLimits.publicApi, stamped by
withRouteHandler). The Python SDK parsed it with int(), raising a bare
ValueError that no handler in execute_workflow catches -- so every
successful v2 execution raised instead of returning. None of the legacy
endpoints the SDK previously called record a rate-limit snapshot, which is
why the latent int() survived until the v2 move. The TypeScript SDK
already branches on the format; _parse_reset_header mirrors it, including
degrading an unrecognised value to 0, because a quota hint must not take
down the call it rode in on.
Timing metadata. The v2 rewrite stopped forwarding startedAt/endedAt, which
main passed through and the TypeScript SDK still reports; restored under
the same startTime/endTime keys the TypeScript SDK uses.
Tests: cancelled/failed/paused status coverage, the ISO reset header, and
the restored metadata keys, each verified red against the unfixed line
first. The TypeScript suite gains matching cancelled/paused and ISO-reset
pins -- they pass against today's source by design, and were confirmed to
fail against a deliberately degraded copy so they are not toothless.
Deliberately not included: a CI guard failing a PR that changes SDK source
without a version bump. It would have caught this twice over, but it is a
new script and workflow rather than a fix to the defect at hand.
Review revision. bun.lock recorded packages/ts-sdk at 0.1.3 and was left
stale by the first pass, so the repo asserted two versions for the same
workspace package -- in a change whose whole thesis is that the version
strings had diverged. It does not break CI (bun 1.3.14 accepts the
mismatch under --frozen-lockfile, confirmed here), but 092311ea68 bumped
the lock in lockstep with package.json, and the next unfrozen install
would otherwise drop the line into an unrelated PR.
_parse_reset_header gated the numeric branch on str.isdigit(), which
accepts characters int() rejects ('²'.isdigit() is True, int('²')
raises) -- and that int() sits outside the try, so the one function added
to stop a quota hint raising could still raise, contradicting its own
docstring. str.isdecimal() is exactly the set int() accepts. The
tolerates-unparseable test is parametrized over both forms and was
confirmed red on '²' against isdigit.
Docs and docstrings: apps/docs api-reference/python.mdx mirrors the
README's dataclass block and was the only copy left without the new
status field. RateLimitInfo now names its units, because reset is epoch
seconds for the legacy integer and milliseconds for the ISO form that v2
sends. execute_workflow's Args entry still described the pre-v2 body
shape ("spread at root level"); every input is nested under input now,
and this is the commit that ships that help() text to PyPI. The
"declared last so positional construction keeps working" sentence was a
maintainer's note that belongs in this message, not in every user's
help(WorkflowExecutionResult).
Sim Python SDK
The official Python SDK for Sim, allowing you to execute workflows programmatically from your Python applications.
Server compatibility
0.2.x talks to the v2 API and has no fallback to the older endpoints, so it requires a Sim deployment that serves POST /api/v2/workflows/{id}/execute. That surface is newer than the endpoints 0.1.x used, and a deployment can also have it switched off — a self-hosted build serves /api/v2 only when the operator enables V2_API. Where it is unavailable every v2 route answers 404, so execute_workflow raises SimStudioError('HTTP 404: Not Found') — enable or upgrade the v2 API on the server, or pin simstudio-sdk<0.2, which keeps using /api/workflows/{id}/execute and /api/jobs/{id}.
Upgrading from 0.1.x to 0.2.0
0.2.0 is a breaking release.
- Requests move to
/api/v2.execute_workflowposts to/api/v2/workflows/{workflow_id}/execute, sends the workflow input nested underinput, and carriesasync/executionTimeoutSecondsin the body instead of theX-Execution-ModeandX-Execution-Timeout-Secondsheaders. AsyncExecutionResult.job_idis nowrun_id, andexecution_idhas been removed from that dataclass. Replaceresult.job_idwithresult.run_id.get_job_status(job_id)is legacy. It still calls/api/jobs/{job_id}and only resolves IDs from a0.1.xasync execution. For runs started by0.2.x, useget_workflow_run(workflow_id, run_id), which reads/api/v2/workflows/{workflow_id}/runs/{run_id}.WorkflowExecutionResult.successis derived from the run status rather than read from the response body, and isTrueonly forcompletedandpausedruns — so a run cancelled while it was in flight now reportssuccess=False, as it did before the v2 migration. The newWorkflowExecutionResult.statusfield carries the server's terminal status ('completed','failed','paused'or'cancelled'), which is how you tell a cancelled run from a failed one.metadatais now built by the SDK, with the keysduration,runId,startTimeandendTime. The v2 response carries no execution logs or trace spans, sologsandtrace_spansare alwaysNone; the pre-v2metadata['executionId']is nowmetadata['runId'].
Note one deliberate difference from the TypeScript SDK: a failed synchronous run throws there, but here it returns normally with error set and status='failed'.
Installation
pip install simstudio-sdk
Quick Start
import os
from simstudio import SimStudioClient
# Initialize the client
client = SimStudioClient(
api_key=os.getenv("SIM_API_KEY", "your-api-key-here"),
base_url="https://sim.ai" # optional, defaults to https://sim.ai
)
# Execute a workflow
try:
result = client.execute_workflow("workflow-id")
print("Workflow executed successfully:", result)
except Exception as error:
print("Workflow execution failed:", error)
API Reference
SimStudioClient
Constructor
SimStudioClient(api_key: str, base_url: str = "https://sim.ai")
api_key(str): Your Sim API keybase_url(str, optional): Base URL for the Sim API (defaults tohttps://sim.ai)
Methods
execute_workflow(workflow_id, input=None, *, timeout=30.0, stream=None, selected_outputs=None, async_execution=None, execution_timeout_seconds=None)
Execute a workflow with optional input data.
# With dict input (sent as the v2 input object)
result = client.execute_workflow("workflow-id", {"message": "Hello, world!"})
# With primitive input (sent as { input: { input: value } })
result = client.execute_workflow("workflow-id", "NVDA")
# With options (keyword-only arguments)
result = client.execute_workflow(
"workflow-id",
{"message": "Hello"},
timeout=60.0,
async_execution=True,
execution_timeout_seconds=3600,
)
Parameters:
workflow_id(str): The ID of the workflow to executeinput(any, optional): Input data to pass to the workflow. Dicts become the v2inputobject; primitives and lists become{ input: value }inside it. File objects are automatically converted to base64.timeout(float, keyword-only): Timeout in seconds (default: 30.0)stream(bool, keyword-only): Enable streaming responsesselected_outputs(list, keyword-only): Block outputs to stream (e.g.,["agent1.content"])async_execution(bool, keyword-only): Execute asynchronously and return a run IDexecution_timeout_seconds(int, keyword-only): Server-side async execution cap from 1 to 604800 seconds. Requiresasync_execution=Trueand cannot extend the account policy.
Returns: WorkflowExecutionResult or AsyncExecutionResult
get_workflow_status(workflow_id)
Get the status of a workflow (deployment status, etc.).
status = client.get_workflow_status("workflow-id")
print("Is deployed:", status.is_deployed)
Parameters:
workflow_id(str): The ID of the workflow
Returns: WorkflowStatus
validate_workflow(workflow_id)
Validate that a workflow is ready for execution.
is_ready = client.validate_workflow("workflow-id")
if is_ready:
# Workflow is deployed and ready
pass
Parameters:
workflow_id(str): The ID of the workflow
Returns: bool
execute_workflow_sync(workflow_id, input=None, *, timeout=30.0, stream=None, selected_outputs=None)
Execute a workflow synchronously (ensures non-async mode).
result = client.execute_workflow_sync("workflow-id", {"data": "some input"}, timeout=60.0)
Parameters:
workflow_id(str): The ID of the workflow to executeinput(any, optional): Input data to pass to the workflowtimeout(float, keyword-only): Timeout in seconds (default: 30.0)stream(bool, keyword-only): Enable streaming responsesselected_outputs(list, keyword-only): Block outputs to stream (e.g.,["agent1.content"])
Returns: WorkflowExecutionResult
get_workflow_run(workflow_id, run_id, *, include_output=None, selected_outputs=None)
Get the status and optional outputs of a workflow run. Use the run ID returned by async execution.
status = client.get_workflow_run(
"workflow-id",
"run-id",
include_output=True,
selected_outputs=["agent.content"]
)
print("Run status:", status["status"])
Parameters:
workflow_id(str): The workflow IDrun_id(str): The run ID returned from async executioninclude_output(bool, keyword-only): Include the final output for completed executionsselected_outputs(list, keyword-only): Block output selectors to include
Returns: dict
get_job_status(job_id)
Get the status of a job created through the legacy async execution endpoint. New integrations should use get_workflow_run() with a run ID.
status = client.get_job_status("legacy-job-id")
Returns: dict
execute_with_retry(workflow_id, input=None, *, timeout=30.0, stream=None, selected_outputs=None, async_execution=None, max_retries=3, initial_delay=1.0, max_delay=30.0, backoff_multiplier=2.0)
Execute a workflow with automatic retry on rate limit errors.
result = client.execute_with_retry(
"workflow-id",
{"message": "Hello"},
timeout=30.0,
max_retries=3,
initial_delay=1.0,
max_delay=30.0,
backoff_multiplier=2.0
)
Parameters:
workflow_id(str): The ID of the workflow to executeinput(any, optional): Input data to pass to the workflowtimeout(float, keyword-only): Timeout in seconds (default: 30.0)stream(bool, keyword-only): Enable streaming responsesselected_outputs(list, keyword-only): Block outputs to streamasync_execution(bool, keyword-only): Execute asynchronouslymax_retries(int, keyword-only): Maximum retry attempts (default: 3)initial_delay(float, keyword-only): Initial delay in seconds (default: 1.0)max_delay(float, keyword-only): Maximum delay in seconds (default: 30.0)backoff_multiplier(float, keyword-only): Backoff multiplier (default: 2.0)
Returns: WorkflowExecutionResult or AsyncExecutionResult
get_rate_limit_info()
Get current rate limit information from the last API response.
rate_info = client.get_rate_limit_info()
if rate_info:
print("Remaining requests:", rate_info.remaining)
Returns: RateLimitInfo or None
get_usage_limits()
Get current usage limits and quota information.
limits = client.get_usage_limits()
print("Current usage:", limits.usage)
Returns: UsageLimits
set_api_key(api_key)
Update the API key.
client.set_api_key("new-api-key")
set_base_url(base_url)
Update the base URL.
client.set_base_url("https://my-custom-domain.com")
close()
Close the underlying HTTP session.
client.close()
Data Classes
WorkflowExecutionResult
@dataclass
class WorkflowExecutionResult:
success: bool
output: Optional[Any] = None
error: Optional[str] = None
logs: Optional[list] = None
metadata: Optional[Dict[str, Any]] = None
trace_spans: Optional[list] = None
total_duration: Optional[float] = None
status: Optional[str] = None
success is True only for the completed and paused statuses. status carries the server's terminal status verbatim, so a cancelled run (success=False, error=None) is distinguishable from a failed one.
WorkflowStatus
@dataclass
class WorkflowStatus:
is_deployed: bool
deployed_at: Optional[str] = None
needs_redeployment: bool = False
SimStudioError
class SimStudioError(Exception):
def __init__(self, message: str, code: Optional[str] = None, status: Optional[int] = None):
super().__init__(message)
self.code = code
self.status = status
AsyncExecutionResult
@dataclass
class AsyncExecutionResult:
success: bool
run_id: str
status_url: str
message: str = ""
async_execution: bool = True
RateLimitInfo
@dataclass
class RateLimitInfo:
limit: int
remaining: int
reset: int
retry_after: Optional[int] = None
UsageLimits
@dataclass
class UsageLimits:
success: bool
rate_limit: Dict[str, Any]
usage: Dict[str, Any]
Examples
Basic Workflow Execution
import os
from simstudio import SimStudioClient
client = SimStudioClient(api_key=os.getenv("SIM_API_KEY"))
def run_workflow():
try:
# Check if workflow is ready
is_ready = client.validate_workflow("my-workflow-id")
if not is_ready:
raise Exception("Workflow is not deployed or ready")
# Execute the workflow
result = client.execute_workflow(
"my-workflow-id",
{
"message": "Process this data",
"user_id": "12345"
}
)
if result.success:
print("Output:", result.output)
print("Duration:", result.metadata.get("duration") if result.metadata else None)
else:
print("Workflow failed:", result.error)
except Exception as error:
print("Error:", error)
run_workflow()
Error Handling
from simstudio import SimStudioClient, SimStudioError
import os
client = SimStudioClient(api_key=os.getenv("SIM_API_KEY"))
def execute_with_error_handling():
try:
result = client.execute_workflow("workflow-id")
return result
except SimStudioError as error:
if error.code == "UNAUTHORIZED":
print("Invalid API key")
elif error.code == "TIMEOUT":
print("Workflow execution timed out")
elif error.code == "USAGE_LIMIT_EXCEEDED":
print("Usage limit exceeded")
elif error.code == "INVALID_JSON":
print("Invalid JSON in request body")
else:
print(f"Workflow error: {error}")
raise
except Exception as error:
print(f"Unexpected error: {error}")
raise
Context Manager Usage
from simstudio import SimStudioClient
import os
# Using context manager to automatically close the session
with SimStudioClient(api_key=os.getenv("SIM_API_KEY")) as client:
result = client.execute_workflow("workflow-id")
print("Result:", result)
# Session is automatically closed here
Environment Configuration
import os
from simstudio import SimStudioClient
# Using environment variables
client = SimStudioClient(
api_key=os.getenv("SIM_API_KEY"),
base_url=os.getenv("SIM_BASE_URL", "https://sim.ai")
)
File Upload
File objects are automatically detected and converted to base64 format. Include them in your input under the field name matching your workflow's API trigger input format:
The SDK converts file objects to this format:
{
'type': 'file',
'data': 'data:mime/type;base64,base64data',
'name': 'filename',
'mime': 'mime/type'
}
Alternatively, you can manually provide files using the URL format:
{
'type': 'url',
'data': 'https://example.com/file.pdf',
'name': 'file.pdf',
'mime': 'application/pdf'
}
from simstudio import SimStudioClient
import os
client = SimStudioClient(api_key=os.getenv("SIM_API_KEY"))
# Upload a single file - include it under the field name from your API trigger
with open('document.pdf', 'rb') as f:
result = client.execute_workflow(
'workflow-id',
{
'documents': [f], # Must match your workflow's "files" field name
'instructions': 'Analyze this document'
}
)
# Upload multiple files
with open('doc1.pdf', 'rb') as f1, open('doc2.pdf', 'rb') as f2:
result = client.execute_workflow(
'workflow-id',
{
'attachments': [f1, f2], # Must match your workflow's "files" field name
'query': 'Compare these documents'
}
)
Batch Workflow Execution
from simstudio import SimStudioClient
import os
client = SimStudioClient(api_key=os.getenv("SIM_API_KEY"))
def execute_workflows_batch(workflow_data_pairs):
"""Execute multiple workflows with different input data."""
results = []
for workflow_id, workflow_input in workflow_data_pairs:
try:
# Validate workflow before execution
if not client.validate_workflow(workflow_id):
print(f"Skipping {workflow_id}: not deployed")
continue
result = client.execute_workflow(workflow_id, workflow_input)
results.append({
"workflow_id": workflow_id,
"success": result.success,
"output": result.output,
"error": result.error
})
except Exception as error:
results.append({
"workflow_id": workflow_id,
"success": False,
"error": str(error)
})
return results
# Example usage
workflows = [
("workflow-1", {"type": "analysis", "data": "sample1"}),
("workflow-2", {"type": "processing", "data": "sample2"}),
]
results = execute_workflows_batch(workflows)
for result in results:
print(f"Workflow {result['workflow_id']}: {'Success' if result['success'] else 'Failed'}")
Getting Your API Key
- Log in to your Sim account
- Navigate to your workflow
- Click on "Deploy" to deploy your workflow
- Select or create an API key during the deployment process
- Copy the API key to use in your application
Development
Running Tests
To run the tests locally:
-
Clone the repository and navigate to the Python SDK directory:
cd packages/python-sdk -
Create and activate a virtual environment:
python3 -m venv venv source venv/bin/activate # On Windows: venv\Scripts\activate -
Install the package in development mode with test dependencies:
pip install -e ".[dev]" -
Run the tests:
pytest tests/ -v
Code Quality
Run code quality checks:
# Code formatting
black simstudio/
# Linting
flake8 simstudio/ --max-line-length=100
# Type checking
mypy simstudio/
# Import sorting
isort simstudio/
Requirements
- Python 3.8+
- requests >= 2.25.0
License
Apache-2.0