SplitStep API — Client Guide

Overview

This guide walks through how to submit a video for processing using the SplitStep API. You submit a job and receive results via a webhook when the job completes or fails.

Prerequisites

You will need:

• An API key
• The API base URL
• A webhook signing secret
• Python with the click and requests packages installed
• The splitstep_client.py script
• A job request JSON file (see the example provided below)

Submitting a Job

Run the script from your terminal. Your API key can be passed via the SPLITSTEP_API_KEY environment variable (recommended) or directly with the --api-key flag:

# Using the SPLITSTEP_API_KEY environment variable (recommended)
SPLITSTEP_API_KEY=your_key python splitstep_client.py send path/to/job_request.json

# Or passing the key directly
python splitstep_client.py send path/to/job_request.json --api-key your_key

The script will print the immediate queuing response as JSON, for example:

{
  "job_id": "a1b2c3d4-...",
  "video_id": "your_match_id",
  "status": "queued",
  "message": "Job queued successfully"
}

If a required field is missing or invalid, the API will reject the request immediately with an error, for example:

{
  "detail": {
    "code": "MISSING_REQUIRED_FIELD",
    "category": "invalid_input",
    "message": "A field required for this job type is missing from the request.",
    "detail": "WebhookUrl is required"
  }
}

See Error Codes for the full list and for how to handle codes your integration does not recognise.

splitstep_client.py

Reference implementation of the client script used above:

#!/usr/bin/env python3
import json
from datetime import datetime, timezone

import click
import requests

BASE_URL = "https://api.example.com"  # dummy endpoint — replace with your assigned URL


def format_duration(duration: float) -> str:
    """Format a duration in seconds into a human readable string.

    Parameters
    ----------
    duration : float
        Duration in seconds to format

    Returns
    -------
    str
        Formatted duration string
    """
    if duration < 1:
        return f"{duration * 1000:.0f}ms"
    elif duration < 60:
        return f"{duration:.1f}s"
    elif duration < 3600:
        minutes = str(int(duration // 60))
        seconds = str(int(duration % 60))
        seconds = "0" + seconds if len(seconds) == 1 else seconds
        return f"{minutes}m{seconds}s"
    else:
        hours = str(int(duration // 3600))
        minutes = str(int((duration % 3600) // 60))
        minutes = "0" + minutes if len(minutes) == 1 else minutes
        return f"{hours}h{minutes}m"


@click.group()
def cli():
    """Submit jobs to the SplitStep API, list in-flight jobs, check status, or remove queued jobs."""


@cli.command()
@click.argument("job_request_path", type=click.Path(exists=True))
@click.option("--api-key", envvar="SPLITSTEP_API_KEY", required=True)
def send(job_request_path, api_key):
    """Send a job request to the SplitStep API.

    Parameters
    ----------
    job_request_path : str
        Path to a JSON file containing the job request payload.
    api_key : str
        API key for authenticating with the API. Falls back to the
        SPLITSTEP_API_KEY environment variable.
    """
    with open(job_request_path, "r") as f:
        data = json.load(f)

    response = requests.post(
        f"{BASE_URL}/jobs",
        headers={"X-Api-Key": api_key, "Content-Type": "application/json"},
        json=data,
    )

    click.echo(json.dumps(response.json(), indent=2))


@cli.command()
@click.argument("job_id")
@click.option("--api-key", envvar="SPLITSTEP_API_KEY", required=True)
def status(job_id, api_key):
    """Get the status of a job from the SplitStep API.

    Parameters
    ----------
    job_id : str
        ID of the job to look up, as returned when the job was submitted.
    api_key : str
        API key for authenticating with the API. Falls back to the
        SPLITSTEP_API_KEY environment variable.
    """
    response = requests.get(
        f"{BASE_URL}/jobs/{job_id}",
        headers={"X-Api-Key": api_key},
    )

    click.echo(json.dumps(response.json(), indent=2))


@cli.command(name="list")
@click.option("--api-key", envvar="SPLITSTEP_API_KEY", required=True)
def list_jobs(api_key):
    """List in-flight (queued or processing) jobs for this API key.

    Parameters
    ----------
    api_key : str
        API key for authenticating with the API. Falls back to the
        SPLITSTEP_API_KEY environment variable.
    """
    response = requests.get(
        f"{BASE_URL}/jobs",
        headers={"X-Api-Key": api_key},
    )
    payload = response.json()
    if response.status_code != 200:
        click.echo(json.dumps(payload, indent=2))
        return

    jobs = payload.get("jobs") or []
    if not jobs:
        click.echo("No in-flight jobs.")
        return

    now = datetime.now(timezone.utc)
    rows = []
    for job in jobs:
        updated_at = job.get("updated_at")
        if updated_at:
            updated = datetime.fromisoformat(updated_at)
            time_in_status = format_duration((now - updated).total_seconds())
        else:
            time_in_status = "-"
        rows.append(
            (
                job.get("job_id", ""),
                job.get("video_id", ""),
                job.get("status", ""),
                time_in_status,
            )
        )

    headers = ("job_id", "video_id", "status", "time_in_status")
    widths = [len(h) for h in headers]
    for row in rows:
        for i, cell in enumerate(row):
            widths[i] = max(widths[i], len(cell))

    click.echo("  ".join(h.ljust(widths[i]) for i, h in enumerate(headers)))
    for row in rows:
        click.echo("  ".join(cell.ljust(widths[i]) for i, cell in enumerate(row)))


@cli.command()
@click.argument("job_id")
@click.option("--api-key", envvar="SPLITSTEP_API_KEY", required=True)
def remove(job_id, api_key):
    """Remove a queued job from the SplitStep API.

    Only jobs that are still queued can be removed. Processing jobs are rejected.

    Parameters
    ----------
    job_id : str
        ID of the job to remove.
    api_key : str
        API key for authenticating with the API. Falls back to the
        SPLITSTEP_API_KEY environment variable.
    """
    response = requests.delete(
        f"{BASE_URL}/jobs/{job_id}",
        headers={"X-Api-Key": api_key},
    )
    payload = response.json() if response.content else {}

    if response.status_code == 200:
        click.echo(f"Removed job {job_id} from queue.")
        return

    error = payload.get("error") or {}
    code = error.get("code", "")
    detail = error.get("detail", "")

    if response.status_code == 404 or code == "JOB_NOT_FOUND":
        click.echo(f"Job {job_id} not found.")
    elif response.status_code == 409 or code == "JOB_NOT_REMOVABLE":
        if "job_processing" in detail:
            reason = "already processing"
        elif "job_completed" in detail:
            reason = "already completed"
        elif "job_failed" in detail:
            reason = "already failed"
        else:
            reason = detail or "not removable"
        click.echo(f"Cannot remove job {job_id}: {reason}.")
    elif response.status_code == 401 or code == "UNAUTHORIZED":
        click.echo("Unauthorized.")
    else:
        message = error.get("message") or response.reason
        click.echo(f"Failed to remove job {job_id}: {message}")


if __name__ == "__main__":
    cli()

Job Request Format

The job request is a JSON file with the following fields.

Example

{
    "MatchID": "my_match_001",
    "VideoUrl": "https://example.blob.core.windows.net/videos/match.mp4?...",
    "WebhookUrl": "https://your-server.com/webhook/splitstep",
    "InitialTopPlayer": "Smith",
    "InitialBottomPlayer": "Jones",
    "StartTime": 120.0,
    "EndTime": 3600.0,
    "SetGameScores": [[6, 3], [7, 5]],
    "FixedCamera": true,
    "Ad": false,
    "MatchDate": "2026-05-14"
}

Video Guidelines

Specifications

Camera Setup

• Behind the baseline at one end of the court
• Centered on the court, aligned with the center mark
• Elevated — the higher the better
• The full court must be visible, including both baselines
• Use a tripod or fence mount for a fixed camera; if there is panning, set FixedCamera to false

Webhook Responses

You will receive two webhook notifications per job: one when the job is first queued, and one when processing completes or fails.

Every webhook is signed; see Verifying Webhooks below.

Job Queued

Sent immediately after a successful submission:

{
  "job_id": "a1b2c3d4-...",
  "video_id": "my_match_001",
  "status": "queued",
  "message": "Job queued successfully"
}

Job Completed

Sent when processing finishes successfully:

{
  "job_id": "a1b2c3d4-...",
  "video_id": "my_match_001",
  "status": "job_completed",
  "message": "Job completed successfully",
  "sas_url": "https://...",
  "trimmed_video_url": "https://..."
}

Job Failed

Sent if an error occurs at any stage of processing:

{
  "job_id": "a1b2c3d4-...",
  "video_id": "my_match_001",
  "status": "job_failed",
  "message": "Failed to download video: HTTP 403 fetching video: ...",
  "error": {
    "code": "VIDEO_UNREACHABLE",
    "category": "invalid_input",
    "message": "The video could not be retrieved. The SAS token may have expired, or the blob may have been moved or deleted.",
    "detail": "HTTP 403 fetching video: ...",
    "step": "downloading_video"
  }
}

Branch on error.code. Use error.message for end-user display and error.detail for diagnostics. The top-level message summarizes the failure and includes the underlying error detail; it is retained for backward compatibility and should not be parsed.

Verifying Webhooks

Your webhook endpoint is a public URL, so you must verify that a request genuinely came from us before acting on it. Every webhook carries a signature computed with a shared secret that only the two of us hold. This secret is not the same value as your API key.

import base64
import hashlib
import hmac

def verify(raw_body: bytes, received_signature: str, secret: str) -> bool:
    digest = hmac.new(secret.encode("utf-8"), raw_body, hashlib.sha256).digest()
    expected = base64.b64encode(digest).decode("utf-8")
    return hmac.compare_digest(expected, received_signature)

Read the signature from the X-HMAC-Signature header and pass it as received_signature.

Checking Job Status

After submitting a job, check its progress with the status command.

SPLITSTEP_API_KEY=your_key python splitstep_client.py status {job_id}

The script prints the status response as JSON.

Response

Example

{
  "job_id": "a1b2c3d4-0000-0000-0000-000000000001",
  "video_id": "my_match_001",
  "status": "job_processing",
  "queued_at": "2026-07-31T18:02:11.482913+00:00",
  "updated_at": "2026-07-31T18:07:03.115204+00:00"
}

Errors

When the request itself fails, the response contains job_id and error only — no status, video_id, or timestamps. See Returned when checking job status for the possible codes.

Example

{
  "job_id": "a1b2c3d4-0000-0000-0000-000000000001",
  "error": {
    "code": "JOB_NOT_FOUND",
    "category": "invalid_input",
    "message": "No job was found with that ID.",
    "detail": ""
  }
}

Interrupted Jobs

If a job starts processing and then stops reporting progress — for example because the machine running it was interrupted — we detect this and mark the job job_failed with the code JOB_STALE, and notify your webhook:

Example

{
  "job_id": "a1b2c3d4-0000-0000-0000-000000000001",
  "video_id": "my_match_001",
  "status": "job_failed",
  "queued_at": "2026-07-31T18:02:11.482913+00:00",
  "updated_at": "2026-07-31T18:22:03.115204+00:00",
  "error": {
    "code": "JOB_STALE",
    "category": "internal",
    "message": "The job stopped reporting progress. Contact support with the job_id.",
    "detail": "no heartbeat since 2026-07-31T18:11:44.902117+00:00"
  }
}

Listing In-Flight Jobs

List jobs that are still queued or processing with the list command.

SPLITSTEP_API_KEY=your_key python splitstep_client.py list

The script prints a table:

job_id                                video_id       status          time_in_status
a1c2c3d4-0000-0000-0000-000000000001  my_match_001   queued          12m34s
b2c3d4e5-0000-0000-0000-000000000002  my_match_002   job_processing  3m05s
c3d4e5f6-0000-0000-0000-000000000003  my_match_003   queued          45.2s

time_in_status is how long the job has been in its current status. If there are no in-flight jobs, the script prints No in-flight jobs.

Removing a Queued Job

Remove a job that is still queued with the remove command. Jobs that have already started processing cannot be removed.

SPLITSTEP_API_KEY=your_key python splitstep_client.py remove {job_id}

On success:

Removed job a1b2c3d4-0000-0000-0000-000000000001 from queue.

The job record is deleted. A later status check for that ID returns JOB_NOT_FOUND.

If the job is already processing:

Cannot remove job b2c3d4e5-0000-0000-0000-000000000002: already processing.

Error Codes

Every error returned by the API or delivered in a job_failed webhook carries an error object with the same shape.

Handling codes you do not recognise

New codes will be added over time as failure modes are identified. Your integration must handle unknown codes gracefully via a default branch. Where possible, branch on category rather than on individual codes, so that new codes are handled correctly without a change on your side.

Returned immediately, in the HTTP response

Delivered in the webhook

Returned when checking job status

See Checking Job Status.

Returned when removing a job

See Removing a Queued Job.

Result Schemas

When a job completes successfully, the sas_url in the webhook payload points to a JSON file of stroke-by-stroke analysis. The strokes schema below is our standard delivery format.

Upon request, we can also provide frame-by-frame tracking for players and ball. We can provide a statistics-based schema as well — contact us for more details.

Strokes Schema (Standard)

The results file is a JSON array. Each element describes one detected stroke (contact), including court and pixel positions, bounce location, ball flight metrics, and score context. Missing values use type-specific sentinels: -9999.0 for floats, -9999 for integers, and "None" for strings.

Court coordinates

Positions ending in _m are in meters on the court plane. The origin is at court center (net mid-point). Positive y is toward the top of the video / far baseline; positive x is toward the right sideline.

Singles court in meters. Sidelines at x ≈ ±4.12; service lines at y ≈ ±6.4; baselines at y ≈ ±11.89.

Example

[
  {
    "video_id": "my_match_001",
    "event_id": 0,
    "frame": 1060,
    "time": 17.67,
    "rally_id": 1,
    "rally_stroke_number": 1,
    "player_id": "client_player_id",
    "point_score": "0-0",
    "game_score": "0-0",
    "set_score": "0-0",
    "pred_rally_id": 1,
    "pred_rally_stroke_number": 1,
    "pred_player_id": "client_player_id",
    "pred_point_score": "0-0",
    "pred_game_score": "0-0",
    "pred_set_score": "0-0",
    "stroke_type": "serve",
    "stroke_side": "overhead",
    "stroke_score": 0.998,
    "side_score": 0.996,
    "player_x_m": 0.52,
    "player_y_m": -11.97,
    "player_x1_px": 985.4,
    "player_y1_px": 480.81,
    "player_x2_px": 1092.1,
    "player_y2_px": 758.45,
    "opponent_x_m": -3.08,
    "opponent_y_m": 14.46,
    "opponent_x1_px": 847.28,
    "opponent_y1_px": 178.75,
    "opponent_x2_px": 875.84,
    "opponent_y2_px": 234.68,
    "speed_kmh": 162.27,
    "ang_vel_mag_rpm": 1788.28,
    "spin_type": "topspin",
    "initial_height_m": 2.481,
    "height_at_net_m": 0.981,
    "net_hit": false,
    "bounce_frame": 1085.0,
    "bounce_score": 0.939,
    "bounce_x_m": -1.311,
    "bounce_y_m": 4.646,
    "bounce_x_px": 901.875,
    "bounce_y_px": 292.5,
    "in": true,
    "line_confidence": 0.9
  }
]

Frame-by-Frame Tracking (Optional)

Upon request, we can provide frame-by-frame tracking for players and ball in addition to the standard strokes output. Contact us to enable this for your pipeline.

Statistics Schema (Optional)

We can also deliver a statistics-based schema derived from the match analysis. Contact us for more details on fields and delivery format.