Signicat Mint API - Integration Hell Survival Guide

Reality check: Mint API is Signicat's way of letting you programmatically manage those identity verification workflows you built in their no-code visual editor. Sounds simple, right? Wrong. This is enterprise API territory, which means OAuth role hell, cryptic error messages, and documentation that assumes you're psychic.

The Mint platform is actually solid for building KYC workflows, customer onboarding, and compliance automation - but automating those workflows via API? That's where the fun begins.

The OAuth Setup Pain

First, you'll need API credentials from their dashboard. You'll need both Flow Editor and Flow Viewer roles or half the endpoints won't work. Don't ask me why - their permission management is buried in the dashboard under "API Clients" and the roles aren't obvious.

The gotcha: tokens expire but the docs don't tell you when. Default is 600 seconds, but good luck finding that anywhere obvious. Found out the hard way when our production integration shit the bed at 2:47 AM on a Tuesday. 3 hours of perfect uptime, then boom - 401s everywhere.

## This will work (using OAuth client credentials):
curl -X POST "https://api.signicat.com/auth/open/connect/token" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials&scope=signicat-api&client_id=YOUR_CLIENT_ID&client_secret=YOUR_SECRET"

## This will give you vague 403 errors:
## Missing Flow Editor role on your API client

The exact token endpoint URL is documented in their OAuth guide, but good luck finding it quickly when your prod system is down.

Pro tip: The OAuth setup documentation explains the role requirements, but you'll miss it on first read. You need both Flow Editor and Flow Viewer permissions or half the API endpoints return cryptic 403s.

What Actually Works vs. What the Docs Say

The API lets you:

• List workflow instances - Returns massive JSON blobs (seriously, 50KB+ for a simple workflow)
• Start workflow executions - Works fine until you hit rate limits
• Download result files - ZIP downloads can be huge, plan accordingly
• Get execution status - Polling is your friend, but don't poll every second like an asshole

Pro tip: The OpenAPI specification is actually useful here. Generate your client from their API documentation instead of hand-rolling HTTP requests. The Mint API reference shows all available endpoints and expected responses.

Rate Limiting Will Fuck You

They don't document the exact limits, but here's what I learned the hard way:

• ~100 requests per minute per API client (rough estimate)
• Burst limits exist but aren't documented
• Instance listing is expensive - cache this shit
• File downloads count toward your quota

I burned through our monthly quota in 6 hours during testing because I was checking every 2 seconds like a moron. Set your polling to 30-second intervals minimum, or use webhooks if you can.

Real Production Gotchas

Environment configuration hell: Your prod and staging API clients need identical roles. Our production deployment failed at 6 PM on Friday because I forgot to set up the prod roles. Spent the weekend getting screamed at. The account management and role configuration process isn't intuitive.

Workflow state confusion: A workflow can be "Running" but stuck on user input for days. The API doesn't distinguish between "actually processing" and "waiting for human." Your monitoring will think everything's broken when it's just waiting. Check the workflow activities endpoint to see what step it's actually on.

File retention policies: They delete result files after 30 days. We lost 3 months of compliance documents because nobody told us about the retention policy. Download and archive immediately. This isn't clearly documented in their data retention policies.

Error messages are useless: "Workflow execution failed" doesn't tell you if it was a network timeout, bad configuration, or cosmic rays. Enable detailed logging on your side. The troubleshooting guide is minimal.

Here's what actually happens in production: one workflow generated a 2GB zip that crashed our download service. Plan for large files, implement streaming downloads, and don't assume ZIP files are small.

The API works, but it's enterprise software - assume everything will break in creative ways and plan accordingly.

The Rate Limiting Nightmare

Here's what nobody tells you: Mint API rate limiting isn't just about requests per second - it's about total monthly quota. Costs $0.50 per workflow execution. Sounds cheap until you're processing 10,000 customers and your monthly bill hits $5,000.

The real killer? File download operations count against your API quota AND your billing quota. We hit our limit at 2 PM on Black Friday. Cost us 200 customer onboarding flows and a very uncomfortable call with the VP.

## Don't do this - you'll get rate limited
while true; do
  curl -H "Authorization: Bearer $TOKEN" \
    "https://api.signicat.com/mint/api/instances/$ID" 
  sleep 1
done

## Do this instead - exponential backoff
check_status() {
  local delay=5
  while [ $delay -lt 300 ]; do
    status=$(curl -s -H "Authorization: Bearer $TOKEN" \
      "https://api.signicat.com/mint/api/instances/$1" | jq -r .status)
    [[ "$status" != "Running" ]] && break
    sleep $delay
    delay=$((delay * 2))
  done
}

OAuth Environment Configuration Hell

The problem: Their OAuth implementation requires different client credentials for sandbox vs production. But here's the fun part - the roles need to be configured separately for each environment.

The solution nobody documents: Create your prod API client by copying settings from sandbox, then manually verify every single permission. Missing one role = mysterious 403s that take hours to debug. Check the API client setup guide for the complete list of required permissions.

Real production incident: I copied our sandbox client config to prod, but forgot to enable "Flow Instance Download" permission. Worked fine for starting workflows, failed silently on result downloads. Took 6 hours to figure out because the error was generic. The troubleshooting documentation doesn't cover this scenario.

Webhook Alternative That Actually Works

Skip the polling bullshit entirely. Set up webhooks in your Mint flows:

1. Add a "HTTP Request" step at the end of your workflow
2. Point it to your callback endpoint: https://yourapp.com/webhooks/mint
3. Include the instance ID in the payload
4. Handle the webhook to trigger your download

Check the Mint step reference for all available workflow components and their configuration options.

// Webhook handler that doesn't suck
app.post('/webhooks/mint', async (req, res) => {
  const { instanceId, status } = req.body;
  
  if (status === 'Finished') {
    // Queue the file download job - don't block the webhook
    await downloadQueue.add('mint-result', { instanceId });
  }
  
  res.status(200).send('OK');
});

This approach saved us 90% of our API quota because we stopped polling like idiots. Learn more about webhook best practices and HTTP request configuration in Mint flows.

File Download Optimization

The naive approach: Download everything immediately when workflow completes.

The smart approach: Download on-demand when users actually need the files.

The production approach: Stream downloads with resumable uploads to your own storage.

For large file handling, consider the patterns described in API design best practices and file download optimization techniques.

## Don't load 2GB ZIP files into memory
import requests

def stream_download(instance_id, token):
    url = f"https://api.signicat.com/mint/api/instances/{instance_id}/result-file"
    headers = {"Authorization": f"Bearer {token}"}
    
    with requests.get(url, headers=headers, stream=True) as r:
        r.raise_for_status()
        with open(f"results_{instance_id}.zip", 'wb') as f:
            for chunk in r.iter_content(chunk_size=8192):
                f.write(chunk)

Cache everything: Workflow definitions, user roles, even error responses. Their API is slow enough that caching makes a 10x difference. Implement Redis caching or similar for frequently accessed data.

Monitor your quotas: Build dashboard alerts for API usage and billing. Don't be that developer who crashes their rate limiter during peak traffic. Use monitoring tools like DataDog, New Relic, or Grafana to track API performance.

The TL;DR: Treat this like any other enterprise API - defensive programming, extensive caching, and assume everything will break at the worst possible moment. Follow enterprise API integration patterns and fault tolerance best practices.