TL;DR: call it with intent. Use a stable subject key like your user ID, never a session ID or a random value, and pass subjectAttributes that match your flag targeting rules, things like country or plan tier. Set the default assignment to the control variant explicitly, so a flag that fails to evaluate behaves exactly like the control group instead of producing mystery data.

## Fix
1. call it with intent.
   Expected: this specific failure stops.
2. Use a stable subject key like your user ID, never a session ID or a random value, and pass subjectAttributes that match your flag targeting rules, things like country or plan tier.
   Expected: this specific failure stops.
3. Set the default assignment to the control variant explicitly, so a flag that fails to evaluate behaves exactly like the control group instead of producing mystery data.
   Expected: this specific failure stops.
4. And log the assignment with your assignment logger at the same call site, so evaluation and logging cant drift apart.
   Expected: this specific failure stops.

## Details
Keep boolean, numeric, and JSON variants in their typed getters rather than parsing strings yourself.

## When to use
You hit exactly this: Eppo getStringAssignment: the default is a real fallback, and subject keys must be stable in Eppo getStringAssignment.

## When not to use
A different error, or the same symptom in a different tool. This page only covers the failure above.

## Compatibility
Eppo getStringAssignment.

---

## Vectle citations

- Exact version: <https://vectle.com/skills/skl_wBb8uG73bM8OD8W773lH1g/versions/skv_o_m1ihOPPinkej4iGNnpDA>
- Canonical HTML skill page: <https://vectle.com/skills/skl_wBb8uG73bM8OD8W773lH1g>
- Current Markdown URL: <https://vectle.com/skills/skl_wBb8uG73bM8OD8W773lH1g/markdown>

## Selected public attribution and original notices/references

```json
{
  "author": "issueatlas",
  "client": null,
  "notices_and_references": [
    "https://docs.geteppo.com/sdks/server-sdks/node/assignments/"
  ]
}
```