> ## Documentation Index
> Fetch the complete documentation index at: https://docs.qwedai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting guide

> Resolve common QWED verification issues including authentication errors, API key problems, and rate limits. Step-by-step debugging solutions included.

Common issues and how to resolve them.

***

## Authentication errors

### API key invalid

```
Error: 401 Unauthorized - Invalid API key
```

**Solution:**

1. Check your API key is correct: `echo $QWED_API_KEY`
2. Make sure the value is not a placeholder — `qwed init` ignores common dummy values like `your-api-key`, `changeme`, `placeholder`, and `xxx`. Replace them with a real key.
3. Regenerate key at [cloud.qwedai.com](https://cloud.qwedai.com)
4. Ensure no extra spaces or newlines

```python theme={null}
# Correct
client = QWEDClient(api_key="qwed_live_abc123...")

# Wrong - has newline
client = QWEDClient(api_key="qwed_live_abc123...\n")
```

### Rate limit exceeded

```
Error: 429 Too Many Requests
```

**Solution:**

* Free tier: 100 requests/minute
* Pro tier: 1,000 requests/minute
* Enterprise: Unlimited

```python theme={null}
from qwed_sdk import QWEDClient
import time

client = QWEDClient()

# Implement backoff
for attempt in range(3):
    try:
        result = client.verify("2+2=4")
        break
    except RateLimitError:
        time.sleep(2 ** attempt)
```

***

## Verification failures

### Math: floating-point precision

```python theme={null}
# Fails due to floating point
result = client.verify_math("0.1 + 0.2 = 0.3")
# False! (0.1 + 0.2 = 0.30000000000000004)
```

**Solution:** Use tolerance parameter:

```python theme={null}
result = client.verify_math("0.1 + 0.2 = 0.3", tolerance=1e-10)
# True
```

### Logic: unsatisfiable constraints

```
Error: No satisfying assignment found
```

**Solution:** Check for contradictions:

```python theme={null}
# This is unsatisfiable
"(AND (GT x 10) (LT x 5))"  # x > 10 AND x < 5 - impossible!

# Check satisfiability first
result = client.check_satisfiability("(AND (GT x 10) (LT x 5))")
print(result.satisfiable)  # False
```

### Stats: Internal verification error

```
Error: Internal verification error
```

The Stats Engine returns this generic message when it fails to generate or translate your query into executable code. QWED masks the actual error details to prevent leaking sensitive information.

**Solution:**

1. Verify your query is a valid statistical question (e.g., "What is the mean of column X?")
2. Check that the column names in your query match the columns in your data
3. If the issue persists, check the server-side logs for the exception type

### Code: timeout

```
Error: Verification timeout after 30s
```

**Solution:**

1. Increase timeout: `client.verify_code(code, timeout=60)`
2. Simplify code (reduce loops, recursion)
3. Use bounded verification

***

## CLI issues

### `qwed init` fails with "attempt to write a readonly database"

```
sqlite3.OperationalError: attempt to write a readonly database
```

This error occurs during Step 3 of `qwed init`. The local server tries to create a bootstrap SQLite database in a directory that is not writable. Common examples include a read-only mount, a container filesystem, or a system-managed path.

**Solution:** Upgrade to QWED v4.0.0 or later:

```bash theme={null}
pip install --upgrade qwed
```

Starting with v4.0.0, `qwed init` automatically resolves a writable runtime directory for the database. It uses the current working directory if writable, otherwise falls back to `~/qwed-demo/`. No manual intervention is needed.

If you cannot upgrade, run `qwed init` from a writable directory:

```bash theme={null}
cd ~/my-project
qwed init
```

***

## Gemini provider issues

### Missing `google-generativeai` package

```
ImportError: google-generativeai package required for Gemini integration.
```

**Solution:** Install the Gemini SDK alongside QWED:

```bash theme={null}
pip install qwed google-generativeai
```

### Gemini API key not found

```
ValueError: Gemini API key not found. Set GOOGLE_API_KEY env var or run: qwed init
```

**Solution:** Set either `GOOGLE_API_KEY` or `GEMINI_API_KEY`:

```bash theme={null}
export GOOGLE_API_KEY=your-google-api-key
```

Or run the setup wizard:

```bash theme={null}
qwed init
```

### Gemini timeout errors

All Gemini API calls have a 30-second timeout. If your requests time out consistently:

1. Check your network connection to Google's API servers
2. Break large inputs into smaller parts
3. For image verification, ensure images are under 10 MB

### Gemini JSON parse errors

```
ValueError: Failed to parse JSON from Gemini endpoint.
```

This can happen when Gemini returns malformed JSON for complex queries. QWED automatically strips Markdown code fences from responses, but edge cases may still occur. **Solution:** Retry the request — the error is usually transient. If it persists, simplify your input or switch to a different provider temporarily.

***

## SDK issues

### Import error

```
ModuleNotFoundError: No module named 'qwed_sdk'
```

**Solution:**

```bash theme={null}
pip install qwed
# or
pip install qwed-sdk
```

### Async not working

```python theme={null}
# Wrong - missing await
result = client.verify("2+2=4")  # Returns coroutine, not result
```

**Solution:**

```python theme={null}
# Sync client
from qwed_sdk import QWEDClient
client = QWEDClient()
result = client.verify("2+2=4")

# Async client
from qwed_sdk import QWEDAsyncClient
async with QWEDAsyncClient() as client:
    result = await client.verify("2+2=4")  # Must await!
```

***

## DSL syntax errors

### Unknown operator

```
SECURITY BLOCK: Unknown operator 'CHECK_IF_VALID'
```

**Solution:** Only use allowed operators:

| Allowed        | Not Allowed     |
| -------------- | --------------- |
| AND, OR, NOT   | CHECK, VALIDATE |
| GT, LT, EQ     | GREATER, LESS   |
| IMPLIES, IFF   | IF, THEN        |
| FORALL, EXISTS | ALL, ANY        |

```python theme={null}
# Wrong
"(CHECK_IF_VALID x)"

# Correct
"(GT x 0)"
```

### Missing parentheses

```
SyntaxError: Missing closing ')'
```

**Solution:** Count your parentheses:

```python theme={null}
# Wrong - 3 open, 2 close
"(AND (GT x 5) (LT y 10)"

# Correct - 3 open, 3 close
"(AND (GT x 5) (LT y 10))"
```

***

## Performance issues

### Slow verification

**Possible causes:**

1. Complex expressions with many variables
2. Large code files
3. Deep recursion in symbolic execution

**Solutions:**

```python theme={null}
# 1. Use caching
from qwed_sdk import QWEDClient
client = QWEDClient(cache=True)

# 2. Batch requests
results = client.verify_batch([
    {"query": "2+2=4"},
    {"query": "3+3=6"},
])

# 3. Use async for parallel requests
async def verify_many(queries):
    async with QWEDAsyncClient() as client:
        tasks = [client.verify(q) for q in queries]
        return await asyncio.gather(*tasks)
```

### High memory usage

**Solution:** Stream large results:

```python theme={null}
# For large batch operations
for result in client.verify_batch_stream(large_list):
    process(result)
    # Processes one at a time, not all in memory
```

***

## Common error codes

| Code   | Meaning            | Solution             |
| ------ | ------------------ | -------------------- |
| `E001` | Invalid expression | Check syntax         |
| `E002` | Type mismatch      | Check variable types |
| `E003` | Division by zero   | Add guards           |
| `E004` | Timeout            | Simplify query       |
| `E005` | Rate limit         | Implement backoff    |
| `E401` | Auth failed        | Check API key        |
| `E500` | Server error       | Contact support      |

***

## Getting help

1. **Documentation:** [docs.qwedai.com](https://docs.qwedai.com)
2. **GitHub Issues:** [github.com/QWED-AI/qwed-verification/issues](https://github.com/QWED-AI/qwed-verification/issues)
3. **Email:** [support@qwedai.com](mailto:support@qwedai.com)
4. **Intercom:** Chat widget on docs site

***

## Debug mode

Enable debug logging:

```python theme={null}
import logging
logging.basicConfig(level=logging.DEBUG)

from qwed_sdk import QWEDClient
client = QWEDClient()

# Now you'll see detailed request/response logs
result = client.verify("2+2=4")
```