# FAQ
## Does BioMCP require API keys?
No for most workflows.
Optional keys improve access for specific enrichments and source variants.
See [API keys](../getting-started/api-keys.md).
## Where are cached files stored?
BioMCP uses platform cache directories.
Typical locations:
- Linux: `~/.cache/biomcp/`
- macOS: `~/Library/Caches/biomcp/`
The cache generally contains:
- `http-cacache/` for HTTP responses,
- `downloads/` for retrieved text artifacts.
## Why do invalid dates fail immediately?
Date validation is performed before network calls.
Examples of invalid inputs:
- `2024-13-01` (invalid month)
- `2024-02-30` (invalid day)
- `2023-02-29` (non-leap-year day)
This behavior provides immediate feedback and avoids unnecessary API requests.
## How do I request full article text now?
Use positional sections:
```bash
biomcp get article 22663011 fulltext
```
The same model applies to other entities:
```bash
biomcp get trial NCT02576665 eligibility
biomcp get gene BRAF pathways
biomcp get variant "BRAF V600E" predict
```
## How do I use BioMCP with Claude Desktop?
Configure an MCP server entry using `biomcp serve`.
See [Claude Desktop setup](../getting-started/claude-desktop.md).
## Why are some fields missing?
BioMCP returns concise defaults and depends on upstream source completeness.
When you need more detail:
1. request a section,
2. switch to JSON,
3. verify source availability with `biomcp health --apis-only`.
## How do I inspect available commands quickly?
```bash
biomcp list
biomcp list trial
biomcp list variant
```
## Is BioMCP suitable for final clinical decisions?
BioMCP is a retrieval and workflow tool.
Clinical decisions require domain-expert review and institutional validation processes.
## How do I report reproducible issues?
Include:
- exact command,
- expected vs actual behavior,
- `biomcp --version`,
- relevant environment details,
- whether the issue reproduces with `--json`.
