---
name: "xpay-clinical-trials-get-available-fields"
description: "Get organized list of available fields for customizing search results.

This tool provides a list of available fields that can be used to customize the results of other search tools.
The fields are organized into categories.

Input:
  - `category`: An optional string to specify a category of fields to return.
                If not provided, all categories and default fields will be returned.
                Example: `'conditions'`"
version: "1.0.0"
price: "$0.01/call"
provider: "Clinical Trials"
---

# Get Available Fields

Get organized list of available fields for customizing search results.

This tool provides a list of available fields that can be used to customize the results of other search tools.
The fields are organized into categories.

Input:
  - `category`: An optional string to specify a category of fields to return.
                If not provided, all categories and default fields will be returned.
                Example: `'conditions'`

**Provider:** Clinical Trials
**Price:** $0.01/call
**Pricing model:** Flat rate per call

## When to Use

Use this tool when you need to get organized list of available fields for customizing search results.

this tool provides a list of available fields that can be used to customize the results of other search tools.
the fields are organized into categories.

input:
  - `category`: an optional string to specify a category of fields to return.
                if not provided, all categories and default fields will be returned.
                example: `'conditions'`. This is part of the Clinical Trials provider on xpay✦.

## MCP Connection

Connect to xpay✦ to access this tool (and 11+ others):

```json
{
  "mcpServers": {
    "xpay": {
      "url": "https://mcp.xpay.sh/mcp?key=YOUR_API_KEY"
    }
  }
}
```

For Claude Code:
```bash
claude mcp add --transport http xpay "https://mcp.xpay.sh/mcp?key=YOUR_API_KEY"
```

## How to Execute

Use the xpay✦ meta-tools to run this tool:

1. **`xpay_details`** — Get full input schema: `xpay_details("clinical-trials/get_available_fields")`
2. **`xpay_run`** — Execute: `xpay_run("clinical-trials/get_available_fields", { ...inputs })`

## Input Parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `category` | string | No | Optional: specific category to return (identification, status, conditions, design, interventions, arms, outcomes, eligibility, locations, sponsors, descriptions, contacts, results) |

## Pricing

- **Cost:** $0.01/call
- **Balance check:** Use `xpay_balance` to check remaining credits
- Get your API key at [xpay.tools](https://xpay.tools/account/settings/api-keys/) — $5 free credits included

## Related Skills

- [Clinical Trials (all tools)](https://xpay.tools/skills/clinical-trials/SKILL.md) — 12 tools
- [Search Trials By Condition](https://xpay.tools/skills/clinical-trials/search-trials-by-condition/SKILL.md) — $0.01/call
- [Search Trials By Intervention](https://xpay.tools/skills/clinical-trials/search-trials-by-intervention/SKILL.md) — $0.01/call
- [Search Trials By Sponsor](https://xpay.tools/skills/clinical-trials/search-trials-by-sponsor/SKILL.md) — $0.01/call
- [Search Trials By Acronym](https://xpay.tools/skills/clinical-trials/search-trials-by-acronym/SKILL.md) — $0.01/call
- [Search Trials By Nct Ids](https://xpay.tools/skills/clinical-trials/search-trials-by-nct-ids/SKILL.md) — $0.01/call

## Links

- Tool page: https://xpay.tools/clinical-trials/get-available-fields/
- Provider: https://xpay.tools/clinical-trials/
- All tools: https://xpay.tools/explore