# is-port-21-open-bulk

> is-port-21-open-bulk is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-11).

Checks whether TCP port 21 (FTP) is open on up to 20 hosts in a single concurrent batch call, returning ordered results with per-item error fields and a failure count.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/bulk/ip/port/21?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-port-21-open-bulk-a5b4c3c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hfM35qUk-6trxLZWJIpRr

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability is-port-21-open-bulk-a5b4c3c8
```

Example prompt: Check whether port 21 is open on these hosts: 192.168.1.1, 10.0.0.5, ftp.example.com, and 203.0.113.10 — give me a result for each one and flag any that failed.

## When to prefer this

Choose this endpoint when you have a list of 2–20 hosts to check for open FTP (port 21) and want to minimize round-trips and API cost compared to calling the single-host endpoint repeatedly. It processes all hosts concurrently so total latency is roughly the same as a single check. Prefer it over the single endpoint any time you hold a batch of IPs or hostnames to scan.

## Known failure modes

- Host unreachable or DNS resolution failure — per-item error field populated, failure count incremented
- Timeout on TCP connection attempt — individual host marked as error, others still returned
- Batch exceeds 20-host limit — request rejected or truncated
- Network firewall blocking probe traffic — port may appear closed when it is actually filtered
- Payment not processed — x402 payment required error before results are returned

## How this service works

Bulk is port 21 open: up to 20 hosts in one call, processed concurrently, results in input order with a per-item error field and a failure count. Same answer per item as the single endpoint. Batch enrichment for agents that hold a list. $0.10 per batch.

## Output

An ordered array of results matching the input host list, where each item contains the open/closed status of port 21 and an error field if the check failed for that host. A top-level failure count indicates how many items encountered errors across the batch.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/is-port-21-open-bulk-a5b4c3c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ip.intel.rallylive.ca](https://www.zero.xyz/host/ip.intel.rallylive.ca/llms.txt)