> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agentlinkops.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Check a link for free
> One free placement check with evidence and honest uncertainty.
`verify_link_free`
One free placement check with evidence and honest uncertainty. Supply a source page that should carry a link and the destination you care about; the source page is fetched once and the tool reports whether that page links to the destination in the HTML it served at that moment. Four states: success (link found, every occurrence with anchor and rel), valid-negative (a COMPLETE read contains no link; never a claim the link is gone), unknown (the web did not answer; never means the link was removed or lost), failed (the check never ran: invalid input, the anonymous daily limit, or service , never a verdict on the web). No account or any connection required. No browser rendering: a page that needs JavaScript to render returns unknown. Anonymous ceilings: 3 checks per UTC day per visitor, 1 concurrent, one page fetched per check, 15-minute result cache. Raw publisher HTML is never returned.
Anonymous hosted check. No account required.
| Access | Behavior |
| --------- | --------------------- |
| Anonymous | Writes or admits work |
The anonymous allowance is three checks per UTC day per visitor, one concurrent check and a fifteen-minute result cache. This inline result does not create a workspace, queued job or recurring monitor.
## Example request
Use the anonymous MCP endpoint at `/free/mcp` or HTTP `/free/check`.
```json MCP theme={null}
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "verify_link_free",
"arguments": {
"sourceUrl": "https://publisher.example.com/resources",
"targetUrl": "https://example.com/guide"
}
}
}
```
```bash HTTP theme={null}
curl https://app.agentlinkops.com/free/check \
-H 'Content-Type: application/json' \
--data '{"sourceUrl":"https://publisher.example.com/resources","targetUrl":"https://example.com/guide"}'
```
## Returned result
Illustrative data validated against the documented response schema. IDs and dates are examples, not a live account capture. MCP returns structured data with a Markdown explanation. The HTTP result also establishes an anonymous visitor cookie.
```json theme={null}
{
"state": "success",
"reason": "link_found",
"requested_url": "https://publisher.example.com/resources",
"inspected_url": "https://publisher.example.com/resources",
"target_url": "https://example.com/guide",
"scope": "exact",
"checked_at": "2026-09-13T12:00:00.000Z",
"complete": true,
"occurrences": [
{
"targetUrl": "https://example.com/guide",
"anchor": "Example",
"rel": []
}
],
"checker_version": "example-checker",
"uncertainty": [
"This page links to https://example.com/guide in the HTML it served at 2026-09-13T12:00:00.000Z.",
"Static HTML observation: JavaScript execution and visual visibility were not checked.",
"Nothing here says anything about indexing, ranking or traffic."
],
"result_id": "fc_example",
"permalink": null,
"cached": false
}
```
## Input fields
Omit optional fields when you do not want to supply them. Null is accepted only where listed. Unknown input properties are rejected.
| Field | Type | Presence | Meaning and constraints |
| ----------- | ------ | -------- | --------------------------------------------------------------------------------------------------------------------------------- |
| `sourceUrl` | string | Required | Public publisher page URL containing the placement to inspect. minLength: 1; maxLength: 8192 |
| `targetUrl` | string | Required | Public destination URL expected in the placement. minLength: 1; maxLength: 8192 |
| `scope` | string | Optional | URL matching rule: exact URL, domain, subdomain, or path prefix. default: "exact"; values: "exact", "domain", "subdomain", "path" |
### Validation and omitted values
This operation returns its result directly; it does not create a workspace job. Anonymous allowance is three checks per UTC day per visitor, one concurrent check, with a fifteen-minute result cache.
The failed state means the check did not run. Unknown and valid-negative are evidence outcomes and do not establish confirmed loss.
### Defaults when omitted
| Field | Default |
| ------- | --------- |
| `scope` | `"exact"` |
## Output fields
Fields inside optional or nullable parents apply only when that parent exists. [Common schema conventions](/reference/schemas) explain evidence states, empty lists and extensions.
| Field | Type | Presence | Meaning and constraints |
| ------------------------- | ------------- | -------- | -------------------------------------------------------------------------------------------------------------------------- |
| `state` | string | Required | Saved lifecycle or evidence state, as enumerated for this record. values: "success", "valid-negative", "unknown", "failed" |
| `reason` | string | Required | Recorded explanation; null when no explanation applies. |
| `requested_url` | string / null | Required | requested url recorded for this result. |
| `inspected_url` | string / null | Required | inspected url recorded for this result. |
| `target_url` | string / null | Required | Destination URL recorded in this evidence. |
| `scope` | string | Required | scope recorded for this result. |
| `checked_at` | string | Required | UTC timestamp of the saved check. |
| `complete` | boolean | Required | complete recorded for this result. |
| `occurrences` | array | Required | occurrences recorded for this result. |
| `occurrences[].targetUrl` | string | Required | target Url recorded for this result. |
| `occurrences[].anchor` | string | Required | anchor recorded for this result. |
| `occurrences[].rel` | array | Required | rel recorded for this result. |
| `checker_version` | string / null | Required | checker version recorded for this result. |
| `uncertainty` | array | Required | uncertainty recorded for this result. |
| `failure` | string | Optional | failure recorded for this result. values: "invalid\_input", "budget", "cooling", "service" |
| `retry_at` | string | Optional | retry at recorded for this result. |
| `retry_after_seconds` | number | Optional | retry after seconds recorded for this result. |
| `result_id` | string | Optional | result id recorded for this result. |
| `permalink` | string / null | Optional | permalink recorded for this result. |
| `cached` | boolean | Optional | cached recorded for this result. |
[Download input schema](/schemas/verify_link_free.input.json) ยท [Download output schema](/schemas/verify_link_free.output.json)
## Errors and retries
This command is not annotated idempotent. After a timeout, inspect existing state before repeating a write.
See [error recovery](/reference/errors) for status, scope, cooldown, cursor and retry handling. Unknown observations are result data and do not establish loss.
## HTTP resource routes
Use `POST /free/check`. HTTP also supports retrieving a cached anonymous result; see [anonymous HTTP result retrieval](/reference/http/protocol).
## Continue
Follow the [related workflow](/guides/first-result), inspect [capability status](/capability-status), or return to the [command index](/reference/index).