Markdown Link Validator
text.validate_markdown_links
Overview
Two validation levels, both offline: (1) SYNTACTIC — parses Markdown (CommonMark) and checks link/image and external-URL syntax and flags dangerous URI schemes; (2) LOCAL RESOLUTION — resolves internal heading anchors and relative file references against a provided known-files list. It does NOT do NETWORK resolution: 'valid' means no error-level syntactic or local-resolution finding, never that an external URL is reachable.
Broken links hurt docs quality — we lint Markdown link and anchor syntax locally, with no network crawl.
Reliability
VERIFIABLE and deterministic — identical markdown and options always yield the same findings. No network access; valid means no error-level syntactic or local-resolution finding, not that external URLs are reachable. Input validation (not retryable): maxFindings outside 1 to 20,000; markdown missing, not a string, or longer than 2,000,000 characters.
Context footprint
Bounded input (2 MB); findings capped by maxFindings. A successful call costs 1 execution credit.
When to use it
Before you publish Markdown, to catch broken anchors, malformed links, and dangerous URI schemes.
Do not use when you need to verify that external URLs actually resolve (use web.check_url_status for reachability).
Scope
Non-goals
- Does not check whether external URLs are reachable
- Does not fetch or crawl any URL
- Does not render the Markdown
Properties
Capabilities
Cost & billing
Flat rate per invocation
File handling
How we handle your data
What this means
This skill may receive sensitive content, but it does not target sensitive data and returns only a structured non-sensitive result.
Squillify guarantees
- Runs inside Squillify
- This skill runs inside Squillify.
- Payloads are not sent to an external service by this skill.
- Squillify does not permanently store submitted payloads.
- Telemetry records metadata only, not submitted content.
- Submitted payloads are not used for training.
- Submitted payloads are not reviewed by humans.
- This skill does not target sensitive data.
- The response does not contain submitted content.
Your responsibility
Squillify does not determine whether submitted content is sensitive. Your application is responsible for deciding what data it is allowed to submit. Your application is responsible for securing the response.
Input schema
| Field | Type | Required | Description |
|---|---|---|---|
| markdown | string | Yes | Markdown document whose links and anchors are validated. |
| basePath | string | No | Reserved base path; omit it because it has no effect in this version. |
| knownFiles | array | No | Bounded optional array of known relative file paths; omit it to treat no relative file as known. The item shape is defined by the nested schema and the array contains from 0 through 20000 items. |
| checkImages | boolean | No | Whether image links are checked; omit it for true. |
| checkExternalUrlSyntax | boolean | No | Whether external URL syntax is checked; omit it for true. |
| checkInternalAnchors | boolean | No | Whether heading anchors are checked; omit it for true. |
| maxFindings | integer | No | Finding cap; omit it for one thousand. |
Output schema
| Field | Type | Required | Description |
|---|---|---|---|
| valid | boolean | Yes | Whether no error-severity finding exists. |
| links | array | Yes | Bounded array of discovered link receipts in document order with text, target, kind, line, and column. The item shape is defined by the nested schema and the array contains from 0 through 20000 items. |
| findings | array | Yes | Bounded array of link findings with severity, code, message, target, and optional source coordinates. The item shape is defined by the nested schema and the array contains from 0 through 20000 items. |
API contract
POST /v1/executecurl -sS -X POST "$BASE/v1/execute" -H "Authorization: Bearer $KEY" -H 'Content-Type: application/json' -d '{"skillKey":"text.validate_markdown_links","input":{"markdown":"[x](#missing)"}}'import { Squillify } from "@squillify/sdk";
const sq = new Squillify({ apiKey: process.env.SQUILLIFY_API_KEY });
const { output } = await sq.execute("text.validate_markdown_links", {"markdown":"# Title\n[jump](#missing)\n"});Errors
| Code | HTTP | Retryable | Description |
|---|---|---|---|
| VALIDATION_ERROR | 400 | No | The request payload failed schema validation. |
| UNAUTHORIZED | 401 | No | Missing or invalid API key. |
| SKILL_NOT_ACCESSIBLE | 403 | No | The API key is not granted access to this skill. |
| SKILL_NOT_AVAILABLE_FOR_PLAN | 403 | No | This skill is not included in your current plan. |
| PLAN_ELIGIBILITY_UNAVAILABLE | 503 | Yes | Plan eligibility could not be decided. Retry after backoff. |
| SKILL_NOT_FOUND | 404 | No | The requested skill or version does not exist. |
| TENANT_RATE_LIMITED | 429 | Yes | Request rate limit exceeded. Retry after backoff. |
| QUOTA_EXCEEDED | 429 | Yes | Plan quota exhausted. Retryable once the quota period resets. |
| EXECUTION_TIMEOUT | 504 | Yes | Execution exceeded the allowed time budget. |
Other limits
| Limit | Value |
|---|---|
| Recommended inline bytes | 32 KiB |
Limitations
- Does not check whether external URLs are reachable
- Does not fetch or crawl any URL
- Does not render the Markdown
- Checking external URL availability
- Rendering Markdown to HTML
How to call
POST /v1/execute (requires authentication)
{
"skillKey": "text.validate_markdown_links",
"input": {
"markdown": "# Title\n[jump](#missing)\n"
}
}Examples
Broken internal anchor
{
"markdown": "# Title\n[jump](#missing)\n"
}{
"links": [
{
"column": 1,
"target": "#missing",
"kind": "inline",
"text": "jump",
"line": 2
}
],
"valid": false,
"findings": [
{
"message": "Internal anchor not found: #missing",
"code": "BROKEN_ANCHOR",
"severity": "error",
"target": "#missing",
"column": 1,
"line": 2
}
]
}Valid external link syntax
{
"markdown": "[docs](https://example.com/docs)"
}{
"links": [
{
"column": 1,
"target": "https://example.com/docs",
"kind": "inline",
"text": "docs",
"line": 1
}
],
"valid": true,
"findings": []
}Recommended use cases
- Lint agent-generated documentation for broken links
- Validate internal anchors before publishing docs
- Catch dangerous URI schemes in Markdown
Avoid for
- Checking external URL availability
- Rendering Markdown to HTML
Related skills
Composable with
Safety & privacy
- Runs without calling any external service.
- Your payloads are never stored permanently.
- Telemetry captures metadata only — never your payload contents.
- We never train models on your payloads.
- No human reviews your payloads.