# Backlink Audit

> Audita el perfil de backlinks de un dominio usando la API de SemRush (o Ahrefs), identifica enlaces tóxicos y detecta oportunidades de link building.

Fuente: https://skillsagentes.com/skills/openclaudia/openclaudia-skills/backlink-audit
Markdown: https://skillsagentes.com/skills/openclaudia/openclaudia-skills/backlink-audit.md

Repositorio: https://github.com/OpenClaudia/openclaudia-skills
Autor: OpenClaudia
Licencia: MIT
Actualizado: hace 7 meses
Coste de contexto: 72 tok instalada, 3.5k tok al activarse, 3.5k tok con todos los archivos del bundle
Bundle: 1 archivo, 14 KB
Permisos que pide: ninguno declarado

## Instalación

Un skill son archivos markdown: los mismos archivos valen para cualquier agente y lo único que cambia es el directorio de destino, es decir la bandera `--agent`. Añade `-g` para instalarlo en todos los proyectos de la máquina.

```bash
# Claude Code
npx -y skills add OpenClaudia/openclaudia-skills --skill backlink-audit --agent claude-code
# Cursor
npx -y skills add OpenClaudia/openclaudia-skills --skill backlink-audit --agent cursor
# Codex
npx -y skills add OpenClaudia/openclaudia-skills --skill backlink-audit --agent codex
# Gemini CLI
npx -y skills add OpenClaudia/openclaudia-skills --skill backlink-audit --agent gemini
# Windsurf
npx -y skills add OpenClaudia/openclaudia-skills --skill backlink-audit --agent windsurf
# Cline
npx -y skills add OpenClaudia/openclaudia-skills --skill backlink-audit --agent cline
```

## Qué hace

- Consulta la API de SemRush o Ahrefs para extraer overview, dominios referentes, anchors, páginas indexadas y datos de competidores
- Calcula un puntaje de toxicidad (0-100) por backlink según señales como PBN, exact match, sitewide links, etc.
- Analiza distribución de anchor text y detecta sobre-optimización o riesgo Penguin
- Genera un archivo de disavow para Google Search Console con URLs y dominios tóxicos
- Compara el perfil de backlinks con 2-3 competidores e identifica oportunidades de link building

## Cuándo usarla

- El usuario pide auditar backlinks, revisar enlaces, o hacer un análisis de link profile
- Se menciona toxic links, disavow, link building opportunities, referring domains o anchor text
- Se pregunta por la autoridad de enlaces de un sitio

## Qué la activa

- "Audita los backlinks de mi dominio"
- "Revisa si tengo enlaces tóxicos y genera un disavow"
- "Analiza la distribución de anchor text de mi sitio"
- "Compara mis referring domains con los de mis competidores"

## Antes de instalar

- Requiere SEMRUSH_API_KEY o AHREFS_API_KEY en variables de entorno o en ~/.claude/.env.global.
- Necesita en el PATH: curl
- Variables de entorno: AHREFS_API_KEY
- makes network requests
- needs API credentials

## Archivos

- SKILL.md — 14 KB

## SKILL.md

Reproducido tal cual desde OpenClaudia/openclaudia-skills bajo MIT. Esta sección es el documento original y está en inglés.

# Backlink Audit Skill

You are an expert link building strategist and backlink auditor. Use the SemRush API to analyze a domain's backlink profile, identify toxic links, and find link building opportunities.

## Prerequisites

This skill requires either `SEMRUSH_API_KEY` or `AHREFS_API_KEY` (or both). Check for them in environment variables or in `~/.claude/.env.global`. Prefer whichever is available; if both are present, use SemRush as primary and Ahrefs to cross-reference. If neither is found, inform the user:

```
This skill requires a SemRush or Ahrefs API key. Set one via:
  export SEMRUSH_API_KEY=your_key_here
  export AHREFS_API_KEY=your_key_here
Or add them to ~/.claude/.env.global
```

## SemRush Backlink API Endpoints

Use `curl` via the Bash tool. Base URL: `https://api.semrush.com/analytics/v1/`

### Core Endpoints

**1. Backlinks Overview**
```
https://api.semrush.com/analytics/v1/?key={KEY}&type=backlinks_overview&target={domain}&target_type=root_domain&export_columns=total,domains_num,urls_num,ips_num,ipclassc_num,follows_num,nofollows_num,texts_num,images_num,forms_num,frames_num
```

**2. Backlinks List (individual links)**
```
https://api.semrush.com/analytics/v1/?key={KEY}&type=backlinks&target={domain}&target_type=root_domain&export_columns=source_url,source_title,target_url,anchor,external_num,internal_num,redirect,nofollow,image,first_seen,last_seen&display_limit=100&display_offset=0
```

**3. Referring Domains**
```
https://api.semrush.com/analytics/v1/?key={KEY}&type=backlinks_refdomains&target={domain}&target_type=root_domain&export_columns=domain,domain_ascore,backlinks_num,ip,country,first_seen,last_seen&display_limit=100&display_sort=domain_ascore_desc
```

**4. Anchor Text Distribution**
```
https://api.semrush.com/analytics/v1/?key={KEY}&type=backlinks_anchors&target={domain}&target_type=root_domain&export_columns=anchor,domains_num,backlinks_num&display_limit=50&display_sort=backlinks_num_desc
```

**5. Indexed Pages (pages receiving links)**
```
https://api.semrush.com/analytics/v1/?key={KEY}&type=backlinks_pages&target={domain}&target_type=root_domain&export_columns=target_url,backlinks_num,domains_num&display_limit=50&display_sort=backlinks_num_desc
```

**6. Competitor Backlinks (for comparison)**
```
# Reuse endpoints above with competitor domain as target
```

**7. Referring Domain Authority Score**
Domain Authority Score (domain_ascore) is returned with referring domains and ranges 0-100.

## Alternative: Ahrefs API

If `AHREFS_API_KEY` is available (and SemRush is not), use the Ahrefs API v3 endpoints below. All endpoints require the Bearer token header.

### Ahrefs Core Endpoints

**1. Backlinks Overview (Stats)**
```bash
# Ahrefs backlinks overview
curl -s "https://api.ahrefs.com/v3/site-explorer/backlinks-stats?target={domain}&output=json" \
  -H "Authorization: Bearer ${AHREFS_API_KEY}"
```
Returns: `live_backlinks`, `all_time_backlinks`, `live_refdomains`, `all_time_refdomains`, `live_refpages`, `dofollow_backlinks`, `nofollow_backlinks`.

**2. Referring Domains**
```bash
# Ahrefs referring domains
curl -s "https://api.ahrefs.com/v3/site-explorer/refdomains?target={domain}&output=json&limit=100" \
  -H "Authorization: Bearer ${AHREFS_API_KEY}"
```
Returns: Array of referring domains with `domain`, `domain_rating`, `backlinks`, `first_seen`, `last_seen`, `dofollow`, `nofollow`. Sort by `domain_rating` to see highest-authority referrers first.

**3. Backlinks List**
```bash
curl -s "https://api.ahrefs.com/v3/site-explorer/backlinks?target={domain}&output=json&limit=100&mode=subdomains" \
  -H "Authorization: Bearer ${AHREFS_API_KEY}"
```
Returns: Individual backlinks with `url_from`, `url_to`, `anchor`, `domain_rating`, `first_seen`, `last_seen`, `nofollow`, `redirect`, `edu`, `gov`.

**4. Anchors**
```bash
curl -s "https://api.ahrefs.com/v3/site-explorer/anchors?target={domain}&output=json&limit=50&mode=subdomains" \
  -H "Authorization: Bearer ${AHREFS_API_KEY}"
```
Returns: Anchor text distribution with `anchor`, `backlinks`, `refdomains`.

**5. Pages by Backlinks (Best by Links)**
```bash
curl -s "https://api.ahrefs.com/v3/site-explorer/best-by-links?target={domain}&output=json&limit=50" \
  -H "Authorization: Bearer ${AHREFS_API_KEY}"
```
Returns: Top linked pages with `url`, `backlinks`, `refdomains`, `dofollow`.

**6. Domain Rating**
```bash
curl -s "https://api.ahrefs.com/v3/site-explorer/domain-rating?target={domain}&output=json" \
  -H "Authorization: Bearer ${AHREFS_API_KEY}"
```
Returns: `domain_rating` (0-100) and `ahrefs_rank`.

### Ahrefs vs. SemRush Field Mapping

When using Ahrefs instead of SemRush, map the fields as follows:
| SemRush Field | Ahrefs Equivalent | Notes |
|---------------|-------------------|-------|
| `domain_ascore` | `domain_rating` | Both are 0-100 authority scores |
| `total` (backlinks) | `live_backlinks` | Ahrefs separates live vs. all-time |
| `domains_num` | `live_refdomains` | Referring domains count |
| `follows_num` | `dofollow_backlinks` | Dofollow link count |
| `nofollows_num` | `nofollow_backlinks` | Nofollow link count |
| `first_seen` / `last_seen` | `first_seen` / `last_seen` | Same concept, both available |

The audit process (Steps 1-7 below) works identically regardless of which API you use. Simply substitute the corresponding endpoints and field names.

## Audit Process

### Step 1: Pull Backlink Overview

Fetch the backlink overview and summarize:

```markdown
## Backlink Profile Summary: {domain}

| Metric | Value |
|--------|-------|
| Total Backlinks | {total} |
| Referring Domains | {domains_num} |
| Referring IPs | {ips_num} |
| Referring Subnets (Class C) | {ipclassc_num} |
| Follow Links | {follows_num} ({%}) |
| Nofollow Links | {nofollows_num} ({%}) |
| Text Links | {texts_num} ({%}) |
| Image Links | {images_num} ({%}) |
| Backlink-to-Domain Ratio | {total/domains_num} |
```

### Step 2: Analyze Referring Domains

Pull the top referring domains sorted by authority score. Evaluate:

**Domain Quality Tiers:**

| Tier | Authority Score | Quality | Action |
|------|----------------|---------|--------|
| Tier 1 | 80-100 | Excellent | Protect and nurture |
| Tier 2 | 60-79 | Good | Maintain relationship |
| Tier 3 | 40-59 | Average | Monitor |
| Tier 4 | 20-39 | Low quality | Review for relevance |
| Tier 5 | 0-19 | Suspicious | Investigate for toxicity |

**Domain Quality Distribution:**
Calculate the percentage of referring domains in each tier. A healthy profile should have:
- Tier 1-2: at least 10-15% of referring domains
- Tier 3: 30-40%
- Tier 4: 20-30%
- Tier 5: < 20% (flag if higher)

**Diversity Analysis:**
- Unique IPs vs. referring domains (ratio close to 1:1 is healthy)
- Unique Class C subnets (should be close to IP count)
- Country distribution (should match target market)
- TLD distribution (.com, .org, .edu, .gov diversity is positive)

### Step 3: Analyze Anchor Text Distribution

Pull anchor text data and classify each anchor:

| Anchor Type | Healthy Range | Description | Example |
|------------|---------------|-------------|---------|
| Branded | 30-50% | Brand name or domain | "Acme Corp", "acme.com" |
| Naked URL | 10-20% | Raw URL | "https://acme.com/product" |
| Generic | 10-15% | Non-descriptive text | "click here", "read more", "this website" |
| Topic/Keyword | 10-20% | Natural topic reference | "project management software" |
| Exact Match | 1-5% | Exact target keyword | "best project management tool" |
| Partial Match | 5-10% | Includes target keyword variation | "top tools for project management" |
| Compound | 5-10% | Brand + keyword | "Acme project management" |
| Image (no alt) | < 5% | Images without alt text | [image] |

**Red flags in anchor text:**
- Exact match > 10% = Over-optimized (Penguin risk)
- Single anchor > 15% of total = Unnatural concentration
- Money keyword anchors from low-quality sites = Likely spam
- Irrelevant anchors (casino, pharma, adult) = Toxic links
- Foreign language anchors unrelated to business = Likely spam

### Step 4: Identify Toxic Links

Score each backlink for toxicity based on these signals:

**Toxicity Signals (each adds to a toxicity score 0-100):**

| Signal | Weight | Detection Method |
|--------|--------|-----------------|
| Source domain AS < 10 | +15 | From referring domains data |
| Source is known link farm/PBN pattern | +30 | Domain name patterns: keyword-keyword-keyword.com, random strings |
| Anchor text is exact match keyword | +10 | From anchor text analysis |
| Source page has 100+ external links | +20 | From external_num column |
| Source is irrelevant niche | +15 | Compare source domain topic to target |
| Source has no organic traffic | +15 | Check via domain_organic if budget allows |
| Link from sitewide (footer/sidebar) | +10 | Same domain, many links to same target |
| Link from non-indexed page | +20 | Page not in Google (manual check) |
| Redirect chain to target | +10 | From redirect column |
| Foreign language + irrelevant | +15 | From anchor text + domain TLD |

**Toxicity Rating:**
- 0-20: Clean - no action needed
- 21-40: Monitor - watch for changes
- 41-60: Suspicious - investigate further
- 61-80: Likely toxic - consider disavow
- 81-100: Toxic - add to disavow list

### Step 5: Link Velocity Analysis

Analyze the `first_seen` and `last_seen` dates to determine:

- **Monthly new links** over the past 12 months
- **Monthly lost links** (links where last_seen is in the past)
- **Net link growth rate**
- **Velocity spikes** (unnatural bursts of links)

**Healthy velocity patterns:**
- Steady, gradual growth = Natural
- Correlated with content publishing = Natural
- Sudden spike then flat = Likely campaign or mention (investigate)
- Massive spike from low-quality domains = Negative SEO attack (flag immediately)
- Declining trend = Losing links, need outreach

### Step 6: Competitor Comparison

Pull backlink overview for 2-3 competitors and compare:

```markdown
## Competitor Backlink Comparison

| Metric | {Your Domain} | {Competitor 1} | {Competitor 2} | {Competitor 3} |
|--------|--------------|----------------|----------------|----------------|
| Total Backlinks | | | | |
| Referring Domains | | | | |
| Avg. Domain AS | | | | |
| Follow % | | | | |
| Link Growth (6mo) | | | | |
```

**Link Gap Analysis:**
Find domains that link to competitors but not to the target:
1. Pull top 100 referring domains for each competitor
2. Filter out domains already linking to the target
3. Sort by authority score
4. These are outreach targets

### Step 7: Generate Disavow File

If toxic links are found, generate a Google Disavow file:

```
# Disavow file for {domain}
# Generated: {date}
# Total entries: {count}

# Individual URLs (confirmed toxic)
{url1}
{url2}

# Full domains (majority of links from domain are toxic)
domain:{domain1}
domain:{domain2}
```

**Disavow rules:**
- Only disavow domains where 80%+ of their links are toxic
- For mixed domains, disavow individual URLs
- Never disavow high-authority domains (AS > 60) without manual verification
- Always recommend the user review the list before submitting

## Output Report Format

```markdown
# Backlink Audit Report: {domain}
**Date:** {date}
**Total Backlinks:** {total}
**Referring Domains:** {count}
**Health Score:** {score}/100

## Executive Summary
{2-3 sentences summarizing the health of the backlink profile}

## Profile Overview
{Overview table from Step 1}

## Referring Domain Quality

### Distribution by Authority
| Tier | Range | Count | Percentage | Status |
|------|-------|-------|-----------|--------|
| Tier 1 | 80-100 | {} | {}% | {Good/Needs more} |
| ... | ... | ... | ... | ... |

### Top 20 Referring Domains
| Domain | Authority | Backlinks | First Seen | Status |
|--------|----------|-----------|-----------|--------|
| {} | {} | {} | {} | {} |

## Anchor Text Analysis

### Distribution
| Type | Percentage | Status |
|------|-----------|--------|
| Branded | {}% | {Healthy/Over/Under} |
| ... | ... | ... |

### Top 20 Anchors
| Anchor | Domains | Backlinks | Type |
|--------|---------|-----------|------|
| {} | {} | {} | {} |

## Toxic Link Analysis

### Summary
- **Total toxic links found:** {count}
- **Toxic referring domains:** {count}
- **Recommended for disavow:** {count}

### Toxic Links Detail
| Source URL | Anchor | Toxicity Score | Signals |
|-----------|--------|---------------|---------|
| {} | {} | {}/100 | {} |

## Link Velocity
{Monthly new/lost links chart description}
{Assessment of velocity health}

## Competitor Comparison
{Comparison table}

## Link Building Opportunities

### Domains Linking to Competitors (Not You)
| Domain | Authority | Links to Competitors | Outreach Strategy |
|--------|----------|---------------------|-------------------|
| {} | {} | {} | {} |

### Recommended Link Building Tactics
1. **{Tactic}** - {Description, estimated effort, expected results}
2. ...

## Action Items

### Immediate (This Week)
1. {Specific action}

### Short Term (This Month)
1. {Specific action}

### Ongoing
1. {Specific action}

## Disavow File
{If applicable, include the generated disavow file content}
```

## Notes

- SemRush API has rate limits. Space out calls if making many requests.
- Backlink data may be up to 30 days old. Note this in the report.
- Never recommend disavowing links from legitimately authoritative domains.
- For new sites (< 6 months), a small backlink profile is normal, not a problem.
- Always recommend manual review of the disavow list before submission to Google Search Console.
- If the user has Google Search Console access, recommend cross-referencing with GSC's link report for the most complete picture.

## Dónde encaja

- Categoría: [SEO y GEO](https://skillsagentes.com/categorias/seo-geo.md) — Keywords, auditorías on-page, datos estructurados y visibilidad en respuestas de IA.
- Creador: [OpenClaudia](https://skillsagentes.com/creators/openclaudia.md) — 76 skills en el directorio
- [Todas las skills](https://skillsagentes.com/skills.md)
- [Ranking de instalaciones](https://skillsagentes.com/ranking.md)

## Otras skills del mismo repositorio

- [Competitor Traffic Report](https://skillsagentes.com/skills/openclaudia/openclaudia-skills/competitor-traffic-report.md): Genera un informe HTML autocontenible de tráfico competitivo: visitas mensuales (SimilarWeb), tráfico orgánico y Domain Rating (Ahrefs), con gráficos ranked, tendencias y tabla de datos.
- [Brand Dev](https://skillsagentes.com/skills/openclaudia/openclaudia-skills/brand-dev.md): Obtiene datos de marca (nombre, descripción, logos, industria) desde la API de brand.dev y guarda los logos localmente.
- [Gsc Portfolio Audit](https://skillsagentes.com/skills/openclaudia/openclaudia-skills/gsc-portfolio-audit.md): Audita TODAS las propiedades de Google Search Console a la vez: ranking por clics e impresiones con deltas, y diff de keywords por sitio (nuevas, suben, bajan, perdidas, o bien rankeadas sin clics).
- [Wechat Moments](https://skillsagentes.com/skills/openclaudia/openclaudia-skills/wechat-moments.md): Clasifica y resume el feed de WeChat Moments (朋友圈) del usuario para que los eventos reales y la información genuina destaquen sobre la promoción, ponderando según cuánto le escribe el usuario a cada autor.
- [Podcast Edit](https://skillsagentes.com/skills/openclaudia/openclaudia-skills/podcast-edit.md): Edita audio o video de podcast: recorta charla previa/posterior, quita muletillas, corta silencios, mejora el audio y aplica el mismo corte a una versión en video.

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