DKIM Validation Skill

Overview

This tool inspects the DKIM record by performing DNS lookups for common selectors. It validates the syntax, surfaces the public-key length in bits, flags testing mode, and derives a composite email-signing posture score so you can tell at a glance whether a domain's DKIM key actually protects its mail.

Live Test DKIM Validation Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as DKIMValidationSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "DKIMValidationSkill",
  "arguments": {
    "domain": "github.com"
  }
}

You do not name the tool yourself; the model picks it. Asking about github.com in the terms this skill covers is enough for it to reach for DKIMValidationSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

https://api.vervekit.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "selector": "s1",
    "host": "github.com",
    "dkim_host": "s1._domainkey.github.com",
    "cname_target": null,
    "has_dkim_record": true,
    "dkim_record": "k=rsa; t=s; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyn3fMCVpb7ryIRKOGXhXVGYmsWUitNlSckqGHOwNFZgFadplOrD+Qzf1XQkP7MH/VB/97DsAAJGtEXW1Uq71Hjnfr/DuBN/YfjF/gU70qEFb7q1sdIiNtjFL2TkOpoW+X/bhhPNheW/fYwyFb6ZHFM6LTgXyuimWRHTOUP3VjZzhNVda79nt+2WZYbS4l8HdMgWpTNHjpVw5PtXESA9KBg/evSRk5fIaXIX5eRXW3baoV9yVzD8O29/IL/DiSk+yNvaO0EHL5c4yGuZJhGzvpiznb2IDVdemJK4Dqzdy5FTN/SGYZhAEr7MguG3Z314hMS2scgMsOMgB64uj/6+6UwIDAQAB",
    "dkim_records_count": 1,
    "key_type": "rsa",
    "issues_found": [
      {
        "code": "V_TAG_NOT_FOUND",
        "type": "warning",
        "message": "The v tag is missing"
      },
      {
        "code": "STRICT_MODE",
        "type": "info",
        "message": "Strict flag set (t=s): the i= identity domain must exactly match d= (no subdomains)"
      }
    ],
    "valid": true,
    "key_bits": 2048,
    "is_test_mode": false,
    "risk_score": 0,
    "risk_level": "low"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 10 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Email Service Onboarding

When a new customer connects a sending domain, verify their public key length and check whether testing mode is active before sending campaigns.

Mail Security Auditing

To prevent spoofing across corporate domains, security analysts inspect DNS selectors to confirm valid DKIM records and flag keys shorter than 2048 bits.

Sender Deliverability Diagnostics

Deliverability consultants check whether outbound domains publish valid DKIM public keys or point to unresolved CNAME targets when diagnosing inbox placement drops.

Tenant Domain Verification

Flag missing or misconfigured DKIM records during custom domain setup so software platforms can alert workspace admins before outgoing notifications fail authentication.

Other ways to use DKIM Validation Skill

Set up DKIM Validation Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Related

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