Agent skill

Verify Email

by gooseworks-ai in gooseworks-ai/goose-skills

Verify if an email address is valid and deliverable. An agent skill from gooseworks-ai/goose-skills.

MITAuto-check passed

Install Verify Email

skills CLI

$ npx skills add gooseworks-ai/goose-skills --skill verify-email -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install gooseworks-ai/goose-skills verify-email --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/gooseworks-ai/goose-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/lead-generation/capabilities/verify-email .claude/skills/verify-email && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "verify-email" agent skill from https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email into .claude/skills/verify-email/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "verify-email", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add gooseworks-ai/goose-skills --skill verify-email -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install gooseworks-ai/goose-skills verify-email --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/gooseworks-ai/goose-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/lead-generation/capabilities/verify-email .agents/skills/verify-email && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "verify-email" agent skill from https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email into .agents/skills/verify-email/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "verify-email", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add gooseworks-ai/goose-skills --skill verify-email -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install gooseworks-ai/goose-skills verify-email --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/gooseworks-ai/goose-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/lead-generation/capabilities/verify-email .cursor/skills/verify-email && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "verify-email" agent skill from https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email into .cursor/skills/verify-email/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "verify-email", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/gooseworks-ai/goose-skills.git --path skills/lead-generation/capabilities/verify-email

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add gooseworks-ai/goose-skills --skill verify-email -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install gooseworks-ai/goose-skills verify-email --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/gooseworks-ai/goose-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/lead-generation/capabilities/verify-email .gemini/skills/verify-email && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "verify-email" agent skill from https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email into .gemini/skills/verify-email/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "verify-email", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install gooseworks-ai/goose-skills verify-email

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add gooseworks-ai/goose-skills --skill verify-email -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/gooseworks-ai/goose-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/lead-generation/capabilities/verify-email .github/skills/verify-email && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "verify-email" agent skill from https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email into .github/skills/verify-email/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "verify-email", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add gooseworks-ai/goose-skills --skill verify-email -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install gooseworks-ai/goose-skills verify-email --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/gooseworks-ai/goose-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/lead-generation/capabilities/verify-email .opencode/skills/verify-email && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "verify-email" agent skill from https://github.com/gooseworks-ai/goose-skills/tree/main/skills/lead-generation/capabilities/verify-email into .opencode/skills/verify-email/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "verify-email", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: verify-email
GitHub stars: 1.2k
Used in: 1 other repo
Token cost: ~1.3k tokens
SKILL.md length: 433 words
Files: 2
Skills in repo: 273
Repo updated: Oct 8, 2026
First seen: Oct 9, 2026
Licence: MIT

At a glance

Verify if an email address is valid and deliverable. An agent skill from gooseworks-ai/goose-skills.

SKILL.md covers Setup, When to Use, How It Works and Usage, plus 6 more sections
Calls curl, python3 and npx; reaches api.gooseworks.ai; needs GOOSEWORKS_API_KEY

What it does

Verify Email is an agent skill from gooseworks-ai/goose-skills. Verify if an email address is valid and deliverable

Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `skill.meta.json`).

The repository describes itself as: Library of Growth & GTM skills + data APIs for Claude Code, Codex, Cursor to run ads, social, content, lead gen, seo and data scraping. The licence is MIT.

Example prompts

“/verify-email”

Requirements

Python 3
Node.js
A credential in GOOSEWORKS_API_KEY

What it can do on your machine

Read from SKILL.md and the folder at commit c650c6d. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- curl
- python3
- npx
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
- api.gooseworks.ai
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names these keys or tokens, usually read from environment variables:
- GOOSEWORKS_API_KEY
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Verify Email loads about 1.3k tokens when it runs. Until then it costs about 16 tokens; SKILL.md has 433 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~16
When it runs · the whole SKILL.md, loaded when a task matches: ~1.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from gooseworks-ai/goose-skills at commit c650c6d, republished under its MIT licence (© gooseworks-ai). 433 words, ~1,283 tokens.

Download SKILL.mdSave it as .claude/skills/verify-email/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.

name: verify-email
description: Verify if an email address is valid and deliverable
source: orthogonal

Email Verification

Setup

Read your credentials from ~/.gooseworks/credentials.json:

bash

export GOOSEWORKS_API_KEY=$(python3 -c "import json;print(json.load(open('$HOME/.gooseworks/credentials.json'))['api_key'])")
export GOOSEWORKS_API_BASE=$(python3 -c "import json;print(json.load(open('$HOME/.gooseworks/credentials.json')).get('api_base','https://api.gooseworks.ai'))")

If ~/.gooseworks/credentials.json does not exist, tell the user to run: npx gooseworks login

All endpoints use Bearer auth: -H "Authorization: Bearer $GOOSEWORKS_API_KEY"

Check if an email address is valid, exists, and can receive mail. Prevent bounces before sending.

When to Use

User wants to verify an email before sending
User asks "is this email address real?"
Cleaning an email list
Before cold outreach to avoid bounces
Validating user-provided email addresses

How It Works

Uses Hunter or Tomba APIs to verify email deliverability through multiple checks including syntax, domain, and mailbox verification.

Usage

Verify with Hunter

bash

curl -s -X POST $GOOSEWORKS_API_BASE/v1/proxy/orthogonal/run \
  -H "Authorization: Bearer $GOOSEWORKS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"api":"hunter","path":"/v2/email-verifier","query":{"email":"john@example.com"}}'

Verify with Tomba

bash

curl -s -X POST $GOOSEWORKS_API_BASE/v1/proxy/orthogonal/run \
  -H "Authorization: Bearer $GOOSEWORKS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"api":"tomba","path":"/v1/email-verifier","query":{"email":"jane@company.com"}}'

Parameters

email (required) - The email address to verify

Response

Hunter Response

Returns data object:

status (string) - valid, invalid, accept_all, or unknown
score (integer) - Confidence score 0-100
result (string) - deliverable, undeliverable, or risky (deprecated — use status)
regexp (boolean) - Syntax is valid
gibberish (boolean) - Address looks random
disposable (boolean) - Temporary email service
webmail (boolean) - Free webmail provider (Gmail, Yahoo, etc.)
mx_records (boolean) - Domain has MX records
smtp_server (boolean) - SMTP server responds
smtp_check (boolean) - Mailbox exists on server
accept_all (boolean) - Server accepts all addresses
block (boolean) - Email is blocked
sources (array) - Web pages where this email was found

Tomba Response

Returns data.email object:

status (string) - valid, invalid, or accept_all
result (string) - deliverable, undeliverable, or risky
score (integer) - Confidence score 0-100
smtp_provider (string) - Email provider name (e.g., "Google Workspace")
mx (object) - records array of MX hostnames
mx_check, smtp_server, smtp_check (boolean) - Verification checks
accept_all, greylisted, block (boolean) - Server behavior flags
gibberish, disposable, webmail, regex (boolean) - Address quality checks
whois (object) - Domain registration: registrar_name, referral_url, created_date

Also returns data.sources array with uri, website_url, extracted_on, last_seen_on, still_on_page.

Show full SKILL.md (157 more words)Show less

Result Types

Status	Meaning	Action
valid	Mailbox exists and accepts mail	Safe to send
invalid	Mailbox doesn't exist or domain has no MX	Don't send
accept_all	Server accepts any address — can't confirm mailbox	Send with caution
unknown	Couldn't verify (timeout, greylisting)	Verify manually

Examples

User: "Check if hello@acme.com is a real email"

bash

curl -s -X POST $GOOSEWORKS_API_BASE/v1/proxy/orthogonal/run \
  -H "Authorization: Bearer $GOOSEWORKS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"api":"hunter","path":"/v2/email-verifier","query":{"email":"hello@acme.com"}}'

User: "Verify sarah.jones@startup.io before I send my pitch"

bash

curl -s -X POST $GOOSEWORKS_API_BASE/v1/proxy/orthogonal/run \
  -H "Authorization: Bearer $GOOSEWORKS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"api":"tomba","path":"/v1/email-verifier","query":{"email":"sarah.jones@startup.io"}}'

Error Handling

400 - Missing or malformed email parameter
401 - Invalid API key — check orth auth
429 - Rate limit exceeded — wait and retry
If both APIs return unknown, the mail server is likely blocking verification — try later
Tomba may return greylisted: true — means the server deferred; retry after a few minutes

Tips

Always verify emails before bulk sending to protect sender reputation
"Valid" doesn't guarantee delivery - content still matters
Role-based emails (info@, sales@) may be valid but less effective for outreach
Disposable emails (tempmail, etc.) are detected and flagged
Some corporate domains block verification - "unknown" doesn't mean invalid

Files

SKILL.md and 1 other file in skills/lead-generation/capabilities/verify-email of gooseworks-ai/goose-skills.

SKILL.md
skill.meta.json

Open the folder on GitHubat commit c650c6d

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in gooseworks-ai/goose-skills, which our catalogue first saw on October 9, 2026.

criptogus/agent-evolve-network.claude/skills/verify-email

Compare with similar skills

Verify Email next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Verify Email compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Verify Email this skillgooseworks-ai/goose-skills	1.2k	1 repos	~1.3k	Automated safety check: Pass	MIT	2 days ago
Google Address Validation AutomationComposioHQ/awesome-claude-skills	77k	3 repos	~798	Automated safety check: Pass	None	23 days ago
Emailasgeirtj/system_prompts_leaks	69k	—	~3.5k	Automated safety check: Pass	CC0-1.0	yesterday
Emailscoreyhaines31/marketingskills	54k	1 repos	~2.8k	Automated safety check: Pass	MIT	2 days ago
Email Marketing Biblesickn33/agentic-awesome-skills	47k	—	~8.7k	Automated safety check: Pass	MIT	2 days ago
Mailtrap Email Integrationaffaan-m/ECC	277k	1 repos	~955	Automated safety check: Pass	MIT	today

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Questions about Verify Email

What does Verify Email do?

Verify if an email address is valid and deliverable. An agent skill from gooseworks-ai/goose-skills. Verify Email is an agent skill from gooseworks-ai/goose-skills.

How do I install Verify Email in Claude Code?

Run `npx skills add gooseworks-ai/goose-skills --skill verify-email -a claude-code`. Or copy the skill folder (skills/lead-generation/capabilities/verify-email in gooseworks-ai/goose-skills) into .claude/skills/verify-email in your project. Claude Code loads it when a task matches its description.

How do I install Verify Email in Codex?

Run `npx skills add gooseworks-ai/goose-skills --skill verify-email -a codex`. Or copy the skill folder (skills/lead-generation/capabilities/verify-email in gooseworks-ai/goose-skills) into .agents/skills/verify-email in your project. Codex loads it when a task matches its description.

Can I use Verify Email in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add gooseworks-ai/goose-skills --skill verify-email -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/verify-email, .gemini/skills/verify-email, .github/skills/verify-email and .opencode/skills/verify-email in your project.

What does Verify Email need to run?

Going by SKILL.md and its folder, Verify Email needs the command-line tools its instructions call (curl, python3 and npx) and credentials named GOOSEWORKS_API_KEY. Our summary lists: Python 3; Node.js; A credential in GOOSEWORKS_API_KEY.

Does Verify Email access the network?

SKILL.md names 1 domain. In commands or code: api.gooseworks.ai; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.

Is Verify Email safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Verify Email use?

Verify Email is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Verify Email use?

About 1.3k tokens (SKILL.md is roughly 5.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Verify Email?

Skills that share tags, products or a category with Verify Email: Google Address Validation Automation (ComposioHQ/awesome-claude-skills, 77k stars), Email (asgeirtj/system_prompts_leaks, 69k stars), Emails (coreyhaines31/marketingskills, 54k stars) and Email Marketing Bible (sickn33/agentic-awesome-skills, 47k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Verify Email?

gooseworks-ai (a GitHub organization) maintains it in gooseworks-ai/goose-skills, which has 1,240 GitHub stars. The repository holds 273 skills in this directory. The repository was last updated on October 8, 2026.

Source: gooseworks-ai/goose-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Verify Email

Facts

At a glance

What it does

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Email Verification

Setup

When to Use

How It Works

Usage

Verify with Hunter

Verify with Tomba

Parameters

Response

Hunter Response

Tomba Response

Result Types

Examples

Error Handling

Tips

Files

Used in 1 other repository

Compare with similar skills

Similar skills

More from gooseworks-ai/goose-skills

Questions about Verify Email