Regex Tester Skill

OnlineCredit Usage:1 per callTool:RegexTesterSkill

The tool

Regex Tester provides powerful regex testing capabilities with detailed analysis, performance metrics, optimization suggestions, and a comprehensive guide to regex syntax.

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

Tool call

{
  "name": "RegexTesterSkill",
  "arguments": {
    "pattern": "\\d{3}-\\d{2}-\\d{4}",
    "text": "My SSN is 123-45-6789"
  }
}

What that looks like in a conversation

You don't name the tool — the model picks it. Asking about \d{3}-\d{2}-\d{4} in the terms this source covers is enough for it to reach for RegexTesterSkill on its own.

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.

Client config

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

Endpoint

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

Per-client setup — Claude Desktop, 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.

Argument	Type	Example	Description
`pattern`Required	string	`\d{3}-\d{2}-\d{4}`	The regular expression pattern to test
`text`Required	string	`My SSN is 123-45-6789`	The text to test the pattern against
`flags`	string	`gi`	Regex flags: g (global), i (case insensitive), m (multiline), s (dotall), u (unicode), y (sticky)
`test_type`	string	`match`	Operation type One of: test, match, search, replace, split.
`replacement`	string	`[REDACTED]`	Replacement text for 'replace' operation

What the model gets back

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

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "pattern": "\\d{3}-\\d{2}-\\d{4}",
    "text": "My SSN is 123-45-6789 and my friend's is 987-65-4321",
    "flags": "g",
    "test_type": "test",
    "replacement": null,
    "is_valid_regex": true,
    "regex_info": {
      "pattern": "\\d{3}-\\d{2}-\\d{4}",
      "flags": {
        "global": true,
        "ignore_case": false,
        "multiline": false,
        "sticky": false,
        "unicode": false,
        "dot_all": false
      },
      "source": "\\d{3}-\\d{2}-\\d{4}",
      "last_index": 21,
      "pattern_length": 17,
      "complexity": "Medium"
    },
    "test_results": {
      "operation": "test",
      "result": true,
      "execution_time_ms": 0,
      "description": "Returns true if pattern matches anywhere in text, false otherwise"
    },
    "performance": {
      "iterations": 192,
      "total_time_ms": 0,
      "average_time_ms": 0,
      "performance_rating": "Excellent"
    },
    "pattern_analysis": {
      "contains_anchors": {
        "start_anchor": false,
        "end_anchor": false,
        "word_boundary": false
      },
      "contains_quantifiers": {
        "zero_or_more": false,
        "one_or_more": false,
        "zero_or_one": false,
        "specific_count": true,
        "range_count": false
      },
      "contains_groups": {
        "capturing_groups": 0,
        "non_capturing_groups": 0,
        "named_groups": 0
      },
      "contains_character_classes": {
        "predefined_classes": true,
        "custom_classes": false,
        "negated_classes": false
      },

Fields

Fields marked Premium need a paid plan. On a plan without them the key is absent rather than wrong, so a model never reasons over a substituted value.

Field	Type	Example	Description
`pattern`	string	`\d{3}-\d{2}-\d{4}`
`text`	string	`My SSN is 123-45-6789 and my friend's is 987-65-4321`
`flags`	string	`g`
`test_type`	string	`test`
`replacement`	object	`null`
`is_valid_regex`	boolean	`true`
`regex_info`	object	`{…}`
`regex_info.pattern`	string	`\d{3}-\d{2}-\d{4}`
`regex_info.flags`	object	`{…}`
`regex_info.flags.global`	boolean	`true`
`regex_info.flags.ignore_case`	boolean	`false`
`regex_info.flags.multiline`	boolean	`false`
`regex_info.flags.sticky`	boolean	`false`
`regex_info.flags.unicode`	boolean	`false`
`regex_info.flags.dot_all`	boolean	`false`
`regex_info.source`	string	`\d{3}-\d{2}-\d{4}`
`regex_info.last_index`	number	`21`
`regex_info.pattern_length`	number	`17`
`regex_info.complexity`	string	`Medium`
`test_results`	object	`{…}`
`test_results.operation`	string	`test`
`test_results.result`	boolean	`true`	Result after replacement or split operation
`test_results.execution_time_ms`	number	`0`
`test_results.description`	string	`Returns true if pattern matches anywhere in text, false otherwise`
`performance`Premium	object	`{…}`	Performance metrics for the regex operation
`performance.iterations`	number	`192`
`performance.total_time_ms`	number	`0`
`performance.average_time_ms`	number	`0`
`performance.performance_rating`	string	`Excellent`
`pattern_analysis`	object	`{…}`
`pattern_analysis.contains_anchors`	object	`{…}`
`pattern_analysis.contains_anchors.start_anchor`	boolean	`false`
`pattern_analysis.contains_anchors.end_anchor`	boolean	`false`
`pattern_analysis.contains_anchors.word_boundary`	boolean	`false`
`pattern_analysis.contains_quantifiers`	object	`{…}`
`pattern_analysis.contains_quantifiers.zero_or_more`	boolean	`false`
`pattern_analysis.contains_quantifiers.one_or_more`	boolean	`false`
`pattern_analysis.contains_quantifiers.zero_or_one`	boolean	`false`
`pattern_analysis.contains_quantifiers.specific_count`	boolean	`true`
`pattern_analysis.contains_quantifiers.range_count`	boolean	`false`
`pattern_analysis.contains_groups`	object	`{…}`
`pattern_analysis.contains_groups.capturing_groups`	number	`0`
`pattern_analysis.contains_groups.non_capturing_groups`	number	`0`
`pattern_analysis.contains_groups.named_groups`	number	`0`
`pattern_analysis.contains_character_classes`	object	`{…}`
`pattern_analysis.contains_character_classes.predefined_classes`	boolean	`true`
`pattern_analysis.contains_character_classes.custom_classes`	boolean	`false`
`pattern_analysis.contains_character_classes.negated_classes`	boolean	`false`
`pattern_analysis.contains_special_chars`	object	`{…}`
`pattern_analysis.contains_special_chars.wildcard`	boolean	`false`
`pattern_analysis.contains_special_chars.pipe`	boolean	`false`
`pattern_analysis.contains_special_chars.escape_sequences`	number	`3`
`suggestions`	array	`["Consider anchoring with ^ or $ if you need exact matches"]`
`common_patterns`	array[10]	`list of rows`
`common_patterns.0.name`	string	`Email Address`
`common_patterns.0.pattern`	string	`^[\w\.-]+@[\w\.-]+\.[a-zA-Z]{2,}$`
`common_patterns.0.description`	string	`Matches valid email addresses`
`common_patterns.0.example`	string	`[email protected]`
`regex_guide`	object	`{…}`
`regex_guide.basic_syntax`	array[8]	`list of rows`

Failure modes

Errors come back as tool errors with a sentence the model can act on, not a bare status code.

Status	What it means
`400 / 422`	The arguments didn't validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Out of credits. Not a bad key — the month's allowance is spent.
`404`	This skill isn't part of VerveKit. Check the catalog.
`429`	Brief rate limit. Retrying after a moment succeeds.

Other ways to use Regex Tester Skill

Set up Regex Tester 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.

Call it as a REST APIOne HTTPS endpoint and an X-API-Key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Frequently asked questions

Do I have to tell the agent to use RegexTesterSkill?

No. The tool's name and description are in the model's context once the server is connected, so it selects the tool when the question calls for it. Naming it explicitly works too and is useful when you want to force the call.

Does connecting the server expose every tool at once?

Yes — one connection lists the whole VerveKit catalog. Clients with a tool budget can usually filter the list; the credit cost is per call, so an unused tool costs nothing.

What does a call cost?

1 credit each time the tool actually runs. A model that reasons about the tool without calling it costs nothing.

Is there a REST version of this?

Yes — the same source is available as a plain HTTPS endpoint on APIVerve, linked above. Same data, same credits, same account.

What's Next?

Continue your journey with these recommended resources

Browse all skills

The full catalog for this door

Connect a client

Claude, Cursor, VS Code and the rest

Plans & credits

What a call costs and how usage resets

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