URL resolve

url-resolve · version 1.0.0 · URLs & IP addresses · free, no key needed

Resolve a URL against an absolute http(s) base using WHATWG. No fetching. Result must be http(s).

Use when you need to: url resolve · resolve relative url · join url against base.

Supported

• url resolve
• resolve relative url
• join url against base

Not supported

• fetch
• dns
• file urls
• security equivalence

Behavior

• base must be an absolute http or https URL. url is resolved with new URL(url, base).
• The resolved href must have http or https scheme; otherwise invalid_input.
• Return WHATWG href serialization. No extra normalize beyond WHATWG resolve/serialize unless the result is returned as href.
• No network and no security-equivalence claim.

Input

• base (string, required): min length 1; max length 8192
• url (string, required): min length 1; max length 8192

Output

• url (string, required)

Limits

• max url bytes: 8192

Example

Request input:

{
  "base": "https://example.com/a/b",
  "url": "../c"
}

Response:

{
  "result": {
    "url": "https://example.com/c"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "url-resolve",
  "version": "1.0.0",
  "input": {
    "base": "https://example.com/a/b",
    "url": "../c"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/url-resolve/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"base":"https://example.com/a/b","url":"../c"}'

The machine-readable contract is at /v1/tools/url-resolve/versions/1.0.0.

CLI

node cli.mjs run url-resolve 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• URL normalize: Normalize an absolute http or https URL via WHATWG parse. No DNS, fetch, or security-equivalence claim.
• URL query build: Build a query string or replace an absolute URL query from ordered pairs. No fetching.
• URL query merge: Merge query pairs into an absolute URL. No fetching.
• URL query parse: Parse query pairs and fragment from an absolute URL. Parse only; no fetching.
• IPv4 address classify: Classify an IPv4 address against the static IANA IPv4 special-purpose address registry.
• IPv4 address compare: Compare two canonical IPv4 addresses by their numeric uint32 value.