Build a curl command from an HTTP request

Supply the method, an absolute URL, any headers, and an optional text body. The builder quotes every dynamic value, including spaces, query strings, punctuation, and embedded apostrophes, so the shell does not reinterpret request data as syntax. It is useful for debugging APIs, reproducing requests from logs, writing documentation, and handing an exact request to another developer without manually assembling flags.

Describe the request you want to reproduce

Start with the HTTP method and the complete URL. The URL must be absolute, which means it includes a scheme such as HTTPS and enough information for curl to locate the destination without relying on browser context or a base address. Add headers as ordered name-and-value rows when the request needs authorization, content negotiation, tracing, conditional behavior, or a declared content type. Add the body only when the request carries one; an empty string is treated as an intentional empty body, while an omitted body adds no data flag. The resulting command uses an explicit method flag, followed by the quoted URL, one header flag for every supplied row, and a raw data flag when a body is present. Header order is preserved, making the output easy to compare with a captured request or a test fixture. The builder does not send anything, resolve the host, inspect credentials, or change the payload. It only converts the values you provide into a deterministic command line.

Understand how shell quoting protects each value

A command line is interpreted by a shell before curl receives it, so copying request values without quoting can silently change their meaning. Ampersands in query strings can start background commands, dollar signs can trigger expansion, spaces can split one value into several arguments, and quotes inside JSON can become shell syntax. This builder wraps every dynamic argument in POSIX single quotes. When a value itself contains an apostrophe, it closes the quoted section, inserts a literal apostrophe through a double-quoted fragment, and resumes the single-quoted section. That familiar sequence looks unusual, but it preserves the exact bytes of the original string in shells such as sh, bash, dash, and zsh. Headers are emitted as a single quoted argument containing the name, a colon, a space, and the value. Bodies use curl's raw data option so an initial at-sign is not interpreted as a filename. The result targets POSIX-style shells; PowerShell and Windows Command Prompt have different quoting rules and should not be assumed to interpret this output identically.

Validate the result before sharing or running it

The builder rejects a missing or relative URL because a fragment such as /users/42 is ambiguous outside the application that supplied its base address. It also validates the method as an HTTP token, checks header names against the token syntax, requires string header values, and rejects line breaks in those values. These checks prevent malformed request structure from being disguised by otherwise correct shell quoting. They do not decide whether a server supports a method, whether a URL points to the intended environment, or whether a credential is safe to disclose. Review the generated command before running it, especially when it contains authorization headers, session cookies, personal data, or a production hostname. Prefer short-lived test credentials in documentation and issue reports, and redact secrets before sending a command through chat or a ticket. Because generation is deterministic, the same structured input always produces the same text. That makes the result suitable for snapshots, developer documentation, reproducible bug reports, and code-review discussions where small request changes need to remain visible.