I wrote this toolkit to make calling Anthropic’s Claude API simple and safe from Windows. The API key lives in a KeePass vault, and it is never stored in the script, typed on the command line, written to disk, or returned to the caller.
Three ways to use it
- As a script, at the keyboard:
.\Invoke-Claude-API-01.ps1 -Prompt "Hello"sends the prompt, prints the reply and the token usage, and ends with an exit code. - As a function, from other PowerShell scripts: dot-source it and call
Invoke-Claude -Prompt "Hello", which returns an object carrying the reply text, model, token counts and an estimated cost. Several prompts can be piped through a single vault unlock. - From another program (Python, C#, a batch file): run it with
-Jsonand standard output carries exactly one JSON object, while status messages and the password prompt stay on standard error.
How the key stays safe
The KeePass master password is asked for on each run and discarded the moment the vault opens; the API key exists in plain text only for the instant of the call. There is deliberately no way to pass the password as a plain command-line argument, since other programs on the machine can read those. A caller that already has it can hand it over as a SecureString, through standard input, or from an environment variable that is then cleared.
What it records
Every call, successful or failed, adds one row to a usage CSV: time, model, label, token counts, estimated cost, response time and more, with the prompt and reply text never recorded. A companion script, Get-ClaudeUsage-Report01.ps1, turns that log into reports, and Get-ClaudeBilling-Report01.ps1 summarizes spend. Errors go to a separate log, with anything shaped like a key masked as a safety net.
Built for Windows PowerShell 5.1 and PowerShell 7+, using the PoshKeePass module.
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