Password Generator

Password Generator

Produce passwords and passphrases whose randomness actually comes from a cryptographically secure random number generator, not from the model.

Why a script and not just "think of a random string": an LLM's output is not a source of entropy — sampled tokens are statistically biased and, given the conversation, effectively predictable. A "random-looking" string typed by the model is not a secure password no matter how random it looks. This skill always shells out to scripts/generate_password.{py,mjs}, which use a real CSPRNG (Python's secrets module / Node's crypto.randomInt), for every character or word chosen.

<SKILL_DIR> below is this skill's own announced base directory (the path shown when this skill loads, ending in .../skills/password-generator).

Step 1 — Resolve mode and parameters

Two modes:

Default to password unless the user says "passphrase," "memorable," "words," or similar, or the target system disallows symbols (in which case a passphrase is often the better fit than a stripped-down password).

Ask only if genuinely ambiguous; otherwise use sane defaults and mention them in the result so the user can redirect:

• password: length 20, all four classes on, ambiguous characters included. If the user mentions a site's specific rules ("no symbols allowed", "must be 12-16 characters", "no ambiguous characters"), map those directly to --length/--no-*/--no-ambiguous instead of asking.
• passphrase: 6 words, - separator, no capitalization, no trailing number, unless the user asks for those.
• count: 1, unless the user asks for multiple (e.g. "give me a few options").
• delivery: clipboard by default when count is 1 — see Step 3. Print instead when the user asks to see/type it, when count > 1, or when they're clearly on a remote/headless session (SSH, container, CI) where a local clipboard tool won't exist anyway.

Step 2 — Run the script

Never hand-generate the value yourself. Try runtimes in order, first one that works:

1. python3 "<SKILL_DIR>/scripts/generate_password.py" [args]
2. else python "<SKILL_DIR>/scripts/generate_password.py" [args]
3. else py -3 "<SKILL_DIR>/scripts/generate_password.py" [args]
4. else node "<SKILL_DIR>/scripts/generate_password.mjs" [args]

If none of these runtimes are available, say so plainly and stop — do not fall back to typing out a password yourself. There is no safe manual fallback here, unlike a pure encoding task.

Common flags (identical between the .py and .mjs versions):

--mode password|passphrase   (default: password)
--length N                   password mode, default 20
--count N                    how many to generate, default 1
--no-upper / --no-lower / --no-digits / --no-symbols
--no-ambiguous                drop visually-confusable chars: 0/O, 1/l/I, quotes, backtick
--words N                    passphrase mode, default 6
--separator STR              passphrase mode, default "-"
--capitalize                 passphrase mode: capitalize each word
--add-number                 passphrase mode: append one random digit
--clipboard                  copy the value to the OS clipboard instead of printing it (count must be 1)

The script prints a JSON array of {"value": ..., "entropy_bits": ...}. When --clipboard succeeds, value comes back redacted ("(copied to clipboard -- not printed)") and the object carries "clipboard": true — the real value never reaches stdout, so it never lands in your terminal scrollback or this chat transcript. generate_password.mjs tries clip/pbcopy/xclip/wl-copy/xsel depending on platform; if none is found, the script falls back to printing the value and sets "clipboard": false.

Step 3 — Deliver the result

Default (count 1): use --clipboard. This is the main fix for the password lingering in the terminal — nothing sensitive is ever printed in the first place, so there's nothing in scrollback or chat history to clean up afterward. Tell the user plainly what happened:

Generated and copied to your clipboard (not shown here) — 20 characters, ~130 bits of entropy. Paste it into your password manager now; the clipboard will still hold it until you copy something else.

If the script reports "clipboard": false (no clipboard tool on the system), or the user asked to see/type it, or --count > 1: print the value(s) in a code block (so nothing gets auto-formatted or mangled) with the entropy in bits. A one-line rule of thumb, only if useful context: ~60 bits is adequate for most accounts behind reasonable lockout/rate-limiting, ~80+ bits for high-value secrets (master passwords, signing keys). Don't over-explain unless asked.

If --count > 1, present all of them and let the user pick — don't just use the first one for anything.

Step 4 — If the value did get printed, reduce residual exposure

Be honest about what actually helps here — don't oversell /clear:

• /clear is a REPL command only the user can run — there is no tool call that invokes it on their behalf, and it wouldn't fully solve this even if there were. It removes the conversation from the model's future context; it does not erase the terminal's scrollback buffer (the printed value is still visible by scrolling up) and does not retroactively scrub any transcript/log already persisted by the surrounding tool.
• What actually removes it from the visible terminal: the user clearing their own scrollback (clear on macOS/Linux, cls in cmd.exe, Clear-Host in PowerShell) — suggest the exact command for their shell if known, otherwise mention both.
• If they also want it out of the Claude session's context going forward, then suggest /clear — framed as an added layer, not the fix, and something they run themselves.
• Prefer steering to --clipboard on the next generation instead of trying to clean up after the fact — cleanup is best-effort, not printing it is reliable.

Step 5 — Handling the secret afterward

• Don't write the generated password to any file, log, or persistent memory unless the user explicitly asks you to save it somewhere.
• If the user asks where to put it, a password manager is the right answer — don't suggest storing it in plaintext in the repo, a config file, or chat history as a substitute.
• If asked to check the strength of a password the user already has (rather than generate one), estimate entropy from its actual character-class composition and length using the same entropy_bits formula (length * log2(alphabet_size)) — don't just eyeball it.

Error handling

• --length shorter than the number of enabled character classes → the script exits with a clear message; relay it and ask whether to shorten the requirement list or lengthen the password, don't silently drop a class.
• --no-ambiguous would empty an entire enabled class → script refuses; relay the message.
• --clipboard combined with --count > 1 → script refuses (a clipboard holds one value); generate one at a time instead.
• Clipboard tool not found → script falls back to printing with "clipboard": false; treat it like the no---clipboard path (Step 3) and optionally mention why it printed (no clip/pbcopy/xclip/wl-copy/ xsel found).
• No Python or Node runtime available → tell the user directly; do not generate a password by any other means.