Buddy Reroll

Brute-force a new /buddy companion by finding a userID that hashes to the desired species and rarity.

How It Works

Claude Code generates companions deterministically: hash(userID + SALT) → mulberry32 PRNG → rarity, species, eyes, hat, shiny. Same userID = same companion, always.

To reroll: replace userID in ~/.claude.json, clear companion field, restart.

Critical: Claude Code is Bun-bundled, so Bun.hash() (xxHash64) is the correct hash function. Node.js FNV-1a produces wrong results — the script MUST run under Bun.

Script Directory

Important: All scripts are located in the scripts/ subdirectory of this skill.

Agent Execution Instructions:

1. Determine this SKILL.md file's directory path as SKILL_DIR
2. Script path = ${SKILL_DIR}/scripts/<script-name>.mjs
3. Replace all ${SKILL_DIR} in this document with the actual path

Script Reference:

Script	Purpose
scripts/reroll.mjs	Brute-force target species+rarity, optionally apply to config
scripts/oauth-setup.mjs	OAuth config helper for Pro/Max subscribers (--check/--prepare/--verify/--restore)
scripts/rename.mjs	Change companion name and/or personality (--name/--desc)

Prerequisites

• Claude Code >= 2.1.89 — the /buddy system was introduced in this version. The script auto-checks and exits if the version is too old.
• Bun — required for correct hashing. Use npx -y bun if not installed globally.
• API users: Works directly — userID in ~/.claude.json can be freely replaced.
• Pro/Max subscribers: Requires OAuth setup first (automated by this skill). Pro/Max accounts have accountUuid which /buddy uses instead of userID. The OAuth method bypasses this — see workflow below.

Usage

# Direct (if bun is installed globally)
bun ${SKILL_DIR}/scripts/reroll.mjs --species dragon --rarity legendary --apply

# Via npx (works even without global bun install)
npx -y bun ${SKILL_DIR}/scripts/reroll.mjs --species dragon --rarity legendary --apply

Options

Flag	Default	Description
--species <name>	dragon	Target species (see list below)
--rarity <level>	legendary	Minimum rarity: common / uncommon / rare / epic / legendary
--max <n>	1000000	Max brute-force iterations
--apply	off	Auto-write result to ~/.claude.json and clear companion

Species (18)

duck	goose	blob	cat	dragon	octopus
owl	penguin	turtle	snail	ghost	axolotl
capybara	cactus	robot	rabbit	mushroom	chonk

Rarity Tiers

Rarity	Stars	Chance	~Iterations to find
common	★	60%	~30
uncommon	★★	25%	~72
rare	★★★	10%	~180
epic	★★★★	4%	~450
legendary	★★★★★	1%	~1800

Invocation

This skill can be invoked with or without arguments:

• No args (/webup-buddy-reroll): Prompts the user interactively via AskUserQuestion before running.
• Reroll only (/webup-buddy-reroll dragon legendary): Skips the prompt and locks to the given species and rarity.
• Reroll + rename (/webup-buddy-reroll dragon legendary 沧海九粟 爱打盹的小龙): Reroll, then immediately apply the given name and personality.
• Rename only (/webup-buddy-reroll 改名叫沧海九粟，个性是爱打盹的小龙): Skip reroll, only change name and/or personality.

Arg parsing (natural language)

The args string is free-form text. Use NLP to extract these fields:

1. species — match against the 18 known species names (duck, goose, blob, cat, dragon, octopus, owl, penguin, turtle, snail, ghost, axolotl, capybara, cactus, robot, rabbit, mushroom, chonk). Also recognize Chinese/Japanese equivalents (龙=dragon, 猫=cat, etc.).
2. rarity — match against the 5 tiers (common, uncommon, rare, epic, legendary) or equivalents (传说=legendary, 史诗=epic, etc.).
3. name — a short proper name for the companion (e.g. "沧海九粟", "Nimbus", "小火"). Look for patterns like "叫X", "名字X", "named X", "name X", or a standalone proper noun that isn't a species/rarity keyword.
4. personality — a description of the companion's vibe or character (e.g. "爱打盹的小龙", "sarcastic robot"). Look for patterns like "个性X", "性格X", "personality X", or descriptive phrases that aren't species/rarity/name.

All four fields are optional. Any combination is valid.

Detect intent:

• If species or rarity found → Reroll Workflow (+ post-reroll rename if name/personality also found)
• If only name and/or personality found (no species/rarity) → Rename Workflow
• If no args at all → prompt interactively, detect from user's message whether they want reroll or rename

Reroll Workflow

0. Detect account type: Run the check script to see if accountUuid exists in ~/.claude.json:

   npx -y bun ${SKILL_DIR}/scripts/oauth-setup.mjs --check
   

   • Exit 0 (no accountUuid): API user or OAuth already set up. Skip to step 1.
   • Exit 1 (accountUuid found): Pro/Max subscriber. Run OAuth Setup below, then continue to step 1.

OAuth Setup (Pro/Max only)

Principle: When logging in via CLAUDE_CODE_OAUTH_TOKEN env var, Claude Code does NOT write accountUuid to ~/.claude.json. This makes /buddy fall back to userID, which can be freely replaced.

a. Tell user to open a separate terminal and run claude setup-token to get their OAuth token. Ask them to paste the token back here.

b. Once token is received, prepare the config (backup + reset): bash npx -y bun ${SKILL_DIR}/scripts/oauth-setup.mjs --prepare

c. Tell user to run in a separate terminal (replace <TOKEN> with actual token): bash CLAUDE_CODE_OAUTH_TOKEN=<TOKEN> claude Wait for Claude to fully load, then exit immediately — do NOT use /buddy.

d. After user confirms they've done this, verify the config: bash npx -y bun ${SKILL_DIR}/scripts/oauth-setup.mjs --verify If verification fails, run --restore to restore backup and retry from step (a).

e. Continue to step 1.

---

1. If no args provided: Use AskUserQuestion to ask the user to pick a species AND a rarity in a single prompt (two questions):

   • Species question: Present 4 popular options (dragon, cat, axolotl, capybara) as choices. Each option's description should list the remaining species so the user knows what's available via "Other", e.g. the first option's description: "Or type any of: duck, goose, blob, octopus, owl, penguin, turtle, snail, ghost, cactus, robot, rabbit, mushroom, chonk".
   • Rarity question: Present all 5 tiers (legendary as first/recommended, then epic, rare, uncommon, common).
   • Do NOT skip this step. Always ask even if the user mentioned a species — confirm their choice.

   If species/rarity parsed from args: Skip the prompt and proceed directly.

2. Run the script with --apply:

   npx -y bun ${SKILL_DIR}/scripts/reroll.mjs --species <choice> --rarity <choice> --apply
   

3. If name or personality was parsed from args: Run the rename script immediately after reroll (no restart needed between):

   npx -y bun ${SKILL_DIR}/scripts/rename.mjs --name "<parsed name>" --desc "<parsed personality>"
   

   Omit --name or --desc if only one was parsed.

4. Tell user to restart Claude Code and run /buddy to hatch the new companion.

   • If OAuth was used: Remind user to start Claude with CLAUDE_CODE_OAUTH_TOKEN=<TOKEN> claude (not plain claude) to prevent accountUuid from being written back.

Manual Apply

If --apply was not used:

1. Copy the output userID
2. Edit ~/.claude.json: replace "userID" value, set "companion": null
3. Restart Claude Code → /buddy

Rename / Customize Companion

Change the companion's name and/or personality description without rerolling species or rarity.

Rename Workflow

If name and/or personality were parsed from args: Skip steps 1–3, go directly to step 4 with the parsed values. When personality is provided directly via args, use it as-is — skip the AI generation step.

1. Use AskUserQuestion to ask what the user wants to change (one question, multiSelect):
   • Name: "Change companion name"
   • Personality: "Change companion personality/description"
2. For name: ask the user for the exact name. Pass it directly.
3. For personality: ask the user for a brief tip or vibe (e.g. "lazy cat that loves keyboards", "sarcastic robot"). Then you (Claude Code) generate a fun, creative personality description (1–2 sentences, matching the companion's species and the user's tip). Show the generated text to the user for confirmation before applying.
4. Run the rename script:

   npx -y bun ${SKILL_DIR}/scripts/rename.mjs --name "<name>" --desc "<personality>"
   

   Omit --name or --desc if only one is being changed.
5. Tell user to restart Claude Code for changes to take effect.

Notes

• userID only affects telemetry bucketing and buddy seed — no impact on conversations, API keys, or local config
• SALT is friend-2026-401 (Claude Code 2.1.89). Update the script if a future version changes it
• 1M iterations finds legendary in seconds on modern hardware