A Claude Code plugin marketplace with one plugin: oracle, a fast, cheap way to get a one-shot answer without derailing your main session's context or train of thought.
claude plugin marketplace add benjaminjackson/oracle
claude plugin install oracle@oracle
(The repo lives at benjaminjackson/oracle; oracle is the marketplace's internal name, used only in the plugin@marketplace install id above.)
Confirm it's installed with claude plugin list.
A couple of notes: if ANTHROPIC_API_KEY is set in your environment, the skill runs headless with --bare (API rates, off your Claude Code quota); otherwise it runs --safe-mode (OAuth, counts against your normal plan quota). Either way it's a small, cheap request. And the headless session has no file access, only WebSearch, so if a question needs a file's contents, the calling session reads the file first and pastes the relevant lines in.
One skill, one agent, same job — answer a question as concisely as possible — at two different price points.
The default path. Writes your question to a scratch file, then shells out to a bare headless Fable session (claude -p --safe-mode or --bare, whichever fits your setup) with a stripped system prompt. No agent scaffolding, no tool loadout beyond WebSearch — measured at ~900 input tokens of overhead per question, nearly all of it cache reads (the WebSearch schema is ~600 of those; omitting --tools entirely would load the CLI's ~17k default toolset instead). Every answer comes back with the exact token count and dollar cost for that call, so you're not guessing.
- Explicitly:
/oracle <question> - Automatically: on phrases like "ask the oracle" or "oracle, ..."
Fallback only, for when the headless call can't run — no claude CLI on PATH, auth broken, sandboxed environment with no shell access. Same brief (shortest correct answer, lead with the word that matters), run as a proper subagent instead of a headless process: Read, Grep, Glob, WebSearch, WebFetch, ~6k tokens per question.
The skill falls back to this agent automatically if the headless command fails, and says so when it does.
Benjamin Jackson (@benjaminjackson)