epicenter

Co-create an explicitly accepted, uncompromising destination before planning or implementation. Use when the user wants to discover what they actually want, asks for an uncompromising vision, wants iterative synthesis and pushback, is exploring an architecture or product model before a plan exists, or says to use dialectic. Do not use for interrogating an existing plan, comparing one bounded implementation choice, or ordinary implementation with a settled destination.

Disciplined diagnosis loop for hard bugs and performance regressions. Reproduce → minimise → hypothesise → instrument → fix → regression-test. Use when user says "diagnose this" / "debug this", reports a bug, says something is broken/throwing/failing, or describes a performance regression.

defineErrors from wellcrafted: variant factories, extractErrorMessage, InferErrors/InferError, call site patterns. Use when creating error types or reviewing error patterns.

Control flow: early returns, guard clauses, linearizing nested logic. Use for "flatten these conditions", "too many nested ifs", "linearize this try-catch", or handlers mixing throw and return. For a broad "simplify this" pass over a diff or package, use collapse-pass instead.

Give Claude one fresh, read-only adversarial consultation on Codex's current synthesis. Use only when the user explicitly invokes $consult-claude or unmistakably asks Codex to consult Claude on an uncompromising greenfield vision, architecture direction, or other bounded decision after Codex has gathered the relevant evidence and directional data.

Run a continuous collapse-and-simplify pass that surgically removes indirection failing to earn its boundary. Use when the user says 'collapse pass', 'simplify pass', 'reduce indirection', 'shrink the surface', 'find what to delete', when asking to audit a package for dead abstractions, when reviewing a pull request, branch, or recent merged change for simplification (isolated in a worktree), or when the goal is a sequence of small refactor commits that delete more than they add.

Detect and collapse production code that was split into two pieces (a 'pure' inner function and a thin wrapper/handler/component that calls it) for the single purpose of letting a unit test reach the inner piece. The smell is structure shaped by the test suite, not by the system. Use when reviewing a helper paired with a `.test.ts` of similar or greater size, when an exported function has exactly one production caller next door, when a function takes optional `deps` whose only non-default value lives in the test, when a getter/setter pair injects state the production code already owns, or when the user says "is this earning its keep", "why is this exported", "trace the callers", "is this split for the test", "the test is shaping the API", "could this be one function". Prefer cohesion over unit-testability; pay the regression-coverage cost a different way (integration tests, type safety, deletion).

Codebase-specific smell catalog with calibrated grep recipes: duck-typing at boundaries, yargs argv re-assertions, value-discarding promise tails, console.* in library code, exhaustive `never` over-broad unions, single-method `Pick` deps, `*Like` boundary shape copies. Use for a periodic audit pass, scoping a cleanup PR, after a major refactor, or reviewing a primitive's consumers. Pairs with refactoring (fix mechanics) and post-implementation-review (second-read hub).

Cloudflare Workers patterns for Worker runtime APIs, Durable Objects, KV, R2, D1, Queues, WebSockets, streaming responses, bindings, wrangler configuration, and deployment limits. Use when users mention Cloudflare Workers, Durable Objects, KV, R2, D1, Queues, wrangler, or edge runtime behavior.

Present proposed code changes visually before implementing: before/after diffs, ASCII diagrams, comparison tables. Use when: "show me options for this change", "compare approaches", or a multi-file change needs a before/after comparison before editing. Not for planning questions with no concrete code change on the table.

Ultra-compressed communication mode. Cuts token usage ~75% by dropping filler, articles, and pleasantries while keeping full technical accuracy. Use when user says "caveman mode", "talk like caveman", "use caveman", "less tokens", or invokes /caveman. A one-off "be brief" is not a trigger; this mode persists until switched off.

Better Auth security hardening: rate limits, secrets, CSRF, trusted origins, cookies, sessions, OAuth tokens, and audit logging. Use when reviewing auth security, brute-force protection, token handling, or deployment safety.

Better Auth server/client setup: `auth.ts`, generated schema, DB adapters, sessions, cookies, env vars, and plugins. Use when mentioning Better Auth, betterauth, auth handlers, OAuth, email/password, or session configuration.

Autumn billing in Epicenter: `autumn.config.ts`, `autumn-js` credit checks, `atmn` CLI, plan gates, and metered AI usage. Use when changing billing, pricing, credits, plan access, refunds, or usage events.

Epicenter auth packages: `@epicenter/auth` and the Svelte wrapper at `@epicenter/svelte/auth`, OAuth sessions, identity state, auth-owned fetch/WebSocket, and workspace boot selection. Use when editing Epicenter auth clients, session state, hosted sign-in, or auth/workspace integration.

Contract and invariants for `attach*` composition primitives in `packages/workspace` (side-effectful building blocks like attachIndexedDb, attachSqlite, attachBroadcastChannel, attachBunSqliteMaterializer, attachMarkdownMaterializer, openCollaboration), and when to use `create*` (pure construction) instead. Use when writing or reviewing an `attach*` or `create*` function, naming a new workspace primitive, composing inside a workspace builder, or deciding whether a primitive registers listeners at call time.

Find the small promise to refuse when preserving it forces a large implementation family: trade a measured amount of fidelity, compatibility, modes, or reproducibility to delete disproportionate complexity. Use when the user says "asymmetric wins", "asymmetric win", "what can we refuse", "what collapses the most code", "does this UI refactor need to be pixel perfect", or when a design adds a fast path, fallback parser, provider-specific SDK, second transport, compatibility alias, exact reproduction requirement, or rare mode beside the canonical path.

Arktype: runtime validation, discriminated unions with .merge()/.or(), spread keys. Use when mentioning arktype, type(), union types, command/event schemas.

Create, revise, place, audit, evaluate, and validate repository agent instructions across AGENTS.md, CLAUDE.md, and `.agents/skills`. Use when adding or moving agent rules, deciding whether guidance belongs globally or in a skill or reference, writing or improving a skill, tuning routing descriptions, validating discovery, or reviewing instruction sprawl and composition.

Create a slash-command `/goal` for long-running Codex or Claude Code work when the user explicitly asks for a `/goal`, agent goal, or completion condition. Outputs one goal line with the objective, starting context, validation evidence, and stop condition.