Effect Errors Schema
Use when modeling Effect errors, defects, Cause handling, Schema contracts, Schema.TaggedErrorClass, boundary decoding/encoding, RPC/tool/persistence validation, and typed failure recovery in Theseus.
Effect Testing Runtime
Use when testing or verifying Effect code in Theseus, including Effect.runPromise boundaries, test layers, fake services, deterministic time, config providers, stream/fiber tests, and runtime edge behavior.
Dispatch Satellite
Use when working on the Theseus dispatch loop, dispatch store, tool-call execution, satellite middleware, dispatch events, or intervention policy in packages/theseus-core/src/dispatch and packages/theseus-core/src/satellite.
Docs Reading
Use before coding or reviewing Theseus runtime, primitive, server, client, or architecture changes when docs may define the intended boundary, status, or domain vocabulary.
Effect Services Layers
Use when defining or wiring Effect services in Theseus, including Context.Service, service interfaces, Layer.effect/succeed/mergeAll/provideMerge, dependency graphs, runtime construction, and test seams.
Roadmap Management
Use when creating, updating, reviewing, or promoting Theseus roadmap items, including public roadmap notes, internal roadmap status maps, planning lanes, GitHub issue readiness, and OSS roadmap hygiene.
Bun Workspace
Use when working with Bun package management, Bun workspaces, bun.lock, package scripts, Bun runtime APIs, Bun build commands, or Node/npm-to-Bun command translation in this repo.
Effect V4
Effect v4 (beta.50) API — curried Layer forms, gen without adapter, Schema in main package, catch (not catchAll), Context.Service (not ServiceMap). Use whenever writing or reviewing Effect code in this repo.
Effect Concurrency Lifecycle
Use when working with Effect Fiber, Deferred, Scope, Queue, PubSub, Stream, interruption, background loops, graceful shutdown, backpressure, races, or bounded concurrency in Theseus.
Docs Management
Use when editing the Theseus docs vault under docs/, including adding, moving, splitting, renaming, archiving, cross-linking, changing doc status, or restructuring section indexes.
Testing Patterns
Use when adding, refactoring, reviewing, or debugging tests in Theseus, especially package-local test placement, characterization tests, Effect service tests, fixtures, mocks, and deciding how broad verification should be.
Tool Authoring
Use when creating, modifying, reviewing, or debugging Theseus Tool primitives or concrete tools in packages/theseus-core/src/tool and packages/theseus-tools.
Theseus Design
A Claude skill from theseus-run/theseus.
Ui Layout Discipline
Use when building, changing, or reviewing UI layouts in Theseus or Icarus, especially data-dense dashboards, tables, calendars, matrices, cards, and cells with optional labels, badges, metrics, or status text.
Biome Tooling
Use when running, interpreting, or modifying Biome linting/formatting/import organization in this repo, including biome.json, Grit plugins, formatting fixes, and lint failures.
Cleanup Audit
Use after substantial edits, refactors, moves, generated changes, or long agent sessions to find leftovers, stale stubs, unused imports, accidental compatibility artifacts, and trash files. Remove only confirmed non-behavioral leftovers; report anything that may affect compatibility or runtime behavior before changing it.
Bun Test
Use when creating, modifying, debugging, or running Bun tests with bun:test, including package-local test commands, async tests, mocks, spies, snapshots, and Effect.runPromise test boundaries.
Typescript Strict
Use when writing, refactoring, reviewing, or debugging strict TypeScript in this repo, including tsconfig paths, package exports, typecheck failures, unknown vs any, readonly data, module boundaries, and Effect language-service diagnostics.
Effect Observability Time
Use when adding or reviewing Effect time, retry, timeout, Clock/Duration, logging, tracing spans, metrics, Config, ConfigProvider, Redacted secrets, or operational observability in Theseus.
Monorepo Maintenance
Use when changing package boundaries, splitting or moving modules, shaping public exports, naming APIs, reducing large files, or reviewing repo structure and maintainability in Theseus.
Agent Self Check
Use before finishing coding work or after deterministic check failures, including lint/typecheck/test loops, interpreting diagnostics as just-in-time prompts, and deciding whether repeated agent mistakes should become stricter rules.
Server Runtime
Use when working on packages/theseus-server RPC/HTTP process assembly, runtime layer wiring, server handlers, provider configuration, or server-side serialization.
Biome Grit Rules
Use when creating, reviewing, or modifying custom Biome Grit plugins in plugins/*.grit, especially deterministic agent-correction rules for stale Effect v3 patterns, local style hazards, and diagnostic messages that tell agents what to do next.
Jsx Md Beautiful Mermaid
Render Mermaid diagrams as ASCII/Unicode art inside @theseus.run/jsx-md components. Use when adding a <BeautifulMermaid> component to a .tsx file that renders Markdown via render(), or when a prompt or document needs a diagram rendered as terminal-friendly ASCII art.
Refactoring Discipline
Use when intentionally restructuring, splitting, renaming, replacing, or reducing complexity in this POC/WIP repo, especially when choosing a clean single path over compatibility, stale aliases, or parallel implementations.
Runtime Engine
Use when working on packages/theseus-runtime runtime host, command/control/query contracts, systems, sinks, projections, active dispatch registry, tool catalog hydration, SQLite runtime stores, snapshots, or runtime tests.
Jsx Md Authoring
Use when writing or modifying JSX-MD prompt components, Markdown-rendering primitives, XML intrinsic prompts, or packages/jsx-md and packages/jsx-md-beautiful-mermaid behavior.
Jsx Md
Write agent instructions, SKILL.md files, and LLM prompts as typed JSX/TSX components using @theseus.run/jsx-md. Use when creating or editing .tsx files that render Markdown strings via render(), authoring jsx-md components, or working with the jsx-md primitives, Context API, or XML intrinsics.
Code Review
Use when reviewing code changes in Theseus, especially to find defects, behavioral regressions, missing tests, weak type modeling, stale compatibility leftovers, and agent-generated implementation artifacts.