Opencode TypeScript

Code like the opencode core team. This skill contains real code extracted from the repo — complete implementations, not abstract rules. Follow the workflow below based on your task.

Implement (new code)

Follow these phases in order:

1. Orient — where does this go?

Load architecture.md. Find:

Which module owns this behavior
What the dependency direction allows
What file naming convention to follow
Whether this is a new module or an addition to an existing one

2. Gather — what already exists?

Load helpers-deep-dive.md. Before writing ANY utility:

Check if it already exists in util/, effect/, bus/, sync/
Check the usage matrix to see how other modules use it
If it exists, use it. If it doesn't, inline first — extract only when awkwardness repeats.

For quick lookups: primitives.md (shorter, import paths + signatures only)

3. Build — write the code

Load the reference that matches what you're building:

Building...	Load this
Service module (namespace + Effect service + schemas + events)	service-module.md
Tool or modifying tool behavior	tool-module.md
Database tables, schemas, events, error types	schemas-and-state.md
Server routes, config, plugins, project lifecycle	server-and-routes.md
Tests	test-writing.md

4. CHECK GATE — code MUST pass all of these before proceeding

Load style-dna.md. If ANY of the following fail, fix the code before proceeding to Review:

Single-word variable names where clear
No try/catch, no else, no any, no unnecessary destructuring
const + ternary over let + mutation
snake_case Drizzle fields, .meta({ref}) on boundary schemas
Effect is used for services, not plain async classes
No patterns from Section 7 ("Things That Compile But Get Rejected") present in the diff

DO NOT proceed if any check fails. Go back to phase 3 and fix.

5. REVIEW GATE — REJECT the diff if any of these apply

Load review-voice.md. The diff MUST NOT contain any of the following. If it does, fix before submitting:

Changes to files outside the scope of the task
as any or as unknown as casts
Custom utilities that duplicate community primitives or @/util/* helpers
Provider-specific code that should live in models.dev
Code removal without a clear reason documented in the commit
Unexplained variable renames or structural changes
Abstraction the core team would ask to remove (check refactoring-patterns.md)

Refactor (changing existing code)

1. Orient — what touches what?

Load architecture.md. Map the blast radius before changing anything.

2. Study — which pattern applies here?

Load refactoring-patterns.md. Start with the Decision Matrix at the top — match the code smell you see to the correct pattern. Then read the specific pattern section for real before/after diffs:

Simplification patterns (removing unnecessary abstraction)
Consolidation patterns (Bun → Node migration)
Extraction patterns (pulling reusable utilities)
Migration patterns (moving to Effect services)
Deletion patterns (removing dead code)
Stabilization patterns (fixing ordering/race conditions)
Variant elimination (removing special cases)

3. Gather — can an existing utility replace this code?

Load helpers-deep-dive.md. The best refactor often replaces 20 lines with one utility call.

4. Check + Review

Same as implement phases 4-5: style-dna.md then review-voice.md.

Key decisions (always apply)

Effect is mandatory — all services use ServiceMap.Service / Layer / makeRuntime. No plain async classes.
Namespace ownership — one export namespace X {} per feature, one file until real split pressure.
Zod for boundaries, Effect Schema for internals — Zod + z.infer for DTOs/tool params. Schema.TaggedErrorClass for Effect errors. Newtype for branded IDs.
Event-sourced writes — mutations go through SyncEvent.run → projectors → SQLite. Direct DB writes only for non-event-sourced features.
No mocks in tests — use tmpdir + Instance.provide + real services. Mocks only for external SDKs.
Single-word variables — state, pending, info, row, cfg, tx. Multi-word only when genuinely ambiguous.

Reference index

File	Size	What it contains
style-dna.md	18K	Mandatory style rules, naming, control flow, 14 review traps
primitives.md	22K	Quick-lookup: every utility with import path + signature
helpers-deep-dive.md	~40K	Full deep-dive: every utility, every usage site, when NOT to use
architecture.md	~30K	Module map, dependency graph, data flow, file conventions
service-module.md	27K	Complete Question + Permission implementations
tool-module.md	28K	Full tool implementations, registry, prompt loop
test-writing.md	42K	5 complete test files with all fixture patterns
schemas-and-state.md	36K	SQL tables, Zod/Effect schemas, SyncEvent flow, errors
server-and-routes.md	32K	Routes, config, plugins, project lifecycle
review-voice.md	~25K	Real PR review comments from Dax + Aiden
refactoring-patterns.md	~25K	Real before/after diffs from cleanup commits

opencode-ts