Agent skill

Rxjava Migration

by rcosteira79 in rcosteira79/android-skills

Use only when the user explicitly requests migration from RxJava to Kotlin coroutines and/or flows.

MITAuto-check passedMobile

Install Rxjava Migration

skills CLI

$ npx skills add rcosteira79/android-skills --skill rxjava-migration -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install rcosteira79/android-skills rxjava-migration --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/rcosteira79/android-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/android-skills/skills/rxjava-migration .claude/skills/rxjava-migration && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "rxjava-migration" agent skill from https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration into .claude/skills/rxjava-migration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rxjava-migration", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add rcosteira79/android-skills --skill rxjava-migration -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install rcosteira79/android-skills rxjava-migration --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/rcosteira79/android-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/android-skills/skills/rxjava-migration .agents/skills/rxjava-migration && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "rxjava-migration" agent skill from https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration into .agents/skills/rxjava-migration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rxjava-migration", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add rcosteira79/android-skills --skill rxjava-migration -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install rcosteira79/android-skills rxjava-migration --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/rcosteira79/android-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/android-skills/skills/rxjava-migration .cursor/skills/rxjava-migration && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "rxjava-migration" agent skill from https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration into .cursor/skills/rxjava-migration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rxjava-migration", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/rcosteira79/android-skills.git --path plugins/android-skills/skills/rxjava-migration

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add rcosteira79/android-skills --skill rxjava-migration -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install rcosteira79/android-skills rxjava-migration --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/rcosteira79/android-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/android-skills/skills/rxjava-migration .gemini/skills/rxjava-migration && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "rxjava-migration" agent skill from https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration into .gemini/skills/rxjava-migration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rxjava-migration", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install rcosteira79/android-skills rxjava-migration

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add rcosteira79/android-skills --skill rxjava-migration -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/rcosteira79/android-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/android-skills/skills/rxjava-migration .github/skills/rxjava-migration && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "rxjava-migration" agent skill from https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration into .github/skills/rxjava-migration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rxjava-migration", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add rcosteira79/android-skills --skill rxjava-migration -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install rcosteira79/android-skills rxjava-migration --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/rcosteira79/android-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/android-skills/skills/rxjava-migration .opencode/skills/rxjava-migration && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "rxjava-migration" agent skill from https://github.com/rcosteira79/android-skills/tree/main/plugins/android-skills/skills/rxjava-migration into .opencode/skills/rxjava-migration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rxjava-migration", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: rxjava-migration
GitHub stars: 150
Token cost: ~1.2k tokens
SKILL.md length: 491 words
Files: 2
Skills in repo: 21
Repo updated: Sep 19, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Use only when the user explicitly requests migration from RxJava to Kotlin coroutines and/or flows.

Explicitly requests migration from RxJava to Kotlin coroutines and/or flows
SKILL.md covers Step 1: Complexity gate, Type mapping (state it…, Retry — the accuracy trap and Interop during incremental…, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Rxjava Migration is an agent skill from rcosteira79/android-skills. Use only when the user explicitly requests migration from RxJava to Kotlin coroutines and/or flows.

Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `migration-map.md`).

It sits in Mobile. It works with Kotlin. The repository describes itself as: Claude Code skills for Android & KMP development. The licence is MIT.

When your agent uses it

Explicitly requests migration from RxJava to Kotlin coroutines and/or flows

Example prompts

“/rxjava-migration”

What it can do on your machine

Read from SKILL.md and the folder at commit 0f9af5a. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are kotlin).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Rxjava Migration loads about 1.2k tokens when it runs. Until then it costs about 29 tokens; SKILL.md has 491 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~29
When it runs · the whole SKILL.md, loaded when a task matches: ~1.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from rcosteira79/android-skills at commit 0f9af5a, republished under its MIT licence (© rcosteira79). 491 words, ~1,219 tokens.

Download SKILL.mdSave it as .claude/skills/rxjava-migration/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.

name: rxjava-migration
description: Use only when the user explicitly requests migration from RxJava to Kotlin coroutines and/or flows.

RxJava Migration

Migrate RxJava to Kotlin coroutines/flows incrementally. Only invoke this skill when the user explicitly asks to migrate RxJava code. Simple cases map directly; complex cases need a strategy and user input before any code is written.

Step 1: Complexity gate

Classify before writing any migrated code. A chain is Complex if ANY of: nested flatMap/switchMap with an inner Single/Observable; a custom Scheduler; complex error recovery (retryWhen, backoff, retry counts); multi-source zip/combineLatest (3+ sources); Flowable with an explicit backpressure strategy; a Subject shared across classes; or an unclear API return type. Any single Complex criterion makes the whole chain Complex — a two-operator chain with retryWhen is Complex.

Always confirm what each called API returns before migrating — do not assume. A leaf you think is migrated may still return Single/Observable.

Type mapping (state it explicitly — don't silently transform)

RxJava	Coroutines/Flow
`Observable<T>` / `Flowable<T>`	`Flow<T>` (Flowable: match the original backpressure with `buffer()` / `conflate()`)
`Single<T>` / `Maybe<T>` / `Completable`	`suspend fun`: `T` / `T?` / `Unit`
`PublishSubject` / `ReplaySubject(n)`	`MutableSharedFlow(replay = 0 / n)`
`BehaviorSubject<T>`	ask — `MutableStateFlow` vs `MutableSharedFlow(replay = 1)`

BehaviorSubject — ask first: StateFlow always has a current value (needs an initial, exposes .value, replays it to new collectors); SharedFlow(replay = 1) also replays the last emission but has no .value and no initial-value requirement. "Do you always have an initial value and need .value access, or is the stream sometimes empty at start?"

Schedulers and the `observeOn` shift

Schedulers.io() → Dispatchers.IO, computation() → Default, mainThread() → Main, single() → newSingleThreadContext(...), newThread() → IO (per-task thread spawning isn't idiomatic in coroutines).

observeOn(AndroidSchedulers.mainThread()) does NOT become a dispatcher switch in the repository/use case — it means the caller collects on Main, which in the coroutines model is the ViewModel's job (viewModelScope runs on Main). Explain this shift to the developer.
When the called API is already a suspend fun, it manages its own dispatcher via withContext — subscribeOn has no equivalent and simply disappears. Do not wrap an already-main-safe suspend function in another withContext.
subscribeOn + observeOn → flowOn applies upstream only; restructure accordingly.

For the full operator mapping, see migration-map.md.

Show full SKILL.md (161 more words)Show less

Retry — the accuracy trap

RxJava's retryWhen is stateful; Flow's retry predicate receives the Throwable, not an index.

kotlin

// WRONG — 'attempt' is a Throwable, not a Long; this does not compile
flow.retry(3) { attempt -> delay(attempt * 1000L); true }

// CORRECT — retry(n)'s predicate gets the cause
flow.retry(3) { cause -> cause is IOException }

// CORRECT — stateful backoff: attempt IS the 0-based index here
flow.retryWhen { cause, attempt ->
    if (cause is IOException && attempt < 3) { delay((attempt + 1) * 1000L); true } else false
}

Use retryWhen { cause, attempt -> } for any policy that depends on the attempt count.

Interop during incremental migration

Add kotlinx-coroutines-rx3 (or rx2); keep interop at layer boundaries only, never mixing RxJava and coroutines inside one function body.

kotlin

observable.asFlow(); single.await(); maybe.awaitSingleOrNull(); completable.await()   // Rx → coroutines
flow.asObservable(); flow.asSingle()   // coroutines → Rx (asSingle throws if the flow emits 0 or 2+ elements)

Migrate leaf-up (data source → repository → use case → ViewModel), remove each bridge once its layer is fully migrated, and commit per layer.

Complex cases — stop and ask before migrating

retryWhen (count? linear vs exponential? which error types? what after exhaustion?); a custom Scheduler (which CoroutineDispatcher?); Flowable backpressure (buffer / conflate / DROP_OLDEST?); flatMap/switchMap over writes — switchMap → flatMapLatest is safe for reads (search/live data) but cancels in-flight work, so it's dangerous for writes; a Subject shared across classes (state → StateFlow, event → SharedFlow?). For onErrorResumeNext → catch, rethrow cancellation: catch { e -> if (e is CancellationException) throw e else emit(fallback) }.

(compositeDisposable.clear() in onCleared() → delete it entirely: viewModelScope is cancelled automatically when the ViewModel is cleared.)

Files

SKILL.md and 1 other file in plugins/android-skills/skills/rxjava-migration of rcosteira79/android-skills.

SKILL.md
migration-map.md

Open the folder on GitHubat commit 0f9af5a

Compare with similar skills

Rxjava Migration next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Rxjava Migration compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Rxjava Migration this skillrcosteira79/android-skills	150	—	~1.2k	Automated safety check: Pass	MIT	18 days ago
Compose Multiplatform Patternsmonta-app/ocpp-emulator	179	5 repos	~2k	Automated safety check: Pass	Apache-2.0	6 days ago
Kotlin Patternsgetknit/knit	130	5 repos	~4.7k	Automated safety check: Pass	GPL-3.0	3 days ago
Summoncodeyousef/summon	167	—	~1.1k	Automated safety check: Pass	Apache-2.0	1 mo ago
Add JSON Schemayontrack/yontrack	102	—	~883	Automated safety check: Pass	MIT	yesterday
Add Ktnip Parameter Strategyvendelieu/telegram-bot	249	—	~613	Automated safety check: Pass	Apache-2.0	3 days ago

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Works with

Kotlin

Questions about Rxjava Migration

What does Rxjava Migration do?

Use only when the user explicitly requests migration from RxJava to Kotlin coroutines and/or flows. Rxjava Migration is an agent skill from rcosteira79/android-skills. Use only when the user explicitly requests migration from RxJava to Kotlin coroutines and/or flows.

When should I use Rxjava Migration?

Rxjava Migration fits situations like: explicitly requests migration from RxJava to Kotlin coroutines and/or flows.

How do I install Rxjava Migration in Claude Code?

Run `npx skills add rcosteira79/android-skills --skill rxjava-migration -a claude-code`. Or copy the skill folder (plugins/android-skills/skills/rxjava-migration in rcosteira79/android-skills) into .claude/skills/rxjava-migration in your project. Claude Code loads it when a task matches its description.

How do I install Rxjava Migration in Codex?

Run `npx skills add rcosteira79/android-skills --skill rxjava-migration -a codex`. Or copy the skill folder (plugins/android-skills/skills/rxjava-migration in rcosteira79/android-skills) into .agents/skills/rxjava-migration in your project. Codex loads it when a task matches its description.

Can I use Rxjava Migration in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add rcosteira79/android-skills --skill rxjava-migration -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/rxjava-migration, .gemini/skills/rxjava-migration, .github/skills/rxjava-migration and .opencode/skills/rxjava-migration in your project.

What does Rxjava Migration need to run?

SKILL.md names no scripts, command-line tools or credentials: Rxjava Migration is instructions for the agent only.

Does Rxjava Migration access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Rxjava Migration safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Rxjava Migration use?

Rxjava Migration is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Rxjava Migration use?

About 1.2k tokens (SKILL.md is roughly 4.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Rxjava Migration?

Skills that share tags, products or a category with Rxjava Migration: Compose Multiplatform Patterns (monta-app/ocpp-emulator, 179 stars), Kotlin Patterns (getknit/knit, 130 stars), Summon (codeyousef/summon, 167 stars) and Add JSON Schema (yontrack/yontrack, 102 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Rxjava Migration?

rcosteira79 (a GitHub user) maintains it in rcosteira79/android-skills, which has 150 GitHub stars. The repository holds 21 skills in this directory. The repository was last updated on September 19, 2026.

Source: rcosteira79/android-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Rxjava Migration

Facts

At a glance

What it does

When your agent uses it

Example prompts

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

RxJava Migration

Step 1: Complexity gate

Type mapping (state it explicitly — don't silently transform)

Schedulers and the observeOn shift

Retry — the accuracy trap

Interop during incremental migration

Complex cases — stop and ask before migrating

Files

Compare with similar skills

Similar skills

More from rcosteira79/android-skills

Related

Questions about Rxjava Migration

Schedulers and the `observeOn` shift