Start
Donchitos/Claude-Code-Game-Studios
First-time onboarding — asks where you are, then guides you to the right workflow.
Starts (or confirms) the standalone legend-engine backend - engine Server + H2 + local metadata server on fixed ports 9095/9092 - so a Pure LSP started with -Dlegend.test.
Apache-2.0Auto-check passed
Install Pure Backend Start
$ npx skills add finos/legend-engine --skill pure-backend-start -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install finos/legend-engine pure-backend-start --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/finos/legend-engine.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/pure-dev/skills/pure-backend-start .claude/skills/pure-backend-start && rm -rf skills-srcUse ~/.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/
Install the "pure-backend-start" agent skill from https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-start into .claude/skills/pure-backend-start/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pure-backend-start", 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 install https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-startType 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.
$ npx skills add finos/legend-engine --skill pure-backend-start -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install finos/legend-engine pure-backend-start --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/finos/legend-engine.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/pure-dev/skills/pure-backend-start .agents/skills/pure-backend-start && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "pure-backend-start" agent skill from https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-start into .agents/skills/pure-backend-start/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pure-backend-start", 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.
$ npx skills add finos/legend-engine --skill pure-backend-start -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install finos/legend-engine pure-backend-start --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/finos/legend-engine.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/pure-dev/skills/pure-backend-start .cursor/skills/pure-backend-start && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "pure-backend-start" agent skill from https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-start into .cursor/skills/pure-backend-start/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pure-backend-start", 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 https://github.com/finos/legend-engine.git --path plugins/pure-dev/skills/pure-backend-start--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add finos/legend-engine --skill pure-backend-start -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install finos/legend-engine pure-backend-start --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/finos/legend-engine.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/pure-dev/skills/pure-backend-start .gemini/skills/pure-backend-start && rm -rf skills-srcUse ~/.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/
Install the "pure-backend-start" agent skill from https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-start into .gemini/skills/pure-backend-start/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pure-backend-start", 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.
$ gh skill install finos/legend-engine pure-backend-startInstalls 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).
$ npx skills add finos/legend-engine --skill pure-backend-start -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/finos/legend-engine.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/pure-dev/skills/pure-backend-start .github/skills/pure-backend-start && rm -rf skills-srcUse ~/.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/
Install the "pure-backend-start" agent skill from https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-start into .github/skills/pure-backend-start/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pure-backend-start", 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.
$ npx skills add finos/legend-engine --skill pure-backend-start -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install finos/legend-engine pure-backend-start --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/finos/legend-engine.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/pure-dev/skills/pure-backend-start .opencode/skills/pure-backend-start && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "pure-backend-start" agent skill from https://github.com/finos/legend-engine/tree/master/plugins/pure-dev/skills/pure-backend-start into .opencode/skills/pure-backend-start/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "pure-backend-start", 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
pure-backend-start- GitHub stars
- 113
- Token cost
- ~1.2k tokens
- SKILL.md length
- 529 words
- Files
- 1
- Skills in repo
- 15
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
Starts (or confirms) the standalone legend-engine backend - engine Server + H2 + local metadata server on fixed ports 9095/9092 - so a Pure LSP started with -Dlegend.test.
- The user wants to run Pure queries through the real engine
- SKILL.md covers Why this exists, The launcher, Run the script and Then: point the LSP at it, plus 1 more section
- Calls mvn
- Through plan-gen
What it does
Pure Backend Start is an agent skill from finos/legend-engine. Starts (or confirms) the standalone legend-engine backend - engine Server + H2 + local metadata server on fixed ports 9095/9092 - so a Pure LSP started with -Dlegend.test. routes execute()/go() through real plan-generation instead of the interpreted engine. Starts only the backend, not the LSP. Use when the user wants to run Pure queries 'through the real engine', 'through plan-gen' or 'via the backend server', reproduce compiled-mode behaviour the interpreted engine cannot, or mentions legend.test.server…
Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The licence is Apache-2.0.
When your agent uses it
- The user wants to run Pure queries through the real engine
- Through plan-gen
- Via the backend server
- Reproduce compiled-mode behaviour the interpreted engine cannot
Example prompts
- “through the real engine”
- “through plan-gen”
- “via the backend server”
- “/pure-backend-start”
What it can do on your machine
Read from SKILL.md and the folder at commit 43f4e69. 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
Shell commands in SKILL.md call:
mvn
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
Pure Backend Start loads about 1.2k tokens when it runs. Until then it costs about 142 tokens; SKILL.md has 529 words of instructions outside code blocks.
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 finos/legend-engine at commit 43f4e69, republished under its Apache-2.0 licence (© finos). 529 words, ~1,246 tokens.
Download SKILL.mdSave it as
.claude/skills/pure-backend-start/SKILL.md (or your agent's skills folder).- name
- pure-backend-start
- description
- Starts (or confirms) the standalone legend-engine backend - engine Server + H2 + local metadata server on fixed ports 9095/9092 - so a Pure LSP started with -Dlegend.test.* routes execute()/go() through real plan-generation instead of the interpreted engine. Starts only the backend, not the LSP. Use when the user wants to run Pure queries 'through the real engine', 'through plan-gen' or 'via the backend server', reproduce compiled-mode behaviour the interpreted engine cannot, or mentions legend.test.server, EngineServerForTest or LegendTest.
Start the standalone engine backend (H2 + metadata server + engine Server)
Why this exists
The Pure LSP go()/pure-lsp-go runs the interpreted engine, which (a) can't reproduce
compiled-mode behaviour (plan generation + generated Specifics.prepare Java, e.g. relational
graph-fetch temp-table nodes) and (b) has its own gaps (e.g. interpreted RFPM graph-fetch is
unimplemented). meta::pure::router::execute(...) wraps the query in the mayExecuteLegendTest
native which — if legend.test.server.host/port/clientVersion/serverVersion System
properties are set on the JVM — does real plan-generation and POSTs to a running backend
Server instead. This skill boots that backend on fixed ports; pure-lsp-launch-engine then points
the LSP JVM at it via --jvm-arg=-D....
Result: go() through the so-configured LSP runs the same plan-gen + execute path as
Test_*_UsingPureClientTestSuite, verified end-to-end (returns real query results and shows
generated SQL in the go() output trace), without a 15-30 min mvn test.
The launcher
org.finos.legend.engine.ide.EngineServerForTest (in the legend-engine-pure-ide-light-http-server
module, alongside PureIDELight). It starts H2 (fixed 9092), a local test metadata server
(dynamic), and the full org.finos.legend.engine.server.Server on a FIXED port (9095), then
blocks forever.
Run the script
All of check-if-already-up / compile-once / generate-classpath-once / launch-in-background /
poll-for-ready is implemented deterministically in bin/pure-backend-start:
pure-backend-start [--port N] [--h2-port N] [--force-classpath]Defaults: --port 9095, --h2-port 9092. If something's already listening on --port, it reports
that and exits 0 without relaunching (it's a full engine JVM — never stack a second one).
On success it prints one JSON line to stdout, e.g. {"port": 9095, "h2Port": 9092, "state": "ready"},
and exits 0. Exit codes:
1— the launcher module didn't compile, or its runtime classpath is missing/empty (pass--force-classpathto regenerate the cached classpath after a dependency change)3— launched but never reachedREADYwithin the timeout (~2 minutes) — check/tmp/engine-server.log
Then: point the LSP at it
This skill only brings up the backend — it does not start the Pure LSP. pure-lsp-launch-engine
calls pure-backend-start automatically by default and wires the resulting
-Dlegend.test.server.* jvm-args into the LSP launch; pass --no-backend to skip this and launch
interpreted-only instead. For a custom/manual launch, use pure-lsp-server's --jvm-arg passthrough
with the flags pure-backend-start prints (see references/lsp-devloop-internals.md).
Show full SKILL.md (205 more words)Show less
Things worth knowing / gotchas
- The go() wrapper must seed the DB and use the right execute FQN —
createTablesAndFillDb()first,meta::pure::router::executenotmeta::pure::mapping::execute, and onego()per session (reusewelcome.pure). All three are the database-setup andwelcome.pureconventions inreferences/lsp-devloop-usage-rules.md. - Pure-only edits do NOT require rebuilding/restarting this backend Server — because plan
generation runs LOCALLY in the LSP's interpreted JVM and only plan execution is delegated here.
That is how
legendExecuteincore/pure/protocol/vX_X_X/invocations/execution.pureis wired (seepure-lsp-go's "Execution routing" section):let planGenerated = if(true, {|local executionPlan(...)}, {|remote generatePlan(...)})keeps plan-gen local, so it uses the Pure graph in the LSP session (reflecting files you'vepure-lsp checked live, on top of the jar baseline), and onlyexecutePlan($host,$port)hits this server. Plan execution is almost all Java, so it ignores your Pure edits. Net loop with NOmvn install/ NO server restart: edit.pure→pure-lsp checkit into the session →go()→ live local plan-gen + server execute. (Rebuild/ restart this server only for Java execution-layer changes, or if you flip plan-gen to run remotely by editing thatif(true,...).) - clientVersion
vX_X_Xis the dev placeholder and is accepted (seePureClientVersions). - Logs:
/tmp/engine-server.log. Stop it withpkill -f EngineServerForTest(match the java process precisely; a bare pgrep can match your own shell command).
© finos, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in plugins/pure-dev/skills/pure-backend-start of finos/legend-engine.
Open the folder on GitHubat commit 43f4e69
Compare with similar skills
Pure Backend Start 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.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Pure Backend Start this skillfinos/legend-engine | 113 | — | ~1.2k | Automated safety check: Pass | Apache-2.0 | |
| StartDonchitos/Claude-Code-Game-Studios | 26k | — | ~6.5k | Automated safety check: Pass | MIT | |
| Developing StandaloneTriliumNext/Trilium | 38k | — | ~3.4k | Automated safety check: Pass | AGPL-3.0 | |
| Session Start Hookasgeirtj/system_prompts_leaks | 69k | 1 repos | ~1.2k | Automated safety check: Pass | CC0-1.0 | |
| Save As Standalone HTMLasgeirtj/system_prompts_leaks | 69k | — | ~1.4k | Automated safety check: Pass | CC0-1.0 | |
| Where Do I Startmohitagw15856/pm-claude-skills | 1.4k | — | ~912 | Automated safety check: Pass | MIT |
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Questions about Pure Backend Start
What does Pure Backend Start do?
Starts (or confirms) the standalone legend-engine backend - engine Server + H2 + local metadata server on fixed ports 9095/9092 - so a Pure LSP started with -Dlegend.test. Pure Backend Start is an agent skill from finos/legend-engine.test.
When should I use Pure Backend Start?
Pure Backend Start fits situations like: the user wants to run Pure queries through the real engine; through plan-gen; via the backend server; reproduce compiled-mode behaviour the interpreted engine cannot.
How do I install Pure Backend Start in Claude Code?
Run `npx skills add finos/legend-engine --skill pure-backend-start -a claude-code`. Or copy the skill folder (plugins/pure-dev/skills/pure-backend-start in finos/legend-engine) into .claude/skills/pure-backend-start in your project. Claude Code loads it when a task matches its description.
How do I install Pure Backend Start in Codex?
Run `npx skills add finos/legend-engine --skill pure-backend-start -a codex`. Or copy the skill folder (plugins/pure-dev/skills/pure-backend-start in finos/legend-engine) into .agents/skills/pure-backend-start in your project. Codex loads it when a task matches its description.
Can I use Pure Backend Start 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 finos/legend-engine --skill pure-backend-start -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/pure-backend-start, .gemini/skills/pure-backend-start, .github/skills/pure-backend-start and .opencode/skills/pure-backend-start in your project.
What does Pure Backend Start need to run?
Going by SKILL.md and its folder, Pure Backend Start needs the command-line tools its instructions call (mvn).
Does Pure Backend Start 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 Pure Backend Start 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 Pure Backend Start use?
Pure Backend Start is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Pure Backend Start use?
About 1.2k tokens (SKILL.md is roughly 5k 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 Pure Backend Start?
Skills that share tags, products or a category with Pure Backend Start: Start (Donchitos/Claude-Code-Game-Studios, 26k stars), Developing Standalone (TriliumNext/Trilium, 38k stars), Session Start Hook (asgeirtj/system_prompts_leaks, 69k stars) and Save As Standalone HTML (asgeirtj/system_prompts_leaks, 69k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Pure Backend Start?
finos (a GitHub organization) maintains it in finos/legend-engine, which has 113 GitHub stars. The repository holds 15 skills in this directory. The repository was last updated on October 8, 2026.
Source: finos/legend-engine on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.