Borrowing it
Nothing to install: this file belongs to luthersystems/elps. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/luthersystems/elps/main/.claude/skills/implement/SKILL.mdgit clone --depth 1 https://github.com/luthersystems/elpsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/luthersystems/elps/implement)<a href="https://agentmods.dev/skills/luthersystems/elps/implement"><img src="https://agentmods.dev/badge/skills/luthersystems/elps/implement/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/luthersystems/elps/implement"><img src="https://agentmods.dev/badge/skills/luthersystems/elps/implement.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.01870 |
| Opus 5.5 | $0.00000 | $0.00748 |
| Sonnet 5.5 | $0.00000 | $0.00374 |
| Haiku 4.5 | $0.00000 | $0.00187 |
Grade A, and why
implement scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/implement — Code Change Skill
Implements any code change in the ELPS codebase. This is the foundation skill — all other skills reference its patterns.
Trigger
Use when asked to implement a feature, fix a bug, add a builtin, modify the parser, update the formatter, add CLI flags, update docs, or make any other code change.
Workflow
1. Classify the Change
Determine the change type to know which files to touch:
| Type | Primary Files | Test Pattern |
|---|---|---|
builtin |
lisp/builtins.go (langBuiltins) |
elpstest.TestSuite in a topical lisp/*_test.go (e.g. math_test.go) |
special-op |
lisp/op.go (langSpecialOps) |
elpstest.TestSuite in a topical lisp/*_test.go |
macro |
lisp/macro.go (langMacros) |
elpstest.TestSuite in lisp/macro_test.go or a topical file |
linter |
lint/analyzers.go, lint/lint.go |
lint/lint_test.go (use /add-linter-check skill) |
elpsvet |
cmd/elpsvet/ |
go test ./cmd/elpsvet/ (use /elpsvet skill) |
fuzz |
<pkg>/fuzz_test.go, internal/fuzzseed/ |
make fuzz (use /fuzz skill) |
stdlib |
lisp/lisplib/lib<name>/ |
elpstest.Runner + .lisp test file (use /add-stdlib-package skill) |
cli |
cmd/<command>.go |
Manual verification or integration tests |
formatter |
formatter/formatter.go |
formatter/formatter_test.go (TestASTPreservation, TestRepoFileRoundTrip) |
parser |
parser/rdparser/parser.go, parser/lexer/ |
parser/rdparser/parser_test.go |
diagnostic |
diagnostic/diagnostic.go, diagnostic/renderer.go |
diagnostic/renderer_test.go |
bug-fix |
Varies — find the root cause first | Regression test reproducing the bug |
docs |
docs/lang.md (embedded), docs/templates.md, docs/embed.md, docs/minify.md, docs/lint-checks.md, AGENTS.md, skills |
./elps doc --guide to verify rendering of embedded guides |
deps |
go.mod, go.sum |
make test to verify compatibility |
ci |
.github/workflows/*.yml |
Push and verify Actions run |
profiler |
lisp/x/profiler/ |
Profiler-specific tests |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 138 lines · 0 tokens per session scan A fd9c0ac40c29
implement is a skill published in the GitHub repository luthersystems/elps (36 stars, last pushed today), licensed BSD-3-Clause. It costs nothing until one of its globs matches a file; then it loads 1,870 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-26.
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