Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/kartik-2239/lightcode/copilot-instructionsgit clone --depth 1 https://github.com/Kartik-2239/lightcodeWhat 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 | $0.00829 | $0.00829 |
| Opus 5 | $0.00415 | $0.00415 |
| Sonnet 5 | $0.00166 | $0.00166 |
| Haiku 4.5 | $0.00083 | $0.00083 |
Grade A, and why
lightcode copilot-instructions.md 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 — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Copilot Instructions
Build and test commands
- Build the main binary:
go build ./cmd/lightcodeormake build - Run the app:
go run ./cmd/lightcode/main.go - Run the full test suite:
go test ./... - Run the existing focused test file:
go test ./internal/server/tools - Run a single test:
go test ./internal/server/tools -run TestSkill_BasicSkill
There is no repo-defined lint target or linter config in this repository. Do not invent one in a Copilot session.
go test ./... is currently not green: internal/server/tools/skill_test.go expects SKILL_PATH-based behavior, but internal/server/tools/skill.go resolves the skills directory through config.SkillsPath() from ~/.lightcode/config.json.
High-level architecture
cmd/lightcode/main.go is the only real entrypoint. By default it starts the local HTTP server and then launches the Bubble Tea TUI; -server runs only the server and -tui runs only the TUI.
The app is split into two halves that communicate over localhost HTTP instead of direct package calls:
internal/serverexposes endpoints for session CRUD, message history, streaming chat completions, and the current todo list.internal/tuiis the Bubble Tea frontend. It talks to the server throughinternal/tui/client, including streaming assistant responses from/chat-completion.
Persistent app state lives under ~/.lightcode/:
config.jsonstores theme, port, providers, skills path, and the currently selected model.lightcode.dbis a SQLite database managed through GORM.skills/holds user skills that theskilltool loads.
The agent loop is in internal/server/agent/agent.go. Each iteration reads the session's stored messages from SQLite, converts them into llm.Chat messages, appends the session todo list as an extra user message, calls the model, persists the assistant reply, executes any tool calls, persists tool outputs, and repeats until the model returns plain assistant text or the iteration limit is hit.
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 · 43 lines · 829 tokens per session scan A 5537ce6f4433
lightcode copilot-instructions.md is an instructions file published in the GitHub repository Kartik-2239/lightcode (22 stars, last pushed 10d ago), licensed MIT. It adds 829 tokens to every session, about $0.0041 per session on Opus 5. 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 2026-08-30.
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