BitFun is a desktop AI agent that turns tasks into interactive mini-apps while also writing code, creating documents, and controlling computers. It is for software development and general desktop work across Windows, macOS, and Linux. Its catalogue entries extend the agent with skills, agents, and instructions.
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 skills add GCWing/BitFun --skill gstack-investigategit clone --depth 1 https://github.com/GCWing/BitFunWrote 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/gcwing/bitfun/gstack-investigate)<a href="https://agentmods.dev/skills/gcwing/bitfun/gstack-investigate"><img src="https://agentmods.dev/badge/skills/gcwing/bitfun/gstack-investigate/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/gcwing/bitfun/gstack-investigate"><img src="https://agentmods.dev/badge/skills/gcwing/bitfun/gstack-investigate.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 51 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00112 | $0.02269 |
| Opus 5.5 | $0.00045 | $0.00908 |
| Sonnet 5.5 | $0.00022 | $0.00454 |
| Haiku 4.5 | $0.00011 | $0.00227 |
Grade A, and why
investigate 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 1mo 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 — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Systematic Debugging
Iron Law
NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST.
Fixing symptoms creates whack-a-mole debugging. Every fix that doesn't address root cause makes the next bug harder to find. Find the root cause, then fix it.
OpenBitFun Dispatch
When this skill is invoked by OpenBitFun, this skill supplies the debugging methodology. Use existing Task sub-agents to gather independent evidence, then keep hypothesis selection and fixes in the main session.
- Do not assume a Debugger sub-agent exists. Choose only from the Task tool's available agents.
- Prefer matching custom debugging/domain sub-agents if available; otherwise use
Explorefor code-path tracing and locating logs, configs, tests, and affected files. - Split independent evidence tracks into parallel Task calls when useful: reproduction path, recent-change audit, config/environment audit, and suspected subsystem trace.
- Keep Task work read-only until root cause is proven. Ask for facts, file paths, commands tried, observations, and confidence.
- The main session owns the root-cause statement, fix plan, implementation, and regression test.
Phase 1: Root Cause Investigation
Gather context before forming any hypothesis.
-
Collect symptoms: Read the error messages, stack traces, and reproduction steps. If the user hasn't provided enough context, ask ONE question at a time via AskUserQuestion.
-
Read the code: Trace the code path from the symptom back to potential causes. Use Grep to find all references, Read to understand the logic.
-
Check recent changes:
git log --oneline -20 -- <affected-files>Was this working before? What changed? A regression means the root cause is in the diff.
-
Reproduce: Can you trigger the bug deterministically? If not, gather more evidence before proceeding.
Prior Learnings
Use only OpenBitFun in-session memory, project docs, .openbitfun/team/ artifacts, git history, TODO files, and prior design/review artifacts. Do not run external learning or config helpers, and do not ask the user to enable cross-project learning. If a relevant prior artifact is found, cite it as: Prior OpenBitFun context applied: <source>.
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.
- 1mo ago Changed 2dc92c16711c
- 1mo ago First seen · 213 lines · 112 tokens per session scan A 8dcade7abfa8
investigate is a skill published in the GitHub repository GCWing/BitFun (2,077 stars, last pushed 1mo ago), licensed MIT. It adds 112 tokens to every session and 2,269 once invoked, about $0.0004 per session on Opus 5.5. 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.
Other skills, from other repositories
memstack-development-performance-audit
Use this skill when the user says 'performance audit', 'why is it slow', 'optimize performance', 'page speed', 'Core Web Vitals', 'lighthouse', 'load time', or needs to diagnose and fix frontend or backend performance issues. Do NOT use for code reviews or security audits.
agenttrace-session-audit
Audit local AI coding-agent sessions with agenttrace for cost, tool failures, latency, anomalies, health, diffs, and CI gates.
test-failure-explorer
Import and query an existing Vitest 3.2 JSON report to explore test failures, file-level errors and original diagnostic evidence.
task-coordination
Coordinate access to shared task directories using .processing marker files. Use before accessing a Worker's workspace to prevent conflicts when both Manager and Worker might modify files simultaneously.
mcporter
Discover and call MCP Server tools via the mcporter CLI. Use when your coordinator notifies you about new MCP tools, or when you need to call external APIs. Includes workflow for generating skill documentation for new MCP servers.
task-management
Use before any Worker taskflow call or assigned-task workflow, including reading task state, acknowledging a task, executing a task, tracking progress, handling blockers/questions, submitting structured results, or reporting completion. Always use this skill when the message mentions assigned task, task ID…