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 skills/lftpadilla/agent-dev-kit/multi-harnessnpx skills add LFTPadilla/agent-dev-kit --skill multi-harnessgit clone --depth 1 https://github.com/LFTPadilla/agent-dev-kitWhat 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 | $0.00075 | $0.01900 |
| Opus 5 | $0.00037 | $0.00950 |
| Sonnet 5 | $0.00015 | $0.00380 |
| Haiku 4.5 | $0.00007 | $0.00190 |
Grade A, and why
multi-harness 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 — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Multi Harness (Universal Harness Adapter)
Coordinate local agent harnesses without losing control of scope, safety, or verification.
Use this skill as the primary agent. You remain the orchestrator: decide what to delegate, run the external harness, inspect its output and any file changes, then synthesize the result for the user.
Routing Gate
Apply this gate before diagnostics, profile selection, or running delegate.py:
- Default to the current harness's native subagents when they expose the requested model. Requests for generic subagents, workers, parallelism, or orchestration are not external-harness requests.
- Use this skill only with an explicit external signal: Pi, OpenCode, Codex CLI, Claude Code CLI, DHS, another/external/cross harness, multiple distinct harnesses, harness comparison, or an external-only runtime the user has asked to use.
- When the user explicitly requests an external runtime or specific CLI model, use the Universal Harness Adapter (
delegate.py). - If this skill was auto-triggered without an explicit external signal, do not run diagnostics or delegation scripts. Continue using the current harness's native subagent tools.
- If the requested harness or model is not available locally, report the limitation and ask for confirmation before switching to an alternative model, harness, or native subagents. Never silently substitute.
Examples:
- "Spawn three Codex subagents" -> use native Codex subagents when exposed; if unavailable, report the limitation and confirm before using the Codex CLI profile.
- "Parallelize the review with subagents" -> native subagents; do not use
multi-harness. - "Delegate this review to Pi with GLM or DeepSeek" -> use
multi-harness. - "Run this implementation via DeepSeek Harness (DHS/DSH) or OpenCode" -> use
multi-harness.
Universal CLI Harness Execution
The adapter supports running bounded tasks across:
- Codex CLI:
codex exec --ephemeral [-m <model>] [-C <dir>] [--yolo] - Claude Code CLI:
claude -p "<prompt>" [--dangerously-skip-permissions] - DeepSeek Harness (DHS / DSH):
dsh exec --dir <dir> [--model <model>] [--yolo](Headless execution engine; no terminal TUI) - Pi:
pi --print --mode text [--model <model>] --tools <tools> - OpenCode:
opencode run --dir <dir> [--model <model>] [--auto]
What ships with it
5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 · 140 lines · 75 tokens per session scan A 3e2666c8448e
multi-harness is a skill published in the GitHub repository LFTPadilla/agent-dev-kit (2 stars, last pushed 4d ago), licensed MIT. It adds 75 tokens to every session and 1,900 once invoked, about $0.0004 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 2026-08-31.
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