OpenSpace is a skill-management layer for AI agents that stores, retrieves, evaluates, shares, and improves reusable workflows. It is intended for people using multiple coding agents who want skills to be reused and refined based on task outcomes. The catalogue provides 200 skills for use with OpenSpace and the agents it supports.
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 HKUDS/OpenSpace --skill python-execution-fallback-9d4989git clone --depth 1 https://github.com/HKUDS/OpenSpaceWrote 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/hkuds/openspace/python-execution-fallback-9d4989)<a href="https://agentmods.dev/skills/hkuds/openspace/python-execution-fallback-9d4989"><img src="https://agentmods.dev/badge/skills/hkuds/openspace/python-execution-fallback-9d4989.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00025 | $0.00590 |
| Opus 5 | $0.00013 | $0.00295 |
| Sonnet 5 | $0.00005 | $0.00118 |
| Haiku 4.5 | $0.00003 | $0.00059 |
Grade A, and why
python-execution-fallback-9d4989 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 4d 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.
What it actually says
Python Execution Fallback
When to Use
Use this skill when execute_code_sandbox returns 'unknown error' or fails unexpectedly, even on simple Python code like print statements.
Solution
Switch to using run_shell with Python heredoc syntax instead of execute_code_sandbox.
Basic Syntax
python3 << 'EOF'
# Your Python code here
print("Hello World")
result = 2 + 2
print(f"Result: {result}")
EOF
How to Call
Instead of:
execute_code_sandbox(code="print('Hello')")
Use:
run_shell(command="python3 << 'EOF'\nprint('Hello')\nEOF")
For multi-line code, build the command string:
code = """
import json
data = {"status": "ok", "count": 42}
print(json.dumps(data))
"""
run_shell(command=f"python3 << 'EOF'\n{code}\nEOF")
Why This Works
run_shellexecutes commands directly in the shell environment, bypassing sandbox issues- Heredoc syntax (
<< 'EOF') allows clean multi-line Python code without complex escaping - Single quotes around EOF prevent unwanted shell variable expansion
- More reliable for simple to moderate Python execution tasks
Guidelines
- Always use single quotes around EOF (
'EOF') to prevent variable expansion - Test with a simple print statement first to verify Python is available
- For longer scripts, consider writing to a
.pyfile first, then executing:run_shell(command="python3 /path/to/script.py") - Capture stdout from run_shell to get Python output
- Handle errors by checking run_shell's stderr output
Example: Complete Workflow
# Step 1: Try execute_code_sandbox
try:
result = execute_code_sandbox(code="print(2+2)")
except Exception as e:
# Step 2: Fallback to run_shell with heredoc
result = run_shell(command="python3 << 'EOF'\nprint(2+2)\nEOF")
# Parse stdout to get the output
output = result.stdout.strip()
Troubleshooting
| Issue | Solution |
|---|---|
| Python not found | Use which python3 to verify installation |
| Heredoc not working | Ensure single quotes around EOF delimiter |
| Complex imports fail | Install required packages or write to .py file |
| Output not captured | Check run_shell stdout, not return value |
What ships with it
1 file 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.
- 4d ago First seen · 87 lines · 25 tokens per session scan A 47d63bb35737
python-execution-fallback-9d4989 is a skill published in the GitHub repository HKUDS/OpenSpace (7,534 stars, last pushed 26d ago), licensed MIT. It adds 25 tokens to every session and 590 once invoked, about $0.0001 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 2026-09-03.
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