TruLens is an open-source system for tracing and evaluating LLM applications and AI agents. It records each step's inputs, outputs, latency, tokens, and cost, then uses evaluations to find failures and compare application versions.
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 truera/trulens --skill trulens-notebook-executiongit clone --depth 1 https://github.com/truera/trulensWrote 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/truera/trulens/trulens-notebook-execution)<a href="https://agentmods.dev/skills/truera/trulens/trulens-notebook-execution"><img src="https://agentmods.dev/badge/skills/truera/trulens/trulens-notebook-execution/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/truera/trulens/trulens-notebook-execution"><img src="https://agentmods.dev/badge/skills/truera/trulens/trulens-notebook-execution.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00021 | $0.02370 |
| Opus 5 | $0.00010 | $0.01185 |
| Sonnet 5 | $0.00004 | $0.00474 |
| Haiku 4.5 | $0.00002 | $0.00237 |
Grade A, and why
trulens-notebook-execution 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 9d 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 — 364 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TruLens Notebook Execution
Execute Jupyter notebooks, display progress to the user, and handle API key requirements.
When to Use This Skill
Use this skill when:
- Running TruLens quickstart or example notebooks
- Demonstrating TruLens functionality via notebooks
- Testing notebook examples end-to-end
- User asks to "run the notebook" or "execute the notebook"
Execution Method
Always use jupyter nbconvert --execute to run notebooks. This:
- Maintains state across cells (variables persist)
- Captures all output properly
- Handles async operations correctly
- Works with OTEL tracing
DO NOT try to run notebooks by:
- Extracting cells and running them individually in bash
- Using
python -cwith heredocs - Running as a standalone Python script (loses notebook context)
Basic Execution Command
jupyter nbconvert --to notebook --execute --inplace <notebook_path>
Execution with Timeout (for long-running notebooks)
jupyter nbconvert --to notebook --execute --inplace \
--ExecutePreprocessor.timeout=600 \
<notebook_path>
Execution with Output to stdout
jupyter nbconvert --to notebook --execute --stdout <notebook_path>
Displaying Progress to User
When running a notebook, display section headers as each cell executes - NOT generic "BASH_OUTPUT" messages.
Step 1: Parse the Notebook Structure First
Before executing, read the notebook JSON to build a map of:
- Markdown headers (## Section Name)
- Which code cells belong to which section
import json
with open("notebook.ipynb") as f:
nb = json.load(f)
sections = []
current_section = "Setup"
for i, cell in enumerate(nb["cells"]):
if cell["cell_type"] == "markdown":
source = "".join(cell["source"])
# Extract header
for line in source.split("\n"):
if line.startswith("## "):
current_section = line.replace("## ", "").strip()
sections.append((i, current_section))
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.
- 9d ago First seen · 364 lines · 21 tokens per session scan A aff80571f9a5
trulens-notebook-execution is a skill published in the GitHub repository truera/trulens (3,536 stars, last pushed 4d ago), licensed MIT. It adds 21 tokens to every session and 2,370 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 2026-08-30.
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