Borrowing it
Nothing to install: this file belongs to timothywarner-org/ab900. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/timothywarner-org/ab900/main/AGENTS.mdgit clone --depth 1 https://github.com/timothywarner-org/ab900Wrote 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/instructions/timothywarner-org/ab900/agents-md)<a href="https://agentmods.dev/instructions/timothywarner-org/ab900/agents-md"><img src="https://agentmods.dev/badge/instructions/timothywarner-org/ab900/agents-md/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/instructions/timothywarner-org/ab900/agents-md"><img src="https://agentmods.dev/badge/instructions/timothywarner-org/ab900/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00986 | $0.00986 |
| Opus 5.5 | $0.00394 | $0.00394 |
| Sonnet 5.5 | $0.00197 | $0.00197 |
| Haiku 4.5 | $0.00099 | $0.00099 |
Grade A, and why
ab900 AGENTS.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 yesterday.
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 — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Learner-facing AB-900 course home
This public repository is the course home for Tim Warner's Pearson class
Copilot and Agent Administration Fundamentals (October 27, 2026) and the earlier
July 2026 O'Reilly AB-900 course. Start with README.md for the learning route and
TUTORIALS.md for the step-by-step exercises. CLAUDE.md holds the full authoring
rules for the July course and the study-buddy assets under .github/.
Project map
README.mdis the Pearson course home in the series layout shared withcontext-engineering-with-mcp: banner, badges, byline, learning route, what is in the repository, lab prerequisites, portals, author bio, and license. The July edition lives inarchive/july-2026/, and the exam material indocs/certify.mdanddocs/study-buddy.md.NOTICE.mdholds trademarks, the fictional-data statement, and source attribution.images/banner.pngandimages/social-preview.pngare generated byscripts/make_banner.pyfromimages/brand.json. Change the JSON and rerun the script. Don't hand-edit the PNGs.evidence/holds the instructor's dated, observed test runs. Never copy them into the starter matrix, which staysNOT RUNfor learners.TUTORIALS.mdrepeats every Pearson demo as numbered steps: prepare a lab, trace access and adoption, create a DLP policy in simulation, read a data access governance report, build and test the starter agent, and approve and operate it.handouts/holds the four PDF handouts exactly as Pearson distributes them in the session Resources widget (October 19, 2026 bytes, checked by hash), plus a README that maps each one to a tutorial and lists the updates since they were written. Never edit or re-export these PDFs. Record corrections inhandouts/README.md.starter-files/holds the synthetic Contoso, Ltd. service guide, agent instructions, test matrix (T01 to T08, allNOT RUN), and synthetic sharing report.archive/july-2026/holds the four-hour July edition: notes, demo scripts, labs, segment folders, and shared resources.references/serves the study buddy. Both belong to the July O'Reilly course..github/holds the study-buddy prompts, skills, and instructions.scripts/Test-CourseHome.pychecks the course-home documents and the public/private boundary.
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.
- yesterday Changed · +17 lines · +311 tokens per session 8e9b6c6487fd
- 2d ago First seen · 50 lines · 675 tokens per session scan A 605c80c4859d
ab900 AGENTS.md is an instructions file published in the GitHub repository timothywarner-org/ab900 (29 stars, last pushed today), licensed MIT. It adds 986 tokens to every session, about $0.0039 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 2026-10-26.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.