johnxie · johnxie · Feb 24, 2026 · Feb 24, 2026 · Feb 24, 2026 · Feb 24, 2026
diff --git a/tutorials/README.md b/tutorials/README.md
@@ -17,26 +17,26 @@ Use this guide to navigate all tutorial tracks, understand structure rules, and
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 | Tutorial directories | 191 |
 | Tutorial markdown files | 1732 |
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+| Tutorial markdown lines | 1,048,791 |
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 | Tutorial directories | 191 |
 | Tutorial markdown files | 1732 |
-| Tutorial markdown lines | 1,004,205 |
+| Tutorial markdown lines | 1,048,791 |
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 | Tutorial directories | 191 |
 | Tutorial markdown files | 1732 |
-| Tutorial markdown lines | 1,004,205 |
+| Tutorial markdown lines | 1,048,791 |
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 | Tutorial directories | 191 |
 | Tutorial markdown files | 1732 |
-| Tutorial markdown lines | 1,004,205 |
+| Tutorial markdown lines | 1,048,791 |
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 | Tutorial directories | 191 |
 | Tutorial markdown files | 1732 |
-| Tutorial markdown lines | 1,004,205 |
+| Tutorial markdown lines | 1,048,791 |
 
 ## Source Verification Snapshot
 

diff --git a/tutorials/anthropic-skills-tutorial/01-getting-started.md b/tutorials/anthropic-skills-tutorial/01-getting-started.md
diff --git a/tutorials/anthropic-skills-tutorial/02-skill-categories.md b/tutorials/anthropic-skills-tutorial/02-skill-categories.md
diff --git a/tutorials/anthropic-skills-tutorial/03-advanced-skill-design.md b/tutorials/anthropic-skills-tutorial/03-advanced-skill-design.md
diff --git a/tutorials/anthropic-skills-tutorial/04-integration-platforms.md b/tutorials/anthropic-skills-tutorial/04-integration-platforms.md
diff --git a/tutorials/anthropic-skills-tutorial/05-production-skills.md b/tutorials/anthropic-skills-tutorial/05-production-skills.md
diff --git a/tutorials/anthropic-skills-tutorial/06-best-practices.md b/tutorials/anthropic-skills-tutorial/06-best-practices.md
diff --git a/tutorials/anthropic-skills-tutorial/07-publishing-sharing.md b/tutorials/anthropic-skills-tutorial/07-publishing-sharing.md
diff --git a/tutorials/anthropic-skills-tutorial/08-real-world-examples.md b/tutorials/anthropic-skills-tutorial/08-real-world-examples.md
diff --git a/tutorials/anthropic-skills-tutorial/index.md b/tutorials/anthropic-skills-tutorial/index.md
@@ -3,6 +3,7 @@ layout: default
 title: "Anthropic Skills Tutorial"
 nav_order: 91
 has_children: true
+format_version: v2
 ---
 
 # Anthropic Skills Tutorial: Reusable AI Agent Capabilities
@@ -13,6 +14,16 @@ has_children: true
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![Spec](https://img.shields.io/badge/Spec-agentskills.io-blue)](https://agentskills.io/specification)
 
+## Why This Track Matters
+
+Anthropic Skills let you package reusable, reliable behaviors for Claude agents once and deploy them across every integration point — Claude Code, Claude.ai, and the API — without re-engineering each time.
+
+This track focuses on:
+- designing skills with clear invocation boundaries and deterministic outputs
+- packaging repeatable workflows using scripts, references, and asset files
+- publishing versioned skills for team or public reuse
+- operating a skills catalog with ownership and lifecycle controls
+
 ## What are Anthropic Skills?
 
 Anthropic Skills are packaged instructions and supporting files that Claude can load for specific jobs. A skill can be lightweight (one `SKILL.md`) or operationally rich (scripts, templates, and domain references).
@@ -35,7 +46,7 @@ The official `anthropics/skills` repository demonstrates real patterns used for:
 | `references/` | Source material Claude can load on demand for better answers |
 | `assets/` | Non-text files required by the workflow |
 
-## Tutorial Structure
+## Chapter Guide
 
 | Chapter | Topic | What You Will Learn |
 |:--------|:------|:--------------------|
@@ -110,11 +121,24 @@ Ready to begin? Start with [Chapter 1: Getting Started](01-getting-started.md).
 7. [Chapter 7: Publishing and Sharing](07-publishing-sharing.md)
 8. [Chapter 8: Real-World Examples](08-real-world-examples.md)
 
+## Current Snapshot (auto-updated)
+
+- repository: [anthropics/skills](https://github.com/anthropics/skills)
+- stars: about **1.2K**
+- project positioning: official reference implementation for the Agent Skills format specification
+
+## What You Will Learn
+
+- how to design and structure a SKILL.md file with frontmatter and behavioral contracts
+- how to compose multi-file skills with scripts, references, and asset directories
+- how to integrate skills across Claude Code, Claude.ai, and the Claude API
+- how to version, publish, and maintain skills catalogs for team-wide reuse
+
 ## Source References
 
 - [anthropics/skills repository](https://github.com/anthropics/skills)
 
-## Concept Flow
+## Mental Model
 
 ```mermaid
 flowchart TD

diff --git a/tutorials/athens-research-knowledge-graph/01-system-overview.md b/tutorials/athens-research-knowledge-graph/01-system-overview.md
@@ -493,3 +493,97 @@ Suggested trace strategy:
 - [Next Chapter: Chapter 2: Datascript Deep Dive](02-datascript-database.md)
 - [Main Catalog](../../README.md#-tutorial-catalog)
 - [A-Z Tutorial Directory](../../discoverability/tutorial-directory.md)
+
+## Depth Expansion Playbook
+
+<!-- depth-expansion-v2 -->
+
+This chapter is expanded to v1-style depth for production-grade learning and implementation quality.
+
+### Strategic Context
+
+- tutorial: **Athens Research: Deep Dive Tutorial**
+- tutorial slug: **athens-research-knowledge-graph**
+- chapter focus: **Chapter 1: System Overview**
+- system context: **Athens Research Knowledge Graph**
+- objective: move from surface-level usage to repeatable engineering operation
+
+### Architecture Decomposition
+
+1. Define the runtime boundary for `Chapter 1: System Overview`.
+2. Separate control-plane decisions from data-plane execution.
+3. Capture input contracts, transformation points, and output contracts.
+4. Trace state transitions across request lifecycle stages.
+5. Identify extension hooks and policy interception points.
+6. Map ownership boundaries for team and automation workflows.
+7. Specify rollback and recovery paths for unsafe changes.
+8. Track observability signals for correctness, latency, and cost.
+
+### Operator Decision Matrix
+
+| Decision Area | Low-Risk Path | High-Control Path | Tradeoff |
+|:--------------|:--------------|:------------------|:---------|
+| Runtime mode | managed defaults | explicit policy config | speed vs control |
+| State handling | local ephemeral | durable persisted state | simplicity vs auditability |
+| Tool integration | direct API use | mediated adapter layer | velocity vs governance |
+| Rollout method | manual change | staged + canary rollout | effort vs safety |
+| Incident response | best effort logs | runbooks + SLO alerts | cost vs reliability |
+
+### Failure Modes and Countermeasures
+
+| Failure Mode | Early Signal | Root Cause Pattern | Countermeasure |
+|:-------------|:-------------|:-------------------|:---------------|
+| stale context | inconsistent outputs | missing refresh window | enforce context TTL and refresh hooks |
+| policy drift | unexpected execution | ad hoc overrides | centralize policy profiles |
+| auth mismatch | 401/403 bursts | credential sprawl | rotation schedule + scope minimization |
+| schema breakage | parser/validation errors | unmanaged upstream changes | contract tests per release |
+| retry storms | queue congestion | no backoff controls | jittered backoff + circuit breakers |
+| silent regressions | quality drop without alerts | weak baseline metrics | eval harness with thresholds |
+
+### Implementation Runbook
+
+1. Establish a reproducible baseline environment.
+2. Capture chapter-specific success criteria before changes.
+3. Implement minimal viable path with explicit interfaces.
+4. Add observability before expanding feature scope.
+5. Run deterministic tests for happy-path behavior.
+6. Inject failure scenarios for negative-path validation.
+7. Compare output quality against baseline snapshots.
+8. Promote through staged environments with rollback gates.
+9. Record operational lessons in release notes.
+
+### Quality Gate Checklist
+
+- [ ] chapter-level assumptions are explicit and testable
+- [ ] API/tool boundaries are documented with input/output examples
+- [ ] failure handling includes retry, timeout, and fallback policy
+- [ ] security controls include auth scopes and secret rotation plans
+- [ ] observability includes logs, metrics, traces, and alert thresholds
+- [ ] deployment guidance includes canary and rollback paths
+- [ ] docs include links to upstream sources and related tracks
+- [ ] post-release verification confirms expected behavior under load
+
+### Source Alignment
+
+- [Athens Research](https://github.com/athensresearch/athens)
+- [AI Codebase Knowledge Builder](https://github.com/The-Pocket/Tutorial-Codebase-Knowledge)
+
+### Cross-Tutorial Connection Map
+
+- Related tutorials are listed in this tutorial index.
+
+### Advanced Practice Exercises
+
+1. Build a minimal end-to-end implementation for `Chapter 1: System Overview`.
+2. Add instrumentation and measure baseline latency and error rate.
+3. Introduce one controlled failure and confirm graceful recovery.
+4. Add policy constraints and verify they are enforced consistently.
+5. Run a staged rollout and document rollback decision criteria.
+
+### Review Questions
+
+1. Which execution boundary matters most for this chapter and why?
+2. What signal detects regressions earliest in your environment?
+3. What tradeoff did you make between delivery speed and governance?
+4. How would you recover from the highest-impact failure mode?
+5. What must be automated before scaling to team-wide adoption?