diff --git a/wiki/_master-index.md b/wiki/_master-index.md
index 4764d63..495afd5 100644
--- a/wiki/_master-index.md
+++ b/wiki/_master-index.md
@@ -36,5 +36,8 @@ This 3-hop pattern works for hundreds of articles without vector search.
 | [[wiki/infrastructure/_index\|infrastructure/]] | Server inventory: all 10 SSH hosts — optical, optical-dev, optical-prod, baic, librechat, modocmms, box-cli, aimpress, pve | 11 |
 | [[wiki/testing/_index\|testing/]] | Web app testing: functional, performance, security, UI types; TDD/BDD/Agile methodologies; Selenium/Cypress/Playwright/JMeter/OWASP ZAP tools | 1 |
 
+| [[wiki/shared-patterns/_index\|shared-patterns/]] | Oliver Agency standard library patterns: httpx, structlog, pydantic-settings, alembic — reuse before writing from scratch | 4 |
+| [[wiki/mistakes/_index\|mistakes/]] | Anti-patterns extracted from sessions — per-stack running lists (fastapi, react, docker, postgres, general) — injected at session start | 5 |
+
 <!-- New topic folders added here automatically as they are created -->
 <!-- Format: | [[wiki/topic/_index\|topic/]] | One-line description | N articles | -->
diff --git a/wiki/mistakes/_index.md b/wiki/mistakes/_index.md
new file mode 100644
index 0000000..b4c2532
--- /dev/null
+++ b/wiki/mistakes/_index.md
@@ -0,0 +1,18 @@
+---
+title: "Mistakes Index"
+description: "Running log of mistakes to avoid repeating — auto-populated from session flush"
+updated: 2026-05-15
+---
+
+# Mistakes
+
+Anti-patterns and time-wasters extracted from real debugging sessions.
+**Session-start hook injects relevant stack file at the start of every session.**
+
+| Stack | File | Last mistake |
+|-------|------|-------------|
+| FastAPI / Python | [[wiki/mistakes/fastapi]] | — |
+| React / TypeScript | [[wiki/mistakes/react]] | — |
+| Docker / Infra | [[wiki/mistakes/docker]] | — |
+| PostgreSQL / Alembic | [[wiki/mistakes/postgres]] | — |
+| General / Cross-stack | [[wiki/mistakes/general]] | — |
diff --git a/wiki/mistakes/docker.md b/wiki/mistakes/docker.md
new file mode 100644
index 0000000..56a320b
--- /dev/null
+++ b/wiki/mistakes/docker.md
@@ -0,0 +1,13 @@
+---
+title: "Docker / Infrastructure Mistakes"
+tags: [docker, infra, mistakes]
+updated: 2026-05-15
+---
+
+# Docker / Infrastructure — Mistakes to Avoid
+
+Running list. Newest first. Auto-populated from session flush.
+
+---
+
+<!-- mistakes appended below by compile.py -->
diff --git a/wiki/mistakes/fastapi.md b/wiki/mistakes/fastapi.md
new file mode 100644
index 0000000..0d58a08
--- /dev/null
+++ b/wiki/mistakes/fastapi.md
@@ -0,0 +1,13 @@
+---
+title: "FastAPI / Python Mistakes"
+tags: [fastapi, python, mistakes]
+updated: 2026-05-15
+---
+
+# FastAPI / Python — Mistakes to Avoid
+
+Running list. Newest first. Auto-populated from session flush.
+
+---
+
+<!-- mistakes appended below by compile.py -->
diff --git a/wiki/mistakes/general.md b/wiki/mistakes/general.md
new file mode 100644
index 0000000..79768a5
--- /dev/null
+++ b/wiki/mistakes/general.md
@@ -0,0 +1,13 @@
+---
+title: "General / Cross-Stack Mistakes"
+tags: [general, mistakes]
+updated: 2026-05-15
+---
+
+# General / Cross-Stack — Mistakes to Avoid
+
+Running list. Newest first. Auto-populated from session flush.
+
+---
+
+<!-- mistakes appended below by compile.py -->
diff --git a/wiki/mistakes/postgres.md b/wiki/mistakes/postgres.md
new file mode 100644
index 0000000..f5384d4
--- /dev/null
+++ b/wiki/mistakes/postgres.md
@@ -0,0 +1,13 @@
+---
+title: "PostgreSQL / Alembic Mistakes"
+tags: [postgres, alembic, mistakes]
+updated: 2026-05-15
+---
+
+# PostgreSQL / Alembic — Mistakes to Avoid
+
+Running list. Newest first. Auto-populated from session flush.
+
+---
+
+<!-- mistakes appended below by compile.py -->
diff --git a/wiki/mistakes/react.md b/wiki/mistakes/react.md
new file mode 100644
index 0000000..7e10f1f
--- /dev/null
+++ b/wiki/mistakes/react.md
@@ -0,0 +1,13 @@
+---
+title: "React / TypeScript Mistakes"
+tags: [react, typescript, mistakes]
+updated: 2026-05-15
+---
+
+# React / TypeScript — Mistakes to Avoid
+
+Running list. Newest first. Auto-populated from session flush.
+
+---
+
+<!-- mistakes appended below by compile.py -->
diff --git a/wiki/shared-patterns/_index.md b/wiki/shared-patterns/_index.md
new file mode 100644
index 0000000..3fd9549
--- /dev/null
+++ b/wiki/shared-patterns/_index.md
@@ -0,0 +1,17 @@
+---
+title: "Shared Patterns Index"
+description: "Oliver Agency standard library implementations — reuse before writing from scratch"
+updated: 2026-05-15
+---
+
+# Shared Patterns
+
+Cross-project reusable implementations for Oliver Agency standard libraries.
+Read these before writing any HTTP client, logger, config loader, or migration.
+
+| Article | Summary | Updated |
+|---------|---------|---------|
+| [[wiki/shared-patterns/httpx-async-client\|httpx-async-client]] | Async HTTP client patterns — auth headers, retries, Mailgun gotcha, ADO PATCH | 2026-05-15 |
+| [[wiki/shared-patterns/structlog-setup\|structlog-setup]] | structlog configuration — two real styles, request-id middleware, stdlib bridge | 2026-05-15 |
+| [[wiki/shared-patterns/pydantic-settings-env\|pydantic-settings-env]] | BaseSettings patterns — Azure AD, Box API, 4 gotchas (reserved `model` field, case sensitivity) | 2026-05-15 |
+| [[wiki/shared-patterns/alembic-migrations\|alembic-migrations]] | Async Alembic setup — alembic.ini, env.py, 5 gotchas (nullable, Enum drop, server_default) | 2026-05-15 |