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 agentmods add skills/tanstack/ai/build-custom-adapternpx skills add TanStack/ai --skill build-custom-adaptergit clone --depth 1 https://github.com/TanStack/aiWhat 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 | $0.00101 | $0.03906 |
| Opus 5 | $0.00051 | $0.01953 |
| Sonnet 5 | $0.00020 | $0.00781 |
| Haiku 4.5 | $0.00010 | $0.00391 |
Grade A, and why
ai-persistence/build-custom-adapter 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 2d 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 — 329 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Custom Chat Persistence
The deliverable is one file in the app — src/lib/chat-persistence.ts —
exporting a ChatPersistence built from the database client the app already
has. Plus whatever DDL that database needs, added through the app's existing
migration flow.
Do not create a package, a second client, or a migration runner.
Route first. If the app already runs one of these, stop and use that skill — it has the driver-specific code:
| App runs | Use |
|---|---|
| Drizzle ORM (any dialect) | ai-persistence/build-drizzle-adapter |
| Prisma | ai-persistence/build-prisma-adapter |
| Cloudflare Workers + D1 | ai-persistence/build-cloudflare-adapter |
Everything else lands here. The full contracts and their invariants are in
ai-persistence/stores and docs/persistence/store-reference.md; the
complete worked node:sqlite walkthrough is
docs/persistence/build-your-own-chat-adapter.md and
examples/ts-react-chat/src/lib/sqlite-persistence.ts.
1. Read the app before writing anything
| Find | Where to look | What it decides |
|---|---|---|
| The client | src/db.ts, src/lib/db.ts, src/server/db.ts |
What the file imports — never construct a second pool |
| Client lifetime | module singleton vs per-request factory (getDb(), bindings) |
export const chatPersistence vs export function |
| Migration flow | migrations/, drizzle/, supabase/migrations/, an ORM CLI |
How the DDL gets applied — use theirs, add nothing new |
| Naming conventions | existing tables/collections | Prefix (chat_*) so nothing collides |
| JSON support | jsonb (Postgres), json (MySQL 5.7+), text (SQLite) |
Whether mappers stringify/parse |
| Import alias | tsconfig.json paths |
@/db, ~/db, #/db, or a relative path |
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.
- 2d ago First seen · 329 lines · 101 tokens per session scan A 3173bd8c784a
ai-persistence/build-custom-adapter is a skill published in the GitHub repository TanStack/ai (3,056 stars, last pushed today), licensed MIT. It adds 101 tokens to every session and 3,906 once invoked, about $0.0005 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.
Other skills, from other repositories
design
Create a design canvas - a multi-artboard visual design published as an Artifact that runs Claude Design's canvas editor (an early preview of Claude Design inside Claude Code). You DRAFT the design as .dc.html artboards laid out on one pan/zoom canvas; where saving is enabled for the user's account they refine every…
create-design-system
Skill to use if user asks you to create a design system or UI kit.
keybindings-help
Use when the user wants to customize keyboard shortcuts, rebind keys, add chord bindings, or modify /.claude/keybindings.json. Examples: "rebind ctrl+s", "add a chord shortcut", "change the submit key", "customize keybindings".
security-review
Complete a security review of the pending changes on the current branch.
tmux
Remote-control tmux sessions for interactive CLIs by sending keystrokes and scraping pane output.
summarize
Summarize or extract text/transcripts from URLs, podcasts, and local files (great fallback for “transcribe this YouTube/video”).