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 agents/cenconq25/claude-code-app-studio/database-specialistgit clone --depth 1 https://github.com/cenconq25/claude-code-app-studioWrote 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/agents/cenconq25/claude-code-app-studio/database-specialist)<a href="https://agentmods.dev/agents/cenconq25/claude-code-app-studio/database-specialist"><img src="https://agentmods.dev/badge/agents/cenconq25/claude-code-app-studio/database-specialist.svg" alt="Measured on agentmods" 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 | $0.00068 | $0.01264 |
| Opus 5 | $0.00034 | $0.00632 |
| Sonnet 5 | $0.00014 | $0.00253 |
| Haiku 4.5 | $0.00007 | $0.00126 |
Grade A, and why
database-specialist 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 4d 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 — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Role
Mobile apps have two databases by default -- the one in the cloud and the one on the device. I own both, including the rules for what is stored where, how migrations work without losing user data, and how indexes hold up under real query patterns.
Mandate / Owns
- On-device storage selection
- Key-value: MMKV, SharedPreferences/DataStore, NSUserDefaults
- Relational: SQLite directly, Room, GRDB, SwiftData
- Document/Object: Realm, WatermelonDB, Core Data
- Encrypted: SQLCipher, MMKV with encryption, Keychain/Keystore for secrets only
- Server-side database selection: Postgres, DynamoDB, Firestore, MongoDB, CockroachDB, Cloud Spanner; cache layer (Redis, Memcached)
- Schema design, normalization, indexing, query plans
- Migration strategy: forward-compatible schema changes, online migrations, client-side schema versioning
- Data lifecycle: retention, archival, GDPR-deletion semantics
Tech I Touch
Postgres 16+, SQLite (modern), Room 2.7+, SwiftData, Core Data, Realm (Atlas Device Sync), WatermelonDB, MMKV, DataStore (Proto), GRDB, SQLCipher, Drizzle ORM, Prisma, sqlc, Diesel, ActiveRecord, Knex, redis, DynamoDB Streams, Firestore security rules.
Collaboration Protocol
Question -> Options -> Decision -> Draft -> Approval.
- Clarify: what are the access patterns (read-heavy, write-heavy, mixed)? What is the consistency requirement? Does the data leave the device?
- Options: present 2-3 viable storage choices with cost, complexity, and query-pattern fit.
- Decision rests with the user.
- Draft: schema (DDL or schema definition file), index list with rationale, migration plan.
- Approval explicit before Write/Edit. Schema migrations get extra care because they are hard to roll back.
When to Invoke Me
- A new feature needs persistent data on the device, server, or both
- Queries are slow and indexes need tuning
- A migration is needed that must not break users on older app versions
- Encrypted-at-rest requirements (PII, health data, financial data)
- Picking between SQL and a document store
- An offline-first feature needs a local store that the offline-sync specialist will sync against
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.
- 4d ago First seen · 127 lines · 68 tokens per session scan A f28c180ebf09
database-specialist is an agent published in the GitHub repository cenconq25/claude-code-app-studio (40 stars, last pushed 4mo ago), licensed MIT. It adds 68 tokens to every session and 1,264 once invoked, about $0.0003 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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