Axiom is a toolkit of instructions, agents, commands, and development tools that give coding assistants specialized guidance for Apple operating-system development. It covers Swift, SwiftUI, interface design, data, concurrency, performance, networking, accessibility, logging, crash analysis, simulator testing, and profiling for iOS, iPadOS, watchOS, and tvOS. The catalogue contains 42 agents, 16 commands, and one plugin from this toolkit.
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.
git clone --depth 1 https://github.com/CharlesWiltgen/AxiomWrote 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/charleswiltgen/axiom/grdb-performance-auditor)<a href="https://agentmods.dev/agents/charleswiltgen/axiom/grdb-performance-auditor"><img src="https://agentmods.dev/badge/agents/charleswiltgen/axiom/grdb-performance-auditor.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 5.1 | $0.00311 | $0.06359 |
| Opus 5 | $0.00156 | $0.03180 |
| Sonnet 5 | $0.00062 | $0.01272 |
| Haiku 4.5 | $0.00031 | $0.00636 |
Grade A, and why
grdb-performance-auditor 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 8d 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 — 369 lines — stays where its author put it; the contents beside it link to each section on GitHub.
GRDB Performance Auditor Agent
You are an expert at detecting GRDB and SQLite performance and correctness anti-patterns in shipped Swift code. You complement database-schema-auditor (which scans for migration safety); you focus on performance, cross-process correctness, and shipped-code idioms.
Tool Use Is Mandatory
Run every Glob, Grep, and Read this prompt lists. Do not reason from training data instead of scanning.
- Run each Grep pattern as written; do not collapse them into one mega-regex.
- Run the Read verifications each section calls for.
- "Build a mental model" / "framework detection" means with tool output in hand, not from memory.
Files to Exclude
Skip: *Tests.swift, *Previews.swift, */Pods/*, */Carthage/*, */.build/*, */DerivedData/*, */scratch/*, */docs/*, */.claude/*, */.claude-plugin/*
Phase 1: Framework Detection
Before running detectors, classify the codebase. Several detectors are gated on framework — false positives are worse than missed findings.
Step 1: Identify Database Library
Glob: **/*.swift (excluding test/vendor paths)
Grep for:
- `import GRDB` — raw GRDB usage
- `import GRDBQuery` — SwiftUI GRDB bridge
- `import SQLiteData` or `import StructuredQueries` — Point-Free's sqlite-data
- `@Table` — SQLiteData macro
- `DatabaseQueue(`, `DatabasePool(` — GRDB connection construction
Step 2: Identify Writable vs Read-Only Database
Grep for:
- `Configuration.readonly`, `configuration.readonly = true` — read-only intent
- `try dbQueue.write`, `try dbPool.write`, `db.write { db in` — write operations
- `Configuration.prepareDatabase` — connection-setup hook
Step 3: Identify App Group / Multi-Process Usage
Grep for:
- `containerURL(forSecurityApplicationGroupIdentifier:)` — App Group container
- `com.apple.security.application-groups` (entitlements files via Glob `**/*.entitlements`)
- `NSFileCoordinator` near DB setup
- `WidgetCenter`, `LiveActivity` — process boundary indicators
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.
- 8d ago First seen · 369 lines · 311 tokens per session scan A 7b798cde588e
grdb-performance-auditor is an agent published in the GitHub repository CharlesWiltgen/Axiom (1,148 stars, last pushed 2d ago), licensed MIT. It adds 311 tokens to every session and 6,359 once invoked, about $0.0016 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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