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 skills add infraspecdev/tesseract --skill concurrency-reviewgit clone --depth 1 https://github.com/infraspecdev/tesseractWrote 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/skills/infraspecdev/tesseract/concurrency-review)<a href="https://agentmods.dev/skills/infraspecdev/tesseract/concurrency-review"><img src="https://agentmods.dev/badge/skills/infraspecdev/tesseract/concurrency-review/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/infraspecdev/tesseract/concurrency-review"><img src="https://agentmods.dev/badge/skills/infraspecdev/tesseract/concurrency-review.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00047 | $0.00967 |
| Opus 5.5 | $0.00019 | $0.00387 |
| Sonnet 5.5 | $0.00009 | $0.00193 |
| Haiku 4.5 | $0.00005 | $0.00097 |
Grade A, and why
backend-concurrency-review 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 1mo 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 — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Backend Concurrency Review
Overview
Review backend code for concurrency correctness: race conditions on shared mutable state, lock granularity and scope, async-pattern pitfalls (forgotten await, fire-and-forget exception loss, callback hell), idempotency for retried operations, and safe shared state across request threads.
Framework-agnostic but with examples in JVM threading, JS async/await, Python asyncio, Go goroutines.
When to Use
- Reviewing services with shared state (singletons, statics, module globals)
- Reviewing async/await/CompletableFuture/goroutine code
- Auditing retry logic for idempotency
- Reviewing concurrent collections and locking patterns
When NOT to Use
- Pure single-threaded logic — concurrency rubric does not apply
- Distributed coordination (consensus, leader election) — separate skill not in v1
- Database isolation level review — covered by
database-review
Review Process
- Inventory: shared state (singletons, statics, beans with mutable fields), async call sites, locks
- For each, apply Evaluation Points C1–C10
- Cross-cut: trace a request path; flag every shared write that is not synchronized
Evaluation Points
| # | Check | What to Look For | Severity |
|---|---|---|---|
| C1 | Shared mutable state | Singleton beans, static fields, module-level vars holding mutable collections without synchronization | High |
| C2 | Read-modify-write atomicity | x = x + 1 on a shared field. Use atomic types (AtomicInteger, LongAdder) or explicit locks |
High |
| C3 | Concurrent collection choice | HashMap not safe for concurrent access; use ConcurrentHashMap. Same for lists and sets |
High |
| C4 | Lock granularity | Fine-grained locks where contention matters; avoid synchronized(this) over wide methods |
Medium |
| C5 | Async exception loss | CompletableFuture.runAsync / setTimeout / goroutine whose exceptions go nowhere |
High |
| C6 | Forgotten await / .get() |
Async result ignored; exception happens later in detached context | Medium |
| C7 | Idempotency on retry | Operations that may retry must be safe to repeat — no double-charge, double-create, double-send | High |
| C8 | Cancellation handling | Long async tasks honor cancellation tokens / Thread.interrupted / ctx.Done() |
Medium |
| C9 | Deadlock risk | Two locks acquired in inconsistent order across paths. Resource hierarchy not enforced | Medium |
| C10 | Backpressure on async producers | Unbounded queues / unbounded fan-out can OOM. Bound the queue or rate-limit upstream | Medium |
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.
- 1mo ago First seen · 78 lines · 47 tokens per session scan A 33bd713c9c4f
backend-concurrency-review is a skill published in the GitHub repository infraspecdev/tesseract (5 stars, last pushed 3mo ago), licensed MIT. It adds 47 tokens to every session and 967 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-03.
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