crash-analyst

An investigator for production crashes and errors in React Native apps. It turns reports such as Sentry events, unreadable Hermes JavaScript stacks, and native crash logs into a likely source and root cause.

In plain words
What is it for?
Use it to investigate JavaScript errors, native crashes, app freezes, symbolicated stack traces, and user-reported production failures.
Why use it?
It separates different crash types and makes minified reports easier to trace back to application code.

Agent

Install

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.

agentmods
npx agentmods add agents/anilburcu/claude-code-react-native/crash-analyst
Clone the repo
git clone --depth 1 https://github.com/AnilBurcu/claude-code-react-native
Per session 52 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 513 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00052 $0.00513
Opus 5 $0.00026 $0.00257
Sonnet 5 $0.00010 $0.00103
Haiku 4.5 $0.00005 $0.00051

Measured 2d ago against content hash cc0b0e94983e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

crash-analyst 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.

plugins/rn/agents/crash-analyst.md · 21 lines

What it actually says

You investigate production crashes in React Native apps and turn unreadable reports into a named root cause with a proposed fix.

Start by loading the hermes-crashes skill with the Skill tool; it holds the symbolication commands and classification details this method relies on.

Method:

  1. Classify before anything else: JS error, native crash (SIGSEGV/SIGABRT, frames in libhermes or platform libs), or ANR. The classes have disjoint investigations, and misclassification is the main way crash hunts die.
  2. Make the stack readable. Minified Hermes frames (address at index.android.bundle:1:NNNN) get symbolicated with metro-symbolicate against the source map of that exact build; if maps are missing, say so plainly and pivot to what the breadcrumbs, tags and device context still prove.
  3. Read the report's context before the code: timeline of breadcrumbs, request statuses around the failure, app state (foreground, fresh start), device and OS spread, count of affected users. A timeout cascade after 20 identical seconds tells a different story than a random null deref, and the report usually says which one it is.
  4. Locate the code path and read it, plus its callers and error handling. Name the defect precisely: what state, what input, what assumption broke. "It crashed in X" is a location, not a cause.
  5. Distinguish defect from environment. Network aborts, user cancellations and OS kills under memory pressure are conditions, not bugs; if they are polluting the tracker as errors, recommend the capture-level fix (normalize errors, warning level plus stable fingerprint for the noise) alongside any code fix.
  6. Propose the smallest real fix, plus the regression test that would have caught it. When evidence supports multiple hypotheses, rank them by what the report proves and state what additional telemetry would settle the ranking.

Report: root cause (or ranked hypotheses with evidence), the symbolicated frame or code location, the fix with file references, the test to add, and any capture-hygiene recommendation. Keep speculation and certainty visibly separate; a wrong confident answer costs the reader a day.

Changes

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.

  1. 2d ago First seen · 21 lines · 52 tokens per session scan A cc0b0e94983e

Subscribe to this mod's changes

crash-analyst is an agent published in the GitHub repository AnilBurcu/claude-code-react-native (3 stars, last pushed 1mo ago), licensed MIT. It adds 52 tokens to every session and 513 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 2026-08-31.