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 AnilBurcu/claude-code-react-native --skill hermes-crashesgit clone --depth 1 https://github.com/AnilBurcu/claude-code-react-nativeWrote 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/anilburcu/claude-code-react-native/hermes-crashes)<a href="https://agentmods.dev/skills/anilburcu/claude-code-react-native/hermes-crashes"><img src="https://agentmods.dev/badge/skills/anilburcu/claude-code-react-native/hermes-crashes/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/anilburcu/claude-code-react-native/hermes-crashes"><img src="https://agentmods.dev/badge/skills/anilburcu/claude-code-react-native/hermes-crashes.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 | $0.00051 | $0.01060 |
| Opus 5.5 | $0.00020 | $0.00424 |
| Sonnet 5.5 | $0.00010 | $0.00212 |
| Haiku 4.5 | $0.00005 | $0.00106 |
Grade A, and why
hermes-crashes 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 — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Making production crashes readable
First, classify the crash
Three families, three completely different investigations:
- JS error: a thrown Error, a rejected promise, a render error. Stack frames point into the JS bundle (
index.android.bundle,main.jsbundle). Fix in JS. - Native crash: SIGSEGV, SIGABRT, EXC_BAD_ACCESS, frames in
libhermes.soor platform frameworks. The JS code may be the trigger but the defect is in a native module or in JSI usage. - ANR / watchdog kill: no crash at all, the main thread was blocked. Investigate what ran long, not what threw.
Misclassifying wastes days. A SIGSEGV cannot be fixed by editing JavaScript, and an unhandled rejection will never appear in a tombstone.
Decoding "address at index.android.bundle:1:589926"
That address is an offset into Hermes bytecode, not a line and column in your source. The decoder is metro-symbolicate plus the source map that was generated for that exact build:
# paste the raw stack into a file, then:
npx metro-symbolicate path/to/index.android.bundle.map < stack.txt
Rules that make this work:
- The map must come from the same build as the crashing bundle. A map from a rebuild of "the same commit" often still matches, but treat any nonsense output as a map mismatch.
- Expo/EAS builds can emit source maps during the build; keep them as build artifacts. If you have no map for a release, that release's crashes stay unreadable forever, so archiving maps per release is part of the release process, not an optimization.
Sentry (or any crash reporter) symbolication checklist
When events show minified frames instead of source:
- Current tooling matches bundle and map through Debug IDs injected into both at build time; the usual failure is that the upload step ran locally but not in the release lane. Confirm the CI job actually uploaded artifacts for the build that is crashing.
- On older release-plus-dist setups, maps must be uploaded per release AND distribution. A dist mismatch fails silently and looks exactly like "sourcemaps don't work".
- Same for the release name: what the app reports at runtime must equal what the maps were uploaded under. Log both once and compare character by character.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 Changed · -16 tokens per session e5aae527c868
- 2mo ago First seen · 61 lines · 67 tokens per session scan A 75ffe0cb7639
hermes-crashes is a skill published in the GitHub repository AnilBurcu/claude-code-react-native (3 stars, last pushed 1mo ago), licensed MIT. It adds 51 tokens to every session and 1,060 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 2026-08-31.
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