Crash Triage

Crash Triage

Fetch top crashes from Firebase Crashlytics, analyze stack traces against the local codebase, correlate with recent git commits, and generate a structured triage report.

Usage

/crash-triage                                # Triage top 5 crashes from the last 7 days
/crash-triage --top 10                       # Triage top 10 crashes
/crash-triage --type FATAL                   # Only fatal crashes
/crash-triage --type ANR --days 14           # ANRs from the last 14 days
/crash-triage --version "16.1"               # Filter by app version
/crash-triage --issue abc123def456           # Deep-dive a specific issue
/crash-triage --add-notes                    # Add triage notes to Crashlytics issues
/crash-triage --output ./triage-report.md    # Save report to a file

Arguments

Execution Steps

Step 0 — Resolve Firebase App ID

Resolve the Firebase project and Android app ID before any Crashlytics calls.

1. Call mcp__plugin_firebase_firebase__firebase_get_environment to verify authentication and get the active project.
2. Call mcp__plugin_firebase_firebase__firebase_list_apps to list all apps.
3. Select the Android app ID (platform = ANDROID). If multiple Android apps exist, ask the user which one to use.
4. Store the resolved appId for all subsequent Crashlytics calls.

If not authenticated: Halt and instruct the user to run firebase login (via mcp__plugin_firebase_firebase__firebase_login or the CLI).

Step 1 — Fetch Top Issues

If --issue <id> was provided:

• Call mcp__plugin_firebase_firebase__crashlytics_get_issue with the provided issueId.
• Proceed to Step 2 with a single-issue list.

Otherwise (default flow):

1. Compute the time range:
   • intervalStartTime = ISO 8601 timestamp for (now minus --days days)
   • intervalEndTime = ISO 8601 timestamp for now
2. Build the filter:
   • If --type is not all: set issueErrorTypes to the array (e.g., ["FATAL"])
   • If --type is all: omit issueErrorTypes entirely
   • If --version is provided: first call mcp__plugin_firebase_firebase__crashlytics_get_report with report: "topVersions" to discover exact display names, then find the closest match and set versionDisplayNames to that value
   • Set intervalStartTime and intervalEndTime
3. Call mcp__plugin_firebase_firebase__crashlytics_get_report with:
   • report: "topIssues"
   • pageSize: the --top value (default 5)
   • filter: as constructed above
4. Parse the response to get a list of issues with: issue ID, title, subtitle, event count, impacted users count, and sampleEvent resource name.

Step 2 — Fetch Stack Traces

For top issues mode (default):

1. Collect all sampleEvent resource names from Step 1.
2. Call mcp__plugin_firebase_firebase__crashlytics_batch_get_events with the names array containing all sample events. This fetches all stack traces in a single batched call.
3. Parse each event to extract: exception type, exception message, stack trace frames, device model, OS version, and app version.

For single issue mode (--issue):

1. Call mcp__plugin_firebase_firebase__crashlytics_list_events with:
   • filter.issueId set to the issue ID
   • pageSize: 3 to get a few recent events
2. Parse the events as above.

Step 3 — Parse Stack Traces and Identify Source Files

For each stack trace:

1. Filter for project frames: Scan all frames for class names containing mega.privacy.android.. These are the project-owned frames.

2. Map package to source file path using the project's module structure:

   Package prefix	Source root(s)
   mega.privacy.android.app.*	app/src/main/java/, app/src/gms/java/
   mega.privacy.android.domain.*	domain/src/main/kotlin/
   mega.privacy.android.data.*	data/src/main/java/
   mega.privacy.android.feature.<name>.*	feature/<name>/*/src/main/java/, feature/<name>/*/src/main/kotlin/
   mega.privacy.android.shared.*	shared/*/src/main/java/, shared/*/src/main/kotlin/
   mega.privacy.android.core.*	core/*/src/main/java/, core/*/src/main/kotlin/

3. Fallback: If the deterministic path does not resolve, use Glob with pattern **/<ClassName>.kt (or .java) to find the file.

4. Read source context: For each identified file, read the crash line number +/- 20 lines to understand the crash context.

5. Handle edge cases:

   • Obfuscated frames (single-letter names, $ suffixes with no readable class): Note "Stack trace may be from a release build without mapping file. Consider uploading ProGuard/R8 mapping."
   • Native crashes (C/C++ frames from .so files): Mark as "Native crash" and skip source file resolution.
   • Coroutine machinery (kotlinx.coroutines.*, kotlin.coroutines.*): Filter these from the "relevant frames" list but keep in the full trace.
   • Inner classes / lambdas (MyClass$methodName$1): Map to MyClass.kt.
   • No project frames found: List the top 3 external frames and mark as "External/SDK crash — no project source identified."

Step 4 — Correlate with Git History

For each identified source file from Step 3:

1. Run git log --oneline --since="<days> days ago" -n 10 -- <file_path> to find recent commits.
2. Run git log --format="%h %an %as %s" --since="<days> days ago" -n 5 -- <file_path> to get author details.
3. If the stack trace includes a specific line number, run git log -n 3 -L <line>,<line+10>:<file_path> to find who last modified the exact crash location.
4. Collect: short commit hash, author name, date, and commit message.

If no recent commits found: Extend the search to 30 days. If still none, note "No recent changes — likely a pre-existing issue."

Step 5 — Generate the Triage Report

Output a structured markdown report in the following format:

# Crash Triage Report

**Generated:** YYYY-MM-DD HH:mm
**Time Range:** last N days (YYYY-MM-DD to YYYY-MM-DD)
**Filters:** type=FATAL | version=16.1 | (none)
**Issues Triaged:** N

## Summary

| # | Type | Title | Events | Users | Likely Culprit |
|---|------|-------|--------|-------|----------------|
| 1 | FATAL | NullPointerException in LoginViewModel.kt | 1,234 | 892 | @author (abc1234) |
| 2 | ANR | Input dispatching timed out | 567 | 321 | External/SDK |

---

## Issue 1: <Issue Title>

**Type:** FATAL | NON_FATAL | ANR
**Events:** N | **Users Affected:** N

### Stack Trace (Relevant Frames)

```
mega.privacy.android.app.presentation.login.LoginViewModel.onLoginClick(LoginViewModel.kt:142)
mega.privacy.android.domain.usecase.login.LoginUseCase.invoke(LoginUseCase.kt:38)
```

### Source Context

**File:** `app/src/main/java/.../LoginViewModel.kt` (line 142)
```kotlin
// Lines 122-162 shown
```

### Recent Git Activity

| Commit | Author | Date | Message |
|--------|--------|------|---------|
| abc1234 | John Doe | 2026-03-25 | AND-5678 Refactor login flow |
| def5678 | Jane Smith | 2026-03-20 | AND-5679 Fix null check |

### Likely Culprit

**Commit:** abc1234 by John Doe (2026-03-25)
**Reasoning:** Most recent change to the crash location (line 142) within the triage window.

### Suggested Investigation Steps

1. Check if the null check on `userSession` was removed in commit abc1234
2. Verify that `LoginUseCase` handles the case where session token is expired
3. Add a null safety check at LoginViewModel.kt:142

---

## Issue 2: ...

---

## External / SDK Crashes

| Type | Title | Events | Top Frame |
|------|-------|--------|-----------|
| FATAL | libsqlite.so crash | 234 | libsqlite.so+0x1234 |

These crashes occur in external libraries or native code. Consider updating the relevant dependency or filing an issue with the library maintainer.

Step 6 — Add Crashlytics Notes (only if --add-notes was passed)

For each triaged issue:

1. Call mcp__plugin_firebase_firebase__crashlytics_list_notes to check for existing triage notes.
2. If a note starting with [Auto-Triage already exists from today, skip to avoid duplicates.
3. Call mcp__plugin_firebase_firebase__crashlytics_create_note with a concise summary:

[Auto-Triage YYYY-MM-DD]
Likely culprit: commit <hash> by <author> (<date>)
File: <path>:<line>
Recent changes: N commits in last <days> days
Action: <1-line suggested investigation step>

Step 7 — Save Report (only if --output was passed)

1. If the path does not end in .md, append .md.
2. Write the full report to the specified path using the Write tool.
3. Confirm: "Triage report saved to <path>"

Notes

• This skill can be run via /schedule for recurring automated triage (e.g., daily morning crash review).
• For large numbers of issues (--top > 10), expect longer execution times due to source file reads and git log lookups.
• The skill reads source files to understand crash context but does not modify any code.