Parse a pasted stack trace / crash output and explain it.

Auto-detects Python (chained exceptions, ExceptionGroup, SyntaxError), Node/V8 (cause, AggregateError, async frames), Java/Kotlin (Caused by, suppressed, "... N more"), Go (panic, fatal error, goroutine dumps, race reports), Rust (panic + RUST_BACKTRACE) and .NET (inner exceptions). Returns the exception chain with the ROOT CAUSE marked, every frame classified as application vs library/stdlib/framework/runtime, the innermost application frame, and a fingerprint. Truncated or garbled input is parsed as far as possible and flagged PARTIAL with a reason.

Args: text: The raw trace, optionally surrounded by other log lines (max 5,000,000 characters). index: If the text contains several traces, which one (0-based). The report says how many. format: "report" (compact text, default) or "json" (full structure). full: Show every frame instead of collapsing runs of library frames. max_frames: Maximum frames listed for the root cause (default 25). redact: Remove secrets, emails, IPs and home-directory names from the output (default true).

Compute a stable fingerprint for each trace in the text.

The hash covers the language, the top-level and root-cause exception types and the innermost application frames (function + file base name). Messages, memory addresses, ids, container-vs-local path prefixes, generated names ($$Proxy123) and, by default, line numbers are ignored, so the same bug on another run, host or commit hashes identically while a different bug does not. The components that went into the hash are listed so a changed fingerprint can be explained.

Args: text: One or more traces (max 5,000,000 characters). include_line_numbers: Also hash line numbers (stricter: edits to the file change the hash). redact: Remove secrets etc. from the output (default true).

Scan a log file for every stack trace and group them by fingerprint.

Streams the file (never loads it whole; caps: 256 MB scanned, 1000 distinct groups) and returns the groups sorted by count with first/last seen timestamps (when the lines have ISO timestamps) or line numbers, the exception, and the innermost application frame. The file must be inside the --dir sandbox (relative paths are relative to the first --dir).

Args: path: Log file path, absolute or relative to the sandbox directory. top: How many groups to list (default 15). redact: Remove secrets etc. from the output (default true).

Map the application frames of a trace onto files in the project and show the code.

Works when the trace's paths differ from the local ones: container paths (/app/src/x.py vs ./src/x.py), Windows vs POSIX separators, webpack/vite URLs, Java package paths. Frames are matched on their trailing path components against files that actually exist under the sandbox directory. For each frame it reports FOUND / NOT FOUND / ambiguous, whether the line number exists, the offending line with +-context lines, and warns when the source line recorded in the trace differs from the file (the code changed since the crash). Paths in the trace are treated as data: '../' tricks cannot reach outside --dir and symlinks that resolve outside it are refused.

Args: text: The trace (max 5,000,000 characters). project_dir: Directory to search; must be inside --dir. Default: the first --dir. context: Lines of context before/after the offending line (0-10, default 3). max_frames: Maximum application frames to map (default 8). index: Which trace if the text contains several (0-based). redact: Remove secrets etc. from the output, including source lines (default true).

Decide whether two traces share a root cause and list the differences by frame.

Reports SAME / LIKELY SAME / POSSIBLY related / DIFFERENT with the fingerprints, the application frames both have, and the frames only one has (same function at a different line is called out as a code change).

Args: a: First trace text (the first trace in it is used). b: Second trace text. redact: Remove secrets etc. from the output (default true).

Explain a common exception type: what it means, its three most common causes, what to check first.

Covers about 80 exceptions across Python, Node, Java/Kotlin, Go, Rust and .NET (for example KeyError, ECONNREFUSED, NullPointerException, "concurrent map writes", "unwrap on None", NullReferenceException). Package prefixes are ignored (java.lang.NullPointerException = NullPointerException).

Args: type: Exception name or distinctive message, e.g. "KeyError", "java.lang.OutOfMemoryError", "nil pointer dereference". language: Optional: python, node, java, go, rust or dotnet. Omit to search all.

Remove secrets and personal data from a trace or log excerpt, returning the cleaned text.

Removes API keys and tokens (JWT, Bearer, AWS, GitHub, Slack, Stripe, Google, sk-...), password=/token= style values, credentials in URLs, emails, IPv4 and full IPv6 addresses, and user names in home directories (C:\Users\name, /home/name, /Users/name). Safe to run before pasting a trace into a ticket. Every other tool also redacts its output by default.

Args: text: Text to clean (max 5,000,000 characters).