xcsym

xcsym — Crash Symbolication

xcsym parses a crash report end-to-end (detect format → discover dSYMs → symbolicate via atos → categorize into a pattern_tag) and emits token-lean JSON, so triage is one call instead of the manual atos/dSYM-hunting dance. Use it instead of raw atos or symbolicatecrash for any .ips, MetricKit, .crash, or .xccrashpoint input — this fleet has no other crash-symbolication path today; native-app-profiling/swiftui-expert-skill cover live Instruments profiling, not post-mortem crash files.

Resolving the binary

xcsym is not bundled with FlowDeck or RocketSim and ships no Homebrew formula or GitHub release — it’s a zero-dependency Go module distributed as source inside CharlesWiltgen/Axiom (tools/xcsym/, MIT). Resolve it once per machine:

command -v xcsym — if found, use it.
If not found, stop and tell the user to build it: git clone --depth 1 https://github.com/CharlesWiltgen/Axiom /tmp/axiom-src && cd /tmp/axiom-src/tools/xcsym && go build -o xcsym . && sudo mv xcsym /usr/local/bin/ (or any directory on PATH). Do not attempt this yourself unless the user has already agreed to installing new tooling.

Don’t confuse this with the full Axiom Claude Code plugin — this fleet deliberately did not adopt that (see docs/references.md); only the standalone xcsym binary is in use here.

Core workflow

crash is the default entry point — it does everything in one call:

xcsym crash path/to/report.ips

Auto-detects .ips (v1/v2), MetricKit JSON, legacy .crash text, and .xccrashpoint bundles (walks Filters/Filter_*/Logs/ automatically, picks the most recent).
Output is compact single-line JSON by default; add --human for terse prose, or pipe through jq for pretty-printing.
Only reach for resolve (single-address lookup), find-dsym (UUID-driven dSYM search), list-dsyms (inventory), or verify (per-image UUID/arch diagnostics) when crash fails or you need one specific sub-step — see references/xcsym-reference.md for their flags.

Read the JSON result for:

pattern_tag — the crash category (e.g. swift_forced_unwrap, watchdog_termination, zombie_or_heap_corruption); pair with pattern_confidence and pattern_reason.
images.missing / images.mismatched — why symbolication is incomplete, if it is.
Exit code — 0 is clean; non-zero codes name the reason (missing dSYM, UUID mismatch, arch mismatch, timeout, partial match), not a generic failure. Full table in the reference.

For the full subcommand reference, exit-code table, all 19 pattern tags, and the dSYM discovery order, see references/xcsym-reference.md — inline that only when the triage above isn’t enough to explain a result.

Triage template

Get the crash file (from Xcode Organizer’s “Show in Finder”, a TestFlight/App Store Connect download, or MetricKit payload).
xcsym crash <file> — read pattern_tag first, then check images for symbolication gaps.
If images.missing is non-empty: xcsym list-dsyms to see what’s discoverable locally, or xcsym find-dsym --uuid <uuid> for a specific image.
If sharing the crash outside this session (a bug report, a test fixture), run xcsym anonymize first — it scrubs bundle IDs, process names, user paths, IPs, device names, and account IDs while preserving dSYM UUIDs, so the scrubbed file still symbolicates.

Reference files

xcsym Reference