Cymbal

Cymbal Skill

Rule

If the task touches existing code, start with cymbal. Do not start with rg, grep, find, or whole-file Read when the user named a symbol, you need dependency flow, or the file is large/unfamiliar.

Default Investigation Loop

search  →  investigate / context  →  impact / trace / refs / impls  →  show / outline
                                                                              │
                                                                              └─ then targeted reads or rg

1. Find it — cymbal search <query> (add --exact, --kind, --lang, --path).
2. Understand it — cymbal investigate <symbol> (kind-adaptive: function → source + callers + shallow impact; type → source + members + references). Use cymbal context <symbol> only when you specifically want source + callers + imports bundled.
3. Trace flow — cymbal impact (upward), cymbal trace (downward), cymbal refs (direct uses), cymbal impls (who implements this).
4. Read — cymbal show <symbol> or cymbal outline <file> before Read / rg.

Goal → Command

Every command supports --json. cymbal resolves the right DB automatically per repo; do not run cymbal index manually — hooks refresh it.

Command Details

search — starting point

cymbal search OpenStore
cymbal search PatchMulti MultiEdit EditTool PatchTool
cymbal search parse --kind function --lang go
cymbal search "TODO" --text                              # full-text grep (uses rg)
cymbal search --text 'os\.WriteFile\(' tools/file.go     # rg-style path operand
cymbal search Handler --path 'internal/**' --exclude '**/*_test.go'

Ranked exact > prefix > fuzzy. Trust the first result — bench shows 100% canonical ranking @1 across the corpus.

investigate — one call, right-shaped answer

cymbal investigate OpenStore
cymbal investigate config.go:Config       # file hint
cymbal investigate auth.Middleware        # parent/package hint
cymbal investigate Foo Bar Baz            # batch

Ambiguous names auto-resolve and list alternatives in also / matches. Use this before show/refs/context on unfamiliar symbols.

context — bundled read

cymbal context OpenStore
cymbal context ParseFile --callers 10

--callers is the only knob (default 20). Use when you already know the symbol matters and want one payload. Do not call both investigate and context on the same symbol — pick one.

show — read source

cymbal show ParseFile
cymbal show internal/index/store.go
cymbal show internal/index/store.go:80-120
cymbal show Foo Bar Baz                              # batch
cymbal outline big.go -s --names | cymbal show --stdin
cymbal show Handler --all                            # every definition
cymbal show Foo --path 'internal/**' --exclude '**/*_test.go'

Supports -C context lines, --path, --exclude, --all, --stdin.

outline — file map

cymbal outline internal/index/store.go
cymbal outline internal/index/store.go --signatures
cymbal outline internal/index/store.go -s --names    # one symbol per line, pipe-ready

Read this before opening large or unfamiliar files. The --names form is the engine for batch mode in show/refs/trace/impact.

refs — direct references

cymbal refs ParseFile
cymbal refs ParseFile --file internal/
cymbal refs ParseFile --importers                    # files importing the defining file
cymbal refs ParseFile --impact                       # = --importers --depth 2
cymbal refs Foo Bar Baz                              # batch
cymbal refs Foo --path 'cmd/**' --exclude '**/testdata/**'

--depth capped at 3. Best-effort AST name matching, not semantic analysis.

impact — upward, transitive

cymbal impact handleRegister
cymbal impact handleRegister -D 3 -C 2
cymbal impact handleRegister --graph                 # renders a visual graph
cymbal impact Save Load Delete                       # union, attributed via hit_symbols
cymbal outline store.go -s --names | cymbal impact --stdin

trace — downward call chain

cymbal trace handleRegister
cymbal trace handleRegister --depth 5
cymbal trace handleRegister --graph                  # renders a visual graph
cymbal trace handleRegister --kinds call,use         # default: call only
cymbal outline svc.go -s --names | cymbal trace --stdin

impls — who implements / extends / conforms

cymbal impls Handler                  # Java/C#/Kotlin/TS implements, Go embedding,
                                      # Swift conformance, Rust impl, Python bases,
                                      # Ruby include/extend, PHP implements, C++ bases

Externally-defined targets come back with resolved=false. Bench: 100% token savings vs ripgrep on FastAPI's FastAPI and APIRouter interfaces.

--graph — visual topology

cymbal trace handleRegister --graph
cymbal impact handleRegister --graph
cymbal importers internal/index --graph
cymbal impls Handler --graph
cymbal trace handleRegister --graph-format json

Use graph mode when you need a high-level relationship map: fan-in/fan-out, inheritance/conformance, or a quick orientation pass you can paste into a viewer. Stay with the normal text/JSON output when you need exact call sites, source lines, or detail you will edit against. Defaults: Mermaid on a TTY, JSON when piped. Use --graph-limit to cap dense graphs. impact --graph defaults to depth 1 unless you explicitly pass --depth. --include-unresolved is useful when external relationships matter.

diff — git diff scoped to a symbol

cymbal diff ParseFile                 # vs HEAD
cymbal diff ParseFile main            # vs branch
cymbal diff --stat ParseFile          # diffstat only

structure / ls / importers

cymbal structure                      # entry points, hotspots, central packages
cymbal ls --stats                     # languages, file/symbol counts
cymbal ls --repos                     # all indexed repos
cymbal importers internal/index       # fan-in for a package

Path Filtering

search, show, and refs accept repeatable --path / --exclude globs. Compose with --kind / --lang:

cymbal search Handler --lang go --path 'internal/**' --exclude '**/*_test.go'
cymbal refs OpenStore --path 'cmd/**'

On large repos this is the difference between useful and useless output. (context, investigate, trace, impact, impls do not take --path; filter at the consumer step instead.)

JSON Mode

--json works on every command. Look for:

• also / matches — alternate resolutions when a name is ambiguous.
• ambiguous: true — cymbal picked one; also lists the rest.
• hit_symbols — in batch mode (refs/impact/trace), which input brought each result in.
• resolved: false — in impls, the target is external (framework/stdlib).

Pivot Rule

If one or two searches miss, stop searching synonyms. Pivot to implementation seams instead:

spec · registry · bundle · runtime · policy · session · state · dispatch · config · store · manifest · descriptor · provider · handler

Run cymbal structure to surface the actual entry points and hotspots, then investigate the seam symbols you find.

Stop Rules

• Do not run both investigate and context on the same symbol.
• Do not retry searches with synonyms more than twice — pivot.
• Do not run cymbal index manually.
• Do not default to --graph when you need precise call-site text or source lines — graph mode is for topology.
• Do not Read a large file right after search — outline it first, then show the slice you need.
• Do not paginate through refs/impact output when --limit or --path would narrow it.
• Do not chain investigate → context → show on the same symbol — one answers it.

Anti-Patterns

1. rg/grep for a symbol name cymbal can resolve directly.
2. Read on a >500-line file without outline first.
3. Calling show before investigate on an unfamiliar symbol.
4. Treating refs as semantic "find all callers" — it is AST name matching.
5. Retrying on ambiguity errors instead of reading also / matches.
6. Running cymbal index before every query.
7. Hand-listing batch inputs when outline -s --names | <cmd> --stdin would.

Real Constraints (proven on bench corpus)

• refs / impact / trace are AST name matching. Cross-package name collisions inflate results — narrow with --path or --file.
• impls returns resolved=false for externally-defined interfaces.
• TypeScript and other non-Go languages may have incomplete signature data.
• Imports are resolved best-effort per language; cross-language edges are not modeled.
• search --text delegates to rg; it does not use the symbol index.

When to Use What (decision tree)

1. "I just cloned this repo, where do I start?" → cymbal structure, then cymbal ls --stats

2. "What is this function/class/type?" → cymbal investigate <symbol>

3. "What happens when X runs?" → cymbal trace <symbol>

4. "If I change X, what breaks?" → cymbal impact <symbol>

5. "Where is X defined?" → cymbal search <name>, then cymbal show <symbol>

6. "What's in this file?" → cymbal outline <file>, then cymbal show <file:L1-L2> for specifics

7. "Find all usages of X" → cymbal refs <symbol>

8. "Who implements this interface?" → cymbal impls <symbol>

9. "What changed in this symbol?" → cymbal diff <symbol> [base]

Why this works (bench-grounded)

Against the maintained corpus (gin, fastapi, kubectl, vite, ripgrep, jq, guava):

• 100% canonical @1 on the hard-mode ranking suite (tuned grep: 60% / 0.65 MRR).
• 85/85 (100%) accuracy across search/show/refs/investigate.
• 84–100% token savings vs ripgrep on the same queries — e.g. refs FastAPI: 396 tokens vs 439,227.

Outcome

Start with cymbal. Pivot on misses. Trust the first rank. Read last.

Source: 1broseidon/cymbal — distributed by TomeVault.