ktn-linter

README

KTN-Linter

Personal Go linter enforcing strict programming standards. 422 analyzers covering naming, structure, testing, performance, modern Go idioms, and staticcheck integration. Bazel is the only quality gate.

Strict rule: 0 issues = 0 issues (even INFO). STOP and fix immediately.

Installation

Universal Installation (Recommended)

curl -sSL https://raw.githubusercontent.com/kodflow/ktn-linter/main/install.sh | bash

The script downloads the binary from GitHub releases (linux/darwin, amd64/arm64) and installs to /usr/local/bin or ~/.local/bin.

Installation from Source

git clone https://github.com/kodflow/ktn-linter
cd ktn-linter
make build

Usage

ktn-linter                                         # TTY: explore, non-TTY: lint ./...
ktn-linter lint ./...                              # Lint the entire project
ktn-linter lint --simple ./pkg/...                 # Simplified format
ktn-linter lint --config .ktn-linter.yaml ./...    # Use a config file
ktn-linter rules --format=markdown                 # Display all rules
ktn-linter explore ./...                           # Interactive directory browser with live file watching
ktn-linter coverage                                # Display per-package test coverage analysis
ktn-linter coverage --threshold 90                 # Custom threshold (default: 80%)
ktn-linter mcp install                             # Install MCP config + Claude Code hooks
ktn-linter skill install                           # Deploy embedded skills into ./.claude/
ktn-linter skill comments ./pkg                    # Refactor doc-comments via OAuth subscription

skill install

Deploys the bundle embedded in the binary (assets/) into <path>/.claude/: slash commands under commands/, agents under agents/, system prompts under prompts/. Files declared ktn-managed: true in their YAML frontmatter are silently replaced across versions; user-authored files at the same path are reported as conflicts and left untouched (--force overwrites them in place — rollback via git restore, no .bak sibling is written so .claude/ stays clean for git add .).

skill comments

Refactors every Go doc-comment under the target path to the canonical go.dev/doc/comment style (free prose, no Javadoc Params:/Returns: blocks).

• Spawns the local claude CLI in print mode (NEVER --bare) so the user's OAuth subscription (Pro, Max, Team, Enterprise) is used. The preflight calls claude auth status and refuses to run unless authMethod == "claude.ai" and apiProvider == "firstParty". ANTHROPIC_API_KEY and other third-party billing variables are stripped from the spawned environment.
• Runs inside a dedicated git worktree (.ktn-comments-<ts>); edits are squash-merged back into the original branch as one commit. Use --no-commit or --no-squash to opt out.
• Preserves verbatim every comment block containing See: <repo>#<n> or a literal //ktn:keep line.
• Keeps KTN-COMMENT-BLOCK //: intention markers; rewrites them only when phrasing is weak.

Configuration

KTN-Linter can be configured via .ktn-linter.yaml:

version: 1

# Skip non-KTN-TEST-* rules on Go test-variant packages (perf opt-in).
# Default: false. Set to true to lint *_test.go with the FULL rule set.
force_all_rules_on_tests: false

exclude:
  - "**/testdata/**"
  - "**/*_generated.go"
  - "vendor/**"

rules:
  KTN-FUNC-MAXSTMT:
    threshold: 50
  KTN-FUNC-CYCLO:
    threshold: 15
  KTN-COMMENT-LINELEN:
    enabled: false

Performance: test-variant skip. When packages.Load runs with Tests: true, the Go loader produces three synthetic test variants per package. By default the orchestrator only runs KTN-TEST-* rules on those variants — every other rule already executed on the production variant. Set force_all_rules_on_tests: true (or strict_mode: true) to lint test files with the full rule set.

Configurable thresholds:

Rule	Parameter	Default
KTN-COMMENT-LINELEN	maxCommentLength	80
KTN-COMMENT-PKGDOC	minPackageCommentLength	3
KTN-COMMENT-STRUCT	minStructDocLines	2
KTN-FUNC-MAXSTMT	maxFunctionLength	35
KTN-FUNC-MAXPARAM	maxParameters	5
KTN-FUNC-NAKEDRET	- (absolute rule)	-
KTN-FUNC-CYCLO	maxCyclomaticComplexity	8
KTN-FUNC-NAMERET	maxNestedDepth	4
KTN-VAR-MAKEAPPEND	maxScopeLines	50
KTN-VAR-HOTLOOP	maxLineLength	120
KTN-VAR-GROUP	maxDeclarations	10

Build & Test

Target	Purpose
make build	Compile ktn-linter to builds/ (Bazel; runs make generate first)
make test	Run all tests + coverage, generate COVERAGE.MD (Bazel)
make test-unit	Unit tests only, cached (Bazel tag: unit)
make test-validate	Testdata regression (always-run, Bazel tag: testdata)
make test-race	Race condition detection (Bazel tag: race)
make test-bench	Benchmark tests (Bazel tag: bench)
make coverage	Coverage analysis per-package (Bazel)
make lint	Runs KTN linter on itself (Bazel)
make generate	Regenerate stdlib allowlists from $(go env GOROOT) (commit the diff)
make generate-check	CI drift gate: fail if make generate would produce a diff
make hooks-install	Idempotent: install Claude Code hooks + (re)start ktn-linter MCP daemon on port 7717

See COVERAGE.MD for detailed coverage report.

Stdlib Allowlist Generation

cmd/gen-stdlib-allowlists/ scans the active Go SDK and emits three committed Go data files consumed at lint time by the structural heuristics added in issues #291–#294 (role-stutter canonical domain, struct-accessor typed-sibling deprecation pair, func-emptysentinel stdlib-mirror absence accessor, interface-anyuse codec method signature). Outputs:

• internal/analyzer/ktn/structure/organization/stdlib_stutters_gen.go (24 stutter pairs across 18 packages)
• internal/analyzer/ktn/iface/usage/stdlib_anyuse_gen.go (123 any-param func names + 7 stdlib interfaces)
• internal/analyzer/ktn/function/returns/stdlib_sentinels_gen.go (27 sentinel accessor names)

All four heuristics are zero-marker / pure structural — no //nolint, no //ktn:scaffold. The files are committed for review; make generate-check is the CI drift gate against the active Go SDK.

Rules (422 total)

KTN-API (3 rules)

Code	Severity	Description
KTN-API-MINIF	WARNING	Minimal interfaces on consumer side for external dependencies
KTN-CLI-FLAGSET-GUARD	WARNING	config.Get().Set<X>(opts.<X>) in Cobra handlers must be guarded by cmd.Flags().Changed()
KTN-CLI-EMPTYSENTINEL	WARNING	Switch on CLI-flag string value must have default arm or case ""

KTN-COMMENT (9 rules)

Code	Severity	Description
KTN-COMMENT-LINELEN	INFO	Inline comments too long (>80 characters)
KTN-COMMENT-PKGDOC	WARNING	Descriptive comment before package
KTN-COMMENT-CONST	WARNING	Required comment for constants
KTN-COMMENT-VAR	WARNING	Required comment for package var
KTN-COMMENT-STRUCT	WARNING	Required documentation for struct (>=2 lines)
KTN-COMMENT-FUNC	WARNING	Function documentation (Params/Returns)
KTN-COMMENT-BLOCK	WARNING	Comments on branches/returns/logic
KTN-COMMENT-TODO	INFO	TODO/FIXME comment format (colon + description)
KTN-COMMENT-DOCDRIFT	INFO	Doc comment cites bare number without in-scope const or 'derived from' annotation

KTN-CONST (10 rules)

Code	Severity	Description
KTN-CONST-TYPED	ERROR	Explicit type required
KTN-CONST-ORDER	INFO	Grouping and placement before var
KTN-CONST-CAMEL	INFO	CamelCase naming (no underscores)
KTN-CONST-MINLEN	WARNING	Min length 2 characters
KTN-CONST-MAXLEN	INFO	Max length 30 characters
KTN-CONST-SHADOW	INFO	Must not shadow built-in identifiers
KTN-CONST-UNUSED	WARNING	Unused private constant
KTN-CONST-IOTA	INFO	Sequential constants should use iota
KTN-CONST-STRENUM	INFO	String enum should use int type with iota + String()
KTN-CONST-MULTINAME-COUNT	WARNING	Counting GenDecl.Specs misses multi-name ValueSpec entries

KTN-ERROR (6 rules)

Code	Severity	Description
KTN-ERROR-ASTYPE	INFO	Prefer errors.AsTypeT (Go 1.26+)
KTN-ERROR-CLOSECHECK	WARNING	Close/Shutdown/Stop error must be checked outside defer
KTN-ERROR-DEFERCLOSE	WARNING	defer Close/Shutdown/Stop must check returned error
KTN-ERROR-DISCARD	WARNING	Error assigned to _ must be logged or propagated
KTN-ERROR-SENTINEL	WARNING	errors.New() should be package-level sentinel
KTN-ERROR-WRAP	WARNING	fmt.Errorf() should wrap errors with %w

KTN-FUNC (24 rules)

Code	Severity	Description
KTN-FUNC-ERRLAST	ERROR	Error always in last return position
KTN-FUNC-CTXFIRST	ERROR	Context always as first parameter
KTN-FUNC-EARLYRET	ERROR	Avoid else after return/continue/break
KTN-FUNC-DEADCODE	ERROR	Unused private functions (dead code)
KTN-FUNC-CYCLO	ERROR	Max cyclomatic complexity 8
KTN-FUNC-MAXLOC	ERROR	Max 50 lines of code (LOC)
KTN-FUNC-MAXSTMT	WARNING	Max 35 statements per function
KTN-FUNC-MAXPARAM	WARNING	Max 5 parameters per function
KTN-FUNC-PUREGET	WARNING	No side effects in getters
KTN-FUNC-UNUSEDARG	WARNING	Unused parameters prefixed with _
KTN-FUNC-BLANKPARAM	WARNING	Blank _ in params must be interface-required
KTN-FUNC-NOMAGIC	INFO	No magic numbers (use named constants)
KTN-FUNC-NAKEDRET	WARNING	Naked returns forbidden when function has return values
KTN-FUNC-NAMEDPARAMS	WARNING	All function parameters and return values must be named
KTN-FUNC-NAMERET	INFO	Named returns for >3 return values
KTN-FUNC-GROUPARG	INFO	Group parameters of same type
KTN-FUNC-MINMAX	INFO	Prefer min/max builtins (Go 1.21+)
KTN-FUNC-USECLEAR	INFO	Use clear() builtin (Go 1.21+)
KTN-FUNC-RANGEINT	INFO	Use range N (Go 1.22+)
KTN-FUNC-ERRFMT	INFO	Error message format (lowercase, no period)
KTN-FUNC-NOINIT	WARNING	Avoid init() functions
KTN-FUNC-GENERICPTR	INFO	Use new(expr) instead of pointer wrapper functions (Go 1.26+)
KTN-FUNC-NILRETURN	WARNING	Return value always same constant (nil/true/false); consider removing
KTN-FUNC-EMPTYSENTINEL	WARNING	Single string return used as failure sentinel; pair with (string, bool) or (string, error)

KTN-GENERIC (5 rules)

Code	Severity	Description
KTN-GENERIC-CMPEQ	ERROR	Comparable constraint required for == and !=
KTN-GENERIC-ORDERED	ERROR	cmp.Ordered constraint required for <, >, +, -, *, /, %
KTN-GENERIC-NOANY	WARNING	Unnecessary generics on interface types
KTN-GENERIC-USECMP	WARNING	golang.org/x/exp/constraints deprecated -> cmp
KTN-GENERIC-SHADOW	WARNING	Type params must not shadow predeclared identifiers

KTN-GOROUTINE (16 rules)

Code	Severity	Description
KTN-GOROUTINE-ATOMICBOOL	INFO	Mutex+bool replaceable by atomic.Bool
KTN-GOROUTINE-ATOMICINT	INFO	Mutex+int replaceable by atomic.Int64/Int32
KTN-GOROUTINE-ATOMICVAL	INFO	RWMutex+single field replaceable by atomic.Value
KTN-GOROUTINE-CTXCANCEL	WARNING	context.With*() without immediate defer cancel()
KTN-GOROUTINE-CTXDROP	WARNING	Func with ctx param calls context.Background()/TODO()
KTN-GOROUTINE-DEFER	WARNING	Immediate defer after resource acquisition
KTN-GOROUTINE-FIREFORGET	WARNING	Goroutine launched without synchronization
KTN-GOROUTINE-LIFECYCLE	WARNING	Missing goroutine documentation
KTN-GOROUTINE-LOCKSCOPE	WARNING	Unrelated statements inside critical section
KTN-GOROUTINE-ONCEINIT	WARNING	Lock+if !initialized replaceable by sync.Once
KTN-GOROUTINE-PTRRETURN	WARNING	Return pointer to mutex-protected field (data race)
KTN-GOROUTINE-RWOVERMU	INFO	Mutex.Lock() for read-only, use RWMutex.RLock()
KTN-GOROUTINE-SELECT	WARNING	Infinite loop goroutine without exit mechanism
KTN-GOROUTINE-SYNCMAP	INFO	RWMutex+map replaceable by sync.Map
KTN-GOROUTINE-SYNCMAPRACE	WARNING	sync.Map Load+Store race, use LoadOrStore
KTN-GOROUTINE-TIMEAFTER	WARNING	time.After() in select inside loop (timer leak)

KTN-INTERFACE (3 rules)

Code	Severity	Description
KTN-INTERFACE-UNUSED	WARNING	Unused private interface
KTN-INTERFACE-ERNAME	INFO	-er convention for single-method interfaces
KTN-INTERFACE-ANYUSE	INFO	Excessive use of interface{}/any

KTN-ITER (5 rules)

Code	Severity	Description
KTN-ITER-SIGNATURE	INFO	Invalid iterator signature
KTN-ITER-YIELD	INFO	Ignored yield return
KTN-ITER-MAPKEYS	INFO	Use maps.Keys/Values iterators
KTN-ITER-COLLECT	INFO	Use slices.Collect for iterators
KTN-ITER-PULLSTOP	INFO	iter.Pull must have defer stop()

KTN-RECEIVER (4 rules)

Code	Severity	Description
KTN-RECEIVER-MIXPTR	ERROR	Mixed receivers (pointer/value) on same type
KTN-RECEIVER-GENERIC	WARNING	Inconsistent generic receivers
KTN-RECEIVER-PTRMAP	WARNING	Unnecessary pointer to map/func/chan
KTN-RECEIVER-NAME	INFO	Receiver name 1-2 chars, not this/self/me

KTN-STRUCT (22 rules)

Code	Severity	Description
KTN-STRUCT-CTOR	WARNING	NewX() constructor required
KTN-STRUCT-ROLE	WARNING	Every exported struct must declare architectural role via suffix (PNPT and constructor exemptions, issue #263)
KTN-STRUCT-ROLE-STUTTER	WARNING	Exported struct name stutters with its package basename (issue #263)
KTN-STRUCT-ROLE-COMPATALIAS	WARNING	Goodhart canary: alias to a suffixed struct introduced to satisfy the role rule (issue #263)
KTN-STRUCT-MISMATCH	WARNING	Declared role suffix must match observed struct structure
KTN-STRUCT-NOGET	WARNING	No Get prefix for getters
KTN-STRUCT-RECVTYPE	WARNING	Receiver type consistency (pointer vs value)
KTN-STRUCT-RECVNAME	WARNING	Receiver name consistency (1-2 letters)
KTN-STRUCT-UNUSEDTYPE	WARNING	Unused private type
KTN-STRUCT-ACCESSOR	INFO	Getters/setters convention: Field() and SetField()
KTN-STRUCT-ONEFILE	INFO	One Go file per struct (DTOs can be grouped)
KTN-STRUCT-PUBFIRST	INFO	Exported fields before private fields
KTN-STRUCT-PRIVTAG	INFO	No serialization tags on private fields
KTN-STRUCT-JSONTAG	INFO	DTO exported fields must have json/xml tags
KTN-STRUCT-FLATINIT	INFO	Use composite literal instead of individual field assignments
KTN-STRUCT-DEEPLIT	INFO	Extract deeply nested composite literals (>3 levels)
KTN-STRUCT-CHECKS	INFO	Per-role specialised checks (event naming, service smells)
KTN-STRUCT-CARGOPARAMS	INFO	Cargo-culted param DTO (off by default)
KTN-STRUCT-FLAGS	INFO	Struct with 3+ bool fields should use bitfield
KTN-STRUCT-SENSITIVE	ERROR/WARNING	sensitive:"" fields must not be exposed on the wire (secret=Error, pii/phi=Warning)
KTN-STRUCT-COLOCATE	INFO	Advisory: co-locate (single parent in different file) or extract (shared across files)
KTN-STRUCT-SPLITPREFIX	INFO	File exceeds size thresholds (500+ LOC, 4+ types, 12+ funcs) — split into siblings

KTN-SWITCH (2 rules)

Code	Severity	Description
KTN-SWITCH-EXHAUSTIVE	WARNING	Switch on enum types must cover all values
KTN-SWITCH-MERGECASE	INFO	Switch cases with identical body should be merged

KTN-TEST (39 rules)

Code	Severity	Description
KTN-TEST-SUFFIX	ERROR	Test files must end with _internal/_external_test.go
KTN-TEST-SETENV	ERROR	t.Setenv/t.Chdir forbidden with t.Parallel
KTN-TEST-HASGO	WARNING	Orphan test file (no source file)
KTN-TEST-COVERAGE	WARNING	Test coverage for public functions
KTN-TEST-TABLE	WARNING	Table-driven pattern required
KTN-TEST-NOSKIP	WARNING	t.Skip() forbidden
KTN-TEST-SPLIT	WARNING	1:1 pattern for test/source files
KTN-TEST-EXTPUB	WARNING	Public tests only in _external_test.go
KTN-TEST-INTPRIV	WARNING	Private tests only in _internal_test.go
KTN-TEST-PKGNAME	WARNING	Package convention (white-box/black-box)
KTN-TEST-ASSERT	WARNING	Tests must contain assertions
KTN-TEST-ERRCASES	WARNING	Tests must cover error cases
KTN-TEST-SUBPARALLEL	WARNING	Subtests should have t.Parallel when parent does
KTN-TEST-CLEANUP	WARNING	Use t.Cleanup instead of defer with parallel subtests
KTN-TEST-IFACECHECK	WARNING	Interface checks must use compile-time pattern
KTN-TEST-PARALLEL	WARNING	Test functions must call t.Parallel()
KTN-TEST-CONSTCHECK	INFO	Test only verifies constant values
KTN-TEST-TMPDIR	INFO	Prefer t.TempDir() over os.TempDir()
KTN-TEST-CHDIR	INFO	Prefer t.Chdir() over os.Chdir()
KTN-TEST-TMPFILE	INFO	Use t.TempDir() in os.CreateTemp
KTN-TEST-MKDIR	INFO	Use t.TempDir() instead of os.MkdirTemp()
KTN-TEST-CASECNT	INFO	Number of cases vs cyclomatic complexity
KTN-TEST-PARALLELPOS	INFO	t.Parallel should be first statement
KTN-TEST-NOPARALLEL	ERROR	t.Parallel() forbidden with global state modification
KTN-TEST-OSENV	WARNING	Prefer t.Setenv() over os.Setenv()/os.Unsetenv()
KTN-TEST-FMTPRINT	WARNING	Prefer t.Log()/t.Logf() over fmt.Print*()
KTN-TEST-CONTEXT	INFO	Prefer t.Context() over context.Background()/TODO()
KTN-TEST-BLOOP	INFO	Prefer b.Loop() over legacy benchmark loop
KTN-TEST-SYNC	WARNING	1:1 function-level sync between source and test files
KTN-TEST-NOOP	ERROR	No-op test only asserts on table fields, no SUT call
KTN-TEST-UNUSED-FIELDS	WARNING	Table struct fields never referenced in loop body
KTN-TEST-ASSERT-TRIVIAL	WARNING	Trivially-passing assertions (NotNil on string, True on true)
KTN-TEST-BRANCHCOV	INFO	Test has fewer assertions than function branches warrant
KTN-TEST-VOIDTEST	WARNING	Void function test missing side-effect verification
KTN-TEST-PLACEHOLDER	WARNING	Tests must call function under test
KTN-TEST-FILES	WARNING	Bidirectional source/test file correspondence
KTN-TEST-PLACEMENT	WARNING	Test functions in correct file type
KTN-TEST-REGISTRY-BIJECTION	WARNING	Registry test only checks one direction; add the reverse pass
KTN-TEST-VACUOUS-IDENTITY	WARNING	Comparison against package literal/const is provably constant and cannot fail

KTN-VAR (68 rules)

Code	Severity	Description
KTN-VAR-CAMEL	ERROR	Required camelCase naming
KTN-VAR-SHADOW	ERROR	Variable shadowing detection
KTN-VAR-MUTEXCOPY	ERROR	Mutex copies (sync.Mutex, sync.RWMutex)
KTN-VAR-EXPLICIT	WARNING	Explicit type required for package var
KTN-VAR-ORDER	WARNING	Ordered declarations (const before var)
KTN-VAR-MINLEN	WARNING	Min variable length (scope-aware)
KTN-VAR-MAXLEN	WARNING	Max length 30 characters
KTN-VAR-HOTLOOP	WARNING	Avoid allocations in hot loops
KTN-VAR-RECVCONS	WARNING	Receiver consistency (pointer vs value)
KTN-VAR-PTRINTF	WARNING	Avoid pointer to interface
KTN-VAR-WEAKRAND	WARNING	crypto/rand for sensitive data
KTN-VAR-TYPEASSERT	WARNING	Unchecked type assertion (use comma-ok)
KTN-VAR-UNUSEDVAR	WARNING	Unused private package-level variable
KTN-VAR-REGEXPCOMPILE	WARNING	regexp.Compile inside function, move to package var
KTN-VAR-SHORTDECL	INFO	:= vs var (zero-value aware)
KTN-VAR-BLANKASSIGN	INFO	x := f(); _ = x → use _ in := directly
KTN-VAR-DEADASSIGN	INFO	Dead blank assignment (_ = expr) is wasted computation
KTN-VAR-SLICECAP	INFO	Preallocate slices with known capacity
KTN-VAR-MAKEAPPEND	INFO	Avoid make([]T, length) with append
KTN-VAR-GROW	INFO	Preallocate bytes.Buffer with Grow
KTN-VAR-STRBUILDER	INFO	Use strings.Builder for concatenations
KTN-VAR-BIGSTRUCT	INFO	Pointers for structs >64 bytes as parameter
KTN-VAR-SYNCPOOL	INFO	sync.Pool for repeated buffers
KTN-VAR-STRCONV	INFO	Avoid repeated string() conversions
KTN-VAR-GROUP	INFO	Group in a single var() block
KTN-VAR-MAPCAP	INFO	Preallocate maps with known capacity
KTN-VAR-ARRAY	INFO	Use [N]T instead of make([]T, N) <=64 bytes
KTN-VAR-NILSLICE	INFO	Prefer nil slice to empty slice
KTN-VAR-USEANY	INFO	any vs interface{} (Go 1.18+)
KTN-VAR-USECLEAR	INFO	Use clear() built-in (Go 1.21+)
KTN-VAR-USEMINMAX	INFO	Use min()/max() built-in (Go 1.21+)
KTN-VAR-RANGEINT	INFO	range over integer (Go 1.22+)
KTN-VAR-LOOPVAR	INFO	Loop var copy obsolete (Go 1.22+)
KTN-VAR-SLICEGROW	INFO	slices.Grow instead of make+copy (Go 1.21+)
KTN-VAR-SLICECLONE	INFO	slices.Clone instead of make+copy (Go 1.21+)
KTN-VAR-MAPCLONE	INFO	maps.Clone instead of manual loop (Go 1.21+)
KTN-VAR-CMPOR	INFO	cmp.Or for default values (Go 1.22+)
KTN-VAR-WGGO	INFO	WaitGroup.Go (Go 1.25+)
KTN-VAR-CONTAINS	INFO	slices.Contains instead of loop (Go 1.21+)
KTN-VAR-INDEX	INFO	slices.Index instead of loop (Go 1.21+)
KTN-VAR-COLLECTKEYS	INFO	maps.Keys/Values iterators (Go 1.23+)
KTN-VAR-EXTRACTCONST	INFO	Extract repeated literals to constants
KTN-VAR-NEWEXPR	INFO	Use new(expr) instead of v := expr; &v (Go 1.26+)
KTN-VAR-PTRCALL	INFO	Use new(expr) instead of pointer helper calls (Go 1.26+)
KTN-VAR-CRYPTONIL	INFO	Pass nil to crypto APIs instead of rand.Reader (Go 1.26+)
KTN-VAR-UNCONVERT	INFO	Unnecessary type conversion (same source and target type)
KTN-VAR-DEFERPERF	WARNING	defer Close unnecessary, close immediately for performance
KTN-VAR-REFLECTITER	INFO	Use reflect Fields()/Methods() iterators (Go 1.26+)
KTN-VAR-FMTSPRINT	INFO	fmt.Sprintf replaceable by strconv.Itoa or direct use
KTN-VAR-ESCAPECLOSURE	INFO	Loop closure captures variable causing heap escape
KTN-VAR-NOESCAPE	INFO	&T{} in loop without escape, reuse variable
KTN-VAR-POINTERSTRUCT	INFO	Struct with pointer fields in large collection (GC scan)
KTN-VAR-SORTALLOC	INFO	sort.Slice → slices.SortFunc (Go 1.21+)
KTN-VAR-BYTESCONV	INFO	Repeated string([]byte) on same variable
KTN-VAR-STRINGCONCAT	INFO	String concatenation outside loop (use strings.Builder)
KTN-VAR-CONSTMAP	WARNING	Constant map literal in function body, hoist to package var
KTN-VAR-CONSTSLICE	WARNING	Constant slice literal in function body, hoist to package var
KTN-VAR-EQUALFOLD	WARNING	Use strings.EqualFold instead of ToLower/ToUpper comparison
KTN-VAR-TOLOWDUP	WARNING	Duplicate strings.ToLower/ToUpper on same variable
KTN-VAR-WALKDIR	WARNING	Use filepath.WalkDir instead of filepath.Walk (Go 1.16+)
KTN-VAR-CONSTABLE	INFO	Package var with constant value should be const
KTN-VAR-DEADSTORE	WARNING	Value assigned but never read before overwrite
KTN-VAR-CSVEMPTYTOKEN	WARNING	CSV-split result (strings.Split/FieldsFunc) may be empty without guard
KTN-VAR-TYPECONV	INFO	Redundant type conversion (source equals target type)
KTN-VAR-MATHBITS	INFO	Manual bit manipulation replaceable by math/bits
KTN-VAR-SPRINTF	INFO	fmt.Sprintf with single verb replaceable by strconv
KTN-VAR-NARROW	INFO	any parameter with single type assertion should be narrowed
KTN-VAR-STRMAP	INFO	map[string]T with constant keys, consider int-keyed map

KTN-GOVET (27 active / 28 total)

Official go vet analyzers wrapped with KTN-GOVET- prefix: appends, assign, atomic, bools, copylocks, defers, directive, errorsas, httpresponse, ifaceassert, loopclosure, lostcancel, nilfunc, printf, sigchanyzer, slog, sortslice, stdmethods, stringintconv, structtag, testinggoroutine, tests, timeformat, unmarshal, unreachable, unusedresult, waitgroup.

Disabled: shift (nil TypesInfo on external packages).

KTN-MODERNIZE (19 active / 20 total)

Official golang.org/x/tools modernize suite: appendassign, bloop, efaceany, fmtappendf, minmax, omitzero, rangeint, slicesclone, slicescontains, slicesdelete, slicesinsert, sortslice, stringbuilder, stringsseq, testingcontext, unsafefn, waitgroup, forvar, reflecttypefor.

Disabled: newexpr (nil pointer panic).

KTN-SC (160 active / 160 total)

All honnef.co/go/tools (staticcheck) analyzers wrapped with KTN-SC- prefix:

• SA (95 rules): Correctness checks — invalid regexp, nil dereference, unused results, concurrency bugs
• S (35 rules): Simplification — unnecessary code patterns, redundant operations
• ST (18 rules): Style — naming conventions, package comments, error strings
• QF (12 rules): Quick fixes — De Morgan's law, if/else to switch, redundant type declarations

Health Advisories

Post-lint meta-analysis that activates only when all lint violations are resolved (0 issues). Health checks operate on package metadata, not AST nodes.

Check	Threshold	Description
PKG-SIZE	20 files	Packages with more than 20 non-test .go files

Health advisories appear as Phase 5 in ktn-linter prompt output and do not affect exit codes.

Statistics

Metric	Value
Go version	1.26+
KTN rules	208
Go Vet rules	27
Modernize rules	20
Staticcheck rules	160
Total rules	415
Test coverage	99.4%
Packages at 100%	26/31

See COVERAGE.MD for detailed per-package metrics.