feat: sync rules across all harnesses + agents to opencode/kilo

Add Rule as a first-class canonical kind (rules/<name>.md, loaded like
agents) and propagate it the way each harness actually loads it:

- claude-code: native ~/.claude/rules directory symlink (preserves rule
  path-scoping frontmatter); rules NOT folded into CLAUDE.md.
- opencode/kilo/zed/crush: fold rule bodies into the global AGENTS.md
  always-on instructions file (frontmatter stripped). crush has no global
  instructions file, so register the absolute AGENTS.md path in
  options.context_paths (defaults are re-prepended at load, so nothing is
  clobbered).
- goose: fold into ~/.config/goose/.goosehints.
- cagent: fold into the per-agent instruction.

Also:
- Wire markdown agents to opencode (~/.config/opencode/agents) and fix the
  kilo agents symlink: plural ~/.config/kilo/agents (singular "agent" is a
  silent no-op on current Kilo CLI).
- Add ManagesAgents/ManagesRules to HarnessCapabilities + ImportResult.Rules;
  claude-code/opencode import rules/agents round-trip.
- Centralize instruction selection in Bundle.InstructionText /
  InstructionTextWithRules (replaces per-adapter override duplication).
- init scaffolds + imports rules; README capability matrix gains
  Agents/Rules columns with native-vs-folded footnotes.

Grounded each harness's sink against official docs + config source this
session. Gate: gofmt, go vet, go test -race ./..., golangci-lint (0),
govulncheck (clean).

README.md

@@ -3,7 +3,7 @@
 </p>
 
 <p align="center">
-  <strong>One canonical source of truth</strong> for skills, agents, MCP servers, LLM endpoints, and global instructions across every LLM harness on your machine.
+  <strong>One canonical source of truth</strong> for skills, agents, rules, MCP servers, LLM endpoints, and global instructions across every LLM harness on your machine.
 </p>
 
 <p align="center">
@@ -40,6 +40,7 @@ Edit once. Forget the others. They drift. Things stop working in odd places.
                  │  • profiles/<name>.yaml          │
                  │  • skills/<name>/SKILL.md        │
                  │  • agents/<name>.md              │
+                 │  • rules/<name>.md               │
                  │  • mcp.yaml                      │
                  │  • instructions/global.md        │
                  └──────────────┬───────────────────┘
@@ -145,21 +146,30 @@ harness-sync goes out of its way to avoid.
 
 ### Capability matrix
 
-What harness-sync writes per harness. Harnesses with a **built-in subscription** receive MCP + skills + instructions only — provider/model/endpoint config is skipped to avoid conflicting with the harness's own auth.
+What harness-sync writes per harness. Harnesses with a **built-in subscription** receive MCP + skills + agents + rules + instructions only — provider/model/endpoint config is skipped to avoid conflicting with the harness's own auth.
 
 Skills paths are grounded in each harness's official documentation (kilo.ai, opencode.ai, goose-docs.ai). kilo, opencode, and goose also scan `~/.claude/skills/` as a compatibility path, so the claude-code symlink passively reaches them already.
 
-| Harness | Built-in sub | Providers | Models | MCP | Skills | Instructions |
+| Harness | Built-in sub | Providers | Models | MCP | Skills | Agents | Rules | Instructions |
-|---|:---:|:---:|:---:|:---:|:---:|:---:|
+|---|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|
-| **claude-code** | ✓ | — | — | ✓ | ✓ | ✓ |
+| **claude-code** | ✓ | — | — | ✓ | ✓ | ✓ | ✓ⁿ | ✓ |
-| **crush** | — | ✓ | ✓ | ✓ | ✓ | — |
+| **crush** | — | ✓ | ✓ | ✓ | ✓ | — | ✓ᶠ | ✓ᶠ |
-| **kilo** | — | ✓ | ✓ | ✓ | ✓ | — |
+| **kilo** | — | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ᶠ | ✓ᶠ |
-| **opencode** | — | ✓ | ✓ | ✓ | ✓ | ✓ |
+| **opencode** | — | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ᶠ | ✓ |
-| **goose** | — | ✓ | ✓ | ✓ | ✓ | — |
+| **goose** | — | ✓ | ✓ | ✓ | ✓ | — | ✓ᶠ | ✓ᶠ |
-| **cagent** | — | ✓ | ✓ | ✓ | — | ✓ |
+| **cagent** | — | ✓ | ✓ | ✓ | — | — | ✓ᶠ | ✓ |
-| **zed** | — | ✓ | ✓ | ✓ | — | — |
+| **zed** | — | ✓ | ✓ | — | — | — | ✓ᶠ | ✓ᶠ |
 
-The matrix is machine-readable via `adapter.Capabilities()` — every adapter implements `HarnessCapabilities` so tooling can inspect what will change before running `apply`.
+The matrix is machine-readable via `adapter.Capabilities()` — every adapter implements `HarnessCapabilities` (`ManagesProviders/Models/MCP/Skills/Agents/Rules/Instructions`) so tooling can inspect what will change before running `apply`.
+
+### Agents & rules — native where possible, folded where necessary
+
+Each kind is delivered the way the target harness actually loads it (grounded in each harness's docs and config source — a wrong path is a silent no-op):
+
+- **Agents** are markdown subagents. They map cleanly to **claude-code** (`~/.claude/agents/`), **kilo** (`~/.config/kilo/agents/` — plural; the older singular `agent/` is a no-op on current Kilo CLI), and **opencode** (`~/.config/opencode/agents/`), all as directory symlinks. **goose** (YAML recipes) and **cagent** (inline YAML `agents:`) use incompatible agent formats, and **crush**/**zed** have no markdown-subagent concept — so agents are not propagated there.
+- **Rules** (`rules/<name>.md`) are topic-scoped instruction fragments. **claude-code** auto-loads a rules *directory* natively (ⁿ), so they're delivered as a `~/.claude/rules` symlink — preserving each rule's optional path-scoping frontmatter. No other harness has a rules directory, so their bodies are **folded** (ᶠ) into that harness's global always-on instructions file — `AGENTS.md` (opencode/kilo/zed/crush), `.goosehints` (goose), or the per-agent `instruction:` (cagent). crush has no global instructions file, so harness-sync writes `~/.config/crush/AGENTS.md` and registers its absolute path in `options.context_paths` (crush always re-adds its built-in defaults at load, so nothing is clobbered).
+
+ⁿ delivered as a native rules directory  ᶠ folded into the harness's global instructions file
 
 > **Merged, not replaced.** For harnesses with user-managed config keys (every one
 > except cagent), harness-sync reads the existing file, overlays only the keys
@@ -279,7 +289,7 @@ end-to-end test that runs the real binary against a fake `$HOME`.
 
 ```
 cmd/harness-sync/main.go              # cobra entrypoint + adapter registration
-internal/canonical/                   # Bundle, Profile, MCPRegistry, Skill, Agent types + loader
+internal/canonical/                   # Bundle, Profile, MCPRegistry, Skill, Agent, Rule types + loader
 internal/adapter/                     # Adapter interface, Registry, FileSet
 internal/adapter/common/              # shared building blocks (BuildProviders, BuildMCPMapStyled, MergeJSONKeys, MergeYAMLKeys, …)
 internal/adapters/<harness>/          # one package per harness, ~50-100 LOC of harness-specific glue

internal/adapter/adapter.go

@@ -31,6 +31,8 @@ type HarnessCapabilities struct {
 	ManagesModels       bool // writes model selection config
 	ManagesMCP          bool // writes MCP server config
 	ManagesSkills       bool // writes skills symlink or equivalent
+	ManagesAgents       bool // writes agents symlink or equivalent
+	ManagesRules        bool // delivers rules (native rules dir, or folded into instructions)
 	ManagesInstructions bool // writes instructions file (CLAUDE.md, AGENTS.md, etc.)
 	HasBuiltInSub       bool // has its own subscription; provider/model config is skipped
 }
@@ -47,6 +49,7 @@ type ImportResult struct {
 	Instructions string
 	Skills       []canonical.Skill
 	Agents       []canonical.Agent
+	Rules        []canonical.Rule
 	MCP          []canonical.MCPServer
 	Profiles     []canonical.Profile
 }

internal/adapters/cagent/cagent.go

@@ -41,6 +41,7 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       true,
 		ManagesMCP:          true,
 		ManagesSkills:       false,
+		ManagesRules:        true,
 		ManagesInstructions: true,
 		HasBuiltInSub:       false,
 	}
@@ -57,10 +58,9 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 	fs := adapter.NewFileSet()
 	cfgPath := filepath.Join(a.Home, ".config", "cagent", "default.yaml")
 
-	instructions := b.Instructions.Global
+	// cagent has no rules concept; the per-agent instruction (system prompt) is
-	if override, ok := b.Instructions.PerHarness[name]; ok && override != "" {
+	// the only sink, so fold rules into it.
-		instructions = override
+	instructions := b.InstructionTextWithRules(name)
-	}
 
 	mcps := map[string]any{}
 	for _, s := range b.MCP.Servers {

internal/adapters/cagent/rules_test.go

@@ -0,0 +1,37 @@
+package cagent
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+
+	"gopkg.in/yaml.v3"
+)
+
+func TestCagentFoldsRulesIntoInstruction(t *testing.T) {
+	home := t.TempDir()
+	b := &canonical.Bundle{
+		Instructions: canonical.Instructions{Global: "# global"},
+		Rules:        []canonical.Rule{{Name: "rust", Body: "# Rust\n\nno unwrap"}},
+	}
+	fs, err := New(WithHome(home)).Render(b)
+	require.NoError(t, err)
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	cfg := seen[filepath.Join(home, ".config", "cagent", "default.yaml")]
+	require.Equal(t, adapter.RenderedFile, cfg.Kind)
+
+	var parsed map[string]any
+	require.NoError(t, yaml.Unmarshal(cfg.Content, &parsed))
+	agents := parsed["agents"].(map[string]any)
+	def := agents["default"].(map[string]any)
+	instr := def["instruction"].(string)
+	assert.Contains(t, instr, "# global")
+	assert.Contains(t, instr, "no unwrap")
+}

internal/adapters/claudecode/claudecode.go

@@ -37,6 +37,8 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       false,
 		ManagesMCP:          true,
 		ManagesSkills:       true,
+		ManagesAgents:       true,
+		ManagesRules:        true,
 		ManagesInstructions: true,
 		HasBuiltInSub:       true,
 	}
@@ -65,15 +67,19 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		Kind:          adapter.SymlinkDir,
 		SymlinkTarget: filepath.Join(b.Root, "agents"),
 	})
+	// Claude Code natively auto-loads ~/.claude/rules/*.md (memory feature), so
+	// rules are delivered as their own directory symlink — NOT folded into
+	// CLAUDE.md — preserving each rule's optional path-scoping frontmatter.
+	fs.Add(adapter.File{
+		Dest:          filepath.Join(base, "rules"),
+		Kind:          adapter.SymlinkDir,
+		SymlinkTarget: filepath.Join(b.Root, "rules"),
+	})
 
-	instructions := b.Instructions.Global
-	if override, ok := b.Instructions.PerHarness[name]; ok && override != "" {
-		instructions = override
-	}
 	fs.Add(adapter.File{
 		Dest:    filepath.Join(base, "CLAUDE.md"),
 		Kind:    adapter.RenderedFile,
-		Content: []byte(instructions),
+		Content: []byte(b.InstructionText(name)),
 	})
 
 	// Claude Code reads MCP servers from two files on disk:

internal/adapters/claudecode/import.go

@@ -32,6 +32,16 @@ func importFrom(home string) (*adapter.ImportResult, error) {
 		})
 	}
 
+	rules, err := common.ImportMarkdownTree(filepath.Join(base, "rules"), "")
+	if err != nil {
+		return nil, err
+	}
+	for _, r := range rules {
+		res.Rules = append(res.Rules, canonical.Rule{
+			Name: r.Name, Description: r.Description, Body: r.Body, Path: r.Path,
+		})
+	}
+
 	body, err := common.ReadIfExists(filepath.Join(base, "CLAUDE.md"))
 	if err != nil {
 		return nil, err

internal/adapters/claudecode/rules_test.go

@@ -0,0 +1,47 @@
+package claudecode
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func TestClaudeCodeRendersRulesSymlink(t *testing.T) {
+	home := t.TempDir()
+	ad := New(WithHome(home))
+	b := &canonical.Bundle{Root: "/canon"}
+	fs, err := ad.Render(b)
+	require.NoError(t, err)
+
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	rulesDest := filepath.Join(home, ".claude", "rules")
+	assert.Equal(t, adapter.SymlinkDir, seen[rulesDest].Kind)
+	assert.Equal(t, "/canon/rules", seen[rulesDest].SymlinkTarget)
+
+	// Rules are delivered natively as a directory — never folded into CLAUDE.md.
+	claudemd := string(seen[filepath.Join(home, ".claude", "CLAUDE.md")].Content)
+	assert.NotContains(t, claudemd, "/canon/rules")
+}
+
+func TestClaudeCodeImportsRules(t *testing.T) {
+	home := t.TempDir()
+	rulesDir := filepath.Join(home, ".claude", "rules")
+	require.NoError(t, os.MkdirAll(rulesDir, 0o750))
+	require.NoError(t, os.WriteFile(filepath.Join(rulesDir, "go.md"),
+		[]byte("# Go Rules\n\ngofmt always"), 0o600))
+
+	ad := New(WithHome(home))
+	res, err := ad.Import(home)
+	require.NoError(t, err)
+	require.Len(t, res.Rules, 1)
+	assert.Equal(t, "go", res.Rules[0].Name)
+	assert.Contains(t, res.Rules[0].Body, "gofmt always")
+}

internal/adapters/crush/crush.go

@@ -2,6 +2,7 @@
 package crush
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -36,7 +37,8 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       true,
 		ManagesMCP:          true,
 		ManagesSkills:       true,
-		ManagesInstructions: false,
+		ManagesRules:        true,
+		ManagesInstructions: true,
 		HasBuiltInSub:       false,
 	}
 }
@@ -60,12 +62,25 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		SymlinkTarget: filepath.Join(b.Root, "skills"),
 	})
 
+	// crush has no global instructions file and no rules directory: it loads
+	// context from the files listed in options.context_paths (defaults are always
+	// prepended; absolute paths load verbatim; the global config applies to every
+	// project). Write a global AGENTS.md with rules folded in, and register its
+	// absolute path so crush loads it in every session.
+	agentsMD := filepath.Join(base, "AGENTS.md")
+	fs.Add(adapter.File{
+		Dest:    agentsMD,
+		Kind:    adapter.RenderedFile,
+		Content: []byte(b.InstructionTextWithRules(name)),
+	})
+
 	cfgPath := filepath.Join(base, "crush.json")
 	existing, err := common.ReadExistingFile(cfgPath)
 	if err != nil {
 		return nil, fmt.Errorf("read %s: %w", cfgPath, err)
 	}
 	overlay := map[string]any{}
+	overlay["options"] = crushOptionsWithContextPath(existing, agentsMD)
 	if providers := common.ProvidersAsCrushMap(&b.Profile); len(providers) > 0 {
 		overlay["providers"] = providers
 	}
@@ -89,6 +104,34 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 	return fs, nil
 }
 
+// crushOptionsWithContextPath returns the crush "options" object with contextFile
+// added to options.context_paths, preserving every other existing option key
+// (lsp, permissions, …). crush always prepends its built-in default context
+// paths at load time, so only the extra path is set here. Idempotent.
+func crushOptionsWithContextPath(existing []byte, contextFile string) map[string]any {
+	opts := map[string]any{}
+	if len(existing) > 0 {
+		var raw map[string]any
+		clean := common.StripJSONComments(string(existing))
+		if json.Unmarshal([]byte(clean), &raw) == nil {
+			if o, ok := raw["options"].(map[string]any); ok {
+				opts = o
+			}
+		}
+	}
+	var paths []any
+	if existingPaths, ok := opts["context_paths"].([]any); ok {
+		paths = existingPaths
+	}
+	for _, p := range paths {
+		if s, ok := p.(string); ok && s == contextFile {
+			return opts // already registered
+		}
+	}
+	opts["context_paths"] = append(paths, contextFile)
+	return opts
+}
+
 // Import reads crush config from home and returns a canonical ImportResult.
 func (a *Adapter) Import(home string) (*adapter.ImportResult, error) {
 	return importFrom(home)

internal/adapters/crush/rules_test.go

@@ -0,0 +1,83 @@
+package crush
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func renderCrush(t *testing.T, home string, b *canonical.Bundle) map[string]adapter.File {
+	t.Helper()
+	fs, err := New(WithHome(home)).Render(b)
+	require.NoError(t, err)
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+	return seen
+}
+
+func TestCrushWritesAGENTSAndRegistersContextPath(t *testing.T) {
+	home := t.TempDir()
+	b := &canonical.Bundle{
+		Root:         "/canon",
+		Instructions: canonical.Instructions{Global: "# global"},
+		Rules:        []canonical.Rule{{Name: "sec", Body: "# Security\n\nno secrets in code"}},
+	}
+	seen := renderCrush(t, home, b)
+
+	base := filepath.Join(home, ".config", "crush")
+	agentsMD := filepath.Join(base, "AGENTS.md")
+	assert.Equal(t, adapter.RenderedFile, seen[agentsMD].Kind)
+	body := string(seen[agentsMD].Content)
+	assert.Contains(t, body, "# global")
+	assert.Contains(t, body, "no secrets in code")
+
+	var cfg map[string]any
+	require.NoError(t, json.Unmarshal(seen[filepath.Join(base, "crush.json")].Content, &cfg))
+	opts := cfg["options"].(map[string]any)
+	paths := opts["context_paths"].([]any)
+	assert.Contains(t, paths, agentsMD, "absolute AGENTS.md path must be registered for global load")
+}
+
+func TestCrushPreservesExistingOptionsAndIsIdempotent(t *testing.T) {
+	home := t.TempDir()
+	base := filepath.Join(home, ".config", "crush")
+	require.NoError(t, os.MkdirAll(base, 0o750))
+	agentsMD := filepath.Join(base, "AGENTS.md")
+
+	// Existing crush.json with other options keys and a pre-existing context path
+	// (including our own — second apply must not duplicate it).
+	existing := map[string]any{
+		"options": map[string]any{
+			"context_paths": []any{"PROJECT.md", agentsMD},
+			"lsp":           map[string]any{"go": true},
+		},
+	}
+	body, _ := json.Marshal(existing)
+	require.NoError(t, os.WriteFile(filepath.Join(base, "crush.json"), body, 0o600))
+
+	seen := renderCrush(t, home, &canonical.Bundle{Root: "/canon"})
+
+	var cfg map[string]any
+	require.NoError(t, json.Unmarshal(seen[filepath.Join(base, "crush.json")].Content, &cfg))
+	opts := cfg["options"].(map[string]any)
+
+	// Other option keys survive.
+	assert.Contains(t, opts, "lsp")
+	// Pre-existing user path survives; ours is present exactly once (idempotent).
+	paths := opts["context_paths"].([]any)
+	count := 0
+	for _, p := range paths {
+		if p == agentsMD {
+			count++
+		}
+	}
+	assert.Equal(t, 1, count, "our context path must not be duplicated on re-apply")
+	assert.Contains(t, paths, "PROJECT.md")
+}

internal/adapters/goose/goose.go

@@ -45,7 +45,8 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       true,
 		ManagesMCP:          true,
 		ManagesSkills:       true,
-		ManagesInstructions: false,
+		ManagesRules:        true,
+		ManagesInstructions: true,
 		HasBuiltInSub:       false,
 	}
 }
@@ -113,6 +114,16 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		Content: merged,
 	})
 
+	// goose has no native rules directory; ~/.config/goose/.goosehints is the
+	// global hints file applied to every session, so fold rules into it.
+	if hints := b.InstructionTextWithRules(name); hints != "" {
+		fs.Add(adapter.File{
+			Dest:    filepath.Join(a.Home, ".config", "goose", ".goosehints"),
+			Kind:    adapter.RenderedFile,
+			Content: []byte(hints),
+		})
+	}
+
 	return fs, nil
 }
 

internal/adapters/goose/rules_test.go

@@ -0,0 +1,31 @@
+package goose
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func TestGooseFoldsRulesIntoGoosehints(t *testing.T) {
+	home := t.TempDir()
+	b := &canonical.Bundle{
+		Instructions: canonical.Instructions{Global: "# global"},
+		Rules:        []canonical.Rule{{Name: "k8s", Body: "# Kube\n\nlabel everything"}},
+	}
+	fs, err := New(WithHome(home)).Render(b)
+	require.NoError(t, err)
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	hints := filepath.Join(home, ".config", "goose", ".goosehints")
+	require.Contains(t, seen, hints)
+	assert.Equal(t, adapter.RenderedFile, seen[hints].Kind)
+	body := string(seen[hints].Content)
+	assert.Contains(t, body, "# global")
+	assert.Contains(t, body, "label everything")
+}

internal/adapters/kilo/kilo.go

@@ -38,7 +38,9 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       true,
 		ManagesMCP:          true,
 		ManagesSkills:       true,
-		ManagesInstructions: false,
+		ManagesAgents:       true,
+		ManagesRules:        true,
+		ManagesInstructions: true,
 		HasBuiltInSub:       false,
 	}
 }
@@ -58,8 +60,11 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 	fs := adapter.NewFileSet()
 	base := filepath.Join(a.Home, ".config", "kilo")
 
+	// Kilo CLI reads global markdown subagents from ~/.config/kilo/agents/<name>.md
+	// (PLURAL — the singular "agent/" used by older OpenCode-fork builds is a
+	// silent no-op on current Kilo).
 	fs.Add(adapter.File{
-		Dest:          filepath.Join(base, "agent"),
+		Dest:          filepath.Join(base, "agents"),
 		Kind:          adapter.SymlinkDir,
 		SymlinkTarget: filepath.Join(b.Root, "agents"),
 	})
@@ -69,6 +74,13 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		Kind:          adapter.SymlinkDir,
 		SymlinkTarget: filepath.Join(b.Root, "skills"),
 	})
+	// kilo has no global rules directory; ~/.config/kilo/AGENTS.md is the
+	// always-on global instructions file, so fold rules into it.
+	fs.Add(adapter.File{
+		Dest:    filepath.Join(base, "AGENTS.md"),
+		Kind:    adapter.RenderedFile,
+		Content: []byte(b.InstructionTextWithRules(name)),
+	})
 
 	cfgPath := filepath.Join(base, "kilo.json")
 	existing, err := common.ReadExistingFile(cfgPath)

internal/adapters/kilo/kilo_test.go

@@ -33,7 +33,8 @@ func TestKiloRender(t *testing.T) {
 	seen := map[string]adapter.File{}
 	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
 
-	agentDest := filepath.Join(home, ".config", "kilo", "agent")
+	// Global markdown subagents dir is PLURAL "agents" on current Kilo CLI.
+	agentDest := filepath.Join(home, ".config", "kilo", "agents")
 	assert.Equal(t, adapter.SymlinkDir, seen[agentDest].Kind)
 	assert.Equal(t, "/canon/agents", seen[agentDest].SymlinkTarget)
 

internal/adapters/kilo/rules_test.go

@@ -0,0 +1,32 @@
+package kilo
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func TestKiloFoldsRulesIntoAGENTS(t *testing.T) {
+	home := t.TempDir()
+	b := &canonical.Bundle{
+		Root:         "/canon",
+		Instructions: canonical.Instructions{Global: "# global"},
+		Rules:        []canonical.Rule{{Name: "py", Body: "# Py\n\ntype hints"}},
+	}
+	fs, err := New(WithHome(home)).Render(b)
+	require.NoError(t, err)
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	agentsMD := filepath.Join(home, ".config", "kilo", "AGENTS.md")
+	require.Contains(t, seen, agentsMD)
+	assert.Equal(t, adapter.RenderedFile, seen[agentsMD].Kind)
+	body := string(seen[agentsMD].Content)
+	assert.Contains(t, body, "# global")
+	assert.Contains(t, body, "type hints")
+}

internal/adapters/opencode/import.go

@@ -5,12 +5,23 @@ import (
 
 	"github.com/lukaszraczylo/harness-sync/internal/adapter"
 	"github.com/lukaszraczylo/harness-sync/internal/adapter/common"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
 )
 
 func importFrom(home string) (*adapter.ImportResult, error) {
 	base := filepath.Join(home, ".config", "opencode")
 	res := &adapter.ImportResult{}
 
+	agents, err := common.ImportMarkdownTree(filepath.Join(base, "agents"), "")
+	if err != nil {
+		return nil, err
+	}
+	for _, a := range agents {
+		res.Agents = append(res.Agents, canonical.Agent{
+			Name: a.Name, Description: a.Description, Body: a.Body, Path: a.Path,
+		})
+	}
+
 	cfgBody, err := common.ReadIfExists(filepath.Join(base, "opencode.jsonc"))
 	if err != nil {
 		return nil, err

internal/adapters/opencode/opencode.go

@@ -37,6 +37,8 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       true,
 		ManagesMCP:          true,
 		ManagesSkills:       true,
+		ManagesAgents:       true,
+		ManagesRules:        true,
 		ManagesInstructions: true,
 		HasBuiltInSub:       false,
 	}
@@ -62,6 +64,12 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		Kind:          adapter.SymlinkDir,
 		SymlinkTarget: filepath.Join(b.Root, "skills"),
 	})
+	// opencode reads markdown subagents from ~/.config/opencode/agents/<name>.md
+	fs.Add(adapter.File{
+		Dest:          filepath.Join(base, "agents"),
+		Kind:          adapter.SymlinkDir,
+		SymlinkTarget: filepath.Join(b.Root, "agents"),
+	})
 
 	cfgPath := filepath.Join(base, "opencode.jsonc")
 	existing, err := common.ReadExistingFile(cfgPath)
@@ -104,14 +112,12 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		Content: merged,
 	})
 
-	instructions := b.Instructions.Global
+	// opencode has no native rules directory; rule content reaches it only via
-	if override, ok := b.Instructions.PerHarness[name]; ok && override != "" {
+	// the global AGENTS.md instructions file, so fold the rules in here.
-		instructions = override
-	}
 	fs.Add(adapter.File{
 		Dest:    filepath.Join(base, "AGENTS.md"),
 		Kind:    adapter.RenderedFile,
-		Content: []byte(instructions),
+		Content: []byte(b.InstructionTextWithRules(name)),
 	})
 
 	return fs, nil

internal/adapters/opencode/rules_test.go

@@ -0,0 +1,52 @@
+package opencode
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func TestOpencodeRendersAgentsSymlinkAndFoldsRules(t *testing.T) {
+	home := t.TempDir()
+	ad := New(WithHome(home))
+	b := &canonical.Bundle{
+		Root:         "/canon",
+		Instructions: canonical.Instructions{Global: "# global"},
+		Rules:        []canonical.Rule{{Name: "go", Body: "# Go\n\ngofmt always"}},
+	}
+	fs, err := ad.Render(b)
+	require.NoError(t, err)
+
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	agentsDest := filepath.Join(home, ".config", "opencode", "agents")
+	assert.Equal(t, adapter.SymlinkDir, seen[agentsDest].Kind)
+	assert.Equal(t, "/canon/agents", seen[agentsDest].SymlinkTarget)
+
+	agentsMD := filepath.Join(home, ".config", "opencode", "AGENTS.md")
+	assert.Equal(t, adapter.RenderedFile, seen[agentsMD].Kind)
+	body := string(seen[agentsMD].Content)
+	assert.Contains(t, body, "# global")
+	assert.Contains(t, body, "gofmt always")
+}
+
+func TestOpencodeImportsAgents(t *testing.T) {
+	home := t.TempDir()
+	agentsDir := filepath.Join(home, ".config", "opencode", "agents")
+	require.NoError(t, os.MkdirAll(agentsDir, 0o750))
+	require.NoError(t, os.WriteFile(filepath.Join(agentsDir, "review.md"),
+		[]byte("---\nname: review\ndescription: d\n---\nbody"), 0o600))
+
+	ad := New(WithHome(home))
+	res, err := ad.Import(home)
+	require.NoError(t, err)
+	require.Len(t, res.Agents, 1)
+	assert.Equal(t, "review", res.Agents[0].Name)
+}

internal/adapters/zed/rules_test.go

@@ -0,0 +1,31 @@
+package zed
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func TestZedFoldsRulesIntoAGENTS(t *testing.T) {
+	home := t.TempDir()
+	b := &canonical.Bundle{
+		Instructions: canonical.Instructions{Global: "# global"},
+		Rules:        []canonical.Rule{{Name: "ts", Body: "# TS\n\nstrict mode"}},
+	}
+	fs, err := New(WithHome(home)).Render(b)
+	require.NoError(t, err)
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	agentsMD := filepath.Join(home, ".config", "zed", "AGENTS.md")
+	require.Contains(t, seen, agentsMD)
+	assert.Equal(t, adapter.RenderedFile, seen[agentsMD].Kind)
+	body := string(seen[agentsMD].Content)
+	assert.Contains(t, body, "# global")
+	assert.Contains(t, body, "strict mode")
+}

internal/adapters/zed/zed.go

@@ -42,7 +42,8 @@ func (a *Adapter) Capabilities() adapter.HarnessCapabilities {
 		ManagesModels:       true,
 		ManagesMCP:          false, // Agent panel uses Extensions; context_servers key causes serde parse errors
 		ManagesSkills:       false,
-		ManagesInstructions: false,
+		ManagesRules:        true,
+		ManagesInstructions: true,
 		HasBuiltInSub:       false,
 	}
 }
@@ -97,6 +98,17 @@ func (a *Adapter) Render(b *canonical.Bundle) (*adapter.FileSet, error) {
 		NoMerge: true,
 	})
 
+	// Zed reads personal/global instructions from ~/.config/zed/AGENTS.md
+	// (always-on for the Agent across all projects). Zed has no rules directory,
+	// so fold rules into it.
+	if instr := b.InstructionTextWithRules(name); instr != "" {
+		fs.Add(adapter.File{
+			Dest:    filepath.Join(a.Home, ".config", "zed", "AGENTS.md"),
+			Kind:    adapter.RenderedFile,
+			Content: []byte(instr),
+		})
+	}
+
 	return fs, nil
 }
 

internal/canonical/instructions.go

@@ -0,0 +1,47 @@
+package canonical
+
+import "strings"
+
+// InstructionText returns the instruction body a harness should receive: the
+// per-harness override when one is set, otherwise the global instructions.
+func (b *Bundle) InstructionText(harness string) string {
+	if override, ok := b.Instructions.PerHarness[harness]; ok && override != "" {
+		return override
+	}
+	return b.Instructions.Global
+}
+
+// InstructionTextWithRules returns InstructionText for the harness with every
+// canonical rule body folded in. Harnesses without a native rules directory
+// (everything except claude-code/kilo) only receive rule content this way —
+// via their global instructions file. Rule frontmatter is stripped so the
+// folded output stays clean; bodies are joined in load order (deterministic).
+func (b *Bundle) InstructionTextWithRules(harness string) string {
+	base := b.InstructionText(harness)
+	var sb strings.Builder
+	sb.WriteString(base)
+	for _, r := range b.Rules {
+		body := strings.TrimSpace(stripFrontmatter(r.Body))
+		if body == "" {
+			continue
+		}
+		if sb.Len() > 0 {
+			sb.WriteString("\n\n")
+		}
+		sb.WriteString(body)
+	}
+	return sb.String()
+}
+
+// stripFrontmatter removes a leading YAML frontmatter block ("---\n…\n---") so
+// folding a rule into a plain instructions file does not leak its metadata.
+func stripFrontmatter(s string) string {
+	if !strings.HasPrefix(s, "---\n") {
+		return s
+	}
+	end := strings.Index(s[4:], "\n---")
+	if end == -1 {
+		return s
+	}
+	return strings.TrimPrefix(s[4+end+len("\n---"):], "\n")
+}

internal/canonical/instructions_test.go

@@ -0,0 +1,102 @@
+package canonical
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestInstructionText(t *testing.T) {
+	t.Run("global when no override", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{Instructions: Instructions{Global: "G"}}
+		assert.Equal(t, "G", b.InstructionText("zed"))
+	})
+	t.Run("per-harness override wins", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{Instructions: Instructions{Global: "G", PerHarness: map[string]string{"zed": "Z"}}}
+		assert.Equal(t, "Z", b.InstructionText("zed"))
+	})
+	t.Run("empty override falls back to global", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{Instructions: Instructions{Global: "G", PerHarness: map[string]string{"zed": ""}}}
+		assert.Equal(t, "G", b.InstructionText("zed"))
+	})
+	t.Run("empty everything", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{}
+		assert.Equal(t, "", b.InstructionText("zed"))
+	})
+}
+
+func TestInstructionTextWithRules(t *testing.T) {
+	t.Run("folds rules after global", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{
+			Instructions: Instructions{Global: "# Global"},
+			Rules: []Rule{
+				{Name: "a", Body: "# Rule A\n\nbe concise"},
+				{Name: "b", Body: "# Rule B\n\nbe safe"},
+			},
+		}
+		got := b.InstructionTextWithRules("opencode")
+		assert.Equal(t, "# Global\n\n# Rule A\n\nbe concise\n\n# Rule B\n\nbe safe", got)
+	})
+
+	t.Run("strips rule frontmatter", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{
+			Instructions: Instructions{Global: "G"},
+			Rules: []Rule{
+				{Name: "scoped", Body: "---\nname: scoped\npaths: \"**/*.go\"\n---\n# Go\n\ngofmt"},
+			},
+		}
+		got := b.InstructionTextWithRules("opencode")
+		assert.Equal(t, "G\n\n# Go\n\ngofmt", got)
+		assert.NotContains(t, got, "paths:")
+		assert.NotContains(t, got, "---")
+	})
+
+	t.Run("no rules returns plain instruction text", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{Instructions: Instructions{Global: "G"}}
+		assert.Equal(t, "G", b.InstructionTextWithRules("opencode"))
+	})
+
+	t.Run("empty global still emits rules", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{Rules: []Rule{{Name: "a", Body: "rule body"}}}
+		assert.Equal(t, "rule body", b.InstructionTextWithRules("opencode"))
+	})
+
+	t.Run("blank rule bodies are skipped", func(t *testing.T) {
+		t.Parallel()
+		b := Bundle{
+			Instructions: Instructions{Global: "G"},
+			Rules: []Rule{
+				{Name: "empty", Body: "   \n  "},
+				{Name: "real", Body: "keep"},
+			},
+		}
+		assert.Equal(t, "G\n\nkeep", b.InstructionTextWithRules("opencode"))
+	})
+}
+
+func TestStripFrontmatter(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{"no frontmatter", "# Title\nbody", "# Title\nbody"},
+		{"with frontmatter", "---\nname: x\n---\n# Title", "# Title"},
+		{"unterminated frontmatter left intact", "---\nname: x\nbody", "---\nname: x\nbody"},
+		{"empty", "", ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			assert.Equal(t, tt.want, stripFrontmatter(tt.in))
+		})
+	}
+}

internal/canonical/load.go

@@ -72,6 +72,14 @@ func LoadFS(fs fsx.FS, root string) (*Bundle, error) {
 		b.Agents = append(b.Agents, Agent(m))
 	}
 
+	rules, err := loadMarkdownDirFS(fs, filepath.Join(root, "rules"), "")
+	if err != nil {
+		return nil, err
+	}
+	for _, m := range rules {
+		b.Rules = append(b.Rules, Rule(m))
+	}
+
 	b.Instructions.PerHarness = map[string]string{}
 	body, err := readFileIfExistsFS(fs, filepath.Join(root, "instructions", "global.md"))
 	if err != nil {

internal/canonical/load_test.go

@@ -28,6 +28,10 @@ func TestLoad(t *testing.T) {
 	require.Len(t, b.Agents, 1)
 	assert.Equal(t, "sample", b.Agents[0].Name)
 
+	require.Len(t, b.Rules, 1)
+	assert.Equal(t, "sample-rule", b.Rules[0].Name)
+	assert.Contains(t, b.Rules[0].Body, "Always be concise.")
+
 	assert.Contains(t, b.Instructions.Global, "Be helpful.")
 }
 

internal/canonical/testdata/sample/rules/sample-rule.md

@@ -0,0 +1,3 @@
+# Sample Rule
+
+Always be concise.

internal/canonical/types.go

@@ -65,6 +65,16 @@ type Agent struct {
 	Path        string
 }
 
+// Rule is a topic-scoped instruction fragment (e.g. ~/.claude/rules/go.md).
+// Claude Code auto-loads a directory of these; harnesses without a native rules
+// directory receive the bodies folded into their global instructions file.
+type Rule struct {
+	Name        string
+	Description string
+	Body        string
+	Path        string
+}
+
 type Instructions struct {
 	PerHarness map[string]string
 	Global     string
@@ -77,6 +87,7 @@ type Bundle struct {
 	Profile      Profile
 	Skills       []Skill
 	Agents       []Agent
+	Rules        []Rule
 	MCP          MCPRegistry
 }
 

internal/cli/init.go

@@ -93,6 +93,7 @@ func runImport(cmd *cobra.Command, reg *adapter.Registry, root, home string, pic
 	}
 	seenSkills := map[string]bool{}
 	seenAgents := map[string]bool{}
+	seenRules := map[string]bool{}
 	seenMCP := map[string]bool{}
 	var instructions []string
 
@@ -121,6 +122,14 @@ func runImport(cmd *cobra.Command, reg *adapter.Registry, root, home string, pic
 			seenAgents[key] = true
 			bundle.Agents = append(bundle.Agents, a)
 		}
+		for _, r := range res.Rules {
+			key := r.Name + "|" + r.Body
+			if seenRules[key] {
+				continue
+			}
+			seenRules[key] = true
+			bundle.Rules = append(bundle.Rules, r)
+		}
 		for _, m := range res.MCP {
 			if seenMCP[m.Name] {
 				continue
@@ -153,8 +162,8 @@ func runImport(cmd *cobra.Command, reg *adapter.Registry, root, home string, pic
 		return err
 	}
 	_, _ = fmt.Fprintf(cmd.OutOrStdout(),
-		"imported from %v into %s\n  skills:       %d\n  agents:       %d\n  mcp servers:  %d\n  instructions: %d source(s)\n",
+		"imported from %v into %s\n  skills:       %d\n  agents:       %d\n  rules:        %d\n  mcp servers:  %d\n  instructions: %d source(s)\n",
-		picked, root, len(bundle.Skills), len(bundle.Agents), len(bundle.MCP.Servers), len(instructions),
+		picked, root, len(bundle.Skills), len(bundle.Agents), len(bundle.Rules), len(bundle.MCP.Servers), len(instructions),
 	)
 	return nil
 }
@@ -172,7 +181,7 @@ const importedProfileBody = "# harness-sync profile \xe2\x80\x94 generated by in
 	"models: []\n"
 
 func writeCanonical(root string, b *canonical.Bundle, picked []string) error {
-	for _, sub := range []string{"profiles", "skills", "agents", "instructions"} {
+	for _, sub := range []string{"profiles", "skills", "agents", "rules", "instructions"} {
 		if err := os.MkdirAll(filepath.Join(root, sub), 0o750); err != nil {
 			return err
 		}
@@ -233,6 +242,19 @@ func writeCanonical(root string, b *canonical.Bundle, picked []string) error {
 			return err
 		}
 	}
+	for _, r := range b.Rules {
+		rel := r.Path
+		if rel == "" {
+			rel = safeFilename(r.Name) + ".md"
+		}
+		path := filepath.Join(root, "rules", rel)
+		if err := os.MkdirAll(filepath.Dir(path), 0o750); err != nil {
+			return err
+		}
+		if err := os.WriteFile(path, []byte(r.Body), 0o600); err != nil {
+			return err
+		}
+	}
 	if b.Instructions.Global != "" {
 		if err := os.WriteFile(filepath.Join(root, "instructions", "global.md"),
 			[]byte(b.Instructions.Global), 0o600); err != nil {

internal/cli/init_test.go

@@ -53,6 +53,34 @@ func TestInitImportWritesCanonical(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestInitImportsRules(t *testing.T) {
+	root := t.TempDir()
+	home := t.TempDir()
+
+	reg := adapter.NewRegistry()
+	reg.Register(&importableAdapter{
+		name: "stub",
+		res: &adapter.ImportResult{
+			Rules: []canonical.Rule{
+				{Name: "go", Body: "# Go\n\ngofmt", Path: "go.md"},
+				{Name: "py", Body: "# Py\n\ntypes", Path: "py.md"},
+			},
+		},
+	})
+
+	cmd := NewInit(reg)
+	cmd.SetArgs([]string{"--root", root, "--home", home, "--from", "stub", "--no-prompt"})
+	require.NoError(t, cmd.Execute())
+
+	assert.FileExists(t, filepath.Join(root, "rules", "go.md"))
+	assert.FileExists(t, filepath.Join(root, "rules", "py.md"))
+
+	// Round-trips back through the loader.
+	b, err := canonical.Load(root)
+	require.NoError(t, err)
+	require.Len(t, b.Rules, 2)
+}
+
 func makeStubReg() *adapter.Registry {
 	reg := adapter.NewRegistry()
 	reg.Register(&importableAdapter{

tests/e2e/e2e_test.go

@@ -17,11 +17,15 @@ func TestInitApplyDiffCycle(t *testing.T) {
 	home := t.TempDir()
 	root := filepath.Join(home, ".config", "harness-sync")
 
-	// Fake a claude-code install with one skill
+	// Fake a claude-code install with one skill and one rule
 	require.NoError(t, os.MkdirAll(filepath.Join(home, ".claude", "skills", "hi"), 0o750))
 	require.NoError(t, os.WriteFile(
 		filepath.Join(home, ".claude", "skills", "hi", "SKILL.md"),
 		[]byte("---\nname: hi\n---\nbody"), 0o600))
+	require.NoError(t, os.MkdirAll(filepath.Join(home, ".claude", "rules"), 0o750))
+	require.NoError(t, os.WriteFile(
+		filepath.Join(home, ".claude", "rules", "go.md"),
+		[]byte("# Go Rules\n\ngofmt always"), 0o600))
 
 	run := func(args ...string) ([]byte, error) {
 		cmd := exec.Command(bin, args...)
@@ -33,6 +37,7 @@ func TestInitApplyDiffCycle(t *testing.T) {
 	require.NoError(t, err, string(out))
 	assert.FileExists(t, filepath.Join(root, "config.yaml"))
 	assert.FileExists(t, filepath.Join(root, "skills", "hi", "SKILL.md"))
+	assert.FileExists(t, filepath.Join(root, "rules", "go.md"))
 
 	// apply may produce conflicts on a freshly imported tree (because the
 	// claude-code adapter merges into existing settings.json which differs