# Developer Protocol **Server:** macos-mcp-server **Version:** 0.4.0 **Framework:** [@cyanheads/mcp-ts-core](https://www.npmjs.com/package/@cyanheads/mcp-ts-core) `^0.13.18` **Engines:** Bun ≥1.4.0, Node ≥24.0.0 **MCP SDK:** `@modelcontextprotocol/server` ^2.4.0 **Zod:** ^4.6.7 > **Read the framework docs first:** `node_modules/@cyanheads/mcp-ts-core/CLAUDE.md` contains the full API reference — builders, Context, error codes, exports, patterns. This file covers server-specific conventions only. --- ## What's Next? When the user asks what's next or needs direction, suggest options based on the current project state. Common next steps: 1. **Re-run the `setup` skill** — ensures CLAUDE.md, skills, structure, and metadata are populated and up to date with the current codebase 2. **Run the `design-mcp-server` skill** — if the tool/resource surface hasn't been mapped yet, work through domain design 3. **Add tools/resources/prompts** — scaffold new definitions using the `add-tool`, `add-app-tool`, `add-resource`, `add-prompt` skills 4. **Add services** — scaffold domain service integrations using the `add-service` skill 5. **Add tests** — scaffold tests for existing definitions using the `add-test` skill 6. **Field-test definitions** — exercise tools/resources/prompts with real inputs using the `field-test` skill, get a report of issues and pain points 7. **Run `devcheck`** — lint, format, typecheck, and security audit 8. **Run the `security-pass` skill** — audit handlers for MCP-specific security gaps: output injection, scope blast radius, input sinks, tenant isolation 9. **Run the `polish-docs-meta` skill** — finalize README, CHANGELOG, metadata, and agent protocol for shipping 10. **Run the `maintenance` skill** — investigate changelogs, adopt upstream changes, and sync skills after `bun update --latest` Tailor suggestions to what's actually missing or stale — don't recite the full list every time. --- ## Core Rules - **Logic throws, framework catches.** Tool/resource handlers are pure — throw on failure, no `try/catch`. Plain `Error` is fine; the framework catches, classifies, and formats. Use error factories (`notFound()`, `validationError()`, etc.) when the error code matters. - **Use `ctx.log`** for request-scoped logging. No `console` calls. - **Use `ctx.state`** for tenant-scoped storage. Never access persistence directly. - **Need input the caller didn't supply?** `return ctx.requestInput(...)` and read `ctx.inputs` when the handler is re-entered. Never `await` for user input mid-handler. - **Secrets in env vars only** — never hardcoded. - **Cut noise.** Add only what earns its place: no speculative generality, no guards for states the framework already prevents (Zod-validated params, classified errors), no abstraction until a third caller proves it, no option nothing sets. - **Close the loop on issues.** When implementing work tracked by a GitHub issue, comment on the issue with what landed and close it. Do both — a comment without a close leaves stale issues open; a close without a comment leaves no record of what shipped. The comment is for future readers — state the concrete changes, not the conversation that produced them. - **No Docker.** This server requires direct macOS host access (osascript, System Events, screencapture, SwitchAudioSource, NSScreen). None of these exist inside a Linux container. Skip Docker build/push steps in any release or publish workflow. --- ## Patterns ### Tool ```ts import { tool, z } from '@cyanheads/mcp-ts-core'; import { withActionRequirements } from '@/mcp-server/tools/action-requirements.js'; import { getOsascriptService } from '@/services/osascript/osascript-service.js'; export const macosControlAppearance = tool('macos_control_appearance', { description: 'Get or set the system appearance (dark mode or light mode).', annotations: { readOnlyHint: false, destructiveHint: false, openWorldHint: false }, input: withActionRequirements( z.object({ action: z.enum(['get', 'set']).describe('get returns current; set applies the mode.'), mode: z.enum(['dark', 'light', 'toggle']).optional().describe('Target mode for action=set.'), }), 'action', { set: [['mode']] }, ), output: z.object({ action: z.string().describe('The action that was performed.'), dark_mode: z.boolean().describe('True when dark mode is currently active.'), }), async handler(input, ctx) { const osascript = getOsascriptService(); if (input.action === 'set') { // ... set logic — input.mode is guaranteed present here ... } const { stdout } = await osascript.runAppleScript( 'tell application "System Events" to tell appearance preferences to return dark mode', ctx, ); const dark_mode = stdout.trim() === 'true'; ctx.log.info('macos_control_appearance', { action: input.action, dark_mode }); return { action: input.action, dark_mode }; }, format: (result) => [ { type: 'text', text: `**action:** ${result.action}\n**Appearance:** ${result.dark_mode ? 'Dark mode' : 'Light mode'}` }, ], }); ``` **Per-action requirements.** A multi-action tool keeps a flat `z.object` root and declares what each action needs with `withActionRequirements(schema, key, { value: [groups] })` — a group of one names a required argument, a group of several is satisfied by any one of them (`launch: [['app_name', 'bundle_id']]`). That one declaration adds a root `superRefine` (a missing or `""` argument fails as `-32602` `invalid_arguments` before the handler runs, with a hint naming what to send) and advertises the same requirement as a root `anyOf` in `inputSchema` (a free-text string argument also carries `minLength: 1` there, so the advertised schema rejects `""` too). Never throw a domain reason (`not_running`, `path_not_found`, `window_not_found`, …) for an absent argument — those mean a value that was present but wrong. Narrow a guaranteed argument in the handler with `suppliedArg(input.x, 'x')`. **Subprocess failures.** Run a macOS system binary by its `SYSTEM_BINARIES` path (`src/services/binaries/binary-paths.ts`), never by bare name; add a new binary to that table. Resolve displayplacer or SwitchAudioSource with `findThirdPartyBinary()` on every call and throw the tool's not-found reason when it returns undefined. Never let an `execFile` rejection reach the caller as-is — its message opens with `Command failed: `. Map the cases a caller can act on to a declared reason, and wrap the rest with `execFailure('', err)` (`src/utils/exec-failure.ts`), which keeps the program's own error text and nothing else. `OsascriptService` does this for every script: a permission denial (recognized by its stderr text or `-25211`; a bare `-1719` "Invalid index" or `-25212` "no value" is not a denial) carries `reason: 'accessibility_required'` and a hint naming the pane actually denied, a generic failure carries the AppleScript error text and number, and the script source goes only to `ctx.log.debug` (client-visible to a client subscribed at debug). A tool that maps osascript failures to its own reasons checks `isPermissionDenial(err)` (`src/services/osascript/permission-denial.ts`) first and rethrows the denial unchanged. **Cancellation.** Pass `signal: ctx.signal` to every `execFile` (and fs read) beside its own timeout. The first line of any catch that maps, degrades, or falls back is `if (ctx.signal.aborted) throw err;` (or `ctx.signal.throwIfAborted()` in an unbound catch), so the caller's cancellation is rethrown untouched and settles as `RequestCancelled`. Call `ctx.signal.throwIfAborted()` right before a spawn that can change state: Bun can still run a child whose signal already fired. **Process enumerations and NSScreen reads.** An NSScreen read starting or exiting mid-enumeration breaks a System Events process enumeration, so the two never overlap within the server. Pass `exclusion: 'process-enumeration'` to `runJxa`/`runAppleScript` for every script that enumerates System Events processes (`processes.whose(...)`, `every process whose …`, a bulk read such as `processes.unixId()`), and `exclusion: 'nsscreen-read'` for every osascript that reads NSScreen; an NSScreen read that calls `execFile` directly wraps it in `runExclusive('nsscreen-read', ctx.signal, timeoutMs, (remainingMs) => …)` (`src/services/osascript/osascript-exclusion.ts`) and passes `remainingMs` as its timeout. `FOREGROUND_PROCESSES_JXA` (`src/services/osascript/foreground-processes.ts`) defines `processTable(se)` (bulk unix id, name, and backgroundOnly reads, re-read on -1719/-10000 or when the unix ids change between reads, 3 attempts), `processByPid(se, table, pid)` (by name when the name is unique among all processes, else `processes.whose({unixId})[0]`), and `foregroundProcesses(se)` (`{pid, name, proc}` per foreground process). Never use a specifier System Events returns from a query (`whose(...)()`, `proc.windows()`) to address a process or window: it is by name and reaches the first of that name. **Text in `content[]`.** Render upstream or caller text in `format()` through `markdownLiteral()` (`src/utils/markdown-literal.ts`) so a CommonMark parse reads it back exactly, and quote a name inside an error message with `quotedText()` (`src/utils/quoted-text.ts`). **AppleScript literals.** A caller string embedded in an AppleScript (non-JXA) script goes through `appleScriptLiteral(value, argName)` (`src/services/osascript/applescript-literal.ts`), never `JSON.stringify`, whose `\u`, `\b`, and `\f` escapes AppleScript can't compile. It escapes `\` and `"`, writes every other character raw, and throws `-32602` with reason `invalid_arguments` naming `argName` for U+0000 or an unpaired surrogate; build the literal before any other lookup so that rejection comes first. JXA keeps `JSON.stringify`. **Strict input.** `tool()` stores `input.strict()`, so an unrecognized argument key is rejected by name before the handler runs and `inputSchema` advertises `additionalProperties: false` (JSON Schema 2020-12). Root-level only — a nested `z.object()` still strips unless it is strict itself; an explicit `.passthrough()` / `.catchall()` is honored. **Advertised vs. parsed output.** `tools/list` advertises a widened `outputSchema` (success fields optional, the `error` envelope declared) so an error result validates in strict clients; success results are still parsed against the strict `output` (plus `enrichment`). `tool()` throws at definition time if `output` or `enrichment` declares its own `error` field — that key belongs to the framework. ### Resource ```ts import { resource, z } from '@cyanheads/mcp-ts-core'; import { getSystemInfoService, SystemInfoSchema, } from '@/services/system-info/system-info-service.js'; export const macosSystemInfoResource = resource('macos://system/info', { name: 'macos-system-info', description: 'Current macOS system snapshot: battery, power source, Wi-Fi association and network name, hostname, version, uptime, display count. A field whose probe fails is null and named in `unavailable`.', mimeType: 'application/json', params: z.object({}), output: SystemInfoSchema, async handler(_params, ctx) { return getSystemInfoService().getSystemInfo(ctx); }, }); ``` ### Server config ```ts // src/config/server-config.ts — lazy-parsed, separate from framework config import { z } from '@cyanheads/mcp-ts-core'; import { parseEnvConfig } from '@cyanheads/mcp-ts-core/config'; const ServerConfigSchema = z.object({ screenshotDir: z.string().default('').describe('Default directory for screenshot files.'), displayLayouts: z.string().default('{}').describe('JSON object mapping layout names to displayplacer args.'), }); let _config: ReturnType | undefined; export function getServerConfig() { _config ??= parseEnvConfig(ServerConfigSchema, { screenshotDir: 'MACOS_SCREENSHOT_DIR', displayLayouts: 'MACOS_DISPLAY_LAYOUTS', }); return _config; } ``` `parseEnvConfig` maps Zod schema paths → env var names so errors name the variable (`MACOS_SCREENSHOT_DIR`) not the path (`screenshotDir`). Throws `ConfigurationError`, which the framework prints as a clean startup banner. For env booleans use `z.stringbool()`, never `z.coerce.boolean()` — `Boolean("false")` is `true`, so a coerced flag can't be disabled through the environment. `z.stringbool()` parses `true/false/1/0/yes/no/on/off` and rejects anything else, so `=false` actually disables. ### Server identity and instructions `createApp()` accepts optional identity fields forwarded to the SDK's `initialize` response and the server manifest (`/.well-known/mcp.json`): ```ts await createApp({ name: 'macos-mcp-server', title: 'macos-mcp-server', // display name — always the hyphenated repo name instructions: '…', // session-level context, sent on every initialize sessionMode: 'stateless', // or { default: 'stateful', require: 'stateful' } tools: [...], resources: [...], }); ``` Also available: `websiteUrl` (canonical homepage) and `icons`. Don't set `description` — it derives from `package.json`, and an explicit copy is drift. `sessionMode` declares the HTTP session posture in `src/` instead of leaving it to a deployment's `MCP_SESSION_MODE`, which still wins whenever it carries a meaningful value (an empty string and an unsubstituted `${…}` placeholder read as unset and fall through to the option). Add `require: 'stateful'` when a tool asks the caller for input mid-handler via `ctx.requestInput`: startup then fails with a `ConfigurationError` rather than serving a mode in which a 2025-era client can never answer the prompt. Stdio is never refused. This server declares `stateless` — no tool gates on `ctx.requestInput` and no handler keeps per-session state. `teardown(core)` is the `setup()` counterpart — release a watcher, socket, or non-`unref()`'d timer there. It runs after the transport stops and before the logger closes, on every shutdown path, and a signal-triggered shutdown then exits the process explicitly (0, or 1 if a step never settles within the framework's 10 s ceiling). Not declared here: every service is a stateless `execFile` wrapper holding no handle to release. `instructions` is optional server-level orientation. Use it for deployment guidance — here, the permission prerequisites and what `macos_check_permissions` can and cannot see — instead of repeating the same context across tool descriptions. Client adoption is uneven, but there's no downside when set. --- ## Context Handlers receive a unified `ctx` object. Key properties: | Property | Description | |:---------|:------------| | `ctx.log` | Request-scoped logger — `.debug()`, `.info()`, `.notice()`, `.warning()`, `.error()`. Auto-correlates requestId, traceId, tenantId. Dual-sink: Pino **and** `notifications/message` to the client, so treat it as client-visible. | | `ctx.state` | Tenant-scoped KV — `.get(key)`, `.set(key, value, { ttl? })`, `.delete(key)`, `.getMany(keys)`, `.list(prefix, { cursor, limit })`. Accepts any JSON-serializable value; reads return its JSON form (a `Date` comes back as an ISO string). | | `ctx.requestInput` | Suspend and ask the caller for more input — `return ctx.requestInput({ inputRequests: { key: inputRequired.elicit({ message, requestedSchema }) } })`. Never returns; the handler is re-entered with the answers. Always present. | | `ctx.inputs` | The request's responses — `.accepted(key, schema)`, `.view(key)`, `.state()`, `.dropped` — limited to what the client declared (`elicitation` and its form/url modes, `sampling`, `roots`). Client-supplied: a consent gate trusts only a `ctx.state` record it stored when it asked, bound to the operation, caller, and target (see the `api-context` skill). | | `ctx.clientCapabilities` | What the client declared for this request, `undefined` when no view exists. Decides whether to ask for optional context (e.g. roots); never a reason to skip a consent prompt. | | `ctx.enrich` | Success-path agent context (empty-result notices, query echo, pagination totals) — `ctx.enrich(...)` or `.notice()` / `.total()` / `.echo()` / `.truncated()`. Reaches `structuredContent` and `content[]`; lands only when the definition declares an `enrichment` block (no-op otherwise). | | `ctx.content` | Non-text content blocks — `.image(data, mimeType)`, `.audio(data, mimeType)`, or `ctx.content(block)` for a raw block. Prepended to `content[]` after `format()`; never enters `structuredContent`. | | `ctx.signal` | `AbortSignal` for cancellation. | | `ctx.requestId` | Request ID — the one every log record of the call carries and its error envelope returns as `data.requestId`. | | `ctx.tenantId` | Tenant ID from JWT; `'default'` for stdio or HTTP with auth off. | --- ## Errors Handlers throw — the framework catches, classifies, and formats. **Recommended: typed error contract.** Declare `errors: [{ reason, code, when, recovery, retryable?, severity?, thrownBy? }]` on `tool()` / `resource()` to receive `ctx.fail(reason, …)` typed against the reason union. TypeScript catches typos at compile time, `data.reason` is auto-populated for observability, linter enforces conformance against the handler body. `recovery` is required (≥ 5 words, lint-validated) — the single source of truth for the agent's next move. The framework puts it on the wire whenever a failure carrying that `reason` arrives without a hint — a bare `ctx.fail('reason')` or a service throw with `data: { reason }` — as `data.recovery.hint`, mirrored into `content[]` text unless the message already contains it verbatim; override with an explicit `{ recovery: { hint: '...' } }` when dynamic runtime context matters. Every error envelope also carries `data.requestId`, the id the server's log records for that call carry, and `content[]` closes with `(reason … · request )`. Mark an entry the service layer throws with `thrownBy: 'service'` so `error-contract-unthrown` skips it — lint-only metadata, nothing at runtime reads it; the permission, CLI-missing, and capture failures this server's services raise are all marked that way. Baseline codes (`InternalError`, `ServiceUnavailable`, `Timeout`, `ValidationError`, `SerializationError`, `RequestCancelled`) bubble freely and don't need declaring. ```ts import { JsonRpcErrorCode } from '@cyanheads/mcp-ts-core/errors'; errors: [ { reason: 'no_match', code: JsonRpcErrorCode.NotFound, when: 'No item matched the query', recovery: 'Broaden the query or check the spelling and try again.' }, ], async handler(input, ctx) { const item = await db.find(input.id); if (!item) throw ctx.fail('no_match', `No item ${input.id}`); return item; } ``` **Declare contracts inline on each tool.** The contract is part of the tool's public surface — one file should give the full picture. Don't extract a shared `errors[]` constant; per-tool repetition is the intended cost of locality. **Fallback (no contract entry fits):** throw via factories or plain `Error`. ```ts // Error factories — explicit code import { notFound, serviceUnavailable } from '@cyanheads/mcp-ts-core/errors'; throw notFound('Item not found', { itemId }); throw serviceUnavailable('API unavailable', { url }, { cause: err }); // Plain Error — framework auto-classifies from message patterns throw new Error('Item not found'); // → NotFound throw new Error('Invalid query format'); // → ValidationError // McpError — when no factory exists for the code import { McpError, JsonRpcErrorCode } from '@cyanheads/mcp-ts-core/errors'; throw new McpError(JsonRpcErrorCode.InitializationFailed, 'Connection failed', { pool: 'primary' }); ``` See framework CLAUDE.md and the `api-errors` skill for the full auto-classification table, all available factories, and the contract reference. --- ## Structure ```text src/ index.ts # createApp() entry point config/ server-config.ts # MACOS_SCREENSHOT_DIR, MACOS_DISPLAY_LAYOUTS services/ audio/ audio-service.ts # SwitchAudioSource device listing and switching binaries/ binary-paths.ts # SYSTEM_BINARIES absolute paths; findThirdPartyBinary() PATH + Homebrew lookup display/ display-service.ts # displayplacer list and apply-layout, JXA NSScreen read for each display's index osascript/ applescript-literal.ts # appleScriptLiteral() — AppleScript string literal for caller text foreground-processes.ts # FOREGROUND_PROCESSES_JXA — processTable / processByPid / foregroundProcesses, each process addressed uniquely osascript-exclusion.ts # runExclusive() — NSScreen reads and System Events process enumerations never overlap osascript-service.ts # osascript JXA + AppleScript runner with timeout, denial classification permission-denial.ts # isPermissionDenial() — recognizes the service's accessibility_required resolve-app-pids.ts # resolveAppPids() — app_name to running PIDs from NSWorkspace permissions/ permission-probes.ts # prompt-free Accessibility, Screen Recording, Automation > Finder and Automation > Music checks screencapture/ screencapture-service.ts # screencapture PNG capture, path checks and no-replace placement, sips JPEG preview system-info/ system-info-service.ts # battery (pmset), Wi-Fi (networksetup + ifconfig), version, displays (system_profiler -json); hostname/uptime via node:os utils/ exec-failure.ts # caller-safe execFile failure text (never the command line) markdown-literal.ts # markdownLiteral() — upstream/caller text as markdown a CommonMark parse reads back exactly parse-json-output.ts # parseJsonOutput() — subprocess or file JSON through a schema, undefined when unreadable quoted-text.ts # quotedText() — a name as a JSON string literal for error messages mcp-server/ tools/ action-requirements.ts # withActionRequirements() / suppliedArg() — per-action input requirements definitions/ macos-*.tool.ts # 14 tool definitions (one per file) resources/definitions/ macos-*.resource.ts # 3 resource definitions ``` --- ## Naming | What | Convention | Example | |:-----|:-----------|:--------| | Files | kebab-case with suffix | `search-docs.tool.ts` | | Tool/resource/prompt names | snake_case | `search_docs` | | Directories | kebab-case | `src/services/doc-search/` | | Descriptions | Single string or template literal, no `+` concatenation | `'Search items by query and filter.'` | --- ## Skills Two skill trees live at the project root, written for different readers: | Tree | For | Written by | |:-----|:----|:-----------| | `framework-skills/` | The agent developing this server — framework skills (`metadata.audience: external`) plus any development-time skills of the server's own | `init` and the `maintenance` sync (framework skills); you (your own) | | `skills/` | The agents that install the server and call its tools — tool chains, identifier sources, gates | You, deliberately, with the `add-skill` skill. Absent by default; usually none is needed | Development skills are modular instructions. Read them directly when a task matches — e.g., `framework-skills/add-tool/SKILL.md` when adding a tool. `bun run list-skills` prints the full registry. Their directory is deliberately not `skills/`: Claude Code and Codex auto-load a plugin's root `skills/`, so a server that ships `.claude-plugin/` or `.codex-plugin/` would hand them to every agent that installs it. A published skill in root `skills/` reaches plugin installs and the `.mcpb` bundle as-is, ships in the npm package, and reaches MCP clients when the server opts in with `createApp({ skills: 'skills' })`. `lint:packaging` validates the tree. **Agent skill directory:** Copy `framework-skills/` into the directory your agent discovers (Claude Code: `.claude/skills/`, others: equivalent). Skills then load as context without referencing `framework-skills/` paths. After framework updates, run the `maintenance` skill — Phase B re-syncs the agent directory. Available skills: | Skill | Purpose | |:------|:--------| | `setup` | Post-init project orientation | | `design-mcp-server` | Design tool surface, resources, and services for a new server | | `add-tool` | Scaffold a new tool definition | | `add-app-tool` | Scaffold an MCP App tool + paired UI resource | | `add-resource` | Scaffold a new resource definition | | `add-prompt` | Scaffold a new prompt definition | | `add-skill` | Author a skill the server publishes in root `skills/` for the agents that use it — when one earns its place, structure, validation, delivery | | `add-service` | Scaffold a new service integration | | `add-test` | Scaffold test file for a tool, resource, or service | | `field-test` | Exercise tools/resources/prompts with real inputs, verify behavior, report issues | | `tool-defs-analysis` | Read-only audit of MCP definition language across the surface — voice, leaks, defaults, recovery hints, output descriptions | | `security-pass` | Audit server for MCP-flavored security gaps: output injection, scope blast radius, input sinks, tenant isolation | | `code-simplifier` | Post-session cleanup against `git diff` — modernize syntax, consolidate duplication, align with the codebase | | `polish-docs-meta` | Finalize docs, README, metadata, and agent protocol for shipping | | `git-wrapup` | Land working-tree changes as a commit stack — version bump, changelog, verify, commit by concern, release commit on top. No tag, no push to main; opens the release PR when the project declares release PR mode | | `release-pr-review` | Review pass on an open release PR — simplifier + correctness review, fixes as ordinary commits on top of the stack, PR body kept in sync. Release PR mode only | | `release-and-publish` | Fast-forward merge (release PR mode) + tag + push + npm + MCP Registry + GH Release. Picks up from `git-wrapup` (skip the Docker step — see Core Rules) | | `maintenance` | Investigate changelogs, adopt upstream changes, sync skills to agent dirs | | `orchestrations` | Chain task skills into a gated multi-phase pipeline — build-out, QA-fix, update-ship — when you can spawn sub-agents | | `report-issue-framework` | File a bug or feature request against `@cyanheads/mcp-ts-core` via `gh` CLI | | `report-issue-local` | File a bug or feature request against this server's own repo via `gh` CLI | | `techniques` | Catalog of response/data-shaping techniques — overflow handling, payload shaping, retrieval patterns | | `api-auth` | Auth modes, scopes, JWT/OAuth | | `api-canvas` | DataCanvas: register tabular data, run SQL, export, plus the `spillover()` helper for big result sets — Tier 3 opt-in | | `api-config` | AppConfig, parseConfig, env vars | | `api-context` | Context interface, RequestContext, logger, state, multi-round-trip input | | `api-errors` | McpError, JsonRpcErrorCode, error patterns | | `api-linter` | Definition linter rule catalog — invoked by `bun run lint:mcp` and `devcheck` | | `api-mirror` | MirrorService: persistent self-refreshing local mirror (embedded SQLite + FTS5) of a bulk upstream dataset — Tier 3 opt-in | | `api-services` | LLM, Speech, Graph services | | `api-testing` | createMockContext, test patterns | | `api-utils` | Formatting, parsing, security, pagination, scheduling, telemetry helpers | | `api-telemetry` | OTel catalog: spans, metrics, completion logs, env config, cardinality rules | | `api-workers` | Cloudflare Workers runtime | **Chaining skills into pipelines.** When the user wants a multi-phase effort — build this server out, QA-and-fix the surface, update-and-ship — *and you can spawn sub-agents*, `framework-skills/orchestrations/SKILL.md` sequences the task skills above into a gated pipeline with verification at each step. Read it to drive the run. Optional: skip it if you can't orchestrate sub-agents, and ignore it entirely if you were *spawned* as one — you've already been scoped to a single phase. When you complete a skill's checklist, check the boxes and add a completion timestamp at the end (e.g., `Completed: 2026-03-11`). --- ## Commands **Runtime:** Scripts use Bun's native TypeScript execution — `bun run ` is the standard invocation. `npm run ` also works (npm delegates to bun). | Command | Purpose | |:--------|:--------| | `bun run build` | Compile TypeScript | | `bun run rebuild` | Clean + build | | `bun run clean` | Remove build artifacts | | `bun run devcheck` | Lint + format + typecheck + security + changelog sync | | `bun run audit:fix` | `bun audit fix` — upgrade vulnerable packages to the lowest safe version within existing ranges (`--dry-run` previews, `--latest` rewrites ranges). First response when `devcheck` flags a transitive advisory; then `bun update `, then `bun dedupe` | | `bun run audit:refresh` | Delete `bun.lock` and reinstall. Last resort after `audit:fix`, `bun update `, and `bun dedupe` — re-resolves every ranged dep (the framework pin included) and rewrites the lockfile as `lockfileVersion: 2` | | `bun run lint:mcp` | Run the MCP definition linter standalone (rule catalog: `api-linter` skill) | | `bun run lint:packaging` | Packaging surface checks — `server.json`/`manifest.json` env-var parity, `.mcpbignore` coverage, plugin manifests, the published `skills/` tree (run by devcheck) | | `bun run list-skills` | Print the skill registry | | `bun run tree` | Generate directory structure doc | | `bun run format` | Auto-fix formatting (safe fixes only) | | `bun run format:unsafe` | Also apply Biome's unsafe autofixes — review the diff; they can change behavior | | `bun run test` | Run tests (Vitest — use `bun run test`, not `bun test`) | | `bun run start:stdio` | Production mode (stdio) | | `bun run start:http` | Production mode (HTTP) | | `bun run changelog:build` | Regenerate `CHANGELOG.md` from `changelog/*.md` | | `bun run changelog:check` | Verify `CHANGELOG.md` is in sync (used by devcheck) | | `bun run bundle` | Build, pack, and clean a `.mcpb` for one-click Claude Desktop install | **CI is one file.** `.github/workflows/codeql.yml` (scaffolded) is the only GitHub Actions workflow: CodeQL is GitHub-owned end to end, and the file runs only while the repo's CodeQL *default setup* is turned off. Verification — `devcheck`, tests, the release gates — runs locally; don't add a workflow that re-runs it. --- ## Bundling `npm run bundle` produces a `.mcpb` extension bundle for one-click install in Claude Desktop. `mcpb pack` reads `.mcpbignore`, not `.gitignore`, so every root path the bundle must not ship — source, tests, docs, caches, logs, agent docs, plugin manifests, gitignored local files — needs a root-anchored line there (`/docs/`, never `docs/`, which also strips `node_modules/*/docs/`); `lint:packaging` names each missing or unanchored line. Root `skills/` ships on purpose. The pack step is followed by `scripts/clean-mcpb.ts`, which prunes dev dependencies (`mcpb clean`) and strips four classes of `node_modules/**` content that root-anchored `.mcpbignore` patterns cannot reach: dependency-shipped agent docs (`framework-skills/`, `skills/`, `.claude/`, `.agents/` at a package root, and `SKILL.md`) — a directory of those names deeper in a package is runtime code, such as the MCP SDK's `dist/ext/skills/`, and stays; platform-specific native bindings, which would otherwise lock the bundle to the platform it was packed on; node-gyp build output beside a `binding.gyp` (`config.gypi`, Makefiles, `obj.target/`, `.deps/`, object files and debug symbols), which records the packing machine's paths — compiled `*.node` addons stay; and build-only package files — the framework's `changelog/`, `scripts/`, `templates/`, `CLAUDE.md`, `AGENTS.md`, and config bases (`biome.json`, `vitest.config.base.mjs`, `config/tsconfig.base.json`), and `better-sqlite3`'s `deps/` and `src/` C sources. A server using DataCanvas therefore ships a portable bundle without the DuckDB native — `@duckdb/node-api` is an optional peer loaded lazily, so canvas tools report an actionable install hint and every other tool works normally. MCPB is stdio-only — HTTP and Cloudflare Workers deployments are unaffected. Consumers who don't need it can delete `manifest.json` and `.mcpbignore`; `lint:packaging` skips cleanly. **Adding an env var requires both files:** `server.json` (registry discovery, `environmentVariables[]`) and `manifest.json` (bundle install UX, `mcp_config.env` + `user_config`). `lint:packaging` (run by `devcheck`) verifies the env var names match, that every `user_config` option is wired into `mcp_config.env` as `"X": "${user_config.X}"` (the host substitutes nothing else — `"${X}"` reaches the server as that literal string), and that an optional string option carries `"default": ""`. **README install badges** (Claude Desktop `.mcpb`, Cursor, VS Code) and the `base64` / `encodeURIComponent` config-generation commands are ship-time concerns — run the `polish-docs-meta` skill, which carries the badge format, layout, and generation snippets in `framework-skills/polish-docs-meta/references/readme.md`. --- ## Changelog Directory-based, grouped by minor series via the `.x` semver-wildcard convention. Source of truth: `changelog/.x/.md` (e.g. `changelog/0.1.x/0.1.0.md`) — one file per release, shipped in the npm package. At release, author the per-version file with a concrete version and date, then run `npm run changelog:build` to regenerate the rollup. `changelog/template.md` is a **pristine format reference** — never edited or moved; read it for the frontmatter + section layout when scaffolding. `CHANGELOG.md` is a **navigation index** (header + link + summary per version), regenerated by `npm run changelog:build` — devcheck hard-fails on drift; never hand-edit it. Each per-version file opens with YAML frontmatter: ```markdown --- summary: "One-line headline, ≤350 chars" # required — powers the rollup index breaking: false # optional — true flags breaking changes security: false # optional — true ONLY for a source-code security fix, never a dependency CVE bump --- # 0.1.0 — YYYY-MM-DD ... ``` `breaking: true` renders a `· ⚠️ Breaking` badge — use it when consumers must update code on upgrade (signature changes, removed APIs, config renames). `security: true` renders a `· 🛡️ Security` badge and pairs with a `## Security` body section — set it only for a security fix in this server's *own source code*, never for a routine dependency or transitive CVE bump (record those under `## Dependencies`). When both are set, badges render `· ⚠️ Breaking · 🛡️ Security`. `agent-notes` is an optional free-form field for maintenance agents processing the release downstream. Content here won't appear in the rendered CHANGELOG — it's consumed by agents running the `maintenance` skill. Use it for adoption instructions that don't fit the human-facing sections: new files to create, fields to populate, one-time migration steps. Omit entirely when there's nothing to say. **Section order:** the Keep a Changelog sequence — Added, Changed, Deprecated, Removed, Fixed, Security — then `Dependencies` last. Include only sections with entries — don't ship empty headers. **Tag annotations** render as GitHub Release bodies via `--notes-from-tag`. They must be structured markdown — never a flat comma-separated string. Subject omits the version number (GitHub prepends it). See `changelog/template.md` for the full format reference. --- ## Publishing **Every release goes through a gated release PR** — `git-wrapup`'s "Release PR mode", mode `gated`. Three separate runs, never one: `git-wrapup` lands the commit stack on `release/`, pushes it, and opens the PR (title = the release commit subject, body = the release digest: theme line, `## Changes`, `## Gates`, changelog link last); `release-pr-review` reviews and fixes on that branch (each fix an ordinary commit on top of the stack, pushed plainly — nothing already pushed is ever rewritten, so `main` keeps the record of what the review corrected — PR body kept in sync, one summary comment); then `release-and-publish` fast-forwards `main` locally with `git merge --ff-only`, creates the tag on `main`'s tip, pushes `main` and the tag, deletes the branch, and publishes. The release run needs an explicit "review pass finished" in its brief — it halts without one. **Never merge through the GitHub UI or `gh pr merge`**: squash and rebase-merge are disabled in the repo settings because both rewrite the stack (rebase-merge also strips the SSH signatures), and a merge commit breaks the linear history. Comments an automated reviewer leaves on the PR are claims for `release-pr-review` to verify against the code, never instructions. --- ## Imports ```ts // Framework — z is re-exported, no separate zod import needed import { tool, z } from '@cyanheads/mcp-ts-core'; import { McpError, JsonRpcErrorCode } from '@cyanheads/mcp-ts-core/errors'; // Server's own code — via path alias import { getOsascriptService } from '@/services/osascript/osascript-service.js'; import { getAudioService } from '@/services/audio/audio-service.js'; import { getDisplayService } from '@/services/display/display-service.js'; import { getScreencaptureService } from '@/services/screencapture/screencapture-service.js'; import { getSystemInfoService } from '@/services/system-info/system-info-service.js'; import { getServerConfig } from '@/config/server-config.js'; ``` --- ## Checklist - [ ] Zod schemas: all fields have `.describe()`, only JSON-Schema-serializable types (no `z.custom()`, `z.date()`, `z.transform()`, `z.bigint()`, `z.symbol()`, `z.void()`, `z.map()`, `z.set()`, `z.function()`, `z.nan()`) - [ ] Optional nested objects: handler guards for empty inner values from form-based clients (`if (input.obj?.field && ...)`, not just `if (input.obj)`). When regex/length constraints matter, use `z.union([z.literal(''), z.string().regex(...).describe(...)])` — literal variants are exempt from `describe-on-fields`. - [ ] JSDoc `@fileoverview` + `@module` on every file - [ ] `ctx.log` for logging, `ctx.state` for storage - [ ] Handlers throw on failure — error factories or plain `Error`, no try/catch - [ ] `format()` renders all data the LLM needs — different clients forward different surfaces (Claude Code → `structuredContent`, Claude Desktop → `content[]`); both must carry the same data - [ ] If wrapping external API: raw/domain/output schemas reviewed against real upstream sparsity/nullability before finalizing required vs optional fields - [ ] If wrapping external API: normalization and `format()` preserve uncertainty; do not fabricate facts from missing upstream data - [ ] If wrapping external API: tests include at least one sparse payload case with omitted upstream fields - [ ] Registered in `createApp()` arrays (directly or via barrel exports) - [ ] Tests use `createMockContext()` from `@cyanheads/mcp-ts-core/testing` — pass the definition's own `errors` (`createMockContext({ errors: myTool.errors })`) whenever it declares a contract - [ ] `plugin.json` + `mcp.json` (Agent Plugins 1.0.0 — read by Codex, Cursor, GitHub Copilot, VS Code, Kiro) populated — `plugin.json` `name` = the unscoped repo name (lowercase `a-z`, `0-9`, `-`, `.` only); `version`, `description`, `author`, `homepage`, `repository`, `license`, `keywords` from `package.json`; no other top-level field, `extensions` included. `mcp.json` holds one `"type": "stdio"` entry keyed by the unscoped name, `npx -y `, and the same fixed `env` as `.codex-plugin/mcp.json`. Neither file carries a user-supplied variable (no `""`, no `${…}` besides `${PLUGIN_ROOT}`/`${PLUGIN_DATA}`): keys reach Codex through `.codex-plugin/mcp.json` `env_vars`, which works only while `.codex-plugin/plugin.json` keeps `"mcpServers": "./.codex-plugin/mcp.json"` - [ ] `.codex-plugin/plugin.json` populated — `name`, `version`, `description`, `repository`, `license` from `package.json`; `interface.displayName` = the unscoped repo name (`macos-mcp-server`, never the npm scope — `lint:packaging` enforces this); `interface.shortDescription` from `package.json` description - [ ] `.codex-plugin/mcp.json` updated — server name key is the unscoped repo name; every user-supplied variable (API key, contact email, instance URL) is listed in `env_vars` so Codex forwards it from the user's environment. Never write `"KEY": ""` into `env` — an empty value replaces the user's exported key and is read as unset - [ ] `.claude-plugin/plugin.json` populated — `name`, `version`, `description`, `author`, `repository`, `license`, `keywords` from `package.json`; inline `mcpServers` entry keyed by the unscoped repo name. Every user-supplied variable is declared under `userConfig` (`type`, `title`, `description`; `sensitive: true` for keys and tokens; `required: true` or `default: ""`) and referenced from `env` as `"KEY": "${user_config.