# Developer Protocol **Server:** nist-nvd-mcp-server **Version:** 0.1.14 **Framework:** [@cyanheads/mcp-ts-core](https://www.npmjs.com/package/@cyanheads/mcp-ts-core) `^0.10.14` **Engines:** Bun ≥1.3.0, Node ≥24.0.0 **MCP SDK:** `@modelcontextprotocol/sdk` ^1.29.0 **Zod:** ^4.4.3 > **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. - **Check `ctx.elicit` / `ctx.sample`** for presence before calling. - **Secrets in env vars only** — never hardcoded. - **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. --- ## Patterns ### Tool ```ts import { tool, z } from '@cyanheads/mcp-ts-core'; import { JsonRpcErrorCode } from '@cyanheads/mcp-ts-core/errors'; import { getNvdCpeService } from '@/services/nvd-cpe/nvd-cpe-service.js'; export const nvdSearchCpes = tool('nvd_search_cpes', { title: 'Search CPE Dictionary', description: 'Search the NVD CPE dictionary by product keyword or partial match string.', annotations: { readOnlyHint: true, openWorldHint: false }, input: z.object({ keyword: z.string().optional().describe('Product keyword (e.g., "apache http server").'), cpeMatchString: z.string().optional().describe('Partial CPEv2.3 pattern.'), limit: z.number().int().min(1).max(10_000).default(20).describe('Max results (default 20, max 10000).'), }), output: z.object({ cpes: z.array(z.object({ cpeName: z.string().describe('Full CPEv2.3 name.'), title: z.string().optional().describe('Human-readable title.'), deprecated: z.boolean().describe('Whether this CPE is deprecated.'), })).describe('Matching CPE dictionary entries.'), queryMeta: z.object({ totalResults: z.number().describe('Total matches before limit.'), returned: z.number().describe('Entries returned.'), }).describe('Pagination metadata.'), }), errors: [ { reason: 'missing_search_input', code: JsonRpcErrorCode.ValidationError, when: 'Neither keyword nor cpeMatchString was provided.', recovery: 'Provide at least one of keyword or cpeMatchString.', }, ], async handler(input, ctx) { if (!input.keyword && !input.cpeMatchString) { throw ctx.fail('missing_search_input', 'At least one of keyword or cpeMatchString is required.', { ...ctx.recoveryFor('missing_search_input'), }); } ctx.log.info('Searching CPE dictionary', { keyword: input.keyword, limit: input.limit }); const service = getNvdCpeService(); const result = await service.searchCpes({ keyword: input.keyword, cpeMatchString: input.cpeMatchString, limit: input.limit }, ctx); return { cpes: result.cpes, queryMeta: { totalResults: result.totalResults, returned: result.returned } }; }, format: (result) => [{ type: 'text', text: result.cpes.map(c => `**${c.title ?? c.cpeName}**: \`${c.cpeName}\``).join('\n') }], }); ``` ### Resource ```ts import { resource, z } from '@cyanheads/mcp-ts-core'; import { notFound, validationError } from '@cyanheads/mcp-ts-core/errors'; import { getNvdCveService } from '@/services/nvd-cve/nvd-cve-service.js'; const CVE_ID_REGEX = /^CVE-\d{4}-\d{4,}$/i; export const nvdCveResource = resource('nvd://cve/{cveId}', { name: 'NVD CVE Record', description: 'Fetch a single CVE record by ID — stable URI for injectable context.', mimeType: 'application/json', params: z.object({ cveId: z.string().describe('CVE identifier (e.g., "CVE-2021-44228").'), }), async handler(params, ctx) { if (!CVE_ID_REGEX.test(params.cveId)) { throw validationError(`Invalid CVE ID format: "${params.cveId}". Expected: CVE-YYYY-NNNNN.`, { cveId: params.cveId }); } ctx.log.debug('Fetching CVE resource', { cveId: params.cveId }); const service = getNvdCveService(); const result = await service.fetchById([params.cveId.toUpperCase()], true, ctx); if (result.cves.length === 0) throw notFound(`CVE ${params.cveId} not found.`, { cveId: params.cveId }); return result.cves[0]; }, }); ``` ### 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({ apiKey: z.string().optional().describe('NIST NVD API key.'), requestTimeoutMs: z.coerce.number().default(10_000).describe('HTTP request timeout in ms.'), }); let _config: z.infer | undefined; export function getServerConfig() { _config ??= parseEnvConfig(ServerConfigSchema, { apiKey: 'NVD_API_KEY', requestTimeoutMs: 'NVD_REQUEST_TIMEOUT_MS', }); return _config; } ``` `parseEnvConfig` maps Zod schema paths → env var names so errors name the variable (`MY_API_KEY`) not the path (`apiKey`). Throws `ConfigurationError`, which the framework prints as a clean startup banner. --- ## 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. | | `ctx.state` | Tenant-scoped KV — `.get(key)`, `.set(key, value, { ttl? })`, `.delete(key)`, `.list(prefix, { cursor, limit })`. Accepts any serializable value. | | `ctx.signal` | `AbortSignal` for cancellation. Forwarded to NVD HTTP requests. | | `ctx.requestId` | Unique request ID. | | `ctx.tenantId` | Tenant ID from JWT or `'default'` for stdio. | --- ## Errors Handlers throw — the framework catches, classifies, and formats. **Recommended: typed error contract.** Declare `errors: [{ reason, code, when, recovery, retryable? }]` 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 descriptive metadata for the agent's next move (≥ 5 words, lint-validated); for the wire `data.recovery.hint` (mirrored into `content[]` text), pass explicitly at the throw site when dynamic context matters: `ctx.fail('reason', msg, { recovery: { hint: '...' } })`. Baseline codes (`InternalError`, `ServiceUnavailable`, `Timeout`, `ValidationError`, `SerializationError`) 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.DatabaseError, '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 # NVD_API_KEY + NVD_REQUEST_TIMEOUT_MS (Zod schema) services/ nvd-http/ nvd-http-client.ts # HTTP client with token-bucket rate limiting and retry nvd-cve/ nvd-cve-service.ts # CVE search, fetch-by-ID, CPE audit, history, normalization types.ts # Raw API response + normalized domain types nvd-cpe/ nvd-cpe-service.ts # CPE dictionary search and normalization types.ts # Raw CPE response + normalized CpeRecord mcp-server/ tools/definitions/ nvd-search-cves.tool.ts # nvd_search_cves nvd-get-cve.tool.ts # nvd_get_cve nvd-search-cpes.tool.ts # nvd_search_cpes nvd-audit-cpe.tool.ts # nvd_audit_cpe nvd-get-cve-history.tool.ts # nvd_get_cve_history resources/definitions/ nvd-cve.resource.ts # nvd://cve/{cveId} ``` --- ## 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 Skills are modular instructions in `skills/` at the project root. Read them directly when a task matches — e.g., `skills/add-tool/SKILL.md` when adding a tool. **Agent skill directory:** Copy skills into the directory your agent discovers (Claude Code: `.claude/skills/`, others: equivalent). Skills then load as context without referencing `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-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 versioned commit + annotated tag — version bump, changelog, verify, tag. Local only. | | `release-and-publish` | Push + npm + MCP Registry + GH Release + Docker. Picks up from `git-wrapup` | | `maintenance` | Investigate changelogs, adopt upstream changes, sync skills to agent dirs | | `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, logger, state, progress | | `api-errors` | McpError, JsonRpcErrorCode, error patterns | | `api-linter` | Definition linter rule catalog — invoked by `bun run lint:mcp` and `devcheck` | | `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-mirror` | MirrorService: persistent local SQLite mirror of a bulk upstream dataset — defineMirror, sqliteMirrorStore, FTS5 | | `api-workers` | Cloudflare Workers runtime | | `orchestrations` | Chain task skills into a gated multi-phase pipeline (build-out, QA-fix, update-ship) when sub-agents are available | 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 natively — use `bun run ` for all commands. | 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:refresh` | Delete `bun.lock`, reinstall, re-audit. Use when `devcheck` flags a transitive advisory — stale lockfile can mask already-patched deps. If advisory survives, it's real. | | `bun run tree` | Generate directory structure doc | | `bun run format` | Auto-fix formatting | | `bun run test` | Run tests | | `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 release:github` | Create GitHub Release — constructs title from tag, conditionally attaches `.mcpb` bundle | | `bun run bundle` | Build and pack as `.mcpb` for one-click Claude Desktop install | --- ## Bundling `npm run bundle` produces a `.mcpb` extension bundle for one-click install in Claude Desktop. 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. **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 `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 flags security fixes --- # 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. 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** (Keep a Changelog): Added, Changed, Deprecated, Removed, Fixed, Security. 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. --- ## 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 { getMyService } from '@/services/my-domain/my-service.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` - [ ] `.codex-plugin/plugin.json` populated — `name`, `version`, `description`, `repository`, `license` from `package.json`; `interface.displayName` = package name; `interface.shortDescription` from `package.json` description - [ ] `.codex-plugin/mcp.json` updated — server name key matches `package.json` name; env vars added for any required API keys - [ ] `.claude-plugin/plugin.json` populated — `name`, `version`, `description`, `repository`, `license` from `package.json`; inline `mcpServers` entry with server name key, env vars for any required API keys - [ ] `bun run devcheck` passes