---
summary: Fuzz testing framework with schema-aware property-based testing, retry utility with exponential backoff, GitHub issue templates, and issue reporting skills
breaking: false
---

# 0.2.0 — 2026-03-24

Fuzz testing framework, retry utility, GitHub issue templates, and issue reporting skills.

## Added

- **Fuzz testing module** — `fuzzTool`, `fuzzResource`, `fuzzPrompt` from `@cyanheads/mcp-ts-core/testing/fuzz`. Schema-aware property-based testing via `fast-check`: generates valid inputs from Zod schemas and adversarial payloads (prototype pollution, injection strings, type confusion), then asserts handler invariants (no crashes, no stack trace leaks, no prototype pollution). Returns `FuzzReport` for custom assertions.
- **`zodToArbitrary`** — Converts Zod schemas to `fast-check` arbitraries for custom property-based tests.
- **`ADVERSARIAL_STRINGS`** — Curated set of injection, encoding, and parsing attack strings for targeted testing.
- **`./testing/fuzz` subpath export** — New package export for the fuzz testing module.
- **Retry utility** — `withRetry` from `@cyanheads/mcp-ts-core/utils`. Exponential backoff with jitter, transient error classification (`ServiceUnavailable`, `Timeout`, `RateLimited`), abort signal support, and exhaustion enrichment (attempt count in error message and data).
- **GitHub issue templates** — Structured YAML form templates for bug reports and feature requests in `.github/ISSUE_TEMPLATE/`. Includes version/runtime/transport dropdowns and redaction guidance. Scaffolded to consumer projects via `init`.
- **Issue reporting skills** — `report-issue-framework` (file bugs against `@cyanheads/mcp-ts-core`) and `report-issue-local` (file bugs against the consumer server). Both include triage guidance, `gh` CLI examples, redaction checklist, and title/label conventions.
- **Fuzz test suite** — Three test files (`tests/fuzz/`) covering definition fuzzing, error handler fuzzing, and tool handler pipeline fuzzing (~850 lines).
- **Service resilience documentation** — `add-service` skill gains a "Resilience" section with retry-wraps-full-pipeline pattern, backoff calibration, and parse failure classification. `design-mcp-server` skill gains a resilience planning table.

## Changed

- **Biome config** — `noExplicitAny: off` for `src/testing/**` (fuzz module requires `any` for Zod introspection).
- **Vitest config** — Added `tests/fuzz/**/*.test.ts` to include patterns.
- **`setup` skill** — Documents `.github/ISSUE_TEMPLATE/` in scaffolding output.
- **Template `CLAUDE.md`** — Added `report-issue-framework` and `report-issue-local` to skills table.
- **`.gitignore`** — Added `announcements/` and `agent-feedback/` directories.

## Fixed

- **`jsonParser.test.ts`** — Replaced fragile `rejects.toThrow(new McpError(...))` assertion with try/catch checking error code and message substring. Fixes intermittent test failures from McpError equality semantics.
