"Understanding and Using JSON" matching MCP servers:

Enables validating JSON/JSONC, getting/setting values with jq-like paths, pretty-printing or minifying, validating against Ajv JSON Schema, and diffing local files or inline strings without network calls.

MCP server for validating JSON against JSON Schema and repairing malformed/invalid JSON.

MCP server exposing a "run" tool that benchmarks agent-memory backends and returns a reproducible JSON report.

VAST validation MCP server that checks ad tags against IAB VAST specifications, returning structured JSON with rule IDs, XPath locations, and spec references.

MCP server that validates dashboardbase setup files and widget endpoint responses against the dashboardbase JSON contract, reporting errors and warnings before deployment.

Enables AI coding agents to perform real-browser accessibility scanning of localhost pages using Playwright and axe-core, returning WCAG 2.1 violations with structured fix plans.

MCP server that exposes the JsonFabrica API as tools, so an AI agent can generate realistic synthetic JSON test data while it codes — single documents or full relational batches from reusable templates, reproducible with a seed. Runs locally over stdio; no network service.

Enables AI clients to run comprehensive website scans for security, accessibility, performance, and SEO using the AcuityScan API.

Enables AI coding agents to diagnose and repair Python Selenium UI automation using real evidence from live DOM and test runs, with enforced safety boundaries and verifiable fixes.

An MCP server that gives AI agents geometric spatial awareness of web page layouts using Playwright, enabling detection of visual occlusion, layout shifts, and spatial relationships.

Generates realistic, referentially-coherent test data (SQL INSERTs, JSON, or CSV) from your database schema, resolving foreign keys and respecting constraints. Paste CREATE TABLE DDL or a JSON schema and get ready-to-run seed data with valid relationships.

Compacts noisy test, build, and cloud-log output before an AI agent reads it — dedupes repeats, collapses stack frames, folds Playwright retries, and renders CloudWatch/GCP JSON logs down to the signal. Typically 80–95% fewer tokens on failures. Tool: compact_output. Run: npx -y logslim logslim-mcp

An automated testing MCP server that converts test cases into a fixed JSON format, runs them case-by-case, and provides a visual report with review support for cases that cannot be automatically judged.

Fact-checks and fixes AI outputs by catching hallucinations, repairing broken JSON, and correcting errors before they reach users, with tools for verification, validation, and correction.

Generates synthetic time-series test data with configurable trend, seasonality, noise, anomalies, and multiple correlated streams, outputting JSON, CSV, or SQL.

Enables generating JSON Schema from sample data, generating TypeScript types, validating data against schemas, creating mock data from schemas, and comparing schemas for differences.

Local MCP tool for understanding JSON Schema files while planning tests, summarizing types, required fields, constraints, and generating placeholder paths without copying data.

Enables agents to check whether an execution trace contains the evidence needed for post-hoc causal reconstruction, retrieve individual requirement details, and list evidence requirements per failure class over MCP stdio. It works on files, directories, or inline JSON locally and never transmits or persists data.

An MCP server that enables AI assistants to control GDB debugging sessions, including breakpoint management, thread analysis, and variable inspection, using the GDB/MI protocol.

Deterministic motion compiler + validator for AI-generated web apps: validated MotionSpec JSON compiles to reduced-motion-safe GSAP/CSS. Reports WCAG 2.2.2 pause-path candidates; missing reduced-motion guards flagged as 2.3.3/AAA best practice. Keyless read-only MCP tools: motion_catalog + motion_validate; compile/audit/stats need a key (full toolset free locally: npx motionspec). MIT core on npm.