MCP servers that ship as code — a repository or a package you install and run locally (usually over stdio). They have no hosted endpoint, so we cannot probe or grade them: instead each one shows its repository, install command, license, stars and when it was last updated.
Collected from GitHub repositories and npm, PyPI, Cargo, Go, Maven, NuGet and RubyGems packages tagged as MCP servers, the official MCP Registry, Docker's MCP catalog, ModelScope, Baidu MCP World, Cline and other public directories; one entry per repository. A server that also offers a hosted endpoint is listed under Remote instead. These entries are not counted in our reachability, verification or readiness statistics.
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Deterministic spec lint for manifest-driven golden paths — validates invariants, detects drift, speaks MCP. Never calls an LLM; LLMs call it.
MIT ★ 4 -
json-mender-mcpactive
Deterministic JSON repair, regex testing, and real JSON-Schema validation for AI agents. Local, offline, no telemetry.
npm MIT -
PText: paste text, get a useful result. Open-source deterministic text tools (remove duplicate lines, CSV to JSON, extract emails, JSON formatter and validator, clean text) as a zero-dependency library, CLI and MCP server for AI assistants.
npm MIT -
Local MCP server for deterministic skill selection. Discovers, validates and plans. Zero dependencies, nothing executed.
Apache-2.0 ★ 1 -
@eternal-roman/ledger-mcpgithub.com/eternal-roman/ledgerupdated this year
MCP server for the Ledger kernel. Agents call money_compute, entry_validate, ledger_post — they do not do money math in tokens. Fail-closed, audit-hashed, deterministic.
npm MIT -
t1-t2-protocolgithub.com/Fauxetine/t1-t2-protocolupdated this year
MCP server for heterogeneous AI validation — T1 structured reasoning, T2 cross-model evaluation, and deterministic checksum. Python stdlib-only.
Apache-2.0 -
MCP server that lets AI agents validate 3D mesh manipulations with deterministic geometric checks and multi-view visual renders.
MIT -
ContextHubgithub.com/BryceEWatson/ContextHubupdated this year
Deterministic MCP server for coordinating AI agents across software development lifecycles. SQLite graph traversal, Zod validation gates, RFC 6902 patching, and 100+ tests with <200ms p95 latency.
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healthit-copilotgithub.com/sinteco/healthit-copilotupdated this year
HL7 v2 to FHIR R4 converter & validator — Claude Code plugin with deterministic MCP tools for healthcare interoperability engineers
MIT ★ 2 -
MCP server on the zipnative ZIP engine — 13 tools for AI agents: inspect, list and verify without extracting, extract with zip-slip / zip-bomb / symlink guards, create deterministic reproducible archives, modify without recompression. MCP 2026-07-28 + legacy, stdio & HTTP, sandboxed, no network path, ISO/IEC 21320-1 validated in CI. Node ≥22.
MIT -
Chat-to-SQL with read-only guardrails: the model proposes SQL, deterministic code validates it (SELECT-only, allow-listed tables, limits, timeouts, read-only role) and logs every query. Includes an MCP server for Claude.
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dev-harness-cligithub.com/bakr-bagaber/dev-harnessupdated this year
Agent-agnostic development harness for AI coding agents — gated phase pipeline with a next-step trajectory engine, built-in MCP server, craft skills library, and deterministic gate validation. Works inside Claude Code, Codex, Cursor, VS Code, and any MCP-
npm MIT -
Safe, reviewable Python repository changes with explicit approvals and deterministic validation.
MIT ★ 1 -
Deterministic JSON repair and JSON Schema validation for AI agents and software. No LLM required.
NOASSERTION -
Permission-aware MCP server and agent harness with role-scoped tools, whole-plan validation, deterministic safety evals, and a React playground.
MIT -
RAG Q&A + autonomous triage agent for customer feedback. Built on Gemini free tier with ChromaDB, structured JSON validation, and deterministic routing.
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MCP server that gives an AI assistant deterministic document tooling: PDF/text reading, chunking, JSON Schema validation, structured output — path-confined, fully tested
MIT -
@particlr/mcpactive
MCP server giving agents a deterministic feedback loop for authoring particlr .prt particle effects: validate, simulate, render to PNG, patch — headless, in Node.
npm MIT -
Local-first TouchDesigner AI copilot with 114 MCP tools, truthful concept routing, deterministic visual techniques, transactional execution, live validation, and rollback.
npm MIT -
InkPawgithub.com/syouro/InkPawupdated this year
An MCP server and deterministic DOCX toolkit for AI agents—create, edit, validate, and render reliable Word documents with a local agent playground.
MIT ★ 3 -
MCP server and agentic control layer for KiCad 10, combining LLM-based planning where useful with deterministic execution, state tracking, evidence, rollback, and KiCad validation.
AGPL-3.0 ★ 15 -
Deterministic multi-tradition astrology engine — Western tropical, Vedic/Jyotisha sidereal, Chinese BaZi. Zero-dependency pure-Python ephemeris, 19 modes, arcsecond-accurate (validated vs NASA JPL). CLI + API + MCP.
MIT ★ 2 -
Local-first AI modding workbench for RimWorld 1.6: Def indexing (game + installed mods), typed-plan generation, static validation, deterministic builds, Player.log storm diagnosis — MCP for Hermes / Claude Code / Codex.
MIT ★ 1 -
DODI: a deterministic Terms of Service deception scorer with an MCP server. A 2015-2024 study of 10 platforms with ToS;DR and LLM-judge validation, plus v2, which weighs each contract against what the store promised.
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sqlikeno update data
Deterministic SQL static analysis and query-equivalence checking for Postgres, MySQL, SQLite, and SQL Server. analyze returns validity, anti-patterns, auto-rewrites, and schema/index advice for a query; diff checks whether two queries are equivalent (result-preserving) - a verdict LLMs cannot reliably self-grade. Queries are tokenized locally before leaving your machine.
smithery -
Validated analytics agent for CSV/Excel. LLMs plan - as a JSON plan or a bounded tool-calling loop - while deterministic pandas/scipy/DuckDB computes and re-verifies every number. No arbitrary code execution: the model only selects audited operations.
MIT ★ 4 -
Deterministic power-intent intelligence for IEEE 1801 (UPF): validate, model, analyze and diff UPF before power-aware implementation. 77 rules, cross-file scope modeling, a CI quality gate, local API + web UI, and an MCP server. No EDA tool or LLM required.
MIT -
Hosted anonymous MCP/HTTP: PyPI wheel evidence; mathematical IPv4/IPv6 CIDR-set differences, counts and witnesses. Exact diagnostic planning for small deterministic models; offline decision-ledger, handoff, snapshot and opt-in command-evidence tools. Public non-secret inputs; not compatibility, reachability, routing or security validation.
MIT -
Deterministic physics plausibility tools as a Model Context Protocol (MCP) server. Claude Desktop / Cursor ready. Offline subset, zero network.
MIT -
Governance standard and reference toolset for LLM-maintained knowledge corpora
NOASSERTION ★ 664 -
andongithub.com/gulmezeren2-byte/andonupdated this year
Deterministic verification for AI-generated analysis. Reconciliation, consistency and Excel-integrity checks that stop the line when the numbers don't add up.
MIT ★ 1 -
Pre-execution governance for AI agents. Intercepts MCP tool calls before execution with deterministic blocking, human-in-the-loop holds, and behavioral drift detection.
npm MIT -
yaktool-mcpactive
73 precision tools for product data and business documents, as a local MCP server. GTIN/EAN/UPC, Google Shopping feeds, Shopify CSV, safe CSV⇄XLSX conversion, Digital Link QR, GS1, ISBN, VIN, IMEI, IBAN, Peppol, XRechnung and more. Deterministic, rule-doc
npm MIT