CodeSampleX

Stop solving the same code twice.

Languages: English · 한국어 · 日本語 · 简体中文 · Español · Français · Deutsch · Português (BR) · Русский

CodeSampleX is a local-first distributed reasoning cache for coding LLMs. Instead of every agent on Earth re-deriving how a public library works — and re-hitting the same version incompatibilities — CodeSampleX collects anonymous compatibility Evidence from real development environments and serves verified minimal Samples with the exact delta between a known-good answer and your project.

• Website & Compatibility Explorer: https://codesamplex.dev

• One question your LLM stops re-answering: does axios.post actually work on axios 1.12 + Node 22 + pnpm + Windows 11 — and if not, at which stage does it break?

• Works with Claude Code, Codex, Gemini CLI, OpenCode — and any MCP client (Cursor, Windsurf, Cline, Zed, VS Code).

Install

Windows (PowerShell):

irm https://codesamplex.dev/install.ps1 | iex

macOS / Linux:

curl -fsSL https://codesamplex.dev/install.sh | sh

One binary, one question. csx init shows the community contract and asks a single choice — JOIN COMMUNITY or LOCAL ONLY. Everything else (daemon, MCP registration for Claude Code / Codex / Gemini CLI / OpenCode, agent rules) is automatic.

For scripted or CI setups: csx init --community --yes --no-agents does config + identity only and writes nothing outside CSX_HOME; agent config paths otherwise honor CSX_AGENT_HOME when you need them somewhere other than your OS user home.

Related MCP server: GitHits

The contract

You get                              You contribute
✓ Public compatibility knowledge     ✓ Public package/version usage
✓ Verified code answers              ✓ Public API/symbol usage when detectable
✓ Local agent integration            ✓ Build/typecheck/test result
✓ Public sample cache                ✓ Sanitized failure fingerprints

Never shared automatically
✕ Source code        ✕ Repository/project name   ✕ File names or paths
✕ Source snippets    ✕ Secrets or env variables  ✕ Private packages
✕ Raw compiler/runtime logs

This is not hidden telemetry — it is the protocol. Community peers are consumers and producers. Local-only mode never sends anything. The privacy preview in csx ui shows the exact payloads before they leave your machine.

How it works

you build/test through csx (or your agent does)
→ local analysis: public packages, lockfile-resolved versions, symbols, environment
→ raw errors sanitized locally into fingerprints (paths/names/secrets stripped)
→ anonymous evidence batches → Compatibility Graph on codesamplex.dev
→ your LLM asks CSX first: nearest verified Sample + environment delta
→ it reasons about the DELTA, not the whole problem

Four layers, kept honestly separate:

A project compiling is never presented as a symbol working. Unknown causes stay UNKNOWN. A wrong HIT is worse than a MISS — NO_SAFE_MATCH is a feature.

Agent integration (MCP)

Configured automatically by csx init: Claude Code · Codex · Gemini CLI · OpenCode.

Any other MCP client — Cursor, Windsurf, Cline, Zed, VS Code — works too; csx is a standard stdio MCP server:

{"mcpServers": {"csx": {"command": "csx", "args": ["mcp"]}}}

Model-agnostic: the same compatibility evidence serves Claude, GPT and Codex, Gemini, Llama — any model that can call an MCP tool.

Clients that install MCPB bundles can use codesamplex-mcp.mcpb from the latest release instead. It carries one binary per platform (darwin-arm64, linux-amd64, windows-amd64); on any other architecture use the install script above.

Tools: search_known_solution, get_sample, explain_compatibility, run_observed_command, report_sample_adoption, propose_public_sample, list_local_hits, get_local_stats. Publishing a sample is deliberately not an MCP capability — it requires your explicit CLI approval after a full preview.

csx run -- pnpm build      # observed build → evidence
csx search "axios multipart upload"
csx sample propose --goal "upload a file with axios"
csx ui                     # dashboard + privacy preview

Ecosystems (Public v1)

Node/TypeScript (npm, pnpm, yarn — reference), Python (pip, uv), Go, Rust/Cargo. Honest capability matrix: docs/adapters.md — no adapter claims runtime symbol instrumentation in v1, and symbol resolution confidence is always labeled (EXACT/PROBABLE/UNKNOWN).

Architecture

Single Go binary (csx: daemon + CLI + MCP + peer node + verifier) and a small server (csx-server: PostgreSQL + server-rendered explorer behind Caddy). Samples are content-addressed (sha256) and distributed local-cache-first → peers → main seeder. Downloaded samples never run on your host directly — resolve with --ignore-scripts, compile and contract run network-off in a sandbox, receipts are ed25519-signed. See goal.md (product spec), docs/execution-context.md, docs/operations.md.

Building from source

go build ./cmd/csx && go build ./cmd/csx-server
go test ./...

License

Code: Apache-2.0. Published samples default to MIT-0.