centian AGENTS.md

Repository instructions for Centian, a Go command-line application that acts as a proxy between MCP clients and other MCP services. A proxy is an intermediary that forwards and can inspect or change requests and responses.

In plain words
What is it for?
Use them when modifying Centian’s command-line interface, proxy connections, request processing, logging, authentication, server, or command completion features.
Why use it?
They explain the project’s purpose, source layout, and development conventions so changes fit the existing codebase.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/t4cceptor/centian/agents-md
Clone the repo
git clone --depth 1 https://github.com/T4cceptor/centian

Made for: Codex, OpenCode.

Per session 951 This file is loaded in full into every session.
When invoked 951 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00951 $0.00951
Opus 5 $0.00476 $0.00476
Sonnet 5 $0.00190 $0.00190
Haiku 4.5 $0.00095 $0.00095

Measured 2d ago against content hash 1a985b0d2c11, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

centian AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Repository Guidelines (Source of Truth)

This file is authoritative for repo workflows, structure, and expectations. Other agent guidance should link here and avoid duplication.

Repository Identity & Purpose

Centian is the MCP proxy for this repository.

  • Repository owner: T4cceptor
  • Repository name: centian
  • Repository URL: https://github.com/T4cceptor/centian
  • Primary role: proxy MCP communication through a single CLI-managed endpoint
  • Core capabilities:
    • Proxy MCP communication to downstream systems
    • Log and monitor MCP requests and results
    • Process requests and responses to inspect, modify, or block them
    • Aggregate downstream systems behind one endpoint, using tool namespacing to keep them distinguishable

Project Structure & Module Organization

Centian is a Go CLI application. The executable entrypoint lives in cmd/main.go.

Basic repository structure:

  • cmd/: CLI entrypoint and top-level command wiring
  • internal/cli/: command handlers for config, logs, auth, processor, server, and completion flows
  • internal/proxy/: MCP proxy server, downstream connection handling, tool-call context, and request/response processing hooks
  • internal/logging/: log readers and shared logging helpers
  • internal/config/: config models, validation, accessors, and config-oriented CLI operations
  • internal/processor/: processor interfaces, scaffolding, and CLI processor execution support
  • internal/config/: config models, validation, persistence, config CLI operations, and import of existing MCP config files
  • internal/auth/: API key and authentication helpers
  • internal/common/: shared MCP models, auth context, utilities, and internal logging primitives
  • docs/: architecture and setup documentation
  • demo/: demo assets, configs, and supporting scripts
  • scripts/: repository scripts
  • tests/test_configs/: config fixtures and sample MCP client/server configs
  • tests/integrationtests/: end-to-end and processor integration coverage
  • build/: compiled binaries and generated artifacts

Read the full file on GitHub · 55 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 55 lines · 951 tokens per session scan A 1a985b0d2c11

Subscribe to this mod's changes

centian AGENTS.md is an instructions file published in the GitHub repository T4cceptor/centian (15 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 951 tokens to every session, about $0.0048 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.