carbonado AGENTS.md

A development guide for Carbonado, an archival format designed for durable, verifiable data storage, including Bitcoin-related data. It documents the current cryptographic design, streaming behavior, concurrency work, and important rules.

In plain words
What is it for?
Use it when working on encryption, authentication, streaming, verification, error correction, sharding, or archive implementation details.
Why use it?
It records security-sensitive invariants and separates related concepts that could be confused when changing the format.

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/bitmask-stack/carbonado/agents-md
Clone the repo
git clone --depth 1 https://github.com/bitmask-stack/carbonado

Made for: Codex, OpenCode.

Per session 19,385 This file is loaded in full into every session.
When invoked 19,385 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 $0.19385 $0.19385
Opus 5 $0.09692 $0.09692
Sonnet 5 $0.03877 $0.03877
Haiku 4.5 $0.01938 $0.01938

Measured 2d ago against content hash eccb79c6cd2e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

carbonado 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 · 982 lines

How it starts

The opening of the file, as written. The whole thing — 982 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md — Carbonado Development Guidelines

Project: Carbonado (bitmask-stack/carbonado)
Mission: Apocalypse-resistant archival format for consensus-critical data, with a focus on Bitcoin quantum resistance.
Current Status (as of 2026-07): Symmetric v2 stack (CARBONADO20\n, AES-256-CTR + HMAC-SHA512 EtM) stable. P1: SLICE_LEN=4096, keyed 4 KiB Bao groups, seekable slice verify. P2: streaming-first encode/decode. P3: segment sharding. P4: Adamantine 1.0 directory archives (see §7.1). FEC: reed-solomon-erasure RS 4/8. Outboard + scrub complete.

Unified streaming stack (three independent axes — do not conflate):

Axis Status
Streaming / memory Phase 1 fused sync path shipped (SeekableSpool, streaming EtM, stripe FEC). M1: non-FEC verification (c6) uses SeekWriteAt (O(chunk) RAM); FEC verification retains O(FEC body) shard buffers under segment-wide RS geometry (finish_into avoids a second full logical Vec). Residuals: FEC O(segment body), O(sidecar) outboard verify, async encoded-body spool. See doc/STREAMING_PARALLELISM.md. Not the same as Bao slice/stream verification.
Concurrency Phase 2 optional async / stream_decode_async (disk spool bridge; WASM NotImplemented).
Parallelism Phase 3 parallel feature (default on): std::thread::scope RS parity; WASM serial at runtime. No rayon; Tokio is not the CPU-parallel story.

PQC: bitcoinpqc 0.4, SLH-DSA-SHA2-128s sidecars only (SLH_DSA_SHA2_128S). Dev SHAKE-128s sidecars are incompatible — re-sign.


1. Core Principles

  • Clean cryptographic break. This version of Carbonado does not contain any code to read or write v1 ECIES-encrypted files. Old encrypted archives require external migration (use an older version of the tool to extract plaintext, then re-encode with the new symmetric primitives).
  • "Backward compatibility / migration path" (from the original spec) refers only to preserving the non-crypto properties of the format:
    • Pipeline ordering (compress(zstd-20) → encrypt → FEC → bao and reverse)
    • Flat-file portability
    • WASM/browser support
    • Bao-based streaming verification and replication proofs
    • Forward error correction (4/8 RS model — see v1-vs-v2 rationale)
    • Content addressability via the outer bao hash
  • First-principles security. All cryptographic decisions must be justifiable from security definitions (IND-CPA for CTR, INT-CTXT for EtM, PRF properties of HMAC-SHA512, domain separation, key independence).
  • HMAC-SHA512 is mandatory for both authentication (full 64-byte tags) and all subkey derivation. No simple splits, no SHA-256-only KDFs for key material.

Read the full file on GitHub · 982 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 · 982 lines · 19,385 tokens per session scan A eccb79c6cd2e

Subscribe to this mod's changes

carbonado AGENTS.md is an instructions file published in the GitHub repository bitmask-stack/carbonado (119 stars, last pushed 4d ago), licensed MIT. It adds 19,385 tokens to every session, about $0.0969 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.

Related

Other instructions, from other repositories

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,182 tokens

buildNext

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 6,785 tokens

next.js AGENTS.md

Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,296 tokens

vscode oss-third-party-notices.instructions.md

Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).

microsoft/vscode · 5,001 tokens

spec-kit AGENTS.md

Instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.

github/spec-kit · 7,040 tokens

langchain AGENTS.md

Instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.

langchain-ai/langchain · 4,345 tokens