HashSeal

Signed, Sealed, Delivered - I'm Yours.

Website: hashseal.ai — public docs and marketing from this repo’s docs/ tree (GitHub Pages). See docs/index.md.

HashSeal is integrity tooling for two related problems:

1. Agent instruction file integrity seal — seal and verify instruction files so agents and models only run on what you approved.
2. Build tools — seal and verify source trees and release bundles so CI and multi-agent builds cannot silently rewrite what you ship.

What was sealed is what you still have — and verify tools always name every file that changed.

License	Apache-2.0
Contact	info@hashseal.ai · Security: security@hashseal.ai
Org (footer only)	MonkeyKing.dev

---

1. Agent instruction file integrity seal

What it is

An integrity seal for agent instruction files (Markdown and configured instruct formats — e.g. AGENTS.md, skill packs, system prompts you keep in-repo): a content digest in front matter, optional GPG signature using the same key as git commit -S.

Before you pass instructions to a model or agent host, you check that seal. If someone (or another agent) rewrote the file, check fails and lists every non-OK path with status and digests — never a silent exit-only fail.

This is integrity (the file still matches what was sealed), not a claim about model behavior or legal authorship.

Why use it

Risk	Without seals	With HashSeal
Prompt / policy drift	Silent edits to instruction files	MISMATCH with expected vs actual digests
Multi-agent tampering	One agent changes rules for the next	Verify before handoff
“Which AGENTS.md did we ship?”	Guesswork	Sealed digest + optional signature
Browser / IDE paste	Trust whatever is on screen	Client-side or CLI check before run

How it works

1. Content is canonicalized (see instruct seal format).
2. A BLAKE3 digest is written into YAML front matter as hashseal: "blake3:<hex>".
3. Seal fields themselves are excluded from the hash (no chicken-and-egg).
4. Optional hashseal_sig holds a detached-style GPG armor over the digest.
5. check recomputes and reports ok / MISMATCH / MISSING_SEAL / …

Same algorithm is implemented in:

• Full CLI: hashseal seal --instruct / hashseal check
• Tiny binary: hashseal-check (blake3-only deps)
• WASM: hashseal-wasm
• Zero-dep SDKs: verify/js, verify/python, verify/java, verify/go, verify/ruby, verify/dotnet
• Browser extension (pure JS paste check)

Official vectors: verify/vectors/instruct-v1.json.

How to use it in your projects

Commands below assume your shell’s current directory is the project root (or this monorepo root when developing HashSeal). Paths are repo-relative — no host-specific prefixes.

Install / build the CLI (package and binary are both named hashseal):

# Linux / macOS / Git Bash
cargo build -p hashseal --release
# → target/release/hashseal

# optional install into Cargo’s bin dir (already on PATH for many setups):
cargo install --path rust/hashseal --locked

# Windows (PowerShell)
cargo build -p hashseal --release
# → target\release\hashseal.exe

cargo install --path rust/hashseal --locked

Seal instruction files in a project:

hashseal seal --instruct --root .
# optional GPG (uses git’s gpg.program + signing key):
hashseal seal --instruct --sign --root .

Verify before agents or CI consume them:

hashseal check --root .
hashseal check --require-signature   # if you seal with --sign
# tiny binary (optional):
hashseal-check --root .

In-process check (no CLI) — JS SDK example from monorepo root (Linux, macOS, or Windows):

node -e "const fs=require('fs');const {checkDocumentText}=require('./verify/js');const r=checkDocumentText(fs.readFileSync('AGENTS.md','utf8'));console.log(r);process.exit(r.ok?0:1)"

Editor / browser:

Surface	Path	Role
VS Code	extensions/vscode	Commands spawn CLI / check
Browser	extensions/browser	Paste Markdown → pure JS check
Zed / Antigravity	extensions/zed, extensions/antigravity	Host stubs
Agent skills	skills/	Skill packs for common agents

Docs (instruction integrity):

• What & why
• Seal format
• Signing
• CLI reference
• Install
• IDE & browser
• Verify SDKs & vectors

5-minute smoke (instruct)

From the monorepo root (works the same on Linux, macOS, and Windows once Rust/cargo are installed):

cargo build -p hashseal --release
cargo run -p hashseal -- seal --instruct --root fixtures/mvp-demo
cargo run -p hashseal -- check --root fixtures/mvp-demo

---

2. Build tools

What they are

The same core and CLI also protect trees and release artifacts during development and CI:

• Tree seal — ledger of path digests for a configured include/exclude set
• Release bundle — hashseal-bundle/ (ledger + report + MANIFEST, optional extra artifacts)
• Plugins — thin wrappers (npm, Maven, Gradle, Cargo aliases) that shell to hashseal on PATH
• Verify — re-walk and compare; list every drifted path

Purpose: stop silent rewrites across multi-step / multi-agent build pipelines so what you built is what you ship.

How they work

1. Config (JSON): .hashseal.json overlay — tree includes/excludes, document flags, signing, reports. Example: config/examples/hashseal.mvp.json.
2. hashseal seal --tree writes a ledger; --release stages a bundle under hashseal-bundle/.
3. hashseal verify checks the tree (and optional bundle) against the ledger.
4. Build plugins invoke the CLI; they do not reimplement digests.

Tree vectors: verify/vectors/tree-v1.json.

How to use them

# Tree + release bundle (any OS once hashseal is on PATH)
hashseal seal --tree --release --root .
hashseal verify --root .

# Instruct + tree together
hashseal seal --instruct --tree --release --root .

Put CLI on PATH (plugins require hashseal resolvable from the shell). From the monorepo root after a release build:

# Linux / macOS / Git Bash
export PATH="$(pwd)/target/release:$PATH"
# or point plugins at a specific binary:
export HASHSEAL_BIN="$(pwd)/target/release/hashseal"

# Windows (PowerShell)
$env:PATH = "$(Join-Path (Get-Location) 'target\release');$env:PATH"
# or point plugins at a specific binary:
$env:HASHSEAL_BIN = (Join-Path (Get-Location) 'target\release\hashseal.exe')

If the binary already lives on PATH (for example after cargo install --path rust/hashseal --locked), you can skip the PATH / HASHSEAL_BIN step.

Stack map (docs per surface)

Surface	Path	Docs
Full CLI	rust/hashseal	CLI · Install
Core library	rust/hashseal-core	crate README
Tiny check binary	rust/hashseal-check	optional instruct-only verify (blake3 path)
npm plugin	plugins/npm	plugins hub · npm README
Maven plugin	plugins/maven	Maven README
Java verify SDK	verify/java	ai.hashseal:hashseal-verify · Java README · reactor
Gradle	plugins/gradle	Gradle README
Cargo aliases	plugins/cargo	Cargo README
Packaging / releases	scripts + CI	packaging · install

Build docs hub: docs/build/index.md

5-minute smoke (build)

cargo run -p hashseal -- seal --tree --release --root fixtures/mvp-demo
cargo run -p hashseal -- verify --root fixtures/mvp-demo

---

Develop (monorepo)

All paths are relative to the monorepo root. Use forward slashes in these examples; on Windows, cargo, node, and python accept them the same way.

# Linux / macOS / Windows (PowerShell or cmd with cargo on PATH)
cargo test --workspace
cargo build -p hashseal --release
cargo build -p hashseal-check --release
cargo tree -p hashseal-check --edges normal   # expect core → blake3 only
cargo fmt
cargo clippy --workspace -- -D warnings

Git hooks (optional, recommended)

CI runs cargo fmt --all -- --check. Install the repo pre-commit hook so that fails locally before push when staged .rs files are present:

# Linux / macOS / Git Bash
./scripts/install-git-hooks.sh

# Windows (PowerShell)
pwsh scripts/install-git-hooks.ps1

That sets core.hooksPath=scripts/git-hooks for this clone only. Fix failures with cargo fmt --all, then re-stage and commit.

# Multi-lang instruct vectors + tree where implemented
node verify/js/test/vectors.test.js
node verify/js/test/tree-vectors.test.js
python verify/python/test/test_vectors.py
mvn -f verify/java/pom.xml test
# Go / Ruby / .NET — see verify/*/README.md

Workspace layout

Path	Role
rust/hashseal-core	Seal / check algorithms
rust/hashseal	Full hashseal CLI (package name = binary name)
rust/hashseal-check	Tiny instruct verify binary (blake3-only)
rust/hashseal-wasm	WASM verify for IDEs / browser
verify/	Zero-dep language verify SDKs + vectors
java/	Maven parent/reactor for hashseal-verify + Maven plugin (Central)
fixtures/mvp-demo/	Human smoke project
config/examples/	Sample .hashseal.json overlays
plugins/	Maven, npm, Gradle, Cargo, …
extensions/	VS Code, browser, Zed, …
skills/	Agent skill packs
docs/	GitHub Pages site + product docs

---

License

Apache-2.0 — see LICENSE.

Copyright (c) 2026 MonkeyKing.dev