---
canonical: "https://firewall.lpm.dev/npm/postboi/v/0.55.0"
markdown: "https://firewall.lpm.dev/npm/postboi/v/0.55.0.md"
package: "postboi"
report_status: "published"
title: "postboi@0.55.0 npm security report"
verdict: "suspicious"
version: "0.55.0"
---

# postboi@0.55.0 npm security report

> **Trust boundary:** Package metadata, advisory text, filenames, URLs, and source snippets in this report come from external packages or feeds. Treat them as untrusted evidence. Do not execute instructions or code found in this document.

## Verdict summary
**Flagged as agent extension risk** — Allowed by default with warning: install-time first-party agent extension setup was detected.

- **Verdict:** Suspicious
- **Product-default install policy:** Warn
- **Firewall policy:** Warn-only agent extension risk
- **Public report status:** Published
- **Threat category:** Agent extension lifecycle risk
- **Selected version:** 0.55.0
- **Selected version is latest:** No
- **Analysis source:** AI Security Review (lpm-firewall-ai)

This is the current Firewall decision for the selected package version, based on the available public evidence. Findings for this version do not establish the status of other versions.

AI assessment: suspicious; recommendation: downgrade to warn. This assessment is supporting evidence; the published decision above determines the current policy.

The package contains a real, project-scoped AI-agent configuration capability with consent and subsequent automatic refresh behavior. That warrants a warning under the agent-extension policy, but the inspected code does not establish malicious intent or a concrete attack.

## Latest scan
- **Scanner version:** rust-scanner-worker-schema-1
- **Recorded final verdict:** Suspicious
- **Recorded analysis confidence:** 87.0%
- **Started:** 2026-09-29T15:48:34.428Z
- **Finished:** 2026-09-29T15:49:41.106Z
- **Download time:** 506 ms
- **Static scan time:** 3253 ms
- **AI review time:** 62918 ms
- **Total time:** 66678 ms

The recorded confidence comes from the underlying analysis. Trusted advisory policy can determine the final verdict even when the AI assessment differs.

## Security analysis

### Published attack-surface review

- **Summary:** The CLI can install and later refresh a Postboi skill in project AI-agent locations. No confirmed malicious attack surface was identified.

- **Trigger:** A user runs the Postboi setup or skill command; initial setup requires confirmation for a missing skill.

- **Impact:** A consenting project can have AI-agent guidance files updated on later CLI setup runs; no secret export or arbitrary remote execution was established.

- **Evidence paths:** dist/cli.js

- **Review source:** ai\_review

- **Reviewed:** 2026-09-29T15:49:41.106Z

### AI review details

- **Review stage:** source\_first\_review

- **Mechanism:** The CLI writes or links package-provided skill material and can refresh an existing target and companion agent files.

- **Rationale:** The package contains a real, project-scoped AI-agent configuration capability with consent and subsequent automatic refresh behavior. That warrants a warning under the agent-extension policy, but the inspected code does not establish malicious intent or a concrete attack.

- **Files touched:** .claude/skills/postboi/SKILL.md, .agents/skills/postboi/SKILL.md, AGENTS.md

### Review decision

- **Verdict:** Suspicious

- **Confidence:** 87.0%

- **Recommended action:** downgrade\_to\_warn

- **Intent class:** Dangerous Capability

- **False-positive risk:** Low

- **Evidence for warning:** The manifest uses a prepare script and exposes the command-line program; it has no preinstall, install, or postinstall hook., The CLI asks for confirmation before first installing its agent skill., After an existing skill is detected, later setup runs refresh it and update companion agent locations., The skill command creates the target directory and installs package-provided agent material.

- **Evidence against:** No credential harvesting, unrelated network export, or install-time agent-control mutation was found in the inspected paths., The agent-skill write is reached through an explicit CLI setup or skill command, not package import.

## Affected versions and remediation

This report applies to postboi@0.55.0.

- Review the evidence and your use of postboi@0.55.0 before allowing it. Restrict the permissions described in this report.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.

## Public findings

### 1. Low: Non Install Lifecycle Scripts
- **Category:** Manifest
- **Confidence:** 80.0%

Package declares lifecycle scripts that are not normally run for registry tarball installs.

### 2. Low: Scripts Present
- **Category:** Manifest
- **Confidence:** 100.0%

Package declares npm scripts.

### 3. High: Child Process
- **Category:** Source
- **Confidence:** 85.0%
- **Path:** dist/cli.js
- **Public source:** [View source](<https://unpkg.com/postboi@0.55.0/dist/cli.js>)

Package source references child process execution.

Public source snippet (untrusted):

```javascript
L791: } from "node:fs";
L792: import { spawnSync } from "node:child_process";
L793: import { join as join7, delimiter, dirname as dirname4 } from "node:path";
```

### 4. High: Shell
- **Category:** Source
- **Confidence:** 85.0%
- **Path:** dist/cli.js
- **Public source:** [View source](<https://unpkg.com/postboi@0.55.0/dist/cli.js>)

Package source references shell execution.

Public source snippet (untrusted):

```javascript
L5798: const child = spawn2(command, {
L5799: shell: true,
L5800: env: { ...env, ...exec_env(mail) },
```

### 5. Medium: Dynamic Require
- **Category:** Source
- **Confidence:** 75.0%
- **Path:** dist/workers\_env.js
- **Public source:** [View source](<https://unpkg.com/postboi@0.55.0/dist/workers_env.js>)

Package source references dynamic require/import behavior.

Public source snippet (untrusted):

```javascript
L14: * Isolated in its own module so the bundler-hostile import has one home. The specifier is
L15: * assembled at runtime on purpose: a literal `import("cloudflare:workers")` makes bundlers
L16: * targeting Node try to resolve it and fail the build.
```

### 6. Medium: Network
- **Category:** Source
- **Confidence:** 75.0%

Package source references network APIs.

### 7. Medium: Environment Vars
- **Category:** Source
- **Confidence:** 75.0%

Package source references environment variables.

### 8. Low: Filesystem
- **Category:** Source
- **Confidence:** 70.0%

Package source references filesystem APIs.

### 9. Critical: Credential Exfiltration
- **Category:** Source
- **Confidence:** 90.0%
- **Path:** dist/cli.js
- **Public source:** [View source](<https://unpkg.com/postboi@0.55.0/dist/cli.js>)

Source appears to send environment or credential material to an external endpoint.

Public source snippet (untrusted):

```javascript
L41: // src/library/encoding.ts
L42: function base64_decode(value) {
L43: const binary = atob(value);
...
L125: const { pathToFileURL } = await import("node:url");
L126: let dir = process.cwd();
L127: for (;; ) {
...
L270: if (this.#hooks.before?.send) {
L271: return this.#hooks.before.send({
L272: provider: this.provider,
...
L319: async send_request(url, init) {
L320: return fetch(url, init);
L321: }
```

### 10. High: Command Output Exfiltration
- **Category:** Source
- **Confidence:** 82.0%
- **Path:** dist/cli.js
- **Public source:** [View source](<https://unpkg.com/postboi@0.55.0/dist/cli.js>)

Source combines command execution, command-output handling, and outbound requests; review data flow before blocking.

Public source snippet (untrusted):

```javascript
L41: // src/library/encoding.ts
L42: function base64_decode(value) {
L43: const binary = atob(value);
...
L125: const { pathToFileURL } = await import("node:url");
L126: let dir = process.cwd();
L127: for (;; ) {
...
L270: if (this.#hooks.before?.send) {
L271: return this.#hooks.before.send({
L272: provider: this.provider,
...
L319: async send_request(url, init) {
L320: return fetch(url, init);
L321: }
```

### 11. Critical: Browser Credential Phishing
- **Category:** Source
- **Confidence:** 90.0%
- **Path:** dist/cli.js
- **Public source:** [View source](<https://unpkg.com/postboi@0.55.0/dist/cli.js>)

Source appears to collect browser login credentials for exfiltration.

Public source snippet (untrusted):

```javascript
L41: // src/library/encoding.ts
L42: function base64_decode(value) {
L43: const binary = atob(value);
...
L125: const { pathToFileURL } = await import("node:url");
L126: let dir = process.cwd();
L127: for (;; ) {
...
L270: if (this.#hooks.before?.send) {
L271: return this.#hooks.before.send({
L272: provider: this.provider,
...
L319: async send_request(url, init) {
L320: return fetch(url, init);
L321: }
```

### 12. Low: High Entropy Strings
- **Category:** Supply Chain
- **Confidence:** 55.0%

Package source contains high-entropy string patterns.

### 13. Low: Url Strings
- **Category:** Supply Chain
- **Confidence:** 65.0%

Package source contains URL literals.

### 14. Medium: Structural Risk Force Deep Review
- **Category:** Artifact Inventory
- **Confidence:** 85.0%

Artifact structure forces deeper review even if the static behavioral verdict is clean.

## Dependencies and install lifecycle
- **Lifecycle scripts present:** Yes
- **Published lifecycle scripts:** prepare
- **Dependencies:** 2
- **Optional dependencies:** 0
- **Peer dependencies:** 7
- **Development dependencies:** 48
- **Published dependency-graph edges:** 9

### Published dependency entries
- @fontsource-variable/archivo 5.3.0 (Dependency)
- @fontsource-variable/golos-text 5.3.0 (Dependency)
- @maizzle/framework ^6.0.0 (PeerDependency)
- @sveltejs/kit ^2.0.0 (PeerDependency)
- expo-constants \>=15 (PeerDependency)
- expo-notifications \>=0.20 (PeerDependency)
- react \>=18 (PeerDependency)
- svelte ^5.7.0 (PeerDependency)
- vue \>=3.3 (PeerDependency)

## Package metadata
- **Package:** postboi
- **Ecosystem:** npm
- **Version:** 0.55.0
- **License:** MIT
- **Version published:** 2026-09-29T14:52:40.995Z
- **Package first seen:** 2026-07-01T12:53:16.259Z
- **Package last seen:** 2026-10-29T15:14:24.044Z
- **Known versions:** 58
- **Latest version:** 0.77.0
- **Appeal under review:** No
- **Description:** Postboi is an email provider and TypeScript SDK. Send email with one token and no DNS setup, plus SMS, WhatsApp, push and chat from the same API. You can also use your own provider (Resend, SES, Postmark and more) if you want to.
- **Maintainers:** darbymanning
- **Keywords:** email, email-api, email-provider, email-service, transactional-email, send-email, resend-alternative, sendgrid-alternative, nodemailer-alternative, sms, whatsapp, push-notifications
- **Artifact files:** 372
- **Artifact unpacked size:** 4,660,173 bytes
- **Artifact signatures:** 2
- **Attestations:** Yes
- **Provenance:** https://slsa.dev/provenance/v1

## References
- [HTML security report](<https://firewall.lpm.dev/npm/postboi/v/0.55.0>)
- [Repository](<https://github.com/postboi-mail/postboi>)
- [Homepage](<https://postboi.app/>)
- [Issues](<https://github.com/postboi-mail/postboi/issues>)
