third-party-trust

What this is for

Fetch/axios/Supabase/Stripe calls are TRUST BOUNDARIES going OUTWARD. Which outbound calls accept user-controlled URLs without re-validation? Which API key has no origin restriction? Which webhook receiver lacks signature verification? input-validation-audit checks input-validation coming IN. Missing: outbound trust contract - the mapping of what WE trust to be on the other end of each outbound connection.

PROTECTION RULE - never ~/.claude/

Read-only skill. Guard required if write mode added later.

## What You Must Do When Invoked

During analysis, assign a confidence level to each finding: proven (confirmed by evidence), likely (strong signal, needs review), or suspected (weak signal).

Step 1

If -help is passed, print the ## Usage block below and stop.

Step 2

Confirm -ProjectDir is provided and the path exists.

Step 3

Run: scripts/outbound-calls.ps1 -ProjectDir "<path>"

Step 4

LLM reads the JSON output. For each outbound call:

Step 5

Known-trusted vs unknown: stripe/amazon/googleapis/etc vs

Step 6

arbitrary endpoint. Unknown providers = higher risk.

Step 7

Template URL: variable-based URL (e.g. req.query.url) is

Step 8

attacker-controlled. SSRF-class risk.

Step 9

Auth hint in call window: Authorization header / api-key /

Step 10

bearer present? If yes, rotation-burden risk.

Step 11

Webhook handler with no signature verification (look for

Step 12

webhooks.constructEvent or HMAC verify calls - if absent, the

Step 13

endpoint will accept forged events).

Step 14

Retry attempt count: 3+ retries with no idempotency-key →

Step 15

duplicate side-effects on a 5xx.

Step 16

Write third-party-trust-report.md to the working directory.

Usage

/third-party-trust                          # interactive
/third-party-trust <dir>                    # scan project
/third-party-trust -help                    # show usage

Returns JSON with calls[]: {file, line, lib, url, isTemplateUrl, authHint, retrySignals, webhookHandler, lineContent} plus summary counts.