Detection reference · Credentials and secrets · Updated 2026-11-03
Slack tokens (xoxb-, xoxp-, xapp-) and incoming webhook URLs
A Slack bot token can read and post wherever the bot is installed, and anyone holding an incoming webhook URL can post to its channel. Both have fixed shapes, so Redaxa can name them.
At a glance
| Reported as | API key or token |
|---|---|
| Category | Credentials and secrets |
| Severity | critical: direct account or system compromise, as with keys, passwords and tokens |
| Replaced with | [SECRET] |
| Where it runs | The same engine runs in the Chrome extension (free checks, on your device), in the web check and the Windows app (on Redaxa's server; the text is not stored) and in public repository checks. |
| Engine rule | scanner.ts, line 205 |
What it looks like
xoxb-, xoxp-, xoxa-, xoxr-, xoxs- and xapp- followed by at least 10 letters, digits or hyphens; webhook URLs of the form https://hooks.slack.com/services/T…/B…/ plus a 24-character secret.
Example 1
You paste
SLACK_BOT_TOKEN=xoxb-RedaxaDocs-Sample-NotReal-Reda
Redaxa returns
SLACK_BOT_TOKEN=[SECRET]
| Reported as | API key or token |
|---|---|
| Severity | critical: direct account or system compromise, as with keys, passwords and tokens |
| Replaced with | [SECRET] |
| Probable service | Slack |
| Credential type | Bot token |
| Evidence | Slack-specific prefix; workspace and scopes are not verified. |
| Recommended action | Revoke or rotate if genuine |
Example 2
You paste
SLACK_APP_TOKEN=xapp-RedaxaDocs-Sample-NotReal-Reda
Redaxa returns
SLACK_APP_TOKEN=[SECRET]
| Reported as | API key or token |
|---|---|
| Severity | critical: direct account or system compromise, as with keys, passwords and tokens |
| Replaced with | [SECRET] |
| Probable service | Slack |
| Credential type | App-level token |
| Evidence | Slack-specific prefix; workspace and scopes are not verified. |
| Recommended action | Revoke or rotate if genuine |
Example 3
You paste
post to https://hooks.slack.com/services/T0REDAXA00/B0SAMPLE00/RedaxaDocsSampleNotRealR
Redaxa returns
post to [SECRET]
| Reported as | API key or token |
|---|---|
| Severity | critical: direct account or system compromise, as with keys, passwords and tokens |
| Replaced with | [SECRET] |
| Probable service | Slack |
| Credential type | Incoming webhook URL |
| Evidence | Anyone with this URL can post to its channel; workspace and channel are not verified. |
| Recommended action | Revoke or rotate if genuine |
All values on this page are synthetic or published specimens; none is a working credential or a real person's data.
In a repository check
The same example, committed to a public repository and run through the free repository check:
scripts/notify.py: API key or token, listed for review (severity critical). Credential pattern matched. Validity is not tested; review and rotate if genuine.- Same value in
tests/fixtures/notify.py: Test or example value, counted but not listed. Real-looking keys in test files are still reported.
Values are always shown masked in repository reports. No key is ever tested against its provider.
What it does not flag
https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX: not flagged. This is the placeholder Slack itself prints in its documentation; a secret made only of X is skipped.
If it already leaked
Revoke the token from the app's OAuth & Permissions page (or reinstall the app to issue new tokens). For a webhook, remove it from the app's Incoming Webhooks page and create a new one.
What Redaxa adds to every finding of this kind: If genuine, revoke or rotate it at the issuing service, update the application, then remove the exposed value from code and review Git history. Deleting it from Git does not revoke access.
Official guidance: docs.slack.dev, docs.slack.dev.
Step by step: pasted a key into ChatGPT, or committed one to GitHub.
Check before you paste
The free Chrome extension runs this check inside ChatGPT, Claude, Gemini and Perplexity before a message is sent, on your device and with no daily limit. On the web you get 5 free prompt checks a day with no account.
Add the Chrome extensionTry a free web checkWorried it is already in your code? Check a public GitHub repository free (3 checks a day).
Related
- GitHub tokens
- GitLab personal access tokens
- OpenAI API keys
- Anthropic API keys
- Stripe keys and webhook secrets
- Supabase keys
- Google API keys
- AWS access keys
- npm access tokens
- PyPI API tokens
- Hugging Face access tokens
- SendGrid API keys
- JSON Web Tokens (JWT)
- Bearer tokens
- Passwords in URLs
- Secrets in configuration values
- Passwords written in text
- Private keys (PEM)
- I pasted an API key into ChatGPT: what to do
- Stop API keys leaking into AI prompts
- Check a public GitHub repository for leaked API keys
- Free GitHub secret scanner
- Everything Redaxa detects
Sources
- Redaxa engine: scanner.ts line 205, credential-context.ts line 35 (Slack). Every output on this page was produced by that code when the page was built.
- Slack Docs: Tokens
- Slack Docs: Sending messages using incoming webhooks