> ## Documentation Index > Fetch the complete documentation index at: https://www.truefoundry.com/llms.txt > Use this file to discover all available pages before exploring further. # Secrets Detection Guardrail > Detect and redact sensitive credentials and secrets in LLM inputs/outputs and MCP tool invocations using TrueFoundry's built-in Secrets Detection guardrail. This guide explains how to use TrueFoundry's built-in **Secrets Detection** guardrail to protect sensitive credentials from being exposed in LLM interactions and MCP tool invocations. Secrets Detection can be applied to **all four guardrail hooks**: LLM Input, LLM Output, MCP Pre Tool, and MCP Post Tool—providing comprehensive protection across your entire AI workflow. ## What is Secrets Detection? Secrets Detection is a built-in TrueFoundry guardrail that identifies and handles sensitive credentials and secrets in text content. It runs directly within the AI Gateway without requiring external API calls, providing fast and cost-effective secret detection. ### Key Features 1. **Comprehensive Secret Recognition**: Detects a wide range of sensitive credentials including: * AWS access keys and secret keys * API keys (OpenAI, Anthropic, Google, etc.) * JWT tokens and bearer tokens * Private keys (RSA, SSH, PGP) * Database connection strings * OAuth tokens and refresh tokens * Generic high-entropy strings that may be secrets 2. **Flexible Operation Modes**: * **Validate**: Detect secrets and block requests/responses that contain them * **Mutate**: Detect secrets and redact them with configurable replacement text, allowing the request to continue 3. **Zero External Dependencies**: Runs entirely within the AI Gateway with no external API calls, ensuring low latency and no additional costs. ## Adding Secrets Detection Guardrail To add Secrets Detection to your TrueFoundry setup, follow these steps: Go to the AI Gateway dashboard and navigate to the **Guardrails** section. Create a new guardrails group or select an existing one where you want to add the Secrets Detection guardrail. Click on **Add Guardrail** and select **Secrets Detection** from the TrueFoundry Guardrails section. TrueFoundry guardrail selection interface showing Secrets Detection option Fill in the configuration form: * **Name**: Enter a unique name for this guardrail configuration (e.g., `secrets-detection`) * **Description**: Optional description for this guardrail (default: "Detects likely credentials/secrets (AWS keys, API keys, JWT tokens, private keys)") * **Operation**: Choose the operation mode: * `validate`: Detect and block requests containing secrets * `mutate`: Detect and redact secrets, allowing the request to continue * **Redaction Text** (for mutate mode): Text to replace detected secrets (default: `***REDACTED***`) Click **Save** to add the guardrail to your group. ## Configuration Options | Parameter | Description | Default | | ---------------------- | -------------------------------------------------------- | ---------------- | | **Name** | Unique identifier | Required | | **Operation** | `validate` (block) or `mutate` (redact) | `validate` | | **Priority** | Execution order for mutate guardrails (lower runs first) | `1` | | **Enforcing Strategy** | `enforce`, `enforce_but_ignore_on_error`, or `audit` | `enforce` | | **Redaction Text** | Replacement text (mutate mode only) | `***REDACTED***` | See [Guardrails Overview](/docs/ai-gateway/guardrails-overview#operation-modes) for details on Operation Modes and Enforcing Strategy. ## How It Works ### Validate Mode When configured in **validate** mode, the guardrail scans the content for secrets and blocks the request if any are detected. **Example**: ``` Input: "Use this API key: sk-abc123xyz456 to authenticate" Result: Request blocked with error message indicating secret detected ``` ### Mutate Mode When configured in **mutate** mode, the guardrail scans the content for secrets and replaces them with the configured redaction text. **Example**: ``` Input: "Use this API key: sk-abc123xyz456 to authenticate" Output: "Use this API key: ***REDACTED*** to authenticate" ``` ## Detected Secret Types The Secrets Detection guardrail identifies a comprehensive set of secret patterns across multiple categories. Below is the complete list of detected secret types. ### Cloud Provider Credentials | Secret Type | Pattern Description | Example Format | | --------------------------------------- | ------------------------------------------- | ------------------------------------------------------------- | | **AWS Access Key ID** | AWS access key identifiers | `AKIA` followed by 16 alphanumeric characters | | **AWS Secret Access Key** | AWS secret keys with contextual keywords | 40-character base64 string near `secret` or `access` keywords | | **Google API Key** | Google Cloud API keys | `AIza` followed by 35 characters | | **Google OAuth Token** | Google OAuth access tokens | `ya29.` followed by 20+ characters | | **Azure SAS Token** | Azure Shared Access Signature tokens | URL parameters with `sv=` and `sig=` | | **Azure Storage Account Key** | Azure storage account keys | `AccountKey=` followed by 88-character base64 string | | **Azure Storage Connection String** | Full Azure storage connection strings | `DefaultEndpointsProtocol=...AccountKey=...` | | **Digital Ocean Personal Access Token** | DO API tokens | `dop_v1_` followed by 64 hex characters | | **Databricks Personal Access Token** | Databricks API tokens | `dapi` followed by 32 alphanumeric characters | | **Cloudant Authenticated URL** | IBM Cloudant database URLs with credentials | Cloudant URLs containing embedded credentials | | **Firebase Cloud Messaging Server Key** | FCM server keys | `AAAA` prefix with 140+ character token | | **SoftLayer API Token** | IBM SoftLayer API tokens | 64-character tokens in SoftLayer API URLs | ### AI/ML Provider API Keys | Secret Type | Pattern Description | Example Format | | ------------------------- | ------------------------------- | ----------------------------------------------------------------- | | **OpenAI API Key** | OpenAI API secret keys | `sk-` prefix with `T3BlbkFJ` marker, or `sk-` with 20+ characters | | **Anthropic API Key** | Anthropic Claude API keys | `sk-ant-api` followed by version and 90+ characters | | **Airtable Secret Token** | Airtable personal access tokens | `pat` followed by 14 characters, dot, and 64 hex characters | | **Groq API Key** | Groq Cloud API keys | `gsk_` followed by 52 alphanumeric characters | ### Code Repository & Package Manager Tokens | Secret Type | Pattern Description | Example Format | | ---------------------------------- | ------------------------------------------ | ------------------------------------------------------------------- | | **GitHub Fine-Grained PAT** | GitHub fine-grained personal access tokens | `github_pat_` followed by 20-255 characters | | **GitHub Personal Token** | GitHub classic personal access tokens | `ghp_`, `gho_`, `ghu_`, `ghs_`, or `ghr_` followed by 36 characters | | **GitLab Token** | Various GitLab token types | `glpat-`, `gldt-`, `glft-`, `glsoat-`, `glrt-`, `GR1348941`, etc. | | **NPM Token** | NPM authentication tokens | `npm_` followed by 30+ characters | | **NPM .npmrc Auth Token** | Tokens in .npmrc configuration | `_authToken=` with npm token or UUID format | | **PyPI Token** | Python Package Index tokens | `pypi-` followed by base64 identifier and 70+ characters | | **Artifactory Credential** | JFrog Artifactory API keys | `AKC` followed by 10+ alphanumeric characters | | **Artifactory Encrypted Password** | Encrypted Artifactory passwords | `AP` followed by hex digit and 8+ characters | ### Communication & Collaboration Platforms | Secret Type | Pattern Description | Example Format | | ----------------------- | --------------------------------- | --------------------------------------------------- | | **Slack Token** | Slack API tokens (various types) | `xoxb-`, `xoxa-`, `xoxp-`, `xoxr-`, `xoxs-` formats | | **Slack Bot Token** | Slack bot authentication tokens | `xox[abpors]-` followed by numeric segments | | **Slack Webhook URL** | Slack incoming webhook URLs | `https://hooks.slack.com/services/T.../B.../...` | | **Discord Bot Token** | Discord bot authentication tokens | Three-part token with `M`, `N`, or `O` prefix | | **Discord Webhook URL** | Discord webhook URLs | `https://discord.com/api/webhooks/...` | | **Telegram Bot Token** | Telegram bot API tokens | 8-10 digit bot ID followed by 35-character token | ### Payment & E-Commerce | Secret Type | Pattern Description | Example Format | | -------------------------- | --------------------------------- | ------------------------------------------------------------- | | **Stripe Publishable Key** | Stripe public API keys | `pk_live_` followed by 20+ characters | | **Stripe Secret Key** | Stripe secret/restricted API keys | `sk_live_` or `rk_live_` followed by 24+ characters | | **Square Access Token** | Square API access tokens | `EAAA` followed by 60 characters | | **Square OAuth Secret** | Square OAuth client secrets | `sq0csp-` followed by 43 characters | | **Shopify Token** | Shopify API tokens | `shpat_`, `shppa_`, or `shpss_` followed by 32 hex characters | ### Database Connection Strings | Secret Type | Pattern Description | Example Format | | -------------------------------- | ------------------------------------------- | --------------------------------- | | **MongoDB Connection String** | MongoDB connection URLs with credentials | `mongodb://user:password@host` | | **MySQL Connection String** | MySQL connection URLs with credentials | `mysql://user:password@host` | | **PostgreSQL Connection String** | PostgreSQL connection URLs with credentials | `postgresql://user:password@host` | ### Private Keys & Certificates | Secret Type | Pattern Description | Example Format | | ------------------------------ | --------------------------------------- | -------------------------------------------- | | **Private Key (Generic)** | RSA, EC, DSA, or encrypted private keys | `-----BEGIN PRIVATE KEY-----` blocks | | **RSA/DSA/EC Private Key** | Specific algorithm private keys | `-----BEGIN RSA PRIVATE KEY-----` blocks | | **OpenSSH Private Key** | OpenSSH format private keys | `-----BEGIN OPENSSH PRIVATE KEY-----` blocks | | **PGP Private Key** | PGP/GPG private key blocks | `-----BEGIN PGP PRIVATE KEY BLOCK-----` | | **SSH2 Encrypted Private Key** | SSH2 encrypted private keys | `-----BEGIN SSH2 ENCRYPTED PRIVATE KEY-----` | | **PuTTY Private Key** | PuTTY PPK format private keys | `PuTTY-User-Key-File-` header | | **Certificate** | X.509 certificates | `-----BEGIN CERTIFICATE-----` blocks | ### Authentication Tokens & Credentials | Secret Type | Pattern Description | Example Format | | -------------------------- | ------------------------------------ | ----------------------------------------------------- | | **JWT Token** | JSON Web Tokens | `eyJ...` three-part base64 structure | | **Basic Auth Credentials** | Credentials embedded in URLs | `://username:password@` in URLs | | **Password** | Password assignments in code/config | `password=`, `pass=`, `pwd=` with quoted values | | **Generic Secret** | Generic secret/token/key assignments | `secret=`, `token=`, `key=` with 20+ character values | ### Other Services | Secret Type | Pattern Description | Example Format | | ---------------------------- | ---------------------------------- | --------------------------------------------------------- | | **Twilio Account SID** | Twilio account identifiers | `AC` followed by 32 hex characters | | **Twilio API Key SID** | Twilio API key identifiers | `SK` followed by 32 hex characters | | **Twilio Auth Token** | Twilio authentication tokens | 32-character hex tokens with `auth_token` context | | **SendGrid API Key** | SendGrid email API keys | `SG.` followed by 22 and 43 character segments | | **Mailchimp API Key** | Mailchimp API keys | 32 hex characters followed by `-us` and datacenter number | | **Mapbox Access Token** | Mapbox API tokens | `pk.` or `sk.` followed by 30+ characters | | **Notion Integration Token** | Notion API integration tokens | `secret_` followed by 32+ characters | | **Linear API Key** | Linear project management API keys | `lin_api_` followed by 40+ characters | | **Dropbox Access Token** | Dropbox API tokens | `sl.` followed by 120+ characters | | **Facebook Access Token** | Facebook/Meta API tokens | `EAA` followed by 30+ characters | ### Contextual Pattern Detection In addition to specific patterns, Secrets Detection also identifies secrets based on contextual clues: | Pattern Type | Description | | ----------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Hex Secret (32+ chars)** | Hexadecimal strings near keywords like `secret`, `api_key`, `token`, `password`, `credential`, `auth_token`, `private_key`, `signing_key`, `encryption_key` | | **Base64 Secret (24+ chars)** | Base64-encoded strings near the same contextual keywords | Contextual patterns help detect secrets that don't follow a specific format but appear in contexts that suggest they are sensitive credentials. ## Use Cases Secrets Detection can be applied to any of the four guardrail hooks depending on your use case: ### Recommended Hook Usage | Hook | Use Case | | ----------------- | ------------------------------------------------------------------------------ | | **LLM Input** | Prevent users from accidentally sending credentials to LLMs | | **LLM Output** | Ensure LLM responses don't leak sensitive information | | **MCP Pre Tool** | Detect secrets in tool parameters before invocation | | **MCP Post Tool** | Detect and redact secrets in tool outputs (file contents, API responses, etc.) | ### LLM Input Hook Prevent users from accidentally sending sensitive credentials to LLMs: ```bash theme={"dark"} curl -X POST "{GATEWAY_BASE_URL}/chat/completions" \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -H 'X-TFY-METADATA: {}' \ -H 'X-TFY-GUARDRAILS: {"llm_input_guardrails":["my-guardrail-group/secrets-detection"],"llm_output_guardrails":[]}' \ -H 'X-TFY-LOGGING-CONFIG: {"enabled": true}' \ -d '{ "model": "openai-main/gpt-4o-mini", "messages": [ {"role": "system", "content": "You are an AI assistant."}, {"role": "user", "content": "Help me debug this code that uses API key sk-abc123xyz"} ], "max_tokens": 2500, "stream": true }' ``` ### LLM Output Hook Ensure LLM responses don't leak sensitive information: ```bash theme={"dark"} curl -X POST "{GATEWAY_BASE_URL}/chat/completions" \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -H 'X-TFY-METADATA: {}' \ -H 'X-TFY-GUARDRAILS: {"llm_input_guardrails":[],"llm_output_guardrails":["my-guardrail-group/secrets-detection"]}' \ -H 'X-TFY-LOGGING-CONFIG: {"enabled": true}' \ -d '{ "model": "openai-main/gpt-4o-mini", "messages": [ {"role": "system", "content": "You are an AI assistant."}, {"role": "user", "content": "Generate an example AWS configuration file"} ], "max_tokens": 2500, "stream": true }' ``` ### MCP Tool Hooks ```yaml theme={"dark"} name: guardrails-control type: gateway-guardrails-config rules: - id: mcp-secrets-protection when: target: operator: or conditions: mcpServers: values: - file-reader condition: in subjects: operator: and conditions: in: - team:engineering not_in: - user:security-admin@example.com llm_input_guardrails: [] llm_output_guardrails: [] mcp_tool_pre_invoke_guardrails: [] mcp_tool_post_invoke_guardrails: - my-guardrail-group/secrets-detection ``` For maximum protection, apply Secrets Detection to **all four hooks** to catch secrets from user input, LLM output, and MCP tool results. ## Best Practices Use **mutate mode** to redact secrets while preserving request flow—useful for logging scenarios. High-entropy strings (UUIDs, encoded data) may trigger false positives. Test with your specific data.