Webhook HMAC Signature Validator

Webhook HMAC Signature Validator MCP Connector for Claude

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Verify the authenticity of incoming webhook payloads by validating their HMAC signatures.

3 tools Official Updated Oct 1, 2026 Official Vinkius Partner

Protect your AI agents from spoofed external events with the Webhook HMAC Signature Validator. This MCP server provides essential tools to ensure that incoming webhooks are authentic and untampered. Use validate_webhook_signature to check if a payload matches its signature, decompose_header_string to parse complex headers, and fetch_provider_secrets to retrieve trusted keys for your integrations. By implementing constant-time comparison, this tool prevents timing attacks, securing your automation pipeline.

hmacwebhooksecuritysha256validation

3 tools expose this connector's capabilities to your AI agent.

decompose_header_string

g., "sha256=abc...") and need to extract the components. Decompose a webhook header into algorithm and signature

validate_webhook_signature

Validate a webhook payload against a signature and secret

fetch_provider_secrets

Fetch stored secrets for a specific provider

See how to talk to your AI agent using Webhook HMAC Signature Validator.

I received a webhook from Stripe. How can I verify if the payload is authentic?

First, use `fetch_provider_secrets` for 'stripe' to get your secret key. Then, pass the raw request body, the signature from the header, and that secret key into the `validate_webhook_signature` tool to confirm authenticity.

The webhook header is 'sha256=7f83b1...'. What algorithm and signature are being used?

The `decompose_header_string` tool identifies the algorithm as 'sha256' and the signature as '7f83b1...'.

How do I check if a payload matches a specific signature?

You should use the `validate_webhook_signature` tool by providing the raw payload body, the signature header string, and your shared secret key.

The `validate_webhook_signature` tool computes an HMAC-SHA256 hash of the provided payload body using your secret key. It then compares this computed signature against the one found in your request header using a constant-time comparison to prevent timing attacks.

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