Variables in depth

Try it in the demo.

Variables explains the kinds. This page shows when each one earns its place.

Dynamic: a value from the messageCopy Anchor Link

Pull something out of the event with a path or expression, with the same suggestions as templates:

• data.to[0].address | lower: the first recipient, lowercased.
• data.from | regex_extract("@(.+)$", 1): the sender's domain.

The sheet shows what it resolves to against the sample, and refuses to save a broken expression.

Random: a new value per send, or one fixed valueCopy Anchor Link

• Per send: random_string(16) for a nonce, uuid() for an idempotency key; each delivery gets a new one.
• Fixed: generated once and kept, until you press Regenerate. Use it for a value that must stay the same across sends, such as a fake account id.

Replay sends the stored request (the same values); Re-render with fresh values makes new ones.

Computed: built from other variablesCopy Anchor Link

{{ vars.tenant_id }}-{{ vars.nonce }} combines two variables. Useful for a reference your app expects in one field.

Prompt: asked for at send timeCopy Anchor Link

A Prompt variable has a default. Automatic sends use the default; Send to webhook and the Composer ask for it. Use it for "which customer id should this test use?".

SecretsCopy Anchor Link

Use Secret for tokens and keys a signature needs. After saving, the value is never shown again; editing with the field empty keeps it. Secrets are masked in the UI, API answers, logs and MCP output, and exported to the seed file as ${ENV_VAR} references. When an endpoint asks for a missing variable named like a token, secret, key or password, it is stored as a secret.

Scope and overridesCopy Anchor Link

1. A send-time override (in Send to webhook or the Composer) wins for that one send.
2. Otherwise the endpoint's variable of that name.
3. Otherwise the global one.
4. Otherwise an environment variable named SENDMOCK_VAR_<NAME>, read as vars.<name> in lowercase (SENDMOCK_VAR_TENANT_ID is vars.tenant_id). Only that prefix is read, so other secrets in the environment are never reachable. Use it to pass values from CI.

So one template can serve several endpoints: put the shared value globally and the differing one on each endpoint.

Steps: a per-endpoint tenant idCopy Anchor Link

1. Press Add variable: name tenant_id, scope Global, kind Text, value default-tenant.
2. Press Add variable again: name tenant_id, scope your endpoint, value acme.
3. In the endpoint's template, use {{ vars.tenant_id }}. That endpoint sends acme; every other sends default-tenant.

With the CLICopy Anchor Link

sendmock webhook var set tenant_id acme --endpoint "Laravel inbound mail"
sendmock webhook var set twilio_auth_token "$TWILIO_AUTH_TOKEN" --secret
sendmock webhook var regenerate account_id

RelatedCopy Anchor Link

• Variables
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