Vercel logs

Capture Vercel deployment logs as PostHog events

Configuration

Option	Description
`Authorization header value` Type: string Required: False	If set, the incoming Authorization header must match this value exactly. e.g. "Bearer SECRET_TOKEN"
`Max message length` Type: number Required: False	Truncate log messages longer than this (default: 262144 bytes)
`Log payloads` Type: boolean Required: False	Logs the incoming request for debugging
`Distinct ID salt` Type: string Required: False	High-entropy random secret (e.g. base64) mixed into hashed distinct IDs. Rotate to invalidate prior IDs. Used by rotating_salt, fixed_salt, and the rotating_salt_fallback path of custom; ignored by the ip strategy. If left blank, hashed strategies still produce stable IDs but lose the unguessability the salt provides — set one in production.
`Distinct ID strategy` Type: choice Required: True	How distinct IDs are derived. Default rotates daily so the same client gets a fresh ID each day. The active strategy is recorded on each event as $distinct_id_strategy for debugging.
`Forward client IP and user agent` Type: boolean Required: False	When enabled (default), $ip, $raw_user_agent, proxy_client_ip, and proxy_user_agent are emitted on each event so PostHog can run GeoIP and user-agent enrichment. Disable if you want raw client identifiers stripped — distinct_id derivation still uses them as inputs, but they will not appear on the emitted event.
`Custom distinct ID template` Type: string Required: False	Used only when strategy is "custom". Supports placeholders {day}, {ip}, {host}, {ua}, {path}, {project_id} (literal string substitution, not Hog evaluation; unknown placeholders are left as-is). The salt secret is intentionally not exposed as a placeholder. The result is prefixed with "http_log_". Empty value or all-empty substitutions fall back to rotating_salt.

Using our REST API you can create this source_webhook like so:

Terminal
# Create a new destination
curl --location 'https://us.i.posthog.com/api/environments/:project_id/hog_functions' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer <POSTHOG_PERSONAL_API_KEY>' \
--data '{
    "type": "source_webhook",
    "name": "Vercel logs",
    "inputs": {
        "distinct_id_strategy": {
            "value": ""
        }
    },
    "enabled": true,
    "template_id": "template-source-vercel-log-drain"
}'

Vercel logs

Configuration

Community questions