> Part of the walkerOS documentation. Project overview and full index: [Server](#)[ ](https://github.com/elbwalker/walkerOS/tree/main/packages/server/sources/gcp) [Source code](https://github.com/elbwalker/walkerOS/tree/main/packages/server/sources/gcp)[ ](https://www.npmjs.com/package/@walkeros/server-source-gcp) [Package](https://www.npmjs.com/package/@walkeros/server-source-gcp) # GCP Cloud Functions Google Cloud Functions source for walkerOS. Lightweight runtime adapter with plug-and-play assignment to a Cloud Functions handler, support for the shared [event envelope](https://www.walkeros.io/docs/sources/envelope.md) including batches, a GET tracking pixel, and configurable CORS. The `@walkeros/server-source-gcp` package also ships [`sourcePubSubPull` and `sourcePubSubPush`](https://www.walkeros.io/docs/sources/server/pubsub.md) for ingesting from Pub/Sub topics; this page covers the Cloud Functions handler only. Where this fits The GCP Cloud Functions source is a **server source** in the walkerOS flow: It receives events via HTTP and forwards them to your destinations. ## Installation[​](#installation "Direct link to Installation") ``` npm install @walkeros/server-source-gcp @google-cloud/functions-framework ``` * Integrated * Bundled ``` import { sourceCloudFunction } from '@walkeros/server-source-gcp'; import { startFlow } from '@walkeros/collector'; import { http } from '@google-cloud/functions-framework'; const { sources } = await startFlow({ sources: { gcp: { code: sourceCloudFunction, config: { settings: { cors: true }, }, }, }, destinations: { // Your destinations }, }); // Plug-and-play: source.push IS the Cloud Function handler http('walkerHandler', sources.gcp.push); ``` Add to your `flow.json` sources: ``` "sources": { "gcp": { "package": "@walkeros/server-source-gcp", "config": { "settings": { "cors": true, } } } } ``` Server sources require platform-specific handlers. For containerized deployments, see [Docker](https://www.walkeros.io/docs/apps/docker.md). [See bundled mode setup](https://www.walkeros.io/docs/getting-started/modes/bundled.md) | [CLI reference](https://www.walkeros.io/docs/apps/cli.md) ## Configuration[​](#configuration "Direct link to Configuration") This source uses the standard source config wrapper (consent, data, env, id, ...). For the shared fields see [source configuration](https://www.walkeros.io/docs/sources.md#configuration). Package-specific fields live under `config.settings` and are listed below. ## Settings[​](#settings "Direct link to Settings") | Property | Type | Description | More | | --------------------- | ------------------- | --------------------------------------------------------------------------------------------- | ---- | | `cors` | `boolean \| object` | CORS configuration: false = disabled, true = allow all origins, object = custom configuration | | | `maxBatchSize` | `integer` | Maximum number of events accepted in a single batch request | | | `enablePixelTracking` | `boolean` | Serve a tracking pixel for GET requests | | | `timeout` | `integer` | Request timeout in milliseconds (max: 540000 for GCP) | | ## Mapping[​](#mapping "Direct link to Mapping") This package does not define custom rule-level settings. For the standard rule fields (consent, condition, data, batch, name, policy) see [mapping](https://www.walkeros.io/docs/mapping.md). ## Examples ### POST with provenance A POST body carrying a source map is forwarded in full, so release and trace provenance survive the crossing. Event ``` { "method": "POST", "body": { "name": "page view", "data": { "title": "Home" }, "source": { "release": { "web": "r1" } } }, "headers": { "content-type": "application/json" } } ``` Out ``` elb({ "name": "page view", "data": { "title": "Home" }, "source": { "release": { "web": "r1" } } }) ``` ### Order POST A Cloud Function HTTP POST carrying an order payload becomes a walker order complete event. Event ``` { "method": "POST", "body": { "name": "order complete", "data": { "id": "ORD-700", "total": 99.99, "currency": "EUR" } }, "headers": { "content-type": "application/json" } } ``` Out ``` elb({ "name": "order complete", "data": { "id": "ORD-700", "total": 99.99, "currency": "EUR" } }) ``` ### POST event A GCP Cloud Function HTTP POST with a JSON body becomes a single walker elb event. Event ``` { "method": "POST", "body": { "name": "page view", "data": { "title": "Home", "url": "https://example.com/" } }, "headers": { "content-type": "application/json" } } ``` Out ``` elb({ "name": "page view", "data": { "title": "Home", "url": "https://example.com/" } }) ``` ## Request format[​](#request-format "Direct link to Request format") The event name field is `name`. Every other field of the body is forwarded to the collector as-is, so `source` (carrying `release` and `trace` provenance) rides through instead of being dropped. ### Single event[​](#single-event "Direct link to Single event") ``` { "name": "page view", "data": { "title": "Home Page", "path": "/" } } ``` ### Batch events[​](#batch-events "Direct link to Batch events") Send several events in one request with the shared envelope. See [Event Envelope](https://www.walkeros.io/docs/sources/envelope.md) for the accepted forms, the `maxBatchSize` cap and the 207 partial-failure response. ``` { "batch": [ { "name": "page view", "data": { "title": "Page 1" } }, { "name": "button click", "data": { "id": "btn1" } } ] } ``` ## Responses[​](#responses "Direct link to Responses") | Status | Meaning | | ------ | -------------------------------------------------------------------------------------------------------------------------------------------- | | 200 | Event processed | | 400 | Rejected client input: the pipeline declared the event invalid. The body echoes the validation message, for example `Event name is required` | | 500 | The pipeline failed to process a valid event, or an unexpected server fault | Invalid input is counted on `collector.status.sources..rejected` rather than inflating `status.failed`, and is logged at warn with the reason instead of as an error with a stack trace. ## Ingest metadata[​](#ingest-metadata "Direct link to Ingest metadata") Extract request metadata and forward it through the pipeline. `config.ingest` must use the `map` operator. Keys are output field names; values are direct field paths on the request scope (no `req.` prefix). A bare object like `{ ip: 'ip' }` is silently inert: without the `map` operator the source passes the whole request through and no field is extracted. ``` const { sources } = await startFlow({ sources: { gcp: { code: sourceCloudFunction, config: { settings: { cors: true }, ingest: { map: { ip: { key: 'ip' }, ua: { key: 'headers.user-agent' }, origin: { key: 'headers.origin' }, }, }, }, }, }, }); ``` ### Available ingest paths[​](#available-ingest-paths "Direct link to Available ingest paths") | Path | Description | | ----------- | --------------------------------------- | | `ip` | Client IP address | | `headers.*` | HTTP headers (user-agent, origin, etc.) | | `method` | HTTP method | | `hostname` | Request hostname | ## Pub/Sub[​](#pubsub "Direct link to Pub/Sub") The same `@walkeros/server-source-gcp` package also exports `sourcePubSubPull` (streaming pull subscriber) and `sourcePubSubPush` (HTTP webhook handler) for ingesting events from a Pub/Sub topic. See the [Pub/Sub source page](https://www.walkeros.io/docs/sources/server/pubsub.md) for full settings, lifecycle, decoders, OIDC verification, and setup reference.