canonical: https://jentic.com/apis/googleapis.com/appengine

# Google App Engine Admin API

The App Engine Admin API provisions and manages developers' App Engine applications. It exposes the application itself, services, versions, and instances, plus authorized domains, authorized certificates, domain mappings, firewall ingress rules, and operations. Through it, teams create apps, deploy and migrate traffic across versions, attach SSL certificates, lock down ingress, and inspect running instances.

## For AI agents

Provision App Engine apps, deploy versions, split traffic across services, and manage domains, certificates, and firewall rules. Useful for agents managing serverless deploys on App Engine.

## Scope

Does not handle App Engine source code build, runtime request handling, or non-App-Engine compute platforms - use for App Engine application admin and deployment management only.

## Capabilities

- Create App Engine applications and configure default settings
- Deploy new versions and migrate traffic between them
- Split traffic between versions for canary or A/B rollouts
- Attach authorized SSL certificates to custom domains
- Configure firewall ingress rules at the application level
- Inspect and debug running App Engine instances

## Use cases

### Canary and traffic splitting

Engineering deploys a new version, sends 5 percent of traffic to it, monitors errors, then steps the split up to 25, 50, and finally 100 percent. The traffic split endpoint takes a map of version IDs to fractions, so the agent ratchets the rollout in scripted steps rather than redeploying each time.

Example prompt: Patch service 'orders' under app 'my-app' with traffic split {v41: 0.9, v42: 0.1} and confirm via the returned operation.

### Custom domain and SSL automation

Teams map custom domains to App Engine services and rotate managed SSL certificates without leaving CI. Authorized domains, domain mappings, and authorized certificates are first-class resources, so cert renewal pipelines target the API rather than scripting console clicks.

Example prompt: Create a domain mapping for orders.example.com on app 'my-app' bound to authorized certificate certs/cert-123.

### Ingress firewall hardening

Security tightens public exposure by adding deny-by-default firewall rules and explicit allow rules for known IP ranges. The firewall ingress rules endpoints accept ordered priority entries so policy changes are auditable through Git rather than ad-hoc.

Example prompt: Create an ingress rule with priority 1000 on app 'my-app' denying 198.51.100.0/24 and confirm by listing rules.

### AI agent deploy operator via Jentic

An AI agent acting as a deploy operator handles routine version migrations and cert renewals by calling Jentic-mediated App Engine operations. The agent never holds the project's service account JSON; Jentic securely stores it and supplies short-lived scoped tokens.

Example prompt: On a Slack request 'roll out v42 to 100%', step traffic split from 10 to 50 to 100 percent on the orders service over 10 minutes and post each step in Slack.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| POST | /v1/apps | Create an App Engine application |
| GET | /v1/apps/{appsId} | Get an App Engine application |
| GET | /v1/apps/{appsId}/authorizedCertificates | List authorized SSL certificates |
| GET | /v1/apps/{appsId}/authorizedDomains | List authorized domains |
| GET | /v1/apps/{appsId}/domainMappings | List custom domain mappings |
| GET | /v1/apps/{appsId}/firewall/ingressRules | List firewall ingress rules |
| DELETE | /v1/apps/{appsId}/authorizedCertificates/{authorizedCertificatesId} | Delete an authorized certificate |

## Key resources

- **Apps** — Top-level App Engine applications per project
- **Services** — Microservices within an app, each with versions
- **Versions** — Deployed versions of a service, with traffic splits
- **Instances** — Running compute instances backing a version
- **AuthorizedCertificates** — SSL certificates attached to domains
- **DomainMappings** — Custom domain bindings to services
- **FirewallIngressRules** — Application-level ingress firewall policy

## Why Jentic

- **Setup:** Wiring the App Engine Admin API by hand means configuring Google OAuth2, scoping a service account for App Engine admin access, and minting access tokens across its 43 admin operations yourself. Through Jentic you install once, import the App Engine Admin API from the API Directory, store the OAuth credential once, and your agent calls it.
- **Permission scoping:** This API puts the application id in the URL path (/v1/apps/{appsId}/...), so a rule can pin your agent to one App Engine application: it can read authorized certificates, domains, mappings, and firewall rules there and nothing else. You choose the operations it may call, so destructive ones like deleting an authorized certificate are not included unless you add them.
- **Credential handling:** Your Google Cloud OAuth credential is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'split App Engine traffic' or 'add a domain mapping', and Jentic returns the matching admin operation with its input schema so the agent calls the right endpoint without the gcloud CLI or the full Cloud reference.

## Related APIs

- **API Gateway API** — Fronts App Engine services with auth, quotas, and an OpenAPI contract.
- **App Hub API** — Catalogs apps and the services (including App Engine services) that compose them.
- **API Keys API** — Provisions scoped API keys consumed by App Engine outbound calls.

## FAQ

### What authentication does the App Engine Admin API use?

OAuth 2.0 with Google Cloud credentials. Through Jentic the credentials are vaulted and exchanged for scoped access tokens at runtime.

### Can I split traffic across versions with this API?

Yes. Patch the service resource with a traffic split that maps version IDs to fractional weights, with shardBy controlling stickiness. The returned operation completes when the new split is fully applied.

### What are the rate limits for the App Engine Admin API?

Standard Google Cloud per-project per-minute quotas apply. Deploy and traffic operations are long-running; quota is consumed at issuance, not while polling the operation, so repeated polling is safe.

### How do I migrate traffic to a new version through Jentic?

Search Jentic for 'app engine traffic split', load the schema for the services patch operation, and execute it with the service name and a split map (e.g. {v42: 1.0}). Jentic returns the operation handle for polling until the migration completes.

### Is the App Engine Admin API free?

Management calls are free. App Engine itself bills for instance hours, requests, and outbound traffic according to App Engine pricing.

### How do I add a custom domain with managed SSL?

Add the domain to authorizedDomains, create an authorizedCertificate (or use a managed certificate), then create a domainMapping bound to that certificate. The mapping returns the DNS records you must add at your registrar.

### Can I limit what my agent is allowed to do with the App Engine Admin API?

Yes. Because Jentic One is self-hosted, you set the rules that decide which operations and credentials your agent may use. Since this API carries the application id in the URL path (/v1/apps/{appsId}/...), your rules can pin the agent to a single App Engine application, where it reads services, versions, authorized certificates, domains, mappings, and firewall ingress rules and nothing else. You choose the exact operations it may call, so destructive ones such as deleting an authorized certificate stay out of reach unless you explicitly grant them.