Google Cloud Billing Budget API
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For Agents
Create and manage Cloud Billing budgets, threshold rules, and notification settings for a billing account. Agents can list budgets, patch thresholds, and inspect spend filters.
Use for: I need to create a budget of $5,000 a month for project myproj, List all budgets on a Cloud Billing account, Get the threshold rules attached to a specific budget, Update the alert thresholds on an existing budget
Not supported: Does not block spend, manage billing accounts, or run cost reports — use for budget creation, threshold alerts, and Pub/Sub notification wiring only.
The Cloud Billing Budget API stores spending budgets attached to a Cloud Billing account and the threshold rules that fire as spend accrues against that plan. You can create budgets scoped to whole billing accounts, specific projects, services, or labels, and configure alert thresholds at percentage triggers. Budgets are FinOps guardrails — not enforcement. They emit notifications via Cloud Pub/Sub or email so other systems can react, but they do not stop resource provisioning. Use them to track and alert on Google Cloud spend.
Install Jentic One Beta
Connect the Cloud Billing Budget API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Cloud Billing Budget API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
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Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Cloud Billing Budget API.
Create budgets scoped to a billing account, projects, services, or labels
Configure threshold rules at percentage points of forecasted or actual spend
List budgets under a billing account and inspect their filters
Patch a budget's amount, filter, or threshold rules without recreating it
Delete budgets that are no longer needed
Wire budget notifications to a Pub/Sub topic or notification channel
Use Cases
Patterns agents use Cloud Billing Budget API for, with concrete tasks.
★ Project-Level Spend Alerts
Create a budget per environment so spend on dev, staging, and prod each fire at their own thresholds. Budgets are managed at /v1/{parent}/budgets with a billing account parent and a budgetFilter containing projects[]. Threshold rules at 50/75/90/100 percent trigger emails to billing admins or Pub/Sub messages for downstream automation.
Create a $5,000 monthly budget on billingAccounts/012345-678901-23ABCD scoped to projects/myproj-dev with thresholds at 50, 75, 90 percent.
Service Cost Tracking
Filter budgets by service (BigQuery, Compute Engine, Cloud Storage) to track per-service spend across the org. budgetFilter.services accepts service IDs and combines with projects, labels, and creditTypes for fine-grained scoping. Useful for FinOps teams who chargeback by service.
Create a budget that filters services to BigQuery and Compute Engine across all projects under billingAccount 012345-678901-23ABCD with a $20,000 monthly cap.
Pub/Sub-Driven Automation
Configure notificationsRule.pubsubTopic on a budget so percentage thresholds emit JSON messages that other systems consume. Combined with Cloud Functions or Workflows, this enables automated cost responses such as scaling down non-prod resources when spend crosses 80 percent.
Patch existing budget budgets/abc to add notificationsRule with pubsubTopic projects/myproj/topics/billing-alerts.
Agent-Driven FinOps Setup
An AI agent takes a request like 'put a $10k cap on the analytics project with alerts at 80 and 100 percent' and creates the budget through Jentic. The agent loads the create operation, applies the right filter and thresholds, and reports back the budget resource name. OAuth tokens stay in the Jentic vault.
Given the request 'cap analytics project at $10k with alerts at 80 and 100 percent', create a budget scoped to projects/analytics with the right thresholdRules.
Key Endpoints
5 endpoints — the cloud billing budget api stores spending budgets attached to a cloud billing account and the threshold rules that fire as spend accrues against that plan.
METHOD
PATH
DESCRIPTION
POST
/v1/{+parent}/budgets
Create a budget on a billing account
GET
/v1/{+parent}/budgets
List budgets on a billing account
GET
/v1/{+name}
Get a single budget
PATCH
/v1/{+name}
Update an existing budget
DELETE
/v1/{+name}
Delete a budget
POST
/v1/{+parent}/budgets
Create a budget on a billing account
GET
/v1/{+parent}/budgets
List budgets on a billing account
GET
/v1/{+name}
Get a single budget
PATCH
/v1/{+name}
Update an existing budget
DELETE
/v1/{+name}
Delete a budget
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
Google OAuth 2.0 client credentials and refresh tokens are stored encrypted in the Jentic vault (MAXsystem). Agents receive short-lived scoped access tokens for each call and never hold the refresh token.
Intent-based discovery
Agents search Jentic with intents like 'create a GCP budget' and receive the create budget operation schema, including budgetFilter and thresholdRules, so they can call the right endpoint without consulting the Discovery doc.
Time to first call
Direct integration: half a day for OAuth and the budgetFilter shape. Through Jentic: under 30 minutes — search, load schema, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Cloud Billing Budget API through Jentic.
What authentication does the Cloud Billing Budget API use?
The API uses Google OAuth 2.0 with the cloud-billing or cloud-platform scope. Through Jentic the OAuth refresh token sits in the encrypted vault and the agent only receives short-lived access tokens scoped to the budget operations.
Can I create a budget that covers only a specific project?
Yes. POST /v1/{parent}/budgets with budgetFilter.projects set to projects/PROJECT_ID limits the budget to spend in that project. You can also filter by services, labels, calendarPeriod, and creditTypesTreatment.
What are the rate limits for the Cloud Billing Budget API?
Quotas are billing-account-level: typically a few thousand budgets per billing account and modest write QPS on the same budget. Read QPS is bursty up to several hundred per second per account. Specific values are visible in the Google Cloud quotas console.
How do I wire budget alerts to Pub/Sub through Jentic?
Search Jentic for 'add a Pub/Sub notification to a budget', load the schema for PATCH /v1/{name}, and execute with notificationsRule.pubsubTopic set to projects/PROJECT/topics/TOPIC and an updateMask of notificationsRule. Jentic forwards the OAuth token automatically.
Does a budget stop spending when it hits 100 percent?
No. Budgets only emit notifications at the configured thresholds. They do not block resource provisioning or stop existing workloads. Combine them with Cloud Functions or Workflows triggered from the Pub/Sub topic to enforce automated responses.
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