Google Vertex AI API
Browse all Google APIs33
AI ReadinessNon-Ready (F)33/100
Official vendor OpenAPI document · agent-readyAI/MLMl Inferenceoauth2202 EndpointsREST
For Agents
Train, deploy, and call ML models on Google Cloud - including Gemini foundation models - via 202 endpoints covering datasets, pipelines, endpoints, and predictions.
Use for: Generate text from a Gemini model deployed on Vertex AI, Submit a custom training pipeline with my own container image, Deploy a fine-tuned model to a Vertex AI endpoint, List all Vertex AI endpoints and their deployed model versions
Not supported: Does not handle BigQuery analytics queries, Workspace data, or non-ML Cloud resource provisioning - use for Vertex AI model training, deployment, and prediction only.
The Vertex AI API is Google Cloud's unified surface for training, tuning, deploying, and serving machine learning models, including Google's foundation models such as Gemini and PaLM and customer-trained models. It exposes operations on datasets, training pipelines, models, endpoints, batch prediction jobs, feature stores, indexes, and model lineage. With 202 endpoints, it covers the full MLOps lifecycle from data ingestion through online and batch inference. It is the right tool for teams building production ML systems on Google Cloud rather than just calling a hosted LLM endpoint.
Install Jentic One Beta
Connect the Vertex AI API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Vertex AI 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.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fgoogleapis.com%2Faiplatform" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fgoogleapis.com%2Faiplatform" | 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 Vertex AI API.
Run online predictions against a deployed Vertex AI endpoint, including Gemini and custom models
Submit and monitor training pipelines that produce versioned Vertex AI model resources
Deploy a model to a Vertex AI endpoint and split traffic between deployed model versions
Run batch prediction jobs over BigQuery or Cloud Storage inputs and write results back
Manage datasets, dataset items, and annotation specs that feed AutoML and custom training
Search artifact and context lineage subgraphs to trace how a deployed model was produced
Manage feature stores, feature views, and indexes that back online inference and vector search
Use Cases
Patterns agents use Vertex AI API for, with concrete tasks.
★ Foundation Model Inference at Scale
Teams that want to call Gemini or other Vertex foundation models from production code use the predict and streamGenerateContent endpoints rather than the consumer Gemini API, because Vertex bills against a Google Cloud project and supports IAM, VPC Service Controls, and regional residency. Vertex AI exposes both online prediction for low-latency inference and batch prediction for high-throughput jobs over BigQuery or GCS inputs.
POST to projects/{project}/locations/{location}/publishers/google/models/gemini-1.5-pro:generateContent with the prompt and read the response in JSON.
Custom Training Pipeline Orchestration
Data science teams use Vertex AI training pipelines to package their training code in a container, run it on managed compute, and produce a versioned Vertex AI Model resource that can be deployed to an endpoint. The API covers creating, listing, cancelling, and inspecting CustomJobs, TrainingPipelines, and HyperparameterTuningJobs, replacing bespoke Kubernetes setups for ML training.
Create a TrainingPipeline under projects/{project}/locations/{location}/trainingPipelines pointing at a container image and Cloud Storage training inputs, then poll its state until it produces a Model resource.
Vector Search for Retrieval-Augmented Generation
Applications using RAG store document embeddings in a Vertex AI Index and query the deployed IndexEndpoint to find nearest neighbours at request time. Vertex AI handles index updates, sharding, and serving, so the application only needs to upsert vectors and call findNeighbors. Indexes integrate with the same IAM and VPC controls as the rest of Vertex AI.
Call findNeighbors on a deployed IndexEndpoint with a query embedding and use the returned datapoint IDs to fetch source documents for the LLM context window.
Model Lineage and Governance
Regulated teams need to answer how a deployed model was produced - which dataset, which training run, which evaluation. Vertex AI's metadata store exposes Artifacts, Executions, and Contexts, and the lineage subgraph endpoints walk the graph from a deployed model back to the data that trained it. This produces the audit trail required for ML model risk management.
Call queryArtifactLineageSubgraph on the deployed model's artifact resource name and walk the returned graph to surface the training pipeline run and source dataset.
Agent-Built ML Workflow
An agent integrating Vertex AI through Jentic can search for the predict operation, load its schema, and call Gemini or a custom endpoint without writing the OAuth and project-routing boilerplate by hand. Jentic isolates the Google Cloud service account credential and exposes only the operation's inputs, so an agent can chain dataset creation, training, and prediction in one workflow.
Use the Jentic search query 'generate text with a Vertex AI Gemini model' to discover the operation, then call generateContent on the chosen publisher model with the prompt and parameters.
Key Endpoints
202 endpoints — the vertex ai api is google cloud's unified surface for training, tuning, deploying, and serving machine learning models, including google's foundation models such as gemini and palm and customer-trained models.
METHOD
PATH
DESCRIPTION
POST
/v1/{endpoint}:predict
Run online prediction against a deployed Vertex AI endpoint
POST
/v1/{endpoint}:streamGenerateContent
Stream generation from a deployed publisher or custom model
GET
/v1/datasets
List Vertex AI datasets in a project and location
POST
/v1/{+context}:queryContextLineageSubgraph
Walk the lineage subgraph for a metadata context
POST
/v1/{+dataset}:searchDataItems
Search dataset items with filters
POST
/v1/{endpoint}:predict
Run online prediction against a deployed Vertex AI endpoint
POST
/v1/{endpoint}:streamGenerateContent
Stream generation from a deployed publisher or custom model
GET
/v1/datasets
List Vertex AI datasets in a project and location
POST
/v1/{+context}:queryContextLineageSubgraph
Walk the lineage subgraph for a metadata context
POST
/v1/{+dataset}:searchDataItems
Search dataset items with filters
Jentic AI Readiness Score
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
V
Vertex AI API
- Non-Ready (F)33/100
25
Foundational Compliance56
Developer Experience & Jentic Compatibility20
AI-Readiness & Agent Experience43
Agent Usability63
Security60
AI DiscoverabilityPowered by JenticScoring Framework 1.0.0 | Scoring Engine 0.4.0
Show dimension breakdown
25
Foundational Compliance
Base layer of spec validity and structural soundness.
Grade: FSignals: 4
0%
Lint Results
Aggregated quality score from linter diagnostics, weighted by severity.
100%
Resolution Completeness
Percentage of `$ref` references that resolve successfully.
0%
Specification Validity
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
0%
Structural Integrity
Structural correctness score based on schema issues using logarithmic dampening.
56
Developer Experience & Jentic Compatibility
Clarity, completeness, and ingestion readiness for developers and tooling.
Grade: CSignals: 4
0%
Example Density
How richly the API is illustrated with examples.
100%
Example Validity
Percentage of examples that conform to their schemas.
25%
Response Coverage
Percentage of operations with complete response definitions (success, client error, server error).
100%
Tooling Readiness
Health of API ingestion, bundling, and resolution within Jentic pipelines.
20
AI-Readiness & Agent Experience
Semantic breadth, depth, and agent comprehension for AI systems.
Grade: FSignals: 4
80%
Description Coverage
Coverage of descriptions across API elements.
0%
Error Standardization
Coverage of RFC 9457 Problem Details for error responses.
0%
OperationId Quality
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
0%
Summary Coverage
Coverage of summaries across operations/tags/info.
43
Agent Usability
Functional utility, complexity comfort, and AI orchestration readiness.
Grade: D-Signals: 1
43%
Complexity Comfort
Agent comfort level based on API operational and structural complexity.
63
Security
Trust, risk posture, and security compliance.
Grade: B-Signals: 1
62%
Authentication Strength
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
60
AI Discoverability
Findability, semantic richness, and reasoning readiness.
Grade: C+Signals: 1
60%
Descriptive Richness
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Vertex AI API by hand means configuring Google OAuth 2.0 from a service account, rotating short-lived access tokens yourself, and pointing calls at the aiplatform.googleapis.com host across a large operation surface. Through Jentic you install once, import the Vertex AI API from the API Directory, store the OAuth credential once, and your agent calls it.
Permission scoping
Vertex AI puts the endpoint and dataset resources in the URL path (/v1/{endpoint}:predict, /v1/{+dataset}:searchDataItems), so a rule can pin your agent to one deployed endpoint or dataset: it can predict or read items there and nothing else. You choose the operations it may call, so training, deployment, or dataset writes are not included unless you add them.
Credential isolation
Your Google service account credential is stored once, encrypted, by your own Jentic One instance and rotated into short-lived access tokens at execution time. The key never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'generate text with a Vertex AI Gemini model' or 'run a batch prediction job', and Jentic returns the matching Vertex AI operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Vertex AI API through Jentic.
What authentication does the Vertex AI API use?
Vertex AI uses OAuth 2.0 access tokens minted from a Google Cloud service account or user credential, with the cloud-platform scope. Jentic stores the source credential in its Jentic One instance and gives the agent only short-lived access tokens, so service account keys never enter agent context.
Can I call Gemini models through the Vertex AI API rather than the consumer Gemini API?
Yes. Use the publisher model path projects/{project}/locations/{location}/publishers/google/models/{model}:generateContent or :streamGenerateContent to call Gemini billed against your Google Cloud project, with project-level IAM and VPC controls.
What are the rate limits for the Vertex AI API?
Vertex AI enforces per-region, per-model quotas for online prediction (queries per minute) and concurrent training jobs. Quotas are listed under the Vertex AI service in IAM and Admin, Quotas in the Google Cloud Console and can be raised via quota requests.
How do I run a Gemini prompt on Vertex AI through Jentic?
Search Jentic for 'generate text with a Vertex AI Gemini model', load the schema for the publishers/google/models/{model}:generateContent operation, and execute it. Run pip install jentic and use the async search, load, execute pattern with your project and location.
Can I deploy a custom-trained model to a Vertex AI endpoint via the API?
Yes. Upload or register the model in the Vertex AI Model Registry, then call deployModel on a Vertex AI Endpoint with traffic split percentages to route inference traffic between deployed model versions.
Is Vertex AI free?
Vertex AI is paid: you pay per online prediction request, per training-hour for compute, per node-hour for endpoint serving, and per stored vector for index serving. Pricing varies by model, machine type, and region - see Vertex AI pricing in the Google Cloud Console.
Can I limit what my agent is allowed to do with the Vertex AI API?
Yes. Because you run Jentic One yourself, your own rules decide which Vertex AI operations and which Google service account credential the agent may use. Vertex AI carries the endpoint and dataset in the URL path, such as /v1/{endpoint}:predict and /v1/{+dataset}:searchDataItems, so you can pin the agent to a single deployed endpoint or dataset and let it run predictions or read items there and nothing else. You pick the operations it may call, so training, deployment, and dataset writes stay excluded until you add them.
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