Google Cloud Vertex.AI API Access

You need to create a Google Cloud project in your account an enable the Vertex.AI services. As an access-token you can run gcloud auth print-access-token. Using these services will incurr costs on your Google Cloud account.

All the following procedures can have the following APOC config, i.e. in apoc.conf or via docker env variable .Apoc configuration

key

description

default

apoc.ml.vertexai.url

the OpenAI endpoint base url

the endpoint configuration parameter value

Moreover, they can have the following configuration keys, as the last parameter.

Table 1. Common configuration parameter
key	description	default
endpoint	analogous to `apoc.ml.vertexai.url` APOC config	https://{region}-aiplatform.googleapis.com/v1/projects/{project}/locations/{region}/publishers/google/models/{model}:{resource}
headers	to add or edit the HTTP default header	`{Content-Type: "application/json", Accept: "application/json", Authorization: "Bearer " + <$accessToken, i.e. 2nd parameter> }`
model	The Vertex AI model	depends on the procedure
region	The Vertex AI region	us-central1
resource	The Vertex AI resource (see below)	depends on the procedure
temperature, maxOutputTokens, maxDecodeSteps, topP, topK	Optional parameter which can be passed into the HTTP request. Depend on the API used	{temperature: 0.3, maxOutputTokens: 256, maxDecodeSteps: 200, topP: 0.8, topK: 40}

We can define the endpoint configuration as a full URL, e.g. https://us-central1-aiplatform.googleapis.com/v1/projects/myVertexAIProject/locations/us-central1/publishers/google/models/gemini-pro-vision:streamGenerateContent, or define it via parameters that will then be replaced by the other configurations.

For example, if we define no endpoint config., the default one https://{region}-aiplatform.googleapis.com/v1/projects/{project}/locations/{region}/publishers/google/models/{model}:{resource} will be valued, where:

{model} will be model defined by the model configuration
{region} defined by region configuration
{project} defined by the 3rd parameter (project)
{resource} defined by resource configuration

Or else, we can define an endpoint as https://us-central1-aiplatform.googleapis.com/v1/projects/{project}/locations/us-central1/publishers/google/models/gemini-pro-vision:streamGenerateContent, and in this case we just substitute {project} with the 3rd parameter.

Let’s see some example.

Generate Embeddings API

This procedure apoc.ml.vertexai.embedding can take a list of text strings, and will return one row per string, with the embedding data as a 768 element vector. It uses the embedding endpoint which is documented here.

API Quotas are per project/per region and you can over-ride the default us-central1 in the configuration map e.g. {region:'us-east4'}. GCP Regions can be found here: https://cloud.google.com/about/locations

Additional configuration is passed to the API, the default model used is textembedding-gecko.

Generate Embeddings Call

CALL apoc.ml.vertexai.embedding(['Some Text'], $accessToken, $project, {region:'<region>'}) yield index, text, embedding;

Table 2. Generate Embeddings Response
index	text	embedding
0	"Some Text"	[-0.0065358975, -7.9563365E-4, …. -0.010693862, -0.005087272]

Table 3. Parameters
name	description
texts	List of text strings
accessToken	Vertex.AI API access token
project	Google Cloud project
configuration	optional map for entries like model and other request parameters like `region`

Table 4. Results
name	description
index	index entry in original list
text	line of text from original list
embedding	768 element floating point embedding vector for the textembedding-gecko model

Text Completion API

This procedure apoc.ml.vertexai.completion can continue/complete a given text.

It uses the completion model API which is documented here.

Additional configuration is passed to the API, the default model used is text-bison.

Text Completion Call

CALL apoc.ml.vertexai.completion('What color is the sky? Answer in one word: ', $apiKey, $project, {})

Text Completion Response

{value={safetyAttributes={blocked=false, scores=[0.1], categories=[Sexual]},
recitationResult={recitations=[], recitationAction=NO_ACTION}, content=blue}}

Table 5. Parameters
name	description
prompt	Text to complete
accessToken	Vertex.AI API access token
project	Google Cloud project
configuration	optional map for entries like model, region, temperature, topK, topP, maxOutputTokens, and other request parameters

Table 6. Results
name	description
value	result entry from Vertex.AI (content, safetyAttributes(blocked, categories, scores), recitationResult(recitationAction, recitations))

Chat Completion API

This procedure apoc.ml.vertexai.chat takes a list of maps of chat exchanges between assistant and user (with optional system context), and will return the next message in the flow.

It uses the chat model API which is documented here.

Additional configuration is passed to the API, the default model used is chat-bison.

Chat Completion Call

CALL apoc.ml.vertexai.chat(
/*messages*/
[{author:"user", content:"What planet do timelords live on?"}],
$apiKey, $project,
{temperature:0},
/*context*/ "Fictional universe of Doctor Who. Only answer with a single word!",
/*examples*/ [{input:{content:"What planet do humans live on?"}, output:{content:"Earth"}}])
yield value

Chat Completion Response

{value={candidates=[{author=1, content=Gallifrey.}], safetyAttributes={blocked=false, scores=[0.1, 0.1, 0.1], categories=[Religion & Belief, Sexual, Toxic]}, recitationResults=[{recitations=[], recitationAction=NO_ACTION}]}}

Table 7. Parameters
name	description
messages	List of maps of instructions with `{author:"bot
user", content:"text"}`	accessToken
Vertex.AI API access token	project
Google Cloud project	configuration
optional map for entries like region, model, temperature, topK, topP, maxOutputTokens and other parameters	context
optional context and system prompt for the completion	examples

Table 8. Results
name	description
value	result entry from Vertex.AI (containing candidates(author, content), safetyAttributes(categories, scores, blocked), recitationResults(recitationAction, recitations))

Streaming API

This procedure apoc.ml.vertexai.stream takes a list of maps of contents exchanges between assistant and user (with optional system context), and will return the next message in the flow.

By default, it uses the Gemini AI APIs.

CALL apoc.ml.vertexai.stream([{role: "user", parts: [{text: "translate book in italian"}]}], '<accessToken>', '<projectID>')

Table 9. Results
value
`{finishReason:"STOP", safetyRatings:[{probability:"NEGLIGIBLE", category:"HARM_CATEGORY_HARASSMENT"}, {probability:"NEGLIGIBLE", category:"HARM_CATEGORY_HATE_SPEECH"}, {probability:"NEGLIGIBLE", category:"HARM_CATEGORY_SEXUALLY_EXPLICIT"}, {probability:"NEGLIGIBLE", category:"HARM_CATEGORY_DANGEROUS_CONTENT"}], content:{role:"model", parts:[{text:"Libro"}]}}`

We can adjust the parameter, for example temperature

CALL apoc.ml.vertexai.stream([{role: "user", parts: [{text: "translate book in italian"}]}], '<accessToken>', '<projectID>',
    {temperature: 0})

which corresponds to the following Http body request, where maxOutputTokens, topP and topK have the default values specified above (Common configuration parameter):

{
    "contents": [
        {
            "role": "user",
            "parts": [
                {
                    "text": "translate book in italian"
                }
            ]
        }
    ],
    "generation_config": {
        "temperature": 0,
        "maxOutputTokens": 256,
        "topP": 0.8,
        "topK": 40
    }
}

Custom API

Using this procedure we can potentially invoke any API available with vertex AI.

To permit maximum flexibility, in this case the first parameter is not manipulated and exactly matches the body of the HTTP request, and the return type is ANY.

Gemini Pro Vision example

CALL apoc.ml.vertexai.custom({
    contents: [
        {
            role: "user",
            parts: [
					{text: "What is this?"},
                    {inlineData: {
                        mimeType: "image/png",
                        data: '<base64Image>'}
                }
            ]
        }
    ]
},
"<accessToken>",
"<projectId>",
{model: 'gemini-pro-vision'}
)

Table 10. Results
value
[{usageMetadata: {promptTokenCount: 262, totalTokenCount: 272, candidatesTokenCount: 10}, candidates: [{content: {role: "model", parts: [{text: " This is a photo of a book…"}]}, finishReason: "STOP", safetyRatings: [{category: "HARM_CATEGORY_HARASSMENT", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_HATE_SPEECH", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_SEXUALLY_EXPLICIT", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_DANGEROUS_CONTENT", probability│ │: "NEGLIGIBLE"}]}]}]

CALL apoc.ml.vertexai.custom({contents: {role: "user", parts: [{text: "translate book in italian"}]}},
    "<accessToken>",
    "<projectId>",
    {endpoint: "https://us-central1-aiplatform.googleapis.com/v1/projects/{project}/locations/us-central1/publishers/google/models/gemini-pro-vision:streamGenerateContent"}
)

Table 11. Results
value
`[{usageMetadata: {promptTokenCount: 4, totalTokenCount: 5, candidatesTokenCount: 1}, candidates: [{content: {role: "model", parts: [{text: "libro"}]}, finishReason: "STOP", safetyRatings: [{category: "HARM_CATEGORY_HARASSMENT", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_HATE_SPEECH", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_SEXUALLY_EXPLICIT", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_DANGEROUS_CONTENT", probability: "NEGLIGIBLE"}]}]}]`

CALL apoc.ml.vertexai.custom({contents: {role: "user", parts: [{text: "translate book in italian"}]}},
    "<accessToken>",
    null,
    {endpoint: "https://us-central1-aiplatform.googleapis.com/v1/projects/vertex-project-413513/locations/us-central1/publishers/google/models/gemini-pro-vision:streamGenerateContent"}
)

Table 12. Results
value
`[{usageMetadata: {promptTokenCount: 4, totalTokenCount: 5, candidatesTokenCount: 1}, candidates: [{content: {role: "model", parts: [{text: "libro"}]}, finishReason: "STOP", safetyRatings: [{category: "HARM_CATEGORY_HARASSMENT", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_HATE_SPEECH", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_SEXUALLY_EXPLICIT", probability: "NEGLIGIBLE"}, {category: "HARM_CATEGORY_DANGEROUS_CONTENT", probability: "NEGLIGIBLE"}]}]}]`

Moreover, we can use with other Google API with endpoints that don’t start with https://<region>-aiplatform.googleapis.com, for example we can use the Text-to-Speech API:

CALL apoc.ml.vertexai.custom(
{
  input:{
    text:'just a test'
  },
  voice:{
    languageCode:'en-US',
    name:'en-US-Studio-O'
  },
  audioConfig:{
    audioEncoding:'LINEAR16',
    speakingRate:1
  }
},
"<accessToken>",
"<projectId>",
{endpoint: "https://texttospeech.googleapis.com/v1/text:synthesize"})