Boba is an experimental AI co-pilot for product technique & generative ideation,
designed to enhance the inventive ideation course of. It’s an LLM-powered
utility that we’re constructing to find out about:
An AI co-pilot refers to a man-made intelligence-powered assistant designed
to assist customers with varied duties, usually offering steering, help, and automation
in numerous contexts. Examples of its utility embody navigation techniques,
digital assistants, and software program improvement environments. We like to consider a co-pilot
as an efficient accomplice {that a} person can collaborate with to carry out a selected area
of duties.
Boba as an AI co-pilot is designed to enhance the early phases of technique ideation and
idea technology, which rely closely on speedy cycles of divergent
pondering (also called generative ideation). We usually implement generative ideation
by carefully collaborating with our friends, prospects and material consultants, in order that we are able to
formulate and take a look at revolutionary concepts that tackle our prospects’ jobs, pains and positive aspects.
This begs the query, what if AI might additionally take part in the identical course of? What if we
might generate and consider extra and higher concepts, sooner in partnership with AI? Boba begins to
allow this by utilizing OpenAI’s LLM to generate concepts and reply questions
that may assist scale and speed up the inventive pondering course of. For the primary prototype of
Boba, we determined to deal with rudimentary variations of the next capabilities:
1. Analysis alerts and tendencies: Search the net for
articles and information that can assist you reply qualitative analysis questions,
like:
2. Artistic Matrix: The inventive matrix is a concepting methodology for
sparking new concepts on the intersections of distinct classes or
dimensions. This entails stating a strategic immediate, usually as a “How would possibly
we” query, after which answering that query for every
mixture/permutation of concepts on the intersection of every dimension. For
instance:
3. State of affairs constructing: State of affairs constructing is a technique of
producing future-oriented tales by researching alerts of change in
enterprise, tradition, and know-how. Situations are used to socialize learnings
in a contextualized narrative, encourage divergent product pondering, conduct
resilience/desirability testing, and/or inform strategic planning. For
instance, you possibly can immediate Boba with the next and get a set of future
situations based mostly on totally different time horizons and ranges of optimism and
realism:
4. Technique ideation: Utilizing the Taking part in to Win technique
framework, brainstorm “the place to play” and “find out how to win” selections
based mostly on a strategic immediate and doable future situations. For instance you
can immediate it with:
5. Idea technology: Primarily based on a strategic immediate, reminiscent of a “how would possibly we” query, generate
a number of product or characteristic ideas, which embody worth proposition pitches and hypotheses to check.
6. Storyboarding: Generate visible storyboards based mostly on a easy
immediate or detailed narrative based mostly on present or future state situations. The
key options are:
Utilizing Boba
Boba is an online utility that mediates an interplay between a human
person and a Massive-Language Mannequin, at the moment GPT 3.5. A easy internet
front-end to an LLM simply affords the power for the person to converse with
the LLM. That is useful, however means the person must learn to
successfully work together the LLM. Even within the quick time that LLMs have seized
the general public curiosity, we have realized that there’s appreciable ability to
developing the prompts to the LLM to get a helpful reply, leading to
the notion of a “Immediate Engineer”. A co-pilot utility like Boba provides
a spread of UI parts that construction the dialog. This permits a person
to make naive prompts which the appliance can manipulate, enriching
easy requests with parts that can yield a greater response from the
LLM.
Boba may also help with numerous product technique duties. We cannot
describe all of them right here, simply sufficient to provide a way of what Boba does and
to supply context for the patterns later within the article.
When a person navigates to the Boba utility, they see an preliminary
display just like this
The left panel lists the assorted product technique duties that Boba
helps. Clicking on certainly one of these adjustments the principle panel to the UI for
that activity. For the remainder of the screenshots, we’ll ignore that activity panel
on the left.
The above screenshot seems on the situation design activity. This invitations
the person to enter a immediate, reminiscent of “Present me the way forward for retail”.
The UI affords numerous drop-downs along with the immediate, permitting
the person to recommend time-horizons and the character of the prediction. Boba
will then ask the LLM to generate situations, utilizing Templated Immediate to counterpoint the person’s immediate
with extra parts each from basic information of the situation
constructing activity and from the person’s picks within the UI.
Boba receives a Structured Response from the LLM and shows the
outcome as set of UI parts for every situation.
The person can then take certainly one of these situations and hit the discover
button, citing a brand new panel with an additional immediate to have a Contextual Dialog with Boba.
Boba takes this immediate and enriches it to deal with the context of the
chosen situation earlier than sending it to the LLM.
Boba makes use of Choose and Carry Context
to carry onto the assorted elements of the person’s interplay
with the LLM, permitting the person to discover in a number of instructions with out
having to fret about supplying the proper context for every interplay.
One of many difficulties with utilizing an
LLM is that it is educated solely on knowledge as much as some level up to now, making
them ineffective for working with up-to-date info. Boba has a
characteristic referred to as analysis alerts that makes use of Embedded Exterior Data
to mix the LLM with common search
services. It takes the prompted analysis question, reminiscent of “How is the
resort business utilizing generative AI as we speak?”, sends an enriched model of
that question to a search engine, retrieves the instructed articles, sends
every article to the LLM to summarize.
That is an instance of how a co-pilot utility can deal with
interactions that contain actions that an LLM alone is not appropriate for. Not
simply does this present up-to-date info, we are able to additionally guarantee we
present supply hyperlinks to the person, and people hyperlinks will not be hallucinations
(so long as the search engine is not partaking of the flawed mushrooms).
Some patterns for constructing generative co-pilot purposes
In constructing Boba, we learnt lots about totally different patterns and approaches
to mediating a dialog between a person and an LLM, particularly Open AI’s
GPT3.5/4. This listing of patterns shouldn’t be exhaustive and is restricted to the teachings
we have learnt up to now whereas constructing Boba.
Templated Immediate
Use a textual content template to counterpoint a immediate with context and construction
The primary and easiest sample is utilizing a string templates for the prompts, additionally
generally known as chaining. We use Langchain, a library that gives a normal
interface for chains and end-to-end chains for widespread purposes out of
the field. For those who’ve used a Javascript templating engine, reminiscent of Nunjucks,
EJS or Handlebars earlier than, Langchain supplies simply that, however is designed particularly for
widespread immediate engineering workflows, together with options for perform enter variables,
few-shot immediate templates, immediate validation, and extra subtle composable chains of prompts.
For instance, to brainstorm potential future situations in Boba, you possibly can
enter a strategic immediate, reminiscent of “Present me the way forward for funds” or perhaps a
easy immediate just like the title of an organization. The person interface seems like
this:
The immediate template that powers this technology seems one thing like
this:
You're a visionary futurist. Given a strategic immediate, you'll create {num_scenarios} futuristic, hypothetical situations that occur {time_horizon} from now. Every situation should be a {optimism} model of the future. Every situation should be {realism}. Strategic immediate: {strategic_prompt}
As you possibly can think about, the LLM’s response will solely be pretty much as good because the immediate
itself, so that is the place the necessity for good immediate engineering is available in.
Whereas this text shouldn’t be meant to be an introduction to immediate
engineering, you’ll discover some strategies at play right here, reminiscent of beginning
by telling the LLM to Undertake a
Persona,
particularly that of a visionary futurist. This was a way we relied on
extensively in varied elements of the appliance to provide extra related and
helpful completions.
As a part of our test-and-learn immediate engineering workflow, we discovered that
iterating on the immediate straight in ChatGPT affords the shortest path from
concept to experimentation and helps construct confidence in our prompts rapidly.
Having mentioned that, we additionally discovered that we spent far more time on the person
interface (about 80%) than the AI itself (about 20%), particularly in
engineering the prompts.
We additionally stored our immediate templates so simple as doable, devoid of
conditional statements. After we wanted to drastically adapt the immediate based mostly
on the person enter, reminiscent of when the person clicks “Add particulars (alerts,
threats, alternatives)”, we determined to run a unique immediate template
altogether, within the curiosity of conserving our immediate templates from changing into
too complicated and laborious to take care of.
Structured Response
Inform the LLM to reply in a structured knowledge format
Virtually any utility you construct with LLMs will most definitely must parse
the output of the LLM to create some structured or semi-structured knowledge to
additional function on on behalf of the person. For Boba, we needed to work with
JSON as a lot as doable, so we tried many various variations of getting
GPT to return well-formed JSON. We have been fairly shocked by how effectively and
constantly GPT returns well-formed JSON based mostly on the directions in our
prompts. For instance, right here’s what the situation technology response
directions would possibly appear to be:
You'll reply with solely a legitimate JSON array of situation objects. Every situation object may have the next schema: "title": <string>, //Have to be an entire sentence written up to now tense "abstract": <string>, //State of affairs description "plausibility": <string>, //Plausibility of situation "horizon": <string>
We have been equally shocked by the truth that it might help pretty complicated
nested JSON schemas, even once we described the response schemas in pseudo-code.
Right here’s an instance of how we’d describe a nested response for technique
technology:
You'll reply in JSON format containing two keys, "questions" and "methods", with the respective schemas under: "questions": [<list of question objects, with each containing the following keys:>] "query": <string>, "reply": <string> "methods": [<list of strategy objects, with each containing the following keys:>] "title": <string>, "abstract": <string>, "problem_diagnosis": <string>, "winning_aspiration": <string>, "where_to_play": <string>, "how_to_win": <string>, "assumptions": <string>
An fascinating facet impact of describing the JSON response schema was that we
might additionally nudge the LLM to supply extra related responses within the output. For
instance, for the Artistic Matrix, we would like the LLM to consider many various
dimensions (the immediate, the row, the columns, and every concept that responds to the
immediate on the intersection of every row and column):
By offering a few-shot immediate that features a particular instance of the output
schema, we have been in a position to get the LLM to “suppose” in the proper context for every
concept (the context being the immediate, row and column):
You'll reply with a legitimate JSON array, by row by column by concept. For instance: If Rows = "row 0, row 1" and Columns = "column 0, column 1" then you'll reply with the next: [ {{ "row": "row 0", "columns": [ {{ "column": "column 0", "ideas": [ {{ "title": "Idea 0 title for prompt and row 0 and column 0", "description": "idea 0 for prompt and row 0 and column 0" }} ] }}, {{ "column": "column 1", "concepts": [ {{ "title": "Idea 0 title for prompt and row 0 and column 1", "description": "idea 0 for prompt and row 0 and column 1" }} ] }}, ] }}, {{ "row": "row 1", "columns": [ {{ "column": "column 0", "ideas": [ {{ "title": "Idea 0 title for prompt and row 1 and column 0", "description": "idea 0 for prompt and row 1 and column 0" }} ] }}, {{ "column": "column 1", "concepts": [ {{ "title": "Idea 0 title for prompt and row 1 and column 1", "description": "idea 0 for prompt and row 1 and column 1" }} ] }} ] }} ]
We might have alternatively described the schema extra succinctly and
typically, however by being extra elaborate and particular in our instance, we
efficiently nudged the standard of the LLM’s response within the route we
needed. We consider it is because LLMs “suppose” in tokens, and outputting (ie
repeating) the row and column values earlier than outputting the concepts supplies extra
correct context for the concepts being generated.
On the time of this writing, OpenAI has launched a brand new characteristic referred to as
Operate
Calling, which
supplies a unique solution to obtain the objective of formatting responses. On this
method, a developer can describe callable perform signatures and their
respective schemas as JSON, and have the LLM return a perform name with the
respective parameters supplied in JSON that conforms to that schema. That is
notably helpful in situations once you wish to invoke exterior instruments, reminiscent of
performing an online search or calling an API in response to a immediate. Langchain
additionally supplies comparable performance, however I think about they’ll quickly present native
integration between their exterior instruments API and the OpenAI perform calling
API.
Actual-Time Progress
Stream the response to the UI so customers can monitor progress
One of many first few stuff you’ll understand when implementing a graphical
person interface on prime of an LLM is that ready for your entire response to
full takes too lengthy. We don’t discover this as a lot with ChatGPT as a result of
it streams the response character by character. This is a crucial person
interplay sample to bear in mind as a result of, in our expertise, a person can
solely wait on a spinner for thus lengthy earlier than shedding persistence. In our case, we
didn’t need the person to attend various seconds earlier than they began
seeing a response, even when it was a partial one.
Therefore, when implementing a co-pilot expertise, we extremely suggest
exhibiting real-time progress throughout the execution of prompts that take extra
than a number of seconds to finish. In our case, this meant streaming the
generations throughout the complete stack, from the LLM again to the UI in real-time.
Fortuitously, the Langchain and OpenAI APIs present the power to do exactly
that:
const chat = new ChatOpenAI({ temperature: 1, modelName: 'gpt-3.5-turbo', streaming: true, callbackManager: onTokenStream ? CallbackManager.fromHandlers({ async handleLLMNewToken(token) { onTokenStream(token) }, }) : undefined });
This allowed us to supply the real-time progress wanted to create a smoother
expertise for the person, together with the power to cease a technology
mid-completion if the concepts being generated didn’t match the person’s
expectations:
Nonetheless, doing so provides a variety of extra complexity to your utility
logic, particularly on the view and controller. Within the case of Boba, we additionally had
to carry out best-effort parsing of JSON and keep temporal state throughout the
execution of an LLM name. On the time of scripting this, some new and promising
libraries are popping out that make this simpler for internet builders. For instance,
the Vercel AI SDK is a library for constructing
edge-ready AI-powered streaming textual content and chat UIs.
Choose and Carry Context
Seize and add related context info to subsequent motion
One of many largest limitations of a chat interface is {that a} person is
restricted to a single-threaded context: the dialog chat window. When
designing a co-pilot expertise, we suggest pondering deeply about find out how to
design UX affordances for performing actions throughout the context of a
choice, just like our pure inclination to level at one thing in actual
life within the context of an motion or description.
Choose and Carry Context permits the person to slender or broaden the scope of
interplay to carry out subsequent duties – also called the duty context. That is usually
achieved by choosing a number of parts within the person interface after which performing an motion on them.
Within the case of Boba, for instance, we use this sample to permit the person to have
a narrower, centered dialog about an concept by choosing it (eg a situation, technique or
prototype idea), in addition to to pick and generate variations of a
idea. First, the person selects an concept (both explicitly with a checkbox or implicitly by clicking a hyperlink):
Then, when the person performs an motion on the choice, the chosen merchandise(s) are carried over as context into the brand new activity,
for instance as situation subprompts for technique technology when the person clicks “Brainstorm methods and questions for this situation”,
or as context for a pure language dialog when the person clicks Discover:
Relying on the character and size of the context
you want to set up for a phase of dialog/interplay, implementing
Choose and Carry Context may be anyplace from very straightforward to very tough. When
the context is temporary and might match right into a single LLM context window (the utmost
dimension of a immediate that the LLM helps), we are able to implement it by means of immediate
engineering alone. For instance, in Boba, as proven above, you possibly can click on “Discover”
on an concept and have a dialog with Boba about that concept. The way in which we
implement this within the backend is to create a multi-message chat
dialog:
const chatPrompt = ChatPromptTemplate.fromPromptMessages([ HumanMessagePromptTemplate.fromTemplate(contextPrompt), HumanMessagePromptTemplate.fromTemplate("{input}"), ]); const formattedPrompt = await chatPrompt.formatPromptValue({ enter: enter })
One other strategy of implementing Choose and Carry Context is to take action inside
the immediate by offering the context inside tag delimiters, as proven under. In
this case, the person has chosen a number of situations and needs to generate
methods for these situations (a way usually utilized in situation constructing and
stress testing of concepts). The context we wish to carry into the technique
technology is assortment of chosen situations:
Your questions and methods should be particular to realizing the next potential future situations (if any) <situations> {scenarios_subprompt} </situations>
Nonetheless, when your context outgrows an LLM’s context window, or in the event you want
to supply a extra subtle chain of previous interactions, you’ll have to
resort to utilizing exterior short-term reminiscence, which usually entails utilizing a
vector retailer (in-memory or exterior). We’ll give an instance of find out how to do
one thing comparable in Embedded Exterior Data.
If you wish to be taught extra in regards to the efficient use of choice and
context in generative purposes, we extremely suggest a chat given by
Linus Lee, of Notion, on the LLMs in Manufacturing convention: “Generative Experiences Past Chat”.
Contextual Dialog
Enable direct dialog with the LLM inside a context.
It is a particular case of Choose and Carry Context.
Whereas we needed Boba to interrupt out of the chat window interplay mannequin
as a lot as doable, we discovered that it’s nonetheless very helpful to supply the
person a “fallback” channel to converse straight with the LLM. This permits us
to supply a conversational expertise for interactions we don’t help in
the UI, and help circumstances when having a textual pure language
dialog does take advantage of sense for the person.
Within the instance under, the person is chatting with Boba a couple of idea for
personalised spotlight reels supplied by Rogers Sportsnet. The whole
context is talked about as a chat message (“On this idea, Uncover a world of
sports activities you’re keen on…”), and the person has requested Boba to create a person journey for
the idea. The response from the LLM is formatted and rendered as Markdown:
When designing generative co-pilot experiences, we extremely suggest
supporting contextual conversations along with your utility. Be sure to
provide examples of helpful messages the person can ship to your utility so
they know what sort of conversations they will have interaction in. Within the case of
Boba, as proven within the screenshot above, these examples are provided as
message templates below the enter field, reminiscent of “Are you able to be extra
particular?”
Out-Loud Pondering
Inform LLM to generate intermediate outcomes whereas answering
Whereas LLMs don’t really “suppose”, it’s price pondering metaphorically
a couple of phrase by Andrei Karpathy of OpenAI: “LLMs ‘suppose’ in
tokens.” What he means by this
is that GPTs are likely to make extra reasoning errors when attempting to reply a
query straight away, versus once you give them extra time (i.e. extra tokens)
to “suppose”. In constructing Boba, we discovered that utilizing Chain of Thought (CoT)
prompting, or extra particularly, asking for a series of reasoning earlier than an
reply, helped the LLM to motive its manner towards higher-quality and extra
related responses.
In some elements of Boba, like technique and idea technology, we ask the
LLM to generate a set of questions that increase on the person’s enter immediate
earlier than producing the concepts (methods and ideas on this case).
Whereas we show the questions generated by the LLM, an equally efficient
variant of this sample is to implement an inside monologue that the person is
not uncovered to. On this case, we might ask the LLM to suppose by means of their
response and put that interior monologue right into a separate a part of the response, that
we are able to parse out and ignore within the outcomes we present to the person. A extra elaborate
description of this sample may be present in OpenAI’s GPT Greatest Practices
Information, within the
part Give GPTs time to
“suppose”
As a person expertise sample for generative purposes, we discovered it useful
to share the reasoning course of with the person, wherever applicable, in order that the
person has extra context to iterate on the subsequent motion or immediate. For
instance, in Boba, understanding the sorts of questions that Boba considered offers the
person extra concepts about divergent areas to discover, or to not discover. It additionally
permits the person to ask Boba to exclude sure lessons of concepts within the subsequent
iteration. For those who do go down this path, we suggest making a UI affordance
for hiding a monologue or chain of thought, reminiscent of Boba’s characteristic to toggle
examples proven above.
Iterative Response
Present affordances for the person to have a back-and-forth
interplay with the co-pilot
LLMs are certain to both misunderstand the person’s intent or just
generate responses that don’t meet the person’s expectations. Therefore, so is
your generative utility. One of the highly effective capabilities that
distinguishes ChatGPT from conventional chatbots is the power to flexibly
iterate on and refine the route of the dialog, and therefore enhance
the standard and relevance of the responses generated.
Equally, we consider that the standard of a generative co-pilot
expertise is dependent upon the power of a person to have a fluid back-and-forth
interplay with the co-pilot. That is what we name the Iterate on Response
sample. This may contain a number of approaches:
- Correcting the unique enter supplied to the appliance/LLM
- Refining part of the co-pilot’s response to the person
- Offering suggestions to nudge the appliance in a unique route
One instance of the place we’ve carried out Iterative Response
in
Boba is in Storyboarding. Given a immediate (both temporary or elaborate), Boba
can generate a visible storyboard, which incorporates a number of scenes, with every
scene having a story script and a picture generated with Secure
Diffusion. For instance, under is a partial storyboard describing the expertise of a
“Resort of the Future”:
Since Boba makes use of the LLM to generate the Secure Diffusion immediate, we don’t
know the way good the photographs will prove–so it’s a little bit of a hit and miss with
this characteristic. To compensate for this, we determined to supply the person the
capability to iterate on the picture immediate in order that they will refine the picture for
a given scene. The person would do that by merely clicking on the picture,
updating the Secure Diffusion immediate, and urgent Executed, upon which Boba
would generate a brand new picture with the up to date immediate, whereas preserving the
remainder of the storyboard:
One other instance Iterative Response that we
are at the moment engaged on is a characteristic for the person to supply suggestions
to Boba on the standard of concepts generated, which might be a mix
of Choose and Carry Context and Iterative Response. One
method could be to provide a thumbs up or thumbs down on an concept, and
letting Boba incorporate that suggestions into a brand new or subsequent set of
suggestions. One other method could be to supply conversational
suggestions within the type of pure language. Both manner, we want to
do that in a mode that helps reinforcement studying (the concepts get
higher as you present extra suggestions). instance of this may be
Github Copilot, which demotes code options which have been ignored by
the person in its rating of subsequent greatest code options.
We consider that this is without doubt one of the most necessary, albeit
generically-framed, patterns to implementing efficient generative
experiences. The difficult half is incorporating the context of the
suggestions into subsequent responses, which can usually require implementing
short-term or long-term reminiscence in your utility due to the restricted
dimension of context home windows.
Embedded Exterior Data
Mix LLM with different info sources to entry knowledge past
the LLM’s coaching set
As alluded to earlier on this article, oftentimes your generative
purposes will want the LLM to include exterior instruments (reminiscent of an API
name) or exterior reminiscence (short-term or long-term). We bumped into this
situation once we have been implementing the Analysis characteristic in Boba, which
permits customers to reply qualitative analysis questions based mostly on publicly
obtainable info on the internet, for instance “How is the resort business
utilizing generative AI as we speak?”:
To implement this, we needed to “equip” the LLM with Google as an exterior
internet search software and provides the LLM the power to learn probably lengthy
articles that will not match into the context window of a immediate. We additionally
needed Boba to have the ability to chat with the person about any related articles the
person finds, which required implementing a type of short-term reminiscence. Lastly,
we needed to supply the person with correct hyperlinks and references that have been
used to reply the person’s analysis query.
The way in which we carried out this in Boba is as follows:
- Use a Google SERP API to carry out the net search based mostly on the person’s question
and get the highest 10 articles (search outcomes) - Learn the complete content material of every article utilizing the Extract API
- Save the content material of every article in short-term reminiscence, particularly an
in-memory vector retailer. The embeddings for the vector retailer are generated utilizing
the OpenAI API, and based mostly on chunks of every article (versus embedding your entire
article itself). - Generate an embedding of the person’s search question
- Question the vector retailer utilizing the embedding of the search question
- Immediate the LLM to reply the person’s unique question in pure language,
whereas prefixing the outcomes of the vector retailer question as context into the LLM
immediate.
This may occasionally sound like a variety of steps, however that is the place utilizing a software like
Langchain can velocity up your course of. Particularly, Langchain has an
end-to-end chain referred to as VectorDBQAChain, and utilizing that to carry out the
question-answering took only some traces of code in Boba:
const researchArticle = async (article, immediate) => { const mannequin = new OpenAI({}); const textual content = article.textual content; const textSplitter = new RecursiveCharacterTextSplitter({ chunkSize: 1000 }); const docs = await textSplitter.createDocuments([text]); const vectorStore = await HNSWLib.fromDocuments(docs, new OpenAIEmbeddings()); const chain = VectorDBQAChain.fromLLM(mannequin, vectorStore); const res = await chain.name({ input_documents: docs, question: immediate + ". Be detailed in your response.", }); return { research_answer: res.textual content }; };
The article textual content comprises your entire content material of the article, which can not
match inside a single immediate. So we carry out the steps described above. As you possibly can
see, we used an in-memory vector retailer referred to as HNSWLib (Hierarchical Navigable
Small World). HNSW graphs are among the many top-performing indexes for vector
similarity search. Nonetheless, for bigger scale use circumstances and/or long-term reminiscence,
we suggest utilizing an exterior vector DB like Pinecone or Weaviate.
We additionally might have additional streamlined our workflow by utilizing Langchain’s
exterior instruments API to carry out the Google search, however we determined in opposition to it
as a result of it offloaded an excessive amount of resolution making to Langchain, and we have been getting
combined, sluggish and harder-to-parse outcomes. One other method to implementing
exterior instruments is to make use of Open AI’s just lately launched Operate Calling
API, which we
talked about earlier on this article.
To summarize, we mixed two distinct strategies to implement Embedded Exterior Data:
- Use Exterior Instrument: Search and skim articles utilizing Google SERP and Extract
APIs - Use Exterior Reminiscence: Quick-term reminiscence utilizing an in-memory vector retailer
(HNSWLib)