Chalk

Chalk is a real-time AI/ML data platform ("Context Engine") that lets teams define features, embeddings, LLM outputs, and prompts once in Python and serve them everywhere — training, real-time inference, and agents — computed on infrastructure the customer controls. Instead of stitching together a feature store, vector database, retrieval and prompt tooling, orchestration, and a sandbox runtime, Chalk unifies them: features are point-in-time correct, served in single-digit milliseconds, and deployed via a branch-based model inside the customer's own cloud. It exposes a REST API and gRPC client libraries (Python, TypeScript, Go, Java, C#), a first-party CLI, OAuth 2.0 authentication, and MCP-scoped agent access. Backed by Felicis and General Catalyst.

Chalk is listed with 1 API on the APIs.io network. Tagged areas include Company, Machine Learning, Feature Store, Artificial Intelligence, and Data Platform.

Chalk’s developer surface includes documentation, API reference, getting-started guide, engineering blog, signup flow, changelog, authentication, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

42.1/100 developing ▬ flat Agent 11/100 agent aware Front door AI 5/6 prominent saas Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

AccessSelf serve

1 API

Company Machine Learning Feature Store Artificial Intelligence Data Platform MLOps Real-Time Data LLM AgentsFeature Engineering

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 42.1/100 · developing

Contract Quality 0.0 / 21

Developer Ergonomics 12.5 / 17

Access Clarity 7.2 / 17

Operational Transparency 5.2 / 11

Contract Governance 1.9 / 10

Discoverability 5.6 / 9

Regulatory Posture 6.3 / 15

Agent readiness — 11/100 · agent aware

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/chalk/"><img src="https://apis.io/badge/chalk/card.svg" alt="Chalk on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Raise your score.

Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Access Clarity scores 42.1 — up to +11.6 composite points
Contract Governance scores 18.2 — up to +9.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/chalk/apis.yml: open an issue on github.com/api-evangelist/chalk to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
MLOps and AI/ML Infrastructure (LF AI & Data, MLPerf, Kubeflow)	builds-on	32.6	-	1
Official SDKs on Package Registries	builds-on	32.6	-	1
Agent Skills (SKILL.md packages)	builds-on	32.6	-	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

Chalk API

REST + gRPC API for querying features from the Chalk Context Engine — online single-row queries, bulk (feather/Arrow) queries, and asynchronous offline dataset generation — plus...

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Chalk Authentication

oauth2/http · 3 schemes

SECURITY

Chalk Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Chalk Vulnerability Disclosure

contact published

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Chalk Scopes

3 scopes · authorizationCode/clientCredentials

3 scopes

SCOPES

Resources

Get Started 5

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Login

SignUp

SignUp

Sandbox

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

X-MCPServerCandidate

X-MCPServerCandidate

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Conventions

Conventions

Lifecycle

Lifecycle

Conformance

Conformance

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

Access & Security 6

Authentication, authorization, and security posture

Authentication

OAuthScopes

Compliance

DomainSecurity

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

Security

Operate 3

Status, limits, changes, and where to get help

StatusPage

StatusPage

ChangeLog

ChangeLog

ChangeLog

ChangeLog

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: chalk
name: Chalk
description: 'Chalk is a real-time AI/ML data platform ("Context Engine") that lets teams define features, embeddings, LLM
  outputs, and prompts once in Python and serve them everywhere — training, real-time inference, and agents — computed on
  infrastructure the customer controls. Instead of stitching together a feature store, vector database, retrieval and prompt
  tooling, orchestration, and a sandbox runtime, Chalk unifies them: features are point-in-time correct, served in single-digit
  milliseconds, and deployed via a branch-based model inside the customer''s own cloud. It exposes a REST API and gRPC client
  libraries (Python, TypeScript, Go, Java, C#), a first-party CLI, OAuth 2.0 authentication, and MCP-scoped agent access.
  Backed by Felicis and General Catalyst.'
url: https://raw.githubusercontent.com/api-evangelist/chalk/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- felicis
- general-catalyst
x-tier: stub
x-tier-reason: portfolio-lead
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-18'
image: https://chalk.ai/opengraph.png
tags:
- Company
- Machine Learning
- Feature Store
- Artificial Intelligence
- Data Platform
- MLOps
- Real-Time Data
- LLM
- Agents
- Feature Engineering
tags_raw:
- Company
- Machine Learning
- Feature Store
- Artificial Intelligence
- Data Platform
- MLOps
- Real-Time Data
- LLM
- Agents
- Feature Engineering
- Machine-Learning
apis:
- name: Chalk API
  description: REST + gRPC API for querying features from the Chalk Context Engine — online single-row queries, bulk (feather/Arrow)
    queries, and asynchronous offline dataset generation — plus deployment of feature and resolver definitions. OAuth 2.0
    (client_credentials) Bearer authentication.
  humanURL: https://docs.chalk.ai/api-docs
  baseURL: https://api.chalk.ai
  tags:
  - Machine Learning
  - Feature Store
  - Real-Time Data
  tags_raw:
  - Machine Learning
  - Feature Store
  - Real-Time Data
  - Machine-Learning
  properties:
  - type: Authentication
    url: authentication/chalk-authentication.yml
  - type: OAuthScopes
    url: scopes/chalk-scopes.yml
  - type: Conventions
    url: conventions/chalk-conventions.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://chalk.ai
- type: DeveloperPortal
  url: https://docs.chalk.ai
- type: Documentation
  url: https://docs.chalk.ai/docs/overview
- type: APIReference
  url: https://docs.chalk.ai/api-docs
- type: GettingStarted
  url: https://docs.chalk.ai/docs/getting-started
- type: Blog
  url: https://chalk.ai/blog
- type: GitHubOrganization
  url: https://github.com/chalk-ai
- type: Login
  url: https://chalk.ai/login
- type: SignUp
  url: https://chalk.ai/book-demo
- type: TermsOfService
  url: https://chalk.ai/legal/terms
- type: PrivacyPolicy
  url: https://chalk.ai/legal/privacy
- type: StatusPage
  url: https://chalk.statuspage.io
- type: ChangeLog
  url: https://docs.chalk.ai/docs/changelog
- type: ChangeLog
  url: changelog/chalk-changelog.yml
- type: Authentication
  url: authentication/chalk-authentication.yml
- type: OAuthScopes
  url: scopes/chalk-scopes.yml
- type: Packages
  url: packages/chalk-packages.yml
- type: SDKs
  url: packages/chalk-packages.yml
- type: CLI
  url: cli/chalk-cli.yml
- type: X-MCPServerCandidate
  url: mcp/chalk-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: LLMsTxt
  url: llms/chalk-llms.txt
- type: WellKnown
  url: well-known/chalk-well-known.yml
- type: Conventions
  url: conventions/chalk-conventions.yml
- type: Lifecycle
  url: lifecycle/chalk-lifecycle.yml
- type: Sandbox
  url: sandbox/chalk-sandbox.yml
- type: Conformance
  url: conformance/chalk-conformance.yml
- type: Compliance
  url: https://docs.chalk.ai/docs/security
- type: DomainSecurity
  url: security/chalk-domain-security.yml
- type: VulnerabilityDisclosure
  url: security/chalk-vulnerability-disclosure.yml
- type: Security
  url: https://docs.chalk.ai/docs/security
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

Chalk API — frequently asked questions

Does Chalk have an API?

Yes. APIs.io lists 1 API from Chalk, including Chalk API.

How do I authenticate with the Chalk API?

Chalk documents its authentication (oauth2/http · 3 schemes). The details are profiled on APIs.io as Chalk Authentication.

Is the Chalk API ready for AI agents?

Chalk has a Kin Score of 42.1 out of 100 (developing) and an Agent Readiness score of 10.8 (agent-aware), scored by API Evangelist on 2026-10-31.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/chalk"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/chalk/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/chalk/evidence"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.