InstantDB website screenshot

InstantDB

InstantDB (Instant) is a realtime client-side database and Firebase alternative that gives apps a sync engine with multiplayer, offline mode, and optimistic updates by default. It exposes an HTTP Admin API (api.instantdb.com) for server-side InstaQL queries and InstaML transactions, plus auth, storage, presence, and a realtime WebSocket sync layer.

InstantDB publishes 6 APIs on the APIs.io network, including Realtime Sync API, Auth API, Presence API, and 3 more. Tagged areas include Database, Real-Time, Sync, Backend, and Local-First.

The InstantDB catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

InstantDB’s developer surface includes authentication, documentation, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub
42.2/100 developing ▬ flat Agent 23/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0
AccessFreemiumSelf serve⚡ Free to try
1 APIs
DatabaseReal-TimeSyncBackendLocal-First

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Composite quality — 42.2/100 · developing
Contract Quality 14.1 / 23
Developer Ergonomics 5.8 / 18
Access Clarity 7.1 / 18
Operational Transparency 4.0 / 12
Contract Governance 1.5 / 11
Discoverability 6.2 / 9
Create-or-Update Ergonomics 0.0 / 10
Agent readiness — 23/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 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 7 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 6 / 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 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Well-Known Document 0 / 5
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
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 github.com/api-evangelist/instantdb: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 6

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

InstantDB Realtime Sync API

The realtime sync transport - a persistent WebSocket at wss://api.instantdb.com/runtime/session over which the client Reactor sends init, add-query, transact, and presence ops a...

InstantDB Auth API

Server-side authentication, tokens, and users.

InstantDB Presence API

Room presence lookups.

InstantDB Query API

InstaQL read queries.

InstantDB Storage API

File upload, listing, and deletion.

InstantDB Transactions API

InstaML transaction writes.

Open Collections 7

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

InstantDB Admin HTTP Auth API

OPEN COLLECTION

InstantDB Admin HTTP Auth Presence API

OPEN COLLECTION

InstantDB Admin HTTP Auth Query API

OPEN COLLECTION

InstantDB Admin HTTP Auth Storage API

OPEN COLLECTION

InstantDB Admin HTTP Auth Transactions API

OPEN COLLECTION

InstantDB Admin HTTP API

OPEN COLLECTION

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Instantdb Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Instantdb Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Instantdb Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

InstantDB Realtime Sync (WebSocket)

AsyncAPI 2.6 description of InstantDB's **realtime sync** surface. Unlike a request/response REST API, InstantDB is a sync engine. The client SDK's **Reactor** opens a persisten...

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

InstantDB API Rules

7 rules · 1 errors 5 warnings 1 info

SPECTRAL

Security Posture 2

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

Instantdb Authentication

http · 1 scheme

SECURITY

Instantdb Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Instantdb Agentic Access

14 operations · 12 acting

14 operations · 12 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 FinOps
FinOps

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: instantdb
url: https://raw.githubusercontent.com/api-evangelist/instantdb/refs/heads/main/apis.yml
name: InstantDB
kind: company
description: InstantDB (Instant) is a realtime client-side database and Firebase alternative that gives apps a sync engine
  with multiplayer, offline mode, and optimistic updates by default. It exposes an HTTP Admin API (api.instantdb.com) for
  server-side InstaQL queries and InstaML transactions, plus auth, storage, presence, and a realtime WebSocket sync layer.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/instantdb.png
tags:
- Database
- Real-Time
- Sync
- Backend
- Local-First
tags_raw:
- Database
- Realtime
- Sync
- Backend
- Local First
created: '2026-06-20'
modified: '2026-06-20'
specificationVersion: '0.23'
apis:
- aid: instantdb:instantdb-realtime-sync-api
  name: InstantDB Realtime Sync API
  tags:
  - Real-Time
  - WebSocket
  - Sync
  - Presence
  tags_raw:
  - Realtime
  - WebSocket
  - Sync
  - Presence
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.instantdb.com/essays/architecture
  baseURL: wss://api.instantdb.com/runtime/session
  properties:
  - url: https://www.instantdb.com/essays/architecture
    type: Documentation
  - url: https://www.instantdb.com/docs/presence-and-topics
    type: APIReference
  - url: asyncapi/instantdb-asyncapi.yml
    type: AsyncAPI
  description: The realtime sync transport - a persistent WebSocket at wss://api.instantdb.com/runtime/session over which
    the client Reactor sends init, add-query, transact, and presence ops and the server streams query novelty (refresh-ok),
    presence, and broadcasts back to subscribers.
- aid: instantdb:instantdb-auth-api
  name: InstantDB Auth API
  description: Server-side authentication, tokens, and users.
  humanURL: https://www.instantdb.com/docs/http-api
  baseURL: https://api.instantdb.com
  tags:
  - Authentication
  tags_raw:
  - Auth
  properties:
  - type: OpenAPI
    url: openapi/instantdb-auth-api-openapi.yml
  - type: Documentation
    url: https://www.instantdb.com/docs/http-api
  - type: APIReference
    url: https://www.instantdb.com/docs/http-api
  - type: Postman
    url: collections/instantdb.postman_collection.json
  - type: Documentation
    url: https://www.instantdb.com/docs/instaql
  - type: Documentation
    url: https://www.instantdb.com/docs/instaml
  - type: Documentation
    url: https://www.instantdb.com/docs/auth
  - type: Documentation
    url: https://www.instantdb.com/docs/storage
- aid: instantdb:instantdb-presence-api
  name: InstantDB Presence API
  description: Room presence lookups.
  humanURL: https://www.instantdb.com/docs/http-api
  baseURL: https://api.instantdb.com
  tags:
  - Presence
  properties:
  - type: OpenAPI
    url: openapi/instantdb-presence-api-openapi.yml
  - type: Documentation
    url: https://www.instantdb.com/docs/http-api
  - type: APIReference
    url: https://www.instantdb.com/docs/http-api
  - type: Postman
    url: collections/instantdb.postman_collection.json
  - type: Documentation
    url: https://www.instantdb.com/docs/instaql
  - type: Documentation
    url: https://www.instantdb.com/docs/instaml
  - type: Documentation
    url: https://www.instantdb.com/docs/auth
  - type: Documentation
    url: https://www.instantdb.com/docs/storage
- aid: instantdb:instantdb-query-api
  name: InstantDB Query API
  description: InstaQL read queries.
  humanURL: https://www.instantdb.com/docs/http-api
  baseURL: https://api.instantdb.com
  tags:
  - Query
  properties:
  - type: OpenAPI
    url: openapi/instantdb-query-api-openapi.yml
  - type: Documentation
    url: https://www.instantdb.com/docs/http-api
  - type: APIReference
    url: https://www.instantdb.com/docs/http-api
  - type: Postman
    url: collections/instantdb.postman_collection.json
  - type: Documentation
    url: https://www.instantdb.com/docs/instaql
  - type: Documentation
    url: https://www.instantdb.com/docs/instaml
  - type: Documentation
    url: https://www.instantdb.com/docs/auth
  - type: Documentation
    url: https://www.instantdb.com/docs/storage
- aid: instantdb:instantdb-storage-api
  name: InstantDB Storage API
  description: File upload, listing, and deletion.
  humanURL: https://www.instantdb.com/docs/http-api
  baseURL: https://api.instantdb.com
  tags:
  - Storage
  properties:
  - type: OpenAPI
    url: openapi/instantdb-storage-api-openapi.yml
  - type: Documentation
    url: https://www.instantdb.com/docs/http-api
  - type: APIReference
    url: https://www.instantdb.com/docs/http-api
  - type: Postman
    url: collections/instantdb.postman_collection.json
  - type: Documentation
    url: https://www.instantdb.com/docs/instaql
  - type: Documentation
    url: https://www.instantdb.com/docs/instaml
  - type: Documentation
    url: https://www.instantdb.com/docs/auth
  - type: Documentation
    url: https://www.instantdb.com/docs/storage
- aid: instantdb:instantdb-transactions-api
  name: InstantDB Transactions API
  description: InstaML transaction writes.
  humanURL: https://www.instantdb.com/docs/http-api
  baseURL: https://api.instantdb.com
  tags:
  - Transaction
  tags_raw:
  - Transactions
  properties:
  - type: OpenAPI
    url: openapi/instantdb-transactions-api-openapi.yml
  - type: Documentation
    url: https://www.instantdb.com/docs/http-api
  - type: APIReference
    url: https://www.instantdb.com/docs/http-api
  - type: Postman
    url: collections/instantdb.postman_collection.json
  - type: Documentation
    url: https://www.instantdb.com/docs/instaql
  - type: Documentation
    url: https://www.instantdb.com/docs/instaml
  - type: Documentation
    url: https://www.instantdb.com/docs/auth
  - type: Documentation
    url: https://www.instantdb.com/docs/storage
common:
- type: AgenticAccess
  url: agentic-access/instantdb-agentic-access.yml
- type: DomainSecurity
  url: security/instantdb-domain-security.yml
- type: Authentication
  url: authentication/instantdb-authentication.yml
- type: GitHubOrganization
  url: https://github.com/instantdb
- type: LinkedIn
  url: https://www.linkedin.com/company/instantdb
- type: Website
  url: https://www.instantdb.com
- type: Documentation
  url: https://www.instantdb.com/docs
- type: Plans
  url: plans/instantdb-plans-pricing.yml
- type: RateLimits
  url: rate-limits/instantdb-rate-limits.yml
- type: FinOps
  url: finops/instantdb-finops.yml
- url: https://www.instantdb.com/rss.xml
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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/instantdb"
All providers 
curl "https://apis.io/api/v1/providers?limit=25"
Every operation they expose 
curl "https://apis.io/api/v1/providers/instantdb/operations?limit=25"
How their score was established 
curl "https://apis.io/api/v1/providers/instantdb/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.