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 API contracts indexed 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 9 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

31.1/100 thin ▬ flat Agent 47/100 agent ready Front door AI 4/6 moderate Heartbeat 83/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract 1 MCP Servers

Database Real-Time Sync Backend Local-First

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Cybersecurity Management

BC-620

Auth

POST /admin/magic_code POST /admin/verify_magic_code GET /admin/users POST /admin/sign_out

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 31.1/100 · thin

Contract Quality 10.9 / 19

Developer Ergonomics 4.8 / 15

Access Clarity 1.2 / 15

Operational Transparency 1.0 / 10

Contract Governance 1.2 / 9

Discoverability 5.1 / 8

Regulatory Posture 1.8 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 47/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 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 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

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 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.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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

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)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too
Agent Skills +5 pts — skills artifact present, graded by who authored it
Agentic Commerce Well-Known Document +5 pts — a parsing /.well-known/ucp.json or acp.json declaring a version and at least one service, OR (0.27) a live x402 payment challenge from _data/x402-adoption.json — `self` when its endpoints are on the provider's own domain, `platform` when they are on a vendor's

3 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 7.9 — up to +18.4 composite points
Developer Ergonomics scores 32.1 — up to +13.6 composite points
Operational Transparency scores 10.5 — up to +11.6 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/instantdb/apis.yml: open an issue on github.com/api-evangelist/instantdb 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
Agent Skills (SKILL.md packages)	undeclared	-	-	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.

Standards implemented 5

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (verified)

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

AsyncAPI

measured — observed by APIs.io (published)

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 6

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

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

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

InstantDB MCP Server

Remote MCP server at mcp.instantdb.com over HTTP.

MCP SERVER

InstantDB API pricing

Not yet checked against InstantDB's own pricing page. Compiled by API Evangelist on 2026-06-20 from www.instantdb.com/pricing; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free free	—
Pro paid	—
Startup paid	—
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

API Requests: unlimited (per published plans) requests
Database Storage: 1GB Free / 10GB Pro / 250GB Startup storage
Admin HTTP API: see provider documentation requests

Compiled by API Evangelist, not yet checked against InstantDB's documentation. All 5 limits →

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

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

InstantDB

SLA

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 — asyncapi 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

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

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Source (apis.yml)

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
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-06'
  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: CapabilityMap
  url: capabilities/instantdb-capability-edges.yml
  name: InstantDB Business Capability Map
- 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

InstantDB API — frequently asked questions

Does InstantDB have an API?

Yes. APIs.io lists 6 APIs from InstantDB, including InstantDB Realtime Sync API, InstantDB Auth API and InstantDB Presence API, and 3 more.

Is there an OpenAPI specification for the InstantDB API?

Yes. APIs.io indexes 5 OpenAPI specifications for InstantDB, each linked for download from this page.

How do I authenticate with the InstantDB API?

InstantDB documents its authentication (http · 1 scheme). The details are profiled on APIs.io as Instantdb Authentication.

How much does the InstantDB API cost?

APIs.io lists 4 pricing plans for InstantDB, with each plan's price, limits and inclusions under Pricing on this page.

Does InstantDB have an MCP server?

Yes. APIs.io lists 1 MCP server for InstantDB: Remote MCP server at mcp.instantdb.com over HTTP.

Is the InstantDB API ready for AI agents?

InstantDB has a Kin Score of 31.1 out of 100 (thin) and an Agent Readiness score of 47.4 (agent-ready), scored by API Evangelist on 2026-11-06.

Work with this as data

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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.

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