Express Gateway

Express Gateway is an open-source (Apache-2.0) microservices and serverless API gateway built on Express.js and Node.js. Operators install it themselves and compose policies — key auth, OAuth 2.0, JWT, CORS, rate limiting, request and response transforms, proxying — into pipelines declared in a single YAML config, fronting their own downstream services. Its own HTTP surface is the Admin API, which manages users, applications, credentials, scopes, schemas, policies, endpoints and pipelines, and which binds by default to localhost:9876 rather than to any host the project runs. The project is dormant: the last release reached npm in April 2021.

Express Gateway publishes 4 APIs on the APIs.io network, including Apps API, Credentials API, Scopes API, and 1 more. Tagged areas include API Composition, API Gateway, BFF, Open Source, and Microservices.

Express Gateway’s developer surface includes authentication, documentation, API reference, getting-started guide, support, engineering blog, CLI, and 19 more developer resources.

🌐 Visit website 📡 Source on GitHub

35.4/100 thin ▬ flat Agent 24/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemiumSelf serve⚡ Free to try

1 APIs

API Composition API GatewayBFFOpen SourceMicroservices Authentication Node.js Reverse Proxy

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 35.4/100 · thin

Contract Quality 10.9 / 23

Developer Ergonomics 10.2 / 18

Access Clarity 1.4 / 18

Operational Transparency 2.8 / 12

Contract Governance 2.0 / 11

Discoverability 5.3 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 24/100 · 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 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 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/express-gateway: 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 5

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

Express Gateway

Express Gateway is an API gateway built on Express.js for managing and securing microservices and APIs.

Express Gateway Apps API

The Apps API from Express Gateway — 3 operation(s) for apps.

Express Gateway Credentials API

The Credentials API from Express Gateway — 6 operation(s) for credentials.

Express Gateway Scopes API

The Scopes API from Express Gateway — 2 operation(s) for scopes.

Express Gateway Users API

The Users API from Express Gateway — 3 operation(s) for users.

Open Collections 6

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

API Collection

OPEN COLLECTION

Express Gateway Admin Apps API

OPEN COLLECTION

Express Gateway Admin Apps Credentials API

OPEN COLLECTION

Express Gateway Admin Apps Scopes API

OPEN COLLECTION

Express Gateway Admin Apps Users API

OPEN COLLECTION

Express Gateway Admin API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Express Gateway Plans Pricing

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Express Gateway Rate Limits

0 limits

RATE LIMITS

FinOps 1

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

Express Gateway Finops

FINOPS

Security Posture 2

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

Express Gateway Authentication

apiKey · 1 scheme

SECURITY

Express Gateway Domain Security

TLSv1.3 · HSTS

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Express Gateway Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Agentic Access 1

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

Express Gateway Agentic Access

25 operations · 16 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

AgentSkill

AgentSkill

LLMsTxt

LLMsTxt

X-MCPServerCandidate

X-MCPServerCandidate

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Lifecycle

Conventions

Conformance

ErrorCatalog

DataModel

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

CLI

CLI

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

OAuthScopes

OAuthScopes

Operate 4

Status, limits, changes, and where to get help

Support

Roadmap

ChangeLog

RateLimits

Commercial 1

Pricing, plans, and the legal terms of use

Plans

Plans

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: express-gateway
name: Express Gateway
description: 'Express Gateway is an open-source (Apache-2.0) microservices and serverless API gateway built on Express.js
  and Node.js. Operators install it themselves and compose policies — key auth, OAuth 2.0, JWT, CORS, rate limiting, request
  and response transforms, proxying — into pipelines declared in a single YAML config, fronting their own downstream services.
  Its own HTTP surface is the Admin API, which manages users, applications, credentials, scopes, schemas, policies, endpoints
  and pipelines, and which binds by default to localhost:9876 rather than to any host the project runs. The project is dormant:
  the last release reached npm in April 2021.'
type: Index
deliveryModel:
  model: open-source-self-hosted
  open_source: true
  commercial: false
  callable_host: false
  label: Open source, self-hosted — Apache-2.0, no vendor-operated endpoint
  confidence: high
  source:
  - https://github.com/ExpressGateway/express-gateway
  - https://registry.npmjs.org/express-gateway
  note: 'Corrected 2026-09-07. The GitHub API reports the repository licence as Apache-2.0 and the runtime is distributed
    on npm and Docker Hub, so open_source is true, not false. There is no vendor-operated host: the Admin API''s documented
    default binding is http://localhost:9876. Commercial backing ended with LunchBadger, whose site now returns 522.'
  generated: '2026-09-07'
  method: searched
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/express-gateway.png
tags:
- API Composition
- API Gateway
- BFF
- Open Source
- Microservices
- Authentication
- Node.js
- Reverse Proxy
url: https://raw.githubusercontent.com/api-evangelist/express-gateway/refs/heads/main/apis.yml
created: '2026-03-27'
modified: '2026-09-07'
position: Producing
access: Open Source
specificationVersion: '0.23'
apis:
- aid: express-gateway:express-gateway
  name: Express Gateway
  description: Express Gateway is an API gateway built on Express.js for managing and securing microservices and APIs.
  humanURL: https://www.express-gateway.io/
  tags:
  - API Composition
  - API Gateway
  properties:
  - type: Documentation
    url: https://www.express-gateway.io/docs/
  - type: GettingStarted
    url: https://www.express-gateway.io/getting-started/
- aid: express-gateway:express-gateway-apps-api
  name: Express Gateway Apps API
  description: The Apps API from Express Gateway — 3 operation(s) for apps.
  humanURL: https://www.express-gateway.io/
  tags:
  - Application
  tags_raw:
  - Apps
  properties:
  - type: OpenAPI
    url: openapi/express-gateway-apps-api-openapi.yml
- aid: express-gateway:express-gateway-credentials-api
  name: Express Gateway Credentials API
  description: The Credentials API from Express Gateway — 6 operation(s) for credentials.
  humanURL: https://www.express-gateway.io/
  tags:
  - Credentials
  properties:
  - type: OpenAPI
    url: openapi/express-gateway-credentials-api-openapi.yml
- aid: express-gateway:express-gateway-scopes-api
  name: Express Gateway Scopes API
  description: The Scopes API from Express Gateway — 2 operation(s) for scopes.
  humanURL: https://www.express-gateway.io/
  tags:
  - Scopes
  properties:
  - type: OpenAPI
    url: openapi/express-gateway-scopes-api-openapi.yml
- aid: express-gateway:express-gateway-users-api
  name: Express Gateway Users API
  description: The Users API from Express Gateway — 3 operation(s) for users.
  humanURL: https://www.express-gateway.io/
  tags:
  - User
  tags_raw:
  - Users
  properties:
  - type: OpenAPI
    url: openapi/express-gateway-users-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/express-gateway-agentic-access.yml
- type: DomainSecurity
  url: security/express-gateway-domain-security.yml
- type: Authentication
  url: authentication/express-gateway-authentication.yml
- type: Website
  url: https://www.express-gateway.io/
- type: Documentation
  url: https://www.express-gateway.io/docs/
- type: GitHubOrganization
  url: https://github.com/ExpressGateway
- type: APIReference
  url: https://www.express-gateway.io/docs/admin/
- type: GettingStarted
  url: https://www.express-gateway.io/getting-started/
- type: Support
  url: https://github.com/ExpressGateway/express-gateway/issues
- type: Blog
  url: https://www.express-gateway.io/blog/
- type: Roadmap
  url: https://www.express-gateway.io/docs/roadmap/
- type: Packages
  url: packages/express-gateway-packages.yml
- type: CLI
  url: cli/express-gateway-cli.yml
- type: ChangeLog
  url: changelog/express-gateway-changelog.yml
- type: Lifecycle
  url: lifecycle/express-gateway-lifecycle.yml
- type: Conventions
  url: conventions/express-gateway-conventions.yml
- type: Conformance
  url: conformance/express-gateway-conformance.yml
- type: ErrorCatalog
  url: errors/express-gateway-problem-types.yml
- type: OAuthScopes
  url: scopes/express-gateway-scopes.yml
- type: DataModel
  url: data-model/express-gateway-data-model.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/express-gateway-llms.txt
- type: Overlay
  url: overlays/express-gateway-admin-api-overlay.yaml
- type: Plans
  url: plans/express-gateway-plans-pricing.yml
- type: RateLimits
  url: rate-limits/express-gateway-rate-limits.yml
- type: X-MCPServerCandidate
  url: mcp/express-gateway-mcp.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-09-07'
  status: enriched
  artifacts_added: 16
  pass: local-v3

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