EngFlow

EngFlow provides remote build execution, remote caching, CI runners, and a Build & Test UI that accelerate large-scale software builds for Bazel, BuildStream, Goma, Pants, Soong, CMake, and Buck2. EngFlow clusters expose a gRPC / Protocol Buffers API surface — the open Remote Execution API (REAPI v2) and Remote Asset API, plus EngFlow's own cluster, IAM, authentication, event store, result store, secret, notification, and resource-usage services, all published as Protocol Buffer interface definitions in the EngFlow/engflowapis repository. Clusters authenticate via mTLS, cluster-issued JWT bearer tokens, OIDC federation, SAML, GitHub tokens, and basic auth, and provision users over SCIM 2.0. EngFlow was founded by former Google/Bazel engineers and is backed by a16z.

EngFlow is listed with 1 API on the APIs.io network. Tagged areas include Company, Remote Execution, Remote Caching, Build Systems, and Bazel.

EngFlow’s developer surface includes documentation, API reference, getting-started guide, engineering blog, pricing, signup flow, support, and 25 more developer resources.

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47.2/100 developing ▬ flat Agent 16/100 agent aware Front door AI 2/6 trace Heartbeat 87/100 alive open core · Apache-2.0 Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 API 2 Agent Skills

Company Remote ExecutionRemote CachingBuild SystemsBazelCI/CD Developer Tools gRPC Protocol Buffers DevOps Continuous Integration

Kin Score

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

Composite quality — 47.2/100 · developing

Contract Quality 4.5 / 19

Developer Ergonomics 11.0 / 15

Access Clarity 11.1 / 15

Operational Transparency 1.8 / 10

Contract Governance 1.6 / 9

Discoverability 5.5 / 8

Regulatory Posture 4.4 / 15

Open Source Surface 2.5 / 10

Agent readiness — 16/100 · agent aware

Machine-Readable Contract 18 / 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 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

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.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against 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 75 points between them, because both conditional facets apply and carry 25 points together. 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):

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)
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
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)

10 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 24.0 — up to +19.0 composite points
Operational Transparency scores 18.4 — up to +10.6 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/engflow/apis.yml: open an issue on github.com/api-evangelist/engflow 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
Buf Schema Registry (public Protocol Buffers modules, gRPC / ConnectRPC schema publishers)	standard	26.8 (thin)	-	-

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 2

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.

gRPC

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

Protocol Buffers

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

APIs 1

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

EngFlow Cluster API (gRPC)

The EngFlow cluster gRPC / Protocol Buffers API surface — cluster info, IAM (roles/policies/users/groups), authentication, event store and result store build-event streaming, se...

Agent Skills 2

Packaged agent skills for driving this provider's APIs from an AI assistant.

Manage EngFlow IAM roles

AGENT SKILL

Stream EngFlow build and invocation events

AGENT SKILL

EngFlow API pricing

Prices published by EngFlow, read 2026-10-28 from www.engflow.com/product/pricing. A free plan or tier is listed.

Plan	Price
Free	Free Includes: Single-machine remote execution, in-cluster remote caching, Build and Test UI, Bazel, Linux; max 1 m
Enterprise	Get a custom quote Includes: Remote execution on hundreds to thousands of machines, external storage caching, Bazel/Goma/Soong, L

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

Engflow Plans Pricing

2 plans

PLANS

FinOps 1

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

Engflow Finops

FINOPS

Security Posture 2

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

Engflow Authentication

mutualTLS/http-bearer/oauth2/openIdConnect/saml/http-basic/scim · 7 schemes

SECURITY

Engflow Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

X-MCPServerCandidate

WellKnown

LLMsTxt

AgentSkill

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Conformance

Conventions

Lifecycle

DataModel

Build 5

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

SourceCode

Packages

SDKs

CLI

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Compliance

Compliance

Operate 3

Status, limits, changes, and where to get help

IssueTracker

IssueTracker

Releases

Releases

Support

Support

Commercial 5

Pricing, plans, and the legal terms of use

Plans

License

Pricing

TermsOfService

PrivacyPolicy

Company 3

The organization behind the API

BlogRSS

BlogRSS

Website

Website

Blog

Blog

Source (apis.yml)

aid: engflow
name: EngFlow
description: EngFlow provides remote build execution, remote caching, CI runners, and a Build & Test UI that accelerate large-scale
  software builds for Bazel, BuildStream, Goma, Pants, Soong, CMake, and Buck2. EngFlow clusters expose a gRPC / Protocol
  Buffers API surface — the open Remote Execution API (REAPI v2) and Remote Asset API, plus EngFlow's own cluster, IAM, authentication,
  event store, result store, secret, notification, and resource-usage services, all published as Protocol Buffer interface
  definitions in the EngFlow/engflowapis repository. Clusters authenticate via mTLS, cluster-issued JWT bearer tokens, OIDC
  federation, SAML, GitHub tokens, and basic auth, and provision users over SCIM 2.0. EngFlow was founded by former Google/Bazel
  engineers and is backed by a16z.
url: https://raw.githubusercontent.com/api-evangelist/engflow/refs/heads/main/apis.yml
deliveryModel:
  model: open-core
  license: Apache-2.0
  open_source: true
  commercial: true
  callable_host: false
  label: Open core · an OSS project plus a commercial hosted product
  confidence: high
  source:
  - license
  - 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://avatars.githubusercontent.com/u/61729484?v=4
x-type: company
x-source: vc-portfolio
x-backed-by:
- a16z
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-10-06'
x-docs-platform: mkdocs
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-03
tags:
- Company
- Remote Execution
- Remote Caching
- Build Systems
- Bazel
- CI/CD
- Developer Tools
- gRPC
- Protocol Buffers
- DevOps
- Continuous Integration
apis:
- name: EngFlow Cluster API (gRPC)
  description: The EngFlow cluster gRPC / Protocol Buffers API surface — cluster info, IAM (roles/policies/users/groups),
    authentication, event store and result store build-event streaming, secret management, and notifications — as published
    in the EngFlow/engflowapis interface-definition repository, alongside the open Remote Execution API (REAPI v2) and Remote
    Asset API that EngFlow implements.
  humanURL: https://docs.engflow.com/re/index.html
  baseURL: https://docs.engflow.com
  x-transport: grpc
  x-note: EngFlow clusters are customer-hosted; the gRPC endpoint is per-cluster (grpcs://<cluster-host>). No single public
    base URL exists — humanURL/baseURL point at the public developer docs host.
  properties:
  - type: Protobuf
    name: Cluster service (proto)
    url: grpc/engflow-cluster.proto
  - type: Protobuf
    name: Identity and Access Management service (proto)
    url: grpc/engflow-identity_and_access_management.proto
  - type: Protobuf
    name: Authentication service (proto)
    url: grpc/engflow-authentication.proto
  - type: Protobuf
    name: Event Store service (proto)
    url: grpc/engflow-eventstore.proto
  - type: Protobuf
    name: Result Store service (proto)
    url: grpc/engflow-resultstore.proto
  - type: Protobuf
    name: Secret service (proto)
    url: grpc/engflow-secret.proto
  - type: Protobuf
    name: Notification service (proto)
    url: grpc/engflow-notification.proto
common:
- type: Plans
  url: plans/engflow-plans-pricing.yml
- url: https://blog.engflow.com/feed_rss_created.xml
  type: BlogRSS
- type: IssueTracker
  url: https://github.com/EngFlow/engflowapis/issues
- type: Releases
  url: https://github.com/EngFlow/engflowapis/releases
- type: License
  name: Apache-2.0
  url: https://github.com/EngFlow/engflowapis/blob/main/LICENSE
- type: DomainSecurity
  url: security/engflow-domain-security.yml
- type: Website
  url: https://www.engflow.com
- type: DeveloperPortal
  url: https://docs.engflow.com
- type: Documentation
  url: https://docs.engflow.com
- type: APIReference
  url: https://github.com/EngFlow/engflowapis
- type: GettingStarted
  url: https://docs.engflow.com/re/index.html
- type: Blog
  url: https://blog.engflow.com
- type: GitHubOrganization
  url: https://github.com/EngFlow
- type: Pricing
  url: https://www.engflow.com/product/pricing
- type: SignUp
  url: https://www.engflow.com/contact
- type: Support
  url: https://www.engflow.com/contact
- type: TermsOfService
  url: https://www.engflow.com/terms
- type: PrivacyPolicy
  url: https://www.engflow.com/privacy
- type: SourceCode
  url: https://github.com/EngFlow/engflowapis
- type: Packages
  url: packages/engflow-packages.yml
- type: SDKs
  url: packages/engflow-packages.yml
- type: CLI
  url: cli/engflow-cli.yml
- type: Authentication
  url: authentication/engflow-authentication.yml
- type: Conformance
  url: conformance/engflow-conformance.yml
- type: Compliance
  url: https://docs.engflow.com
- type: Conventions
  url: conventions/engflow-conventions.yml
- type: Lifecycle
  url: lifecycle/engflow-lifecycle.yml
- type: DataModel
  url: data-model/engflow-data-model.yml
- type: X-MCPServerCandidate
  url: mcp/engflow-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: WellKnown
  url: well-known/engflow-well-known.yml
- type: LLMsTxt
  url: llms/engflow-llms.txt
- type: AgentSkill
  url: skills/_index.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

EngFlow API — frequently asked questions

Does EngFlow have an API?

Yes. APIs.io lists 1 API from EngFlow, including EngFlow Cluster API (gRPC).

How do I authenticate with the EngFlow API?

EngFlow uses bearer-token authentication (mutualTLS/http-bearer/oauth2/openIdConnect/saml/http-basic/scim · 7 schemes). The details are profiled on APIs.io as Engflow Authentication.

How much does the EngFlow API cost?

EngFlow publishes its prices; its Enterprise plan is Get a custom quote as of 2026-10-28. APIs.io lists 2 pricing plans for EngFlow, with each plan's price, limits and inclusions under Pricing on this page.

Is the EngFlow API ready for AI agents?

EngFlow has a Kin Score of 47.2 out of 100 (developing) and an Agent Readiness score of 16.4 (agent-aware), scored by API Evangelist on 2026-11-06.

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