Fluentd

Open source data collector for unified logging layer that allows you to unify data collection and consumption for better use and understanding of data.

Fluentd publishes 2 APIs on the APIs.io network: Forward Protocol and Events API. Tagged areas include Data Collection, Logging, and Open-Source.

The Fluentd catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 2 Spectral governance rulesets.

Fluentd’s developer surface includes documentation, getting-started guide, engineering blog, changelog, support, and 16 more developer resources.

🌐 Visit website 📡 Source on GitHub

42.1/100 developing ▬ flat Agent 23/100 agent aware self hosted · Apache-2.0 Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemium

1 APIs

Data Collection Logging Open-Source

Kin Score

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

Composite quality — 42.1/100 · developing

Contract Quality 11.9 / 20

Developer Ergonomics 5.7 / 16

Access Clarity 2.5 / 16

Operational Transparency 3.8 / 10

Contract Governance 1.3 / 10

Discoverability 3.8 / 8

Open Source Surface 10.0 / 10

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 0 / 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

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 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 80 points between them, because the conditional facet above carries the other 20. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 80% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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/fluentd: 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 3

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

Fluentd Plugin API

The Fluentd Plugin API allows developers to write custom input, output, filter, parser, formatter, and buffer plugins in Ruby. Plugins are distributed as RubyGems and integrate ...

Fluentd Forward Protocol

The Fluentd Forward Protocol is a binary protocol used to transport event streams between Fluentd nodes and compatible agents over TCP. It supports multiple transport modes incl...

Fluentd Events API

Operations for posting log events and records to Fluentd via HTTP.

Open Collections 3

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

API Collection

OPEN COLLECTION

Fluentd HTTP Input Events API

OPEN COLLECTION

Fluentd HTTP Input API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Fluentd Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Fluentd Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Fluentd Finops

FINOPS

Event Specifications 1

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

Fluentd Forward Protocol

The Fluentd Forward Protocol is a binary MessagePack-based protocol used to transport event streams between Fluentd nodes, Fluent Bit agents, and compatible forwarders over TCP ...

ASYNCAPI

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Fluentd Context

0 classes · 7 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

Fluentd API Rules

5 rules · 5 warnings

SPECTRAL

Fluentd API Rules

6 rules · 4 warnings 2 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Fluentd Log Event

3 properties

JSON SCHEMA

Security Posture 1

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

Fluentd Domain Security

TLSv1.3 · HSTS

SECURITY

Agentic Access 1

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

Fluentd Agentic Access

2 operations · 2 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 3

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

JSONSchema

JSONSchema

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LlmsText

LlmsText

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

JSONLD

JSONLD

Build 3

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

GitHubOrganization

GitHubOrganization

GitHubRepository

GitHubRepository

Access & Security 2

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

DomainSecurity

DomainSecurity

Operate 6

Status, limits, changes, and where to get help

IssueTracker

Releases

ChangeLog

Community

Support

Slack

Commercial 1

Pricing, plans, and the legal terms of use

License

License

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: fluentd
name: Fluentd
description: Open source data collector for unified logging layer that allows you to unify data collection and consumption
  for better use and understanding of data.
type: Index
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/fluentd.png
url: https://raw.githubusercontent.com/api-evangelist/fluentd/refs/heads/main/apis.yml
created: '2025-01-01'
modified: '2026-05-19'
specificationVersion: '0.23'
tags:
- Data Collection
- Logging
- Open-Source
tags_raw:
- Data Collection
- Logging
- Open Source
apis:
- aid: fluentd:fluentd-plugin-api
  name: Fluentd Plugin API
  description: The Fluentd Plugin API allows developers to write custom input, output, filter, parser, formatter, and buffer
    plugins in Ruby. Plugins are distributed as RubyGems and integrate with Fluentd's plugin management system to extend data
    collection and processing pipelines.
  humanURL: https://docs.fluentd.org/plugin-development
  tags:
  - Open-Source
  - Plugin Development
  - Ruby
  tags_raw:
  - Open Source
  - Plugin Development
  - Ruby
  properties:
  - type: Documentation
    url: https://docs.fluentd.org/plugin-development
  - type: Reference
    url: https://docs.fluentd.org/plugin-development/api-plugin-base
- aid: fluentd:fluentd-forward-protocol
  name: Fluentd Forward Protocol
  description: The Fluentd Forward Protocol is a binary protocol used to transport event streams between Fluentd nodes and
    compatible agents over TCP. It supports multiple transport modes including Message, Forward, PackedForward, and CompressedPackedForward,
    and includes authentication and heartbeat mechanisms.
  humanURL: https://github.com/fluent/fluentd/wiki/Forward-Protocol-Specification-v1
  tags:
  - Logging
  - Networking
  - Protocol
  properties:
  - type: Documentation
    url: https://github.com/fluent/fluentd/wiki/Forward-Protocol-Specification-v1
  - type: Reference
    url: https://docs.fluentd.org/input/forward
  - type: AsyncAPI
    url: asyncapi/fluentd-forward-protocol-asyncapi.yml
- aid: fluentd:fluentd-events-api
  name: Fluentd Events API
  description: Operations for posting log events and records to Fluentd via HTTP.
  humanURL: https://docs.fluentd.org/plugin-development
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/fluentd-events-api-openapi.yml
  - type: Documentation
    url: https://docs.fluentd.org/input/http
common:
- type: IssueTracker
  url: https://github.com/fluent/fluentd/issues
- type: Releases
  url: https://github.com/fluent/fluentd/releases
- type: SecurityPolicy
  url: https://github.com/fluent/fluentd/blob/master/SECURITY.md
- type: CodeOfConduct
  url: https://github.com/fluent/fluentd/blob/master/code-of-conduct.md
- type: ContributionGuide
  url: https://github.com/fluent/fluentd/blob/master/CONTRIBUTING.md
- type: License
  name: Apache-2.0
  url: https://github.com/fluent/fluentd/blob/master/LICENSE
- type: AgenticAccess
  url: agentic-access/fluentd-agentic-access.yml
- type: DomainSecurity
  url: security/fluentd-domain-security.yml
- type: JSONSchema
  url: json-schema/fluentd-log-event-schema.json
- type: JSONLD
  url: json-ld/fluentd-context.jsonld
- type: Website
  url: https://www.fluentd.org/
- type: Documentation
  url: https://docs.fluentd.org/
- type: GettingStarted
  url: https://docs.fluentd.org/quickstart
- type: GitHubOrganization
  url: https://github.com/fluent
- type: GitHubRepository
  url: https://github.com/fluent/fluentd
- type: Blog
  url: https://www.fluentd.org/blog/
- type: ChangeLog
  url: https://github.com/fluent/fluentd/blob/master/CHANGELOG.md
- type: Community
  url: https://www.fluentd.org/community/
- type: Support
  url: https://docs.fluentd.org/quickstart/support
- type: Slack
  url: https://slack.fluentd.org/
- type: LlmsText
  url: https://docs.fluentd.org/llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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