Weights and Biases

Weights and Biases (W&B) is an MLOps and AI developer platform covering the full lifecycle of model and LLM application development. W&B Models provides experiment tracking, hyperparameter sweeps, artifacts, model registry, and reports. W&B Weave provides LLM tracing, evaluation, cost tracking, guardrails, and prompt/playground tooling for production AI applications. Three CoreWeave- powered serverless capabilities sit alongside the core platform: Serverless Inference (OpenAI-compatible API for open-source foundation models), Serverless RL (post-training with ART/RULER), and Serverless Sandboxes (isolated code execution). The platform exposes a Python SDK, a public REST API, and a GraphQL API at api.wandb.ai, with CLI tooling and webhook integrations. W&B was acquired by CoreWeave in 2025.

Weights and Biases publishes 9 APIs on the APIs.io network, including Calls API, Costs API, Feedback API, and 6 more. Tagged areas include MLOps, Experiment Tracking, LLM Observability, Model Registry, and AI Platform.

Weights and Biases’ developer surface includes authentication, documentation, GitHub presence, pricing, engineering blog, and 17 more developer resources.

🌐 Visit website 📡 Source on GitHub

43.4/100 developing ▬ flat Agent 26/100 agent aware open core · Apache-2.0 Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreeSelf serve⚡ Free to try

1 APIs

MLOps Experiment Tracking LLM Observability Model Registry AI Platform Evaluation Tracing

Kin Score

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

Composite quality — 43.4/100 · developing

Contract Quality 10.4 / 20

Developer Ergonomics 3.4 / 16

Access Clarity 6.3 / 16

Operational Transparency 5.5 / 10

Contract Governance 0.0 / 10

Discoverability 6.1 / 8

Open Source Surface 8.5 / 10

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 26/100 · 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 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/wandb: 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 16

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

W&B GraphQL API

Primary programmatic surface for W&B Models. The Python public API (wandb.Api) speaks GraphQL against api.wandb.ai to query and manage runs, projects, sweeps, artifacts, registr...

W&B REST API

REST endpoints exposed by the W&B platform for ingestion, artifact upload, file storage, and integration callbacks. Used internally by the wandb SDK and CLI, and available to cu...

W&B Weave (LLM Observability)

LLM observability and evaluation platform providing tracing, output evaluation, cost estimation, prompt playground, guardrails, and a Python and TypeScript SDK. Traces and evalu...

W&B Python SDK

Official Python SDK (wandb) for logging runs, metrics, gradients, media, and artifacts; running sweeps; and interacting with the W&B public API. Apache-2.0 licensed.

W&B CLI

Command-line interface bundled with the wandb Python package for login, sweep orchestration, artifact management, and local agent execution.

W&B Serverless Inference (CoreWeave)

OpenAI-compatible inference API for hosted open-source foundation models, running on CoreWeave GPU infrastructure with native Weave tracing and usage tracking.

W&B Webhook Automations

Outbound webhook integrations driven by W&B automations. Customers register endpoints that W&B POSTs to when configured events fire (artifact created, alias added, run state cha...

Weights and Biases Calls API

The Calls API from Weights and Biases — 8 operation(s) for calls.

Weights and Biases Costs API

The Costs API from Weights and Biases — 3 operation(s) for costs.

Weights and Biases Feedback API

The Feedback API from Weights and Biases — 4 operation(s) for feedback.

Weights and Biases Files API

The Files API from Weights and Biases — 2 operation(s) for files.

Weights and Biases Objects API

The Objects API from Weights and Biases — 4 operation(s) for objects.

Weights and Biases Refs API

The Refs API from Weights and Biases — 1 operation(s) for refs.

Weights and Biases Service API

The Service API from Weights and Biases — 2 operation(s) for service.

Weights and Biases Table API

The Table API from Weights and Biases — 1 operation(s) for table.

Weights and Biases Tables API

The Tables API from Weights and Biases — 4 operation(s) for tables.

Scroll for all 16

Open Collections 11

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

API Collection

OPEN COLLECTION

Fast Calls API

OPEN COLLECTION

Fast Calls Costs API

OPEN COLLECTION

Fast Calls Feedback API

OPEN COLLECTION

Fast Calls Files API

OPEN COLLECTION

Fast Calls Objects API

OPEN COLLECTION

Fast Calls Refs API

OPEN COLLECTION

Fast Calls Service API

OPEN COLLECTION

Fast Calls Table API

OPEN COLLECTION

Fast Calls Tables API

OPEN COLLECTION

FastAPI

OPEN COLLECTION

Scroll for all 11

GraphQL 1

GraphQL schemas published by this provider.

Weights and Biases GraphQL API

Primary programmatic surface for W&B Models. The Python public API (wandb.Api) speaks GraphQL against api.wandb.ai to query and manage runs, projects, sweeps, artifacts, registr...

GRAPHQL

Pricing Plans 1

Published pricing tiers and plan structures.

Wandb Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Wandb Rate Limits

2 limits

RATE LIMITS

FinOps 1

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

Wandb Finops

FINOPS

Security Posture 3

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

Wandb Authentication

http · 1 scheme

SECURITY

Wandb Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Wandb Vulnerability Disclosure

disclosure policy published

SECURITY

Agentic Access 1

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

Wandb Agentic Access

29 operations · 27 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LlmsText

LlmsText

Build 1

SDKs, sample code, and the tooling you integrate with

GitHub

GitHub

Access & Security 4

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 3

Status, limits, changes, and where to get help

IssueTracker

IssueTracker

Releases

Releases

RateLimits

RateLimits

Commercial 4

Pricing, plans, and the legal terms of use

License

Pricing

Plans

FinOps

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Other 3

Properties that don't map to a standard resource type

ParentCompany

ParentCompany

Weave

Weave

Parent

Parent

Source (apis.yml)

aid: wandb
url: https://raw.githubusercontent.com/api-evangelist/wandb/refs/heads/main/apis.yml
name: Weights and Biases
kind: company
description: 'Weights and Biases (W&B) is an MLOps and AI developer platform covering the full lifecycle of model and LLM
  application development. W&B Models provides experiment tracking, hyperparameter sweeps, artifacts, model registry, and
  reports. W&B Weave provides LLM tracing, evaluation, cost tracking, guardrails, and prompt/playground tooling for production
  AI applications. Three CoreWeave- powered serverless capabilities sit alongside the core platform: Serverless Inference
  (OpenAI-compatible API for open-source foundation models), Serverless RL (post-training with ART/RULER), and Serverless
  Sandboxes (isolated code execution). The platform exposes a Python SDK, a public REST API, and a GraphQL API at api.wandb.ai,
  with CLI tooling and webhook integrations. W&B was acquired by CoreWeave in 2025.'
deliveryModel:
  model: open-core
  license: Apache-2.0
  open_source: true
  commercial: true
  callable_host: true
  label: Open core · an OSS project plus a commercial hosted product
  confidence: high
  source:
  - license
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Free · 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/wandb.png
tags:
- MLOps
- Experiment Tracking
- LLM Observability
- Model Registry
- AI Platform
- Evaluation
- Tracing
created: '2026-05-23'
modified: '2026-05-23'
specificationVersion: '0.23'
apis:
- aid: wandb:graphql
  name: W&B GraphQL API
  description: Primary programmatic surface for W&B Models. The Python public API (wandb.Api) speaks GraphQL against api.wandb.ai
    to query and manage runs, projects, sweeps, artifacts, registries, reports, automations, slack and webhook integrations,
    and viewer/entity context.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - GraphQL
  - Runs
  - Artifacts
  - Sweeps
  - Model Registry
  properties:
  - type: Documentation
    url: https://docs.wandb.ai/ref/python/public-api/api/
  - url: graphql/wandb-graphql.md
    type: GraphQL
- aid: wandb:rest
  name: W&B REST API
  description: REST endpoints exposed by the W&B platform for ingestion, artifact upload, file storage, and integration callbacks.
    Used internally by the wandb SDK and CLI, and available to customers for direct integration.
  humanURL: https://docs.wandb.ai/
  baseURL: https://api.wandb.ai
  tags:
  - REST
  - Ingestion
  - Artifacts
  properties:
  - type: Documentation
    url: https://docs.wandb.ai/
- aid: wandb:weave
  name: W&B Weave (LLM Observability)
  description: LLM observability and evaluation platform providing tracing, output evaluation, cost estimation, prompt playground,
    guardrails, and a Python and TypeScript SDK. Traces and evaluations are persisted to the W&B backend and queryable via
    the Weave SDK.
  humanURL: https://weave-docs.wandb.ai/
  baseURL: https://api.wandb.ai
  tags:
  - LLM
  - Observability
  - Tracing
  - Evaluation
  - Guardrails
  properties:
  - type: Documentation
    url: https://weave-docs.wandb.ai/
  - type: Repository
    url: https://github.com/wandb/weave
- aid: wandb:python-sdk
  name: W&B Python SDK
  description: Official Python SDK (wandb) for logging runs, metrics, gradients, media, and artifacts; running sweeps; and
    interacting with the W&B public API. Apache-2.0 licensed.
  humanURL: https://docs.wandb.ai/ref/python/
  baseURL: https://github.com/wandb/wandb
  tags:
  - SDK
  - Python
  properties:
  - type: Repository
    url: https://github.com/wandb/wandb
  - type: Package
    url: https://pypi.org/project/wandb/
- aid: wandb:cli
  name: W&B CLI
  description: Command-line interface bundled with the wandb Python package for login, sweep orchestration, artifact management,
    and local agent execution.
  humanURL: https://docs.wandb.ai/ref/cli/
  baseURL: https://docs.wandb.ai/ref/cli/
  tags:
  - CLI
  - Sweeps
  - Agents
  properties:
  - type: Documentation
    url: https://docs.wandb.ai/ref/cli/
- aid: wandb:serverless-inference
  name: W&B Serverless Inference (CoreWeave)
  description: OpenAI-compatible inference API for hosted open-source foundation models, running on CoreWeave GPU infrastructure
    with native Weave tracing and usage tracking.
  humanURL: https://docs.wandb.ai/guides/inference
  baseURL: https://api.inference.wandb.ai/v1
  tags:
  - Inference
  - OpenAI-Compatible
  - LLM
  - Serverless
  properties:
  - type: Documentation
    url: https://docs.wandb.ai/guides/inference
- aid: wandb:webhook-automations
  name: W&B Webhook Automations
  description: Outbound webhook integrations driven by W&B automations. Customers register endpoints that W&B POSTs to when
    configured events fire (artifact created, alias added, run state changes, registry events).
  humanURL: https://docs.wandb.ai/guides/automations/
  baseURL: customer-configured
  tags:
  - Webhook
  - Automations
  - Event
  tags_raw:
  - Webhooks
  - Automations
  - Events
  properties:
  - type: Documentation
    url: https://docs.wandb.ai/guides/automations/
- aid: wandb:wandb-calls-api
  name: Weights and Biases Calls API
  description: The Calls API from Weights and Biases — 8 operation(s) for calls.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Calls
  properties:
  - type: OpenAPI
    url: openapi/wandb-calls-api-openapi.yml
- aid: wandb:wandb-costs-api
  name: Weights and Biases Costs API
  description: The Costs API from Weights and Biases — 3 operation(s) for costs.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Costs
  properties:
  - type: OpenAPI
    url: openapi/wandb-costs-api-openapi.yml
- aid: wandb:wandb-feedback-api
  name: Weights and Biases Feedback API
  description: The Feedback API from Weights and Biases — 4 operation(s) for feedback.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Feedback
  properties:
  - type: OpenAPI
    url: openapi/wandb-feedback-api-openapi.yml
- aid: wandb:wandb-files-api
  name: Weights and Biases Files API
  description: The Files API from Weights and Biases — 2 operation(s) for files.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - File
  tags_raw:
  - Files
  properties:
  - type: OpenAPI
    url: openapi/wandb-files-api-openapi.yml
- aid: wandb:wandb-objects-api
  name: Weights and Biases Objects API
  description: The Objects API from Weights and Biases — 4 operation(s) for objects.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Objects
  properties:
  - type: OpenAPI
    url: openapi/wandb-objects-api-openapi.yml
- aid: wandb:wandb-refs-api
  name: Weights and Biases Refs API
  description: The Refs API from Weights and Biases — 1 operation(s) for refs.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Refs
  properties:
  - type: OpenAPI
    url: openapi/wandb-refs-api-openapi.yml
- aid: wandb:wandb-service-api
  name: Weights and Biases Service API
  description: The Service API from Weights and Biases — 2 operation(s) for service.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Service
  properties:
  - type: OpenAPI
    url: openapi/wandb-service-api-openapi.yml
- aid: wandb:wandb-table-api
  name: Weights and Biases Table API
  description: The Table API from Weights and Biases — 1 operation(s) for table.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Table
  properties:
  - type: OpenAPI
    url: openapi/wandb-table-api-openapi.yml
- aid: wandb:wandb-tables-api
  name: Weights and Biases Tables API
  description: The Tables API from Weights and Biases — 4 operation(s) for tables.
  humanURL: https://docs.wandb.ai/ref/python/public-api/api/
  baseURL: https://api.wandb.ai/graphql
  tags:
  - Tables
  properties:
  - type: OpenAPI
    url: openapi/wandb-tables-api-openapi.yml
common:
- type: ParentCompany
  url: https://apis.io/providers/coreweave/
  name: CoreWeave
  x-relationship: acquired
  x-evidence: W&B was acquired by CoreWeave in 2025.
- type: IssueTracker
  url: https://github.com/wandb/weave/issues
- type: Releases
  url: https://github.com/wandb/weave/releases
- type: SecurityPolicy
  url: https://github.com/wandb/weave/blob/master/SECURITY.md
- type: ContributionGuide
  url: https://github.com/wandb/weave/blob/master/CONTRIBUTING.md
- type: License
  name: Apache-2.0
  url: https://github.com/wandb/weave/blob/master/LICENSE
- type: AgenticAccess
  url: agentic-access/wandb-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/wandb-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/wandb-domain-security.yml
- type: Authentication
  url: authentication/wandb-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/wandbai
- type: Website
  url: https://wandb.ai/
- type: Documentation
  url: https://docs.wandb.ai/
- type: GitHub
  url: https://github.com/wandb
- type: Weave
  url: https://weave-docs.wandb.ai/
- type: Pricing
  url: https://wandb.ai/site/pricing/
- type: Parent
  url: https://www.coreweave.com/
- type: Plans
  url: plans/wandb-plans-pricing.yml
- type: RateLimits
  url: rate-limits/wandb-rate-limits.yml
- type: FinOps
  url: finops/wandb-finops.yml
- type: LlmsText
  url: https://docs.wandb.ai/llms.txt
- type: Blog
  url: https://wandb.ai/fully-connected
integrations:
- name: PyTorch
- name: TensorFlow
- name: Hugging Face
- name: Keras
- name: scikit-learn
- name: OpenAI
- name: Anthropic
- name: LangChain
- name: LlamaIndex
- name: Slack
- name: GitHub
- name: Kubernetes
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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