# Weights and Biases

**Canonical:** https://apis.io/providers/wandb/  
**Website:** https://wandb.ai/  
**APIs profiled:** 16

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.

## Kin Score — 37.1 / 100 (thin)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 37.1).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 53.4 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 26.3 |
| Developer Ergonomics | 21.4 |
| Commercial Clarity | 39.5 |
| Access Clarity | 39.5 |

## Agent readiness — 35.9 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | verified |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Free · Self-serve signup — onboarding: self-serve, pricing: free, trial: no (confidence: high).

## APIs (16)

- **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.

## Agentic access (1)

- **Wandb Agentic Access** — 29 operations · 27 acting

## Security (3)

- **Wandb Authentication** — http · 1 scheme
- **Wandb Domain Security** — TLSv1.3 · HSTS · DNSSEC · DMARC
- **Wandb Vulnerability Disclosure** — disclosure policy published

## Plans (1)

- **Wandb Plans Pricing**

## Tags

MLOps, Experiment Tracking, LLM Observability, Model Registry, AI Platform, Evaluation, Tracing

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/wandb/). Scores are computed from the provider's own public artifacts under a published rubric.