Feature for feature these two are close: tracing, experiments, online evals, human review and prompt versioning. HoneyHive is a standalone agent platform with a free tier and Enterprise contracts, and covers coding agents and business-app agents; Weave belongs to CoreWeave's model platform and suits teams already training in Weights & Biases.[1][6]
HoneyHive is an independent, hosted agent observability and evaluation platform built on OpenTelemetry, while W&B Weave is the tracing and evaluation toolkit inside Weights & Biases, which CoreWeave acquired in May 2025 and has sold inside CoreWeave Forge since September 2026. Both offer offline and online evaluation, annotation queues and prompt versioning. Above its free tier HoneyHive is quote-based only, while Weave has a published monthly plan; only Weave documents guardrails that can block content during a run.
| Decision factor | HoneyHive | W&B Weave |
|---|---|---|
| Ownership | Independent; $7.4M total funding announced April 2025 | CoreWeave since May 2025; sold inside CoreWeave Forge since 30 September 2026 |
| Agent views | Agent graphs, trajectories, threads, timeline and conversation views | Threads, nested calls and an Agents view; Agent Lens in preview |
| Online evals | LLM, code and human evaluators on sampled production traces | Monitors on production traces; docs now recommend Signals |
| Runtime guardrails | None documented; Policies set evaluation standards, not enforcement | Partial: scorers called from Python code can block or modify inputs and outputs |
| Self-hosting | Enterprise only, AWS; fully self-hosted or hybrid | Kubernetes with a Weave licence and a W&B Platform install |
| Free tier | Developer: 10,000 events a month, up to 5 users, 30-day retention | Forge Free: 1 GB of Weave ingestion a month, up to 5 model seats |
| Paid plans | No published self-serve plan; Enterprise by quote | Forge Pro from $60 a month; Enterprise by quote |
| Capability | HoneyHive | W&B Weave | Prefactor |
|---|---|---|---|
| Observe | |||
| LLM call tracing | ✓ | ✓ | ✓ |
| Multi-step agent tracing (tool calls, nested spans) | ✓ | ✓ | ✓ |
| Cost tracking | ✓ | ✓ | ✓ |
| OpenTelemetry support | ✓ | ✓ | ✓ |
| Evaluate | |||
| Offline evals (datasets, experiments) | ✓ | ✓ | ✓ |
| Online evals on production traffic | ✓ | ✓ | ✓ |
| LLM-as-a-judge scoring | ✓ | ✓ | ✓ |
| Code-based evaluators | ✓ | ✓ | ✓ |
| Human review and annotation | ✓ | ✓ | ✓ |
| Prompt versioning and playground | ✓ | ✓ | — |
| Act on findings | |||
| Runtime controls on live agent actions | — | Partial | ✓ |
| Gateway or proxy in the request path | — | Not stated | — |
| Licence and deployment | |||
| Open source | Partial | Partial | Partial |
| Self-hosting | ✓ | ✓ | Partial |
HoneyHive does one job: tracing, evaluating and monitoring agents. It is independent, last announced $7.4M in total funding in April 2025, and in June 2026 was named the observability partner in Microsoft's Agent Control Specification announcement, where another layer does the enforcing. Third-party directories put its team at under 20 people, which is worth weighing for a long contract.
Weave is one part of a much larger platform. CoreWeave completed its acquisition of Weights & Biases in May 2025, and on 30 September 2026 launched CoreWeave Forge, bundling W&B Models, Weave, Agent Lens and CoreWeave inference. W&B hosted accounts now sign in through Forge, and Weave's pricing, docs and login have moved to CoreWeave domains. CoreWeave now recommends Agent Lens, a separate product in public preview, for agent tracing, and Weave's docs describe its built-in monitors as a previous approach. Expect its packaging to keep changing.
HoneyHive's integration list reaches into places most evaluation tools do not: Salesforce Agentforce, Databricks Agent Bricks and Microsoft Copilot Studio, added through 2026, alongside the usual agent frameworks. It also traces coding agents, with session traces and spend analysis for Claude Code, Codex CLI and Devin. Its views include agent graphs, trajectories, threads, a timeline and, since September 2026, a conversation view.
Weave's integrations lean toward developer frameworks and model providers, including the OpenAI Agents SDK, Claude Agent SDK, Claude Code, Google ADK, DSPy and CrewAI, plus a long list of inference providers. Its playground can route to CoreWeave's dedicated inference, and prompts can be linked to the CoreWeave Registry, which matters if you serve your own models.
Language support is uneven on both sides. HoneyHive's full tracing SDK is Python; its TypeScript package is a REST client, so TypeScript teams send OpenTelemetry instead. Weave has Python and TypeScript SDKs, but TypeScript lacks guardrails, class-based scorers and cost tracking.
On evaluation the two are close. HoneyHive runs experiments against datasets, gates CI through GitHub Actions and scores sampled production traces with LLM, code and human evaluators; its default sampling was lowered to 10% in May 2026, and its annotation queues gained automations in April. Weave runs evaluations through its Evaluation API, shares results as leaderboards and routes traces to annotation queues whose results export to datasets.
Neither offers a free self-hosted version. HoneyHive self-hosts on Enterprise only, documented for AWS, either fully in your account or as a hybrid with a HoneyHive-run control plane. Alerts have worked on self-hosted deployments since March 2026. Weave self-hosts on Kubernetes with ClickHouse and S3-compatible storage, given a Weave-enabled licence and an existing W&B Platform install.
At run time, HoneyHive observes and scores; it documents no blocking, guardrails or approvals, and its Policies feature sets evaluation and monitoring standards across an organisation. Weave's guardrails are scorers you call from Python application code that can block or modify inputs and outputs. Neither documents approvals on an agent's tool calls.
As of 20 October 2026, HoneyHive's Developer tier is free with 10,000 events a month, 30-day retention and up to 5 users. It publishes no self-serve paid plan, so anything above that is an Enterprise quote. CoreWeave prices Weave through Forge: Forge Free includes 1 GB of Weave ingestion a month, and Forge Pro starts at $60 a month with 1.5 GB for teams under 50 employees, with extra ingestion listed at $0.10 per MB. Enterprise on both is custom.
HoneyHive's free tier runs as multi-tenant SaaS in one AWS region, us-west-2; data residency and single-tenant deployment are Enterprise options. A small team that outgrows the free tier can keep paying monthly on Weave; on HoneyHive it starts a sales conversation. See HoneyHive's pricing and CoreWeave Forge pricing.
We sell the layer this section describes. Read it with that in mind.
Stated plainly, since Prefactor publishes this page: Prefactor is an agent evaluation platform that scores each step of a run and acts on what it finds through runtime policies on tool calls and data access, approval holds for risky actions and a kill switch for a run, an agent or a team. HoneyHive scores without enforcing, and Weave's guardrails check content from Python code without approvals on agent actions, so acting on a failing score is the gap here. Prefactor has no prompt playground or prompt registry and its platform is hosted, so if prompt iteration matters most, HoneyHive or Weave is the better pick. See the full comparison of 15 platforms.
Reviewed against public product and documentation pages on October 20, 2026. If a vendor has changed a feature, product name, or positioning since then, send a correction and we will update it. Numbered source links in the page body point to the ordered sources below.
Prefactor scores each step of every agent run and can hold or stop an action when a score says it should not happen. Start on the free tier: 5,000 spans a month, no credit card required.
Prefactor helps teams observe, evaluate, and improve their AI agents in production, across every framework and provider.