Helicone has been in maintenance mode since March 2026 and is not taking new cloud sign-ups, so for a new deployment Raindrop is usually the practical choice. Existing Helicone users should note that Raindrop has no gateway and no prompt versioning, so moving means finding a home for those, not only for the logs.[3][4]
Helicone is an Apache-2.0 request logger and AI gateway that has been in maintenance mode since March 2026, with new cloud sign-ups disabled, while Raindrop is an actively developed hosted monitor that classifies live agent traffic and groups recurring failures into issues. On 19 October 2026 Helicone said it is no longer part of Mintlify, with no new owner named. For a new deployment Raindrop is usually the practical choice; existing Helicone users should plan which parts of Helicone they need to replace.
| Decision factor | Helicone | Raindrop |
|---|---|---|
| Status | Maintenance mode since March 2026; new cloud sign-ups disabled | Actively developed; Series A led by CRV in September 2026 |
| Ownership | Acquired by Mintlify in March 2026; on 19 October 2026 said it is no longer part of Mintlify, no new owner named | Independent; $50M raised in total |
| Licence | Apache-2.0 platform; the separate Rust gateway is GPL-3.0 | Proprietary platform; Workshop and several SDKs are MIT |
| Gateway | Yes: OpenAI-compatible gateway for 100+ providers, with caching and failover | None |
| Prompt tooling | Versioning, environments and a playground | None documented |
| Evaluation | Not an evaluation framework by its own docs; Python evaluators turned off in October 2026 | Signals on every new event; Issue Detection groups recurring failures |
| Agent tracing | Header-based sessions, not a span model | Traces every message, tool call and decision in a run |
| Self-hosting | Yes: Docker, Docker Compose or Helm | Beta: Enterprise VPC deployment for select partners |
| Capability | Helicone | Raindrop | Prefactor |
|---|---|---|---|
| Observe | |||
| LLM call tracing | ✓ | ✓ | ✓ |
| Multi-step agent tracing (tool calls, nested spans) | Partial | ✓ | ✓ |
| Cost tracking | ✓ | ✓ | ✓ |
| OpenTelemetry support | Partial | ✓ | ✓ |
| Evaluate | |||
| Offline evals (datasets, experiments) | Partial | Partial | ✓ |
| Online evals on production traffic | Partial | ✓ | ✓ |
| LLM-as-a-judge scoring | Partial | Partial | ✓ |
| Code-based evaluators | — | Partial | ✓ |
| Human review and annotation | Partial | Partial | ✓ |
| Prompt versioning and playground | ✓ | — | — |
| Act on findings | |||
| Runtime controls on live agent actions | Partial | — | ✓ |
| Gateway or proxy in the request path | ✓ | — | — |
| Licence and deployment | |||
| Open source | ✓ | Partial | Partial |
| Self-hosting | ✓ | Partial | Partial |
Mintlify announced its acquisition of Helicone on 3 March 2026 and said the product would move to a maintenance-only phase: patches, bug fixes and new model support, with help for customers migrating to other platforms. Cloud sign-ups have shown 'Sign ups are disabled' since the same day, and the public changelog has no feature entries after November 2025. On 19 October 2026 Helicone's site began saying that it is no longer part of Mintlify, with details to come and no new owner named.
Maintenance has not meant nothing changes. In September and October 2026 the team fixed reported vulnerabilities, hardened self-hosted Helicone, turned off Python evaluators and rate-limited LLM-as-a-judge calls. A May 2026 AWS account lock took the dashboard and log processing down for about four days, while the proxy stayed up.
Raindrop is in the opposite position. It shipped Raindrop 2.0 in June 2026, a new classification system in August and Simulations in September, alongside a Series A announcement that brought total funding to $50M.
Helicone is a request logger and gateway. It sits in front of your model provider, logs every request and response, routes across more than 100 providers with failover and caching, tracks cost per request and versions prompts. Its own documentation says it is not an evaluation framework, and its agent tracing groups requests into sessions using headers rather than modelling each step as a span.
Raindrop is a production monitor for agents. It follows every message, tool call and decision, runs classifiers called Signals that you describe in plain language on every new event, groups recurring failures into issues and compares signal rates between cohorts of live traffic. It has no gateway and no prompt versioning, and its classifiers are built by its own models, so you cannot bring your own judge.
For evaluation, Helicone lets you curate datasets from logged requests and attach scores computed elsewhere, for example by Ragas or your own LLM-as-a-judge code. Its codebase contains online evaluators, but the public docs do not describe them. Raindrop runs its classifiers on every event itself, and for pre-release work offers Workshop, an MIT-licensed local tool where a coding agent turns failures into evals, plus Simulations on pull requests, which is in early access.
List what you use Helicone for before you pick a replacement. If it is logs and cost dashboards, Raindrop covers those: it captures model calls, inputs, outputs and token usage, and calculates spend by model, provider and project. If you rely on the gateway for routing, failover or caching, Raindrop does not replace it; you will need a separate gateway, and Raindrop can read total cost reported by one such as OpenRouter. If you version prompts in Helicone, Raindrop has no equivalent.
On instrumentation, Raindrop accepts OTLP traces over HTTP with gen_ai attributes and has SDKs for TypeScript, Python and Go. Helicone's integrations are its proxy and its own OpenLLMetry-based SDKs, so expect some instrumentation work when you move. Teams that want to keep running Helicone can still self-host the Apache-2.0 code, but they take on its upkeep.
As of 20 October 2026, Helicone still lists Hobby free with 10K requests, Pro at $79 a month and Team at $799 a month, but new cloud sign-ups are disabled, so new customers cannot start on any plan. Raindrop's Hobby plan is free for 1,000 events a month, after which ingestion stops until the next month. Pro is $299 a month plus $0.003 per event up to 1M events, then $0.002, with unlimited retention and a 14-day trial.
Existing Helicone customers can check their current terms on Helicone's pricing page and model their event volume against Raindrop's plans.
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 a failing score through runtime policies, approval holds and a kill switch for a run, an agent or a team. Helicone's gateway can block prompt injection and jailbreak attempts for OpenAI models only, and Raindrop has no run-time controls; neither offers approvals or policies on agent tool actions. Prefactor has no prompt playground, prompt registry or gateway, and its platform is hosted, so a Helicone user who depends on those will still need another tool. 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.