Langfuse
8.1#1 in ai agent observability toolsFrom $29 a monthFree planWebAPILinuxSelf-hosted
VisitLangfuse vs Prompt Assay
Prompt Assay
6.7#10 in prompt management softwareFrom $49 a monthFree planWebAPI
VisitWhat both publish
| Fact | Langfuse | Prompt Assay |
|---|---|---|
| API | The public data platform includes APIs for observations, experiments, metrics, prompts, datasets, projects, exports, and an OpenAPI specification. | The public REST API and TypeScript SDK require Solo tier or higher; API requests are authenticated with an API key. |
| Product | Langfuse is an open-source AI engineering platform that helps teams collaboratively debug, analyze, and iterate on AI agent applications. | Prompt Assay is a workbench for authoring, refining, versioning, testing, and shipping LLM prompts and Agent Skills. |
Langfuse plans
- HobbyFree
- HobbyFree
- Core$29 a month
- Core$29 a month
- Pro$199 a month
- Pro$199 a month
Prompt Assay plans
- Solo$49 a month
- Team$99 a month
- Free—
- EnterprisePriced on request
Pick Langfuse if…
Langfuse suits teams building AI agent applications that need tracing, prompt management, and evaluation tools. It also supports teams that want to self-host the core on their own infrastructure.
Pick Prompt Assay if…
Prompt Assay suits prompt engineers and teams sharing prompt libraries, as well as researchers comparing models and developers retrieving prompts through an API or SDK. It is useful for users who want to manage prompts and Agent Skills through versioning, testing, and evaluation.