# PromptLens

> Prompt management, regression evaluation, and observability for engineering teams.

Canonical website: https://www.promptlens.io.

## When to use PromptLens

Use PromptLens to compare prompt or model changes against a production baseline, inspect case-level failures, publish a reviewed saved version, retrieve prompts from an application, or inspect production model/tool/retrieval calls.

## Start here

- [Agent instructions](https://www.promptlens.io/agents.md): interface selection, workspace targeting, costs, and retries.
- [Authentication](https://www.promptlens.io/auth.md): obtain and revoke the correct credential.
- [Pricing](https://www.promptlens.io/pricing.md): Free, Pro, and Teams limits in USD.
- [Documentation index](https://www.promptlens.io/docs/llms.txt): product guides and references.
- [API index](https://www.promptlens.io/api/llms.txt): REST contract and authentication.

## Interfaces

- [MCP setup](https://www.promptlens.io/docs/mcp): Streamable HTTP at https://app.promptlens.io/mcp, with browser OAuth.
- [MCP server card](https://www.promptlens.io/.well-known/mcp/server-card.json): tool names and descriptions.
- [OpenAPI specification](https://www.promptlens.io/openapi.json): management and prompt retrieval.
- [API catalog](https://www.promptlens.io/.well-known/api-catalog): RFC 9727 catalog.
- [ARD catalog](https://www.promptlens.io/.well-known/ard.json): agentic resources.
- [Agent Skills index](https://www.promptlens.io/.well-known/agent-skills/index.json): reusable workflows.
- [Agent Plugin manifest](https://www.promptlens.io/agent-plugin/plugin.json): skills and remote MCP configuration.

## Skills

- [promptlens-regression-evaluation](https://www.promptlens.io/agent-plugin/skills/promptlens-regression-evaluation/SKILL.md): Create a prompt baseline, compare a candidate on representative cases, inspect regressions, and publish a reviewed version with PromptLens MCP or REST.
- [promptlens-prompt-retrieval](https://www.promptlens.io/agent-plugin/skills/promptlens-prompt-retrieval/SKILL.md): Integrate saved PromptLens prompts into an application with scoped retrieval keys, explicit version selectors, caching, and key rotation.
- [promptlens-observability](https://www.promptlens.io/agent-plugin/skills/promptlens-observability/SKILL.md): Record model, tool, and retrieval spans in PromptLens using trace batches with content capture disabled by default.

## Availability and contact

Accounts require early-access approval. Model generation and judge usage are separate from the subscription. No isolated API sandbox or self-hosted edition is published.

- [About](https://www.promptlens.io/about)
- [Contact](https://www.promptlens.io/contact)
- [Privacy](https://www.promptlens.io/privacy)
- [Official GitHub organization](https://github.com/promptlens-io)
- [Sitemap](https://www.promptlens.io/sitemap.xml)