Agenta From $29/mo · Free plan 9.3 Visit Modular Prompt Library
modularprompt.com
What it is
Modular Prompt Library is a web platform for building, managing, sharing, testing, and comparing AI prompts. Users can assemble prompts from reusable components and use them across projects. Version history records changes and supports returning to an earlier version, while shared libraries let teams review and collaborate on prompt work. For testing, users connect their own OpenAI, Anthropic, or Google API keys, fill prompt variables, adjust temperature, top-p, and max tokens, and save presets for a prompt version. The comparison environment displays outputs side by side with latency, token counts, and estimated cost. The site says keys are encrypted at rest, usage is billed directly by the model provider, and prompts, variables, and outputs remain in the user's workspace. Personal Account is free for personal use, with up to five workspaces and unlimited prompts and modules. Starter is free for up to five users or three workspaces; Growth costs $2.50 a month and Professional costs $5 a month. Organizational accounts have a 60-day free trial, and no credit card is required to start.
Spec sheet
- Product
- Modular Prompt Library is an AI prompt management platform for building, managing, sharing, testing, and comparing prompts.Read 8 Oct 2026 · modularprompt.com
- Intended users
- The site identifies AI content creation teams, prompt engineers, marketing agencies, software development teams, customer support teams, and educational institutions as audiences.Read 8 Oct 2026 · modularprompt.com
- Trial
- Organizational accounts have a 60-day free trial for all tiers, and the site says no credit card is required to start.Read 8 Oct 2026 · modularprompt.com
- Support
- The site provides a support contact form for questions and help with the product.Read 8 Oct 2026 · modularprompt.com
- API key handling
- The site says API keys are encrypted at rest, never shared, and model usage is billed directly by the provider.Read 8 Oct 2026 · modularprompt.com
- Free tier limits
- The Personal Account plan is for personal use and allows up to 5 workspaces with unlimited prompts and modules.Read 8 Oct 2026 · modularprompt.com
- Model comparisons
- The test environment compares outputs side by side and shows latency, tokens, and estimated cost.Read 8 Oct 2026 · modularprompt.com
- Model integrations
- Users can connect their own OpenAI, Anthropic, and Google API keys to test prompts across models.Read 8 Oct 2026 · modularprompt.com
- Organizational security
- Organizational plans list MFA security, granular user access control, and organizational management.Read 8 Oct 2026 · modularprompt.com
- Prompt controls
- Users can fill prompt variables, tune temperature, top-p, and max tokens per model, and save presets per prompt version.Read 8 Oct 2026 · modularprompt.com
- Reusable modules
- Users can build prompts from reusable components and combine them across projects.Read 8 Oct 2026 · modularprompt.com
- Team collaboration
- Teams can share libraries, review changes, and collaborate on prompt development.Read 8 Oct 2026 · modularprompt.com
- Version history
- The product tracks prompt changes with version history and supports reverting to previous versions.Read 8 Oct 2026 · modularprompt.com
- Workspace privacy
- The site says prompts, variables, and outputs stay in the user's workspace and that prompt content is never accessed, used, or shared by the maker.Read 8 Oct 2026 · modularprompt.com
Plans and prices
Personal Account Free Up to 5 workspaces · Unlimited prompts & modules · Prompt testing with own API keys · Personal use only Read 8 Oct 2026 · modularprompt.com
Starter Free Up to 5 users OR 3 workspaces · MFA · Team collaboration · Granular user access control · JSON export Read 8 Oct 2026 · modularprompt.com
Growth $2.50 a month $2.5/month 6–10 users OR 4–10 workspaces · MFA · Team collaboration · Granular user access control · JSON export Read 8 Oct 2026 · modularprompt.com
Professional $5 a month $5/month 11–30 users OR 11–15 workspaces · MFA · Team collaboration · Granular user access control · JSON export Read 8 Oct 2026 · modularprompt.com
Enterprise Priced on request Custom 30+ users OR 15+ workspaces · MFA · Team collaboration · Granular user access control · JSON export Read 8 Oct 2026 · modularprompt.com
Strong points and limits
Strong points
- Reusable prompt components and version history
- Compares outputs side by side
- Supports OpenAI, Anthropic, and Google API keys
- Free Personal Account allows unlimited prompts and modules
- Organizational accounts have a 60-day trial
Limits
- Personal Account is for personal use only
- Model usage is billed directly by the provider
- Platform is listed for web only
Who it suits
The product may suit prompt engineers and teams that develop, test, and compare prompts across multiple model providers. The Personal Account tier is for personal use, while organizational plans add collaboration and access controls.
Verdict
Modular Prompt Library specifies prompt workflows, testing controls, provider billing, and workspace privacy. Consider its workspace or user limits and your model-provider costs before selecting a plan.
Where Specifiction places it
- Prompt Management Software#10 of 268.2
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