PromptLayer
PromptLayer is a prompt management platform for AI teams: a versioned prompt registry, evaluations and production observability. Engineers integrate through an SDK or REST API while domain experts edit prompts visually, without redeploying the application.
What is PromptLayer?
PromptLayer is an AI engineering platform that combines a prompt registry and a visual prompt CMS with LLM evaluations, observability and agent tracing. The company calls itself the first-ever prompt engineering platform and builds on one thesis: the best prompt engineers are the domain experts who know the subject, not the ML specialists who own the codebase.
Three pillars are advertised, prompt management, evaluations and observability, with agent tracing forming a fourth block. The registry stores every template alongside its version history, its model parameters such as model, temperature and max tokens, its tools and structured-output schemas, and its release labels. At runtime the application asks the registry for a prompt by name and label rather than hard-coding it, so moving a label updates every service at once. That single mechanism is how a prompt reaches production without an application redeploy, and how a rollback becomes a one-step operation. Templates are model-agnostic, letting one blueprint run across several providers, and templating uses Jinja2 or f-string syntax with snippet imports.
Evaluations offer more than twenty column types, from basic comparisons to LLM assertions and custom webhooks, assembled into multi-metric scorecards. They fire automatically on each new version, through the API, or ad hoc in the interface. Observability rests on a non-proxy design sized for millions of requests per day and supports OpenTelemetry spans. The differentiator PromptLayer claims is the join between the two halves: every log and trace is tied back to the exact prompt version that produced it.
Two audiences share the same registry. Engineers work through the SDK, the REST API and CI/CD; domain experts work only in the web interface, editing, commenting, writing commit messages, reading diffs and testing. Enterprise adds RBAC, deployment approvals, SSO, webhooks and retention control.
On scale, the careers page reports over 75 million evaluations, more than 10 million logs a day, over a billion traces and 99.9% uptime, while the contact page cites 1,000+ companies and an average team size of 20. The company is based in New York City and operates as Magniv, Inc. doing business as PromptLayer.
What it does
- Version every prompt in a central registry with immutable history, visual diffs and commit messages
- Edit and test prompts visually, without writing a line of code
- Ship a prompt to production through a release label, without redeploying the application
- Roll back to an earlier version simply by moving a label
- Run evaluations, from historical backtests and regression tests to AI judges and human review, and compare models side by side on the same prompt
- Trace production requests and multi-step agents, tracking cost, latency and token usage per prompt version
- Fetch prompts at runtime through the SDK or REST API, and A/B test them across user segments
When to use PromptLayer / When not to
A quick filter to help you decide if PromptLayer is the right fit.
When to use PromptLayer
- AI engineering teams running LLM prompts in production that want to treat them as versioned artefacts, with immutable history, diffs and release labels.
- Organisations where non-developer domain experts, from lawyers and clinicians to teachers, content and support leads, need to write and correct the prompts themselves.
- Teams stuck in the bottleneck where every prompt change has to wait for the next application release.
- Product teams shipping multi-step agent features that need end-to-end tracing, tool-call inspection and evaluation before each deployment.
- Regulated environments needing SOC 2 Type 2, HIPAA with a BAA, RBAC, deployment approvals and audit trails, as in the documented case studies at Midpage (legal), NoRedInk (education) and Gorgias (e-commerce support).
When not to use PromptLayer
- Teams that require open-source software or self-hosting on any budget: the platform is proprietary and self-hosting is limited to the Enterprise tier.
- Occasional solo use, since the value comes from team collaboration and production volume rather than individual prompting.
- Teams that do not call LLMs at all: PromptLayer generates no content of its own, it manages the prompts sent to other providers' models.
- Anyone who needs to work from a phone: there is no iOS or Android application.
- Tight budgets past the free plan, as Pro is capped at five users and the next step jumps from 49 to 500 USD per month.
- Teams with EU data residency requirements on a standard plan: Free, Pro and Team are hosted in the United States.
How to use PromptLayer
A typical end-to-end flow, from setup to results.
- Create a free account on the PromptLayer dashboard; the free plan requires no payment details.
- Have an engineer connect the application through the Python SDK or the REST API, following the documentation at docs.promptlayer.com.
- Use the ready-made integrations to shorten the wiring: LangChain, LiteLLM, LlamaIndex, OpenAI, Anthropic, Amazon Bedrock, Azure OpenAI and others.
- Create and edit prompts directly in the dashboard, with no code involved.
- Attach release labels such as prod and dev to the versions you want to expose.
- Change the application so it fetches each prompt at runtime by name and label instead of hard-coding it.
- Let logs and traces flow in automatically once the integration is live, and add OpenTelemetry spans if the team is already instrumented.
- Build evaluations on datasets or on production history, and trigger them in CI/CD the way GitHub Actions runs on a commit.
- Give domain experts access to the web interface, where they edit, comment, write commit messages, read diffs and test without touching the codebase.
- For a demo or an Enterprise plan, use the contact form, write to sales@promptlayer.com or call +1 (201) 464-0959.
Pros & Cons
Pros
- Every log and trace is tied to the exact prompt version that produced it, the platform's central claim and a rare one according to its own comparison tables.
- Two genuinely complete paths on a single registry: SDK, API and CI/CD for engineers, a visual editor for non-technical domain experts.
- Prompt deployment is decoupled from application releases, so a wording fix no longer waits for the next sprint.
- A permanent free plan that is actually usable: 5 users, 2,500 requests per month and 250 evaluation runs.
- Serious certifications for a vendor of this size: SOC 2 Type 2, HIPAA with a BAA, GDPR and CCPA.
- Nineteen named integrations covering the main providers and frameworks, plus broad Enterprise options with self-hosting on GCP, AWS or Azure, EU hosting and single-tenant cloud.
- Verifiable customer references documented as case studies, and a published DPA that names its sub-processors and caps API retention at 30 days.
Cons
- Proprietary product: no open-source edition, and self-hosting is reserved for the Enterprise tier.
- An abrupt pricing gap between Pro at 49 USD per month for 5 users and Team at 500 USD per month for 25 users.
- EU hosting is Enterprise-only; Free, Pro and Team run in the United States.
- Usage above quota is billed per transaction, at 0.003 USD per transaction on Pro and 0.002 USD on Team.
- SSO, RBAC and deployment approvals are unavailable below Enterprise, and support stays 'Basic' on the first three tiers, dedicated only on Enterprise.
- Neither the legal entity name nor the postal address appears on the site: the DPA has to be opened to find them, and the trust centre is unreadable without JavaScript.
- The position on training models with customer data is never stated explicitly, and there is no mobile application.
Pricing & Plans
PromptLayer operates on a freemium model. A permanent free plan at 0 USD per month, presented as being for hackers, covers 5 users, 10 prompts, 2,500 requests per month, one workspace, 250 evaluation cell runs and 750 agent node runs per month, datasets up to 10 MB and 10 playground runs per day. The lowest paid tier is Pro at 49 USD per month for small teams, which lifts the playground, workspace and prompt limits, raises datasets to 150 MB and adds pay-as-you-go billing at 0.003 USD per transaction. Team costs 500 USD per month and covers 25 users, 100k+ requests per month, 7.5k+ evaluation runs, 10k+ agent node runs, 1 GB datasets and webhooks, with overage at 0.002 USD per transaction. Enterprise pricing is quoted on request. Any quota overrun, whether requests, agent runs or evaluation cells, is billed per transaction. Under the terms, fees are invoiced in advance, monthly or annually, are non-refundable unless stated otherwise, and price changes apply from the following billing cycle after reasonable notice. No time-limited free trial is advertised: the free plan is permanent.
- 0 USD per month
- 49 USD per month
- 500 USD per month
- pricing on request
Data, GDPR & hosting
A consolidated view of how PromptLayer handles your data.
GDPR overview
PromptLayer states GDPR compliance directly, claiming on its home page to maintain SOC 2 Type 2, HIPAA and GDPR compliance, with CCPA added in the pricing FAQ. The privacy policy, effective 18 February 2026, lists the rights of access, rectification, erasure, portability, objection and withdrawal of consent, exercised through hello@promptlayer.com or the contact form. The published DPA relies on the Standard Contractual Clauses adopted by the European Commission on 4 June 2021, modules two and three, plus a UK addendum under section 119A(1) of the Data Protection Act 2018. Transfers to the United States, where the servers and offices sit, are acknowledged. Sub-processor changes are notified 15 days ahead to subscribers, with a reasoned right to object at privacy@promptlayer.com. Two gaps: no EU representative under Article 27, and a Vanta trust centre unreadable without JavaScript.
Who owns the data?
The terms are explicit: "You retain ownership of the Content you submit through the Service." Prompts, templates and configurations therefore stay the customer's property. In return, submitting content grants PromptLayer a worldwide, non-exclusive, royalty-free licence to use, store, process and display that content, solely as necessary to provide and improve the service. The data processing agreement places the customer as controller and PromptLayer as processor, and requires the customer to warrant that it holds the right to transmit the data and to authorise its processing. The privacy policy adds a clear exclusion: "We do not sell your personal information."
Reuse rights
Because customers keep ownership of what they submit, they may reuse, export and redistribute their own prompts and outputs without asking PromptLayer for permission; the licence runs the other way. On PromptLayer's side, the privacy policy lists service delivery, personalisation, communication, analytics, security, legal compliance and, with consent, marketing. The data collected covers account details (name, email, company), payment handled by third-party providers, submitted content such as prompts, templates and configurations, and communications, plus automatically gathered usage data, device information, logs (IP addresses, timestamps, referrers) and cookies. Data is shared with service providers, in a business transfer, under legal obligation, or with explicit consent. The DPA also allows de-identified, anonymised or aggregated processing, with a commitment not to re-identify beyond verifying that the process works. Marketing opt-out is available at any time, personal information is not sold, and no document mentions training models on customer data.
Data retention & training
Hosting summary
Hosting depends on the plan. Free, Pro and Team are cloud-hosted in the United States, as PromptLayer states: "PromptLayer Free, Pro, and Team is Cloud-hosted in the US. Enterprise customers have the option of self-hosted on GCP, AWS, and Azure, Cloud-hosted in EU, or Cloud-hosted single-tenant." EU residency and self-hosting are therefore commercial options attached to the Enterprise tier, not the default posture. The privacy policy confirms that servers and offices are located in the United States and acknowledges international transfers, covered by the Standard Contractual Clauses set out in the DPA. Sub-processors named in that document include Google Cloud Platform, alongside Calendly, Datadog, GitHub, Google Drive, Google Workspace, Notion, Sentry, Slack and Vanta. On the infrastructure side, the domain resolves to 216.150.1.1, an anycast node on AS16509 (Amazon.com Inc.) in the United States. A European organisation with data residency requirements should therefore plan for an Enterprise contract; on any standard plan, the applicable jurisdiction is American.
Where PromptLayer works
Country-level availability.
Not available in
Things to keep in mind
Risks and trade-offs to weigh before adopting PromptLayer.
- PromptLayer never states whether customer data is used to train models: neither the privacy policy, the terms nor the DPA addresses the question, and no training opt-out is documented.
- Compliance evidence is hard to check independently, because the Vanta trust centre renders through JavaScript and shows nothing outside a browser.
- The legal entity and the postal address appear nowhere on the site itself and are only found inside the DPA, which makes basic due diligence slower than it should be.
- The 30-day API retention limit sits in the DPA, not in the privacy policy: the two documents have to be read together to understand what is kept and for how long.
- EU hosting and self-hosting are Enterprise-only, so teams on standard plans with data residency obligations have no option short of an Enterprise contract.
- Transaction overage is easy to underestimate on a growing workload, since requests, agent runs and evaluation cells are all billed individually beyond quota.
- Governing law is the State of New York with jurisdiction in New York County, and no EU representative under Article 27 of the GDPR is designated, two points that weigh on a European buyer in a dispute.
Setup & Integrations
Technical difficulty
Two very different entry points. For domain experts, difficulty is low: account creation is immediate and free, and everything happens in the visual editor without code. For engineers it is moderate, since the application has to be wired to the platform through the SDK, documented in Python, or the REST API, though nineteen ready-made integrations with common frameworks and providers absorb most of the work and the non-proxy design means no LLM traffic has to be rerouted. Teams already instrumented can plug in OpenTelemetry. Self-hosting is an Enterprise-only infrastructure project of its own.
Deployment
Integrations
Behind PromptLayer
Fundraising
Social
Resources
All the official URLs gathered for verification and reference.
Alternatives
Tools that compete with or complement PromptLayer.
Frequently asked questions
What is PromptLayer?
Do you need to know how to code to use PromptLayer?
Is there a free plan?
How much does PromptLayer cost?
What happens if you exceed the quotas on your plan?
Where is the data hosted, and can PromptLayer be self-hosted?
Which certifications does PromptLayer hold?
Is a data processing agreement available?
How long is customer data retained?
Is there an API, and what does PromptLayer integrate with?
Should you pick PromptLayer?
PromptLayer arrived early on prompt engineering and now has to defend that position on a segment that has become crowded: Langfuse, LangSmith, Braintrust, Arize Phoenix and Helicone compete for the same budget, and the platform's own comparison pages describe a market in consolidation, with Humanloop shut down, Helicone acquired, Vellum pivoted and PromptHub closed.
Its claimed edge holds up on the facts. Every log and trace points back to the prompt version that produced it, which turns production debugging into a version question rather than an archaeology exercise. The second path is genuine rather than decorative: domain experts edit, comment and test in the browser while engineers keep the SDK, the API and CI/CD, both working on one registry. Decoupling prompt deployment from application releases is the practical payoff. Maturity is real for a company of this size, with SOC 2 Type 2, HIPAA with a BAA, GDPR and CCPA claims, a published DPA naming its sub-processors, documented case studies and volumes stated openly.
The reservations are just as concrete. Scaling is expensive, since the step from Pro at 49 USD per month to Team at 500 USD per month is abrupt and transaction overage accumulates quietly. Self-hosting and EU hosting are Enterprise-only, so a European team with residency requirements has no standard-tier answer. And no document, neither privacy policy nor terms nor DPA, states whether customer data is used to train models; the subject is simply never raised.
For an AI team running prompts in production, especially one where non-developers must own the wording, PromptLayer is a serious and well-documented choice. Teams needing open source, EU residency on a standard plan, or a written commitment on model training should settle those points with the vendor first.
- Choosing a selection results in a full page refresh.
- Opens in a new window.