The Stack · Observability & evals (managed) API

PromptLayer

Prompt management + LLM observability platform for versioning prompts, running evals and tracing agents in production.

API keyFreemium🔵 agent: self serve instant key

Get API key → instant key, usually no card Docs

CategoryObservability & evals (managed)

TypeAPI service

Authapi-key

PricingFreemium

Agent signup🔵 self serve instant key

SDKsPython, TypeScript, REST

Pricing: Free tier available; prompt registry, evals and request logging across OpenAI/Anthropic and others. Paid tiers for team features.

🔵 Agents: self serve instant key

Instant self-serve — free signup gives a key immediately (a human unblocks an agent in under 2 minutes).

Create an account and click to generate an API key; REST API available for logging and prompt retrieval. No account-provisioning API.

PromptLayer — Prompt management + LLM observability platform for versioning prompts, running evals and tracing agents in production.
Website: https://www.promptlayer.com/
Docs: https://docs.promptlayer.com
Get a key: https://www.promptlayer.com/
Agent signup: self serve instant key — Create an account and click to generate an API key; REST API available for logging and prompt retrieval. No account-provisioning API.
Auth: api-key
Pricing: freemium — Free tier available; prompt registry, evals and request logging across OpenAI/Anthropic and others. Paid tiers for team features.
Full record: https://dreaming.press/api/tools/promptlayer.json

Machine record: /api/tools/promptlayer.json

Quickstart

# pip install promptlayer
from promptlayer import PromptLayer

pl = PromptLayer(api_key="pl_...")
OpenAI = pl.openai.OpenAI          # drop-in, logs every request
client = OpenAI()
resp = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "logged to PromptLayer"}],
)

python · full docs →

PromptLayer in our coverage

How to Version Prompts in Production AI Agents: A Prompt Change Is a Deploy

2026-07-05

Prompt Management: Langfuse vs PromptLayer vs Agenta (and Why a Registry Isn't Enough)

2026-06-23

PromptLayer FAQ

What is PromptLayer?

PromptLayer is Prompt management + LLM observability platform for versioning prompts, running evals and tracing agents in production. It's in the Observability & evals (managed) category of the dreaming.press tool directory.

Is PromptLayer free?

PromptLayer is freemium — free to start, paid plans for scale. Free tier available; prompt registry, evals and request logging across OpenAI/Anthropic and others. Paid tiers for team features..

Can an AI agent sign up for PromptLayer automatically?

Almost — signup is instant and self-serve (a free key with no sales call), so a human can unblock an agent in under two minutes. Create an account and click to generate an API key; REST API available for logging and prompt retrieval. No account-provisioning API..

Does PromptLayer have an MCP server?

PromptLayer does not publish an official MCP server as of our last check.

Is PromptLayer open source?

PromptLayer is a hosted API service, not an open-source project.

What languages does PromptLayer support?

PromptLayer offers Python, TypeScript, REST.