PromptLayer website screenshot

PromptLayer

PromptLayer is a prompt engineering, prompt management, and LLM observability platform. Its REST API logs and tracks LLM requests, manages a versioned prompt registry with release labels, ingests OpenTelemetry-style spans and traces, and runs evaluations and datasets so teams can monitor, debug, and improve their LLM applications.

PromptLayer publishes 4 APIs on the APIs.io network, including Evaluations & Datasets API, Logging & Tracking API, Prompt Registry API, and 1 more. Tagged areas include AI, LLM, Prompt Engineering, Prompt Management, and Observability.

PromptLayer’s developer surface includes authentication, documentation, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub
39.3/100 thin ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFreemiumSelf serve⚡ Free to try
4 APIs
AILLMPrompt EngineeringPrompt ManagementObservabilityEvaluation

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 39.3/100 · thin
Contract Quality 15.3 / 25
Developer Ergonomics 3.9 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 7.4 / 10
Agent readiness — 31/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/promptlayer: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

PromptLayer Evaluations & Datasets API

Create, run, and score evaluation reports against datasets.

PromptLayer Logging & Tracking API

Log and track LLM requests, scores, and metadata.

PromptLayer Prompt Registry API

Retrieve and publish versioned prompt templates.

PromptLayer Spans & Traces API

Ingest spans and manage traces for LLM observability.

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

PromptLayer API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Promptlayer Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Promptlayer Rate Limits

6 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Promptlayer Finops

FINOPS

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Promptlayer Authentication

apiKey · 1 scheme

SECURITY

Promptlayer Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Promptlayer Agentic Access

16 operations · 11 acting

16 operations · 11 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 FinOps
FinOps

Company 2

The organization behind the API

LinkedIn
LinkedIn
 Website
Website

Source (apis.yml)

apis.yml Raw ↑ 
aid: promptlayer
url: https://raw.githubusercontent.com/api-evangelist/promptlayer/refs/heads/main/apis.yml
name: PromptLayer
kind: company
description: PromptLayer is a prompt engineering, prompt management, and LLM observability platform. Its REST API logs and
  tracks LLM requests, manages a versioned prompt registry with release labels, ingests OpenTelemetry-style spans and traces,
  and runs evaluations and datasets so teams can monitor, debug, and improve their LLM applications.
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/promptlayer.png
tags:
- AI
- LLM
- Prompt Engineering
- Prompt Management
- Observability
- Evaluation
created: '2026-06-20'
modified: '2026-06-20'
specificationVersion: '0.19'
apis:
- aid: promptlayer:promptlayer-evaluations-datasets-api
  name: PromptLayer Evaluations & Datasets API
  description: Create, run, and score evaluation reports against datasets.
  humanURL: https://docs.promptlayer.com/reference/rest-api-reference
  baseURL: https://api.promptlayer.com
  tags:
  - Evaluations & Datasets
  properties:
  - type: OpenAPI
    url: openapi/promptlayer-evaluations-datasets-api-openapi.yml
  - type: Documentation
    url: https://docs.promptlayer.com/why-promptlayer/how-it-works
  - type: APIReference
    url: https://docs.promptlayer.com/reference/log-request
  - type: PostmanCollection
    url: collections/promptlayer.postman_collection.json
  - type: Documentation
    url: https://docs.promptlayer.com/features/prompt-registry
  - type: APIReference
    url: https://docs.promptlayer.com/reference/get-prompt-template
  - type: Documentation
    url: https://docs.promptlayer.com/features/evaluations/overview
  - type: APIReference
    url: https://docs.promptlayer.com/reference/list-evaluations
  - type: Documentation
    url: https://docs.promptlayer.com/features/tracing
  - type: APIReference
    url: https://docs.promptlayer.com/reference/spans-bulk
- aid: promptlayer:promptlayer-logging-tracking-api
  name: PromptLayer Logging & Tracking API
  description: Log and track LLM requests, scores, and metadata.
  humanURL: https://docs.promptlayer.com/reference/rest-api-reference
  baseURL: https://api.promptlayer.com
  tags:
  - Logging & Tracking
  properties:
  - type: OpenAPI
    url: openapi/promptlayer-logging-tracking-api-openapi.yml
  - type: Documentation
    url: https://docs.promptlayer.com/why-promptlayer/how-it-works
  - type: APIReference
    url: https://docs.promptlayer.com/reference/log-request
  - type: PostmanCollection
    url: collections/promptlayer.postman_collection.json
  - type: Documentation
    url: https://docs.promptlayer.com/features/prompt-registry
  - type: APIReference
    url: https://docs.promptlayer.com/reference/get-prompt-template
  - type: Documentation
    url: https://docs.promptlayer.com/features/evaluations/overview
  - type: APIReference
    url: https://docs.promptlayer.com/reference/list-evaluations
  - type: Documentation
    url: https://docs.promptlayer.com/features/tracing
  - type: APIReference
    url: https://docs.promptlayer.com/reference/spans-bulk
- aid: promptlayer:promptlayer-prompt-registry-api
  name: PromptLayer Prompt Registry API
  description: Retrieve and publish versioned prompt templates.
  humanURL: https://docs.promptlayer.com/reference/rest-api-reference
  baseURL: https://api.promptlayer.com
  tags:
  - Prompt Registry
  properties:
  - type: OpenAPI
    url: openapi/promptlayer-prompt-registry-api-openapi.yml
  - type: Documentation
    url: https://docs.promptlayer.com/why-promptlayer/how-it-works
  - type: APIReference
    url: https://docs.promptlayer.com/reference/log-request
  - type: PostmanCollection
    url: collections/promptlayer.postman_collection.json
  - type: Documentation
    url: https://docs.promptlayer.com/features/prompt-registry
  - type: APIReference
    url: https://docs.promptlayer.com/reference/get-prompt-template
  - type: Documentation
    url: https://docs.promptlayer.com/features/evaluations/overview
  - type: APIReference
    url: https://docs.promptlayer.com/reference/list-evaluations
  - type: Documentation
    url: https://docs.promptlayer.com/features/tracing
  - type: APIReference
    url: https://docs.promptlayer.com/reference/spans-bulk
- aid: promptlayer:promptlayer-spans-traces-api
  name: PromptLayer Spans & Traces API
  description: Ingest spans and manage traces for LLM observability.
  humanURL: https://docs.promptlayer.com/reference/rest-api-reference
  baseURL: https://api.promptlayer.com
  tags:
  - Spans & Traces
  properties:
  - type: OpenAPI
    url: openapi/promptlayer-spans-traces-api-openapi.yml
  - type: Documentation
    url: https://docs.promptlayer.com/why-promptlayer/how-it-works
  - type: APIReference
    url: https://docs.promptlayer.com/reference/log-request
  - type: PostmanCollection
    url: collections/promptlayer.postman_collection.json
  - type: Documentation
    url: https://docs.promptlayer.com/features/prompt-registry
  - type: APIReference
    url: https://docs.promptlayer.com/reference/get-prompt-template
  - type: Documentation
    url: https://docs.promptlayer.com/features/evaluations/overview
  - type: APIReference
    url: https://docs.promptlayer.com/reference/list-evaluations
  - type: Documentation
    url: https://docs.promptlayer.com/features/tracing
  - type: APIReference
    url: https://docs.promptlayer.com/reference/spans-bulk
common:
- type: AgenticAccess
  url: agentic-access/promptlayer-agentic-access.yml
- type: DomainSecurity
  url: security/promptlayer-domain-security.yml
- type: Authentication
  url: authentication/promptlayer-authentication.yml
- type: GitHubOrganization
  url: https://github.com/MagnivOrg
- type: LinkedIn
  url: https://www.linkedin.com/company/promptlayer
- type: Website
  url: https://www.promptlayer.com
- type: Documentation
  url: https://docs.promptlayer.com
- type: Plans
  url: plans/promptlayer-plans-pricing.yml
- type: RateLimits
  url: rate-limits/promptlayer-rate-limits.yml
- type: FinOps
  url: finops/promptlayer-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com