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 API contracts indexed on the APIs.io network, including Evaluations & Datasets API, Logging & Tracking API, Prompt Registry API, and 1 more. Tagged areas include Artificial Intelligence, LLM, Prompt Engineering, Prompt Management, and Observability.

The PromptLayer catalog on APIs.io includes 1 Spectral governance ruleset.

PromptLayer’s developer surface includes pricing, authentication, documentation, and 9 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

37.3/100 thin ▬ flat Agent 22/100 agent aware Front door AI 6/6 dominant Heartbeat 45/100 going silent saas Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract

Artificial Intelligence LLM Prompt Engineering Prompt Management Observability Evaluation

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 37.3/100 · thin

Contract Quality 9.4 / 19

Developer Ergonomics 4.5 / 15

Access Clarity 5.1 / 15

Operational Transparency 2.3 / 10

Contract Governance 1.2 / 9

Discoverability 5.0 / 8

Regulatory Posture 0.8 / 15

Create-or-Update Ergonomics 2.8 / 10

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship Ask about this →
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented) Ask about this →
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link Ask about this →
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document Ask about this →

9 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Developer Ergonomics scores 29.8 — up to +14.0 composite points Ask about this →
Access Clarity scores 34.0 — up to +13.2 composite points Ask about this →
Contract Quality scores 50.2 — up to +12.5 composite points Ask about this →

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/promptlayer/apis.yml: open an issue on github.com/api-evangelist/promptlayer to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

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 5

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

PromptLayer Evaluations & Datasets API

OPEN COLLECTION

PromptLayer Evaluations & Datasets Logging & Tracking API

OPEN COLLECTION

PromptLayer Evaluations & Datasets Prompt Registry API

OPEN COLLECTION

PromptLayer Evaluations & Datasets Spans & Traces API

OPEN COLLECTION

PromptLayer API

OPEN COLLECTION

PromptLayer API pricing

Prices published by PromptLayer, read 2026-10-07 from www.promptlayer.com/pricing/.

Plan	Price
Free	$0 per month Includes: 5 Users, 2.5k/month Requests, 1 Workspace, 250/month Eval Cell Executions, 10MB max per Dataset
Pro	$49 per month Includes: Same limits as in Free, plus Unlimited Playgrounds, Unlimited Workspaces, 150MB max per Dataset
Team	$500 per month Includes: 25 Users, 100k+/month Requests, 7.5k+/month Eval Cell Executions, 1GB max per Dataset
Enterprise	Custom Includes: Custom limits on everything, RBAC, Deployment Approvals, HIPAA with BAA, Flexible Hosting Options, D

Plan details, limits and sources →

Rate limits

Search Request Suggestions rate limit: This endpoint is rate limited to 10 requests per minute.

Rate-limit details →

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

1 limits

RATE LIMITS

FinOps 1

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

PromptLayer Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

PromptLayer API Rules

58 rules · 53 error-severity 1 warn-severity 4 info-severity

SPECTRAL

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 (API Evangelist recommendations) 1

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

PromptLayer Agentic Access

16 operations · 10 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 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

BlogRSS

BlogRSS

LinkedIn

Website

Website

Source (apis.yml)

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.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/promptlayer.png
x-docs-platform: mintlify
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-04
x-docs-hosting: vercel
tags:
- Artificial Intelligence
- LLM
- Prompt Engineering
- Prompt Management
- Observability
- Evaluation
tags_raw:
- AI
- LLM
- Prompt Engineering
- Prompt Management
- Observability
- Evaluation
created: '2026-06-20'
modified: '2026-10-06'
specificationVersion: '0.23'
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: Pricing
  url: https://www.promptlayer.com/pricing/
- url: https://blog.promptlayer.com/rss/
  type: BlogRSS
- 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

PromptLayer API — frequently asked questions

Does PromptLayer have an API?

Yes. APIs.io lists 4 APIs from PromptLayer, including PromptLayer Evaluations & Datasets API, PromptLayer Logging & Tracking API and PromptLayer Prompt Registry API, and 1 more.

Is there an OpenAPI specification for the PromptLayer API?

Yes. APIs.io indexes 4 OpenAPI specifications for PromptLayer, each linked for download from this page.

How do I authenticate with the PromptLayer API?

PromptLayer uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as PromptLayer Authentication.

How much does the PromptLayer API cost?

PromptLayer publishes its prices; its Free plan is $0 per month as of 2026-10-07. APIs.io lists 4 pricing plans for PromptLayer, with each plan's price, limits and inclusions under Pricing on this page.

Is the PromptLayer API ready for AI agents?

PromptLayer has a Kin Score of 37.3 out of 100 (thin) and an Agent Readiness score of 22.4 (agent-aware), scored by API Evangelist on 2026-11-13.

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