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Fixer

Fixer is a lightweight JSON API for real-time and historical foreign exchange rates and currency conversion. Built on top of European Central Bank reference rates and 15+ additional data sources, Fixer supports 170+ world currencies and is delivered through the APILayer marketplace under a freemium subscription model.

agent ready

Solid contracts, transparent operations, and an easy start — typically complete on four or five facets with one clear soft spot.

Kin Score

API Evangelist profiles Fixer the way a machine reads it — 58 machine-readable artifacts across 5 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Fixer scores 64.6/100 (strong), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 64.6/100 · strong
Contract Quality 20.1 / 25
Developer Ergonomics 6.5 / 20
Commercial Clarity 16.8 / 20
Operational Transparency 0.7 / 13
Governance 10.4 / 12
Discoverability 10.0 / 10
Agent readiness — 48/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
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

How we profile Fixer

Each block below is one kind of artifact we hold for Fixer. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 5

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

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

Fixer Conversion API

On-demand currency amount conversion.

Fixer Fluctuation API

Currency fluctuation analysis between two dates.

Fixer Rates API

Real-time and historical foreign exchange rate operations.

Fixer Symbols API

Discovery of supported currency symbols.

Fixer Time Series API

Daily historical rates between two dates.

Open Collections 1

Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.

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

Fixer API

OPEN COLLECTION

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.

Published pricing tiers and plan structures.

Fixer Plans Pricing

5 plans

PLANS

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Fixer Rate Limits

0 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

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

Fixer Finops

FINOPS

Features 9

The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.

Notable capabilities this provider offers.

170+ World Currencies

Coverage of fiat currencies, sourced from the European Central Bank and 15+ additional providers.

Real-Time Exchange Rates

Latest rates with refresh cadence ranging from hourly (Free) to 60 seconds (Professional Plus, Enterprise).

Historical Exchange Rates

End-of-day rates for any working day since 1999-01-04, available on every plan including Free.

Currency Conversion Endpoint

On-demand conversion between any two currencies at real-time or historical rates.

Time Series Endpoint

Daily rates between two arbitrary dates (max 365 days) for trend analysis.

Fluctuation Endpoint

Start rate, end rate, absolute change, and percentage change for a chosen window.

HTTPS Encryption

SSL-secured transport on Basic plan and above; Free is HTTP only.

Source Currency Switching

Choose any of the 170+ symbols as the base currency on Basic plan and above.

APILayer Unified Auth

One APILayer `apikey` works across Fixer and other APILayer marketplace APIs.

Scroll within the panel for all 9 ·

Semantic Vocabularies 1

JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.

JSON-LD contexts and semantic vocabularies used across these APIs.

Fixer Context

9 classes · 20 properties

JSON-LD

Spectral Rules 2

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Fixer API Rules

5 rules · 4 warnings

SPECTRAL

Fixer API Rules

12 rules · 4 errors · 8 warnings

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

Standalone JSON Schema definitions for this provider's data models.

Fixer Convert Response

6 properties

JSON SCHEMA

Fixer Error Response

2 properties

JSON SCHEMA

Fixer Fluctuation Response

6 properties

JSON SCHEMA

Fixer Rates Response

6 properties

JSON SCHEMA

Fixer Symbols Response

2 properties

JSON SCHEMA

Fixer Time Series Response

6 properties

JSON SCHEMA

JSON Structure 5

JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.

JSON Structure definitions describing this provider's data shapes.

Fixer Convert Structure

6 properties

JSON STRUCTURE

Fixer Fluctuation Structure

6 properties

JSON STRUCTURE

Fixer Rates Structure

6 properties

JSON STRUCTURE

Fixer Symbols Structure

2 properties

JSON STRUCTURE

Fixer Timeseries Structure

6 properties

JSON STRUCTURE

Examples 6

Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.

Example request and response payloads for these APIs.

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

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

Fixer Authentication

apiKey · 1 scheme

SECURITY

Fixer Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.

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

Fixer Agentic Access

6 operations

6 operations · 0 acting

AGENTIC

Use Cases 6

What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.

What developers build with this provider.

E-Commerce Multi-Currency Pricing

Convert prices into the shopper's local currency at checkout using /convert.

Treasury and Cash Reporting

Daily mark-to-market of multi-currency balances using /timeseries and /fluctuation.

Travel and Fintech Apps

Power in-app FX widgets, traveler wallets, and remittance quotes with /latest.

Accounting and Ledger Reconciliation

Look up the official end-of-day rate for any historical transaction with /{date}.

Backtesting and Analytics

Pull windowed rate history with /timeseries to feed quant or BI models.

Compliance and Audit Trails

Reference an immutable ECB-sourced rate when auditing cross-border payments.

Integrations 6

Pre-built integrations with other platforms tell you where this provider already fits in a stack.

Pre-built integrations with other platforms and tools.

APILayer Marketplace

Fixer is distributed via the APILayer hub; signup, billing, and key management share the marketplace.

European Central Bank

Primary upstream data source for daily reference exchange rates.

money.js

Client-side JavaScript library historically paired with Fixer for browser-side conversion.

Currencylayer

Sister APILayer product with similar FX surface; often used interchangeably or for redundancy.

Coinlayer

Cryptocurrency exchange rate API on the same APILayer platform.

Currencyfreaks / Open Exchange Rates

Competing FX APIs that consumers benchmark Fixer against.

Solutions 5

Packaged solutions the provider offers on top of the raw API surface.

Packaged solutions this provider offers.

Free Plan

100 requests/month, hourly refresh, EUR base only, HTTP only. Best for prototyping.

Basic Plan

10,000 requests/month at $14.99/mo, HTTPS, source currency switching, /convert endpoint.

Professional Plan

100,000 requests/month at $59.99/mo, 10-minute refresh, /timeseries endpoint.

Professional Plus Plan

500,000 requests/month at $99.99/mo, 60-second refresh, /fluctuation endpoint.

Enterprise Plan

Custom volume, 60-second refresh, dedicated account team and priority support.

Resources

Every other property we hold for Fixer — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Get Started 2

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Build 2

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Operate 2

Status, limits, changes, and where to get help

Company 2

The organization behind the API

Other 1

Properties that don't map to a standard resource type

← All providers · Data indexed from github.com/api-evangelist/fixer · machine-readable index on apis.io