API Ninjas City API

Name: API Ninjas City API
Brand: API Ninjas City API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentData EnrichmentAddress ValidationapiKey1 EndpointsREST

For Agents

Look up city records with name, country, coordinates, population, and capital status by querying API Ninjas' single /city endpoint.

Install Jentic One Beta

Connect the API Ninjas City API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the API Ninjas City API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with API Ninjas City API.

Look up a city by name and receive its country, coordinates, population, and capital flag

Filter cities by country code to surface only matches inside a chosen jurisdiction

Constrain results to a population range using min_population and max_population

GET STARTED

Start building with API Ninjas City API

Explore with Jentic

View OpenAPI Document

Use Cases

Patterns agents use API Ninjas City API for, with concrete tasks.

★ Geocode a City Name in Agent Output

When an agent generates content that mentions a city, it can call /city with the city name to confirm the city exists, retrieve its coordinates, and ground later steps in real geographic data. This is a lightweight alternative to a full geocoding service for cases where only a city-level resolution is required.

Call GET /city with name=Lisbon and read the returned latitude, longitude, and population fields

Filter Cities by Population

Generate a list of mid-sized cities in a country for a market-research, travel, or content workflow by calling /city with a country code, min_population, and max_population. The endpoint returns each matching city with its coordinates, which can then feed a map widget or downstream analytics step. Limit controls how many are returned per call.

Call /city with country=FR min_population=100000 max_population=500000 limit=20 to list mid-sized French cities

Capital City Lookup

Build a quiz or factual lookup feature that returns the capital of a country by querying /city with the country code and filtering for the is_capital flag in the response. The same call surfaces population and coordinates, which is enough to render a single-card answer in a chat or knowledge experience.

Call /city with country=PT and pick the record where is_capital is true to surface Lisbon's coordinates and population

Agent Integration via Jentic

An AI agent built on Jentic can search for the API Ninjas city lookup operation by intent and execute it without holding the X-Api-Key in agent context. Jentic's your Jentic One instance keeps the credential isolated, which matters when many agents share a single API Ninjas key for low-cost data lookups.

Use Jentic search for 'look up a city by name', load the /city operation, execute it with name=Buenos Aires, and read the latitude, longitude, and population from the response

Key Endpoints

1 endpoints — jentic publishes the only available openapi specification for api ninjas city api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

GET

/city

Look up cities by name, country, or population range

GET

/city

Look up cities by name, country, or population range

Why Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

Your API Ninjas key is stored once, encrypted, by your own Jentic One instance and injected as the request header at execution time. It never enters the agent's prompt, logs, or context.

Intent-based discovery

Agents search Jentic by intent such as 'look up a city by name', and Jentic returns the matching city operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

Time to first call

FAQs

Specific to using API Ninjas City API through Jentic.

Why is there no official OpenAPI spec for API Ninjas City API?

API Ninjas does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call API Ninjas City API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

What authentication does the API Ninjas City API use?

The endpoint requires an API key passed as the X-Api-Key header. When called through Jentic the key is held in your Jentic One instance and a scoped execution token is granted to the agent at call time, never the raw key.

Can I filter cities by population with the API Ninjas City API?

Yes. GET /city accepts min_population and max_population query parameters which constrain the returned cities to the chosen range. Combine with country to filter inside a single jurisdiction and with limit to cap the number of records returned.

What are the rate limits for the API Ninjas City API?

API Ninjas applies a per-account monthly request quota that depends on the subscription tier rather than the OpenAPI spec. Check your API Ninjas dashboard for the current monthly ceiling and respect any 429 responses with exponential backoff.

How do I look up a city through Jentic?

Install the Jentic SDK with pip install jentic, search for 'look up a city by name', load the GET /city operation, and execute it with the name and any optional filters such as country or population. Run it through Jentic One, the self-hosted execution layer to get a Jentic agent key.

How many cities does the API Ninjas City API cover?

The free plan covers over 50,000 cities. Premium plans cover more than 5,000,000 cities, towns, and villages, which is enough for fine-grained address-level lookups. Use the country and population filters to keep result sets manageable.

Can I limit what my agent is allowed to do with the API Ninjas City API?

Yes. Because you run Jentic One yourself, your own rules decide which operations and credentials the agent may use, and this API exposes only a single city-lookup operation, so you can restrict the agent to that one call. That operation reads city name, country, coordinates, and population through query-parameter filters and does nothing else, so a scoped agent cannot write data or reach any other endpoint. You keep the API Ninjas key in your own instance and grant the agent access only to the city lookup you approve.