API Ninjas City API
★ 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.
Use for: I need to look up the population and coordinates of Lisbon, Find all capital cities in Africa, Search for cities in France with population over 500,000, Get the latitude and longitude for Buenos Aires
Not supported: Does not handle street-level geocoding, reverse geocoding from coordinates, or routing — use for city-level lookup of name, country, coordinates, and population only.
Jentic publishes the only available OpenAPI specification for API Ninjas City API, keeping it validated and agent-ready. The endpoint returns city records including name, country, latitude and longitude, population, and capital status, covering over 50,000 cities on the free plan and over 5,000,000 cities, towns, and villages on premium. It is a single-endpoint lookup that supports filtering by name, country, minimum and maximum population, and limit. Authentication is by X-Api-Key header.
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.
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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 | sh2
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 instanceJentic 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
Limit the number of returned records with the limit parameter for pagination control
Cross-reference unfamiliar place names in agent text against a structured city database
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 MAXsystem 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
The X-Api-Key is stored encrypted in the Jentic vault. Agents receive scoped execution tokens at call time and never hold the raw key, which is helpful when many agents share a single API Ninjas account.
Intent-based discovery
Agents search by intent such as 'look up a city by name' and Jentic returns the matching /city operation with its full input schema, so the agent can call it without reading the docs.
Time to first call
Direct integration: under an hour for a single endpoint with simple key auth. Through Jentic: a few minutes from search to first executed call.
Related APIs
Alternatives and complements available in the Jentic catalogue.
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 at https://app.jentic.com/sign-up.
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 the Jentic vault 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. Sign up at https://app.jentic.com/sign-up 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.
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