Official vendor OpenAPI document · agent-readyDeveloper ToolsPackage Registrybearer32 EndpointsREST
For Agents
Search and install React UI components, publish components, templates, and themes, and manage libraries on the 21st.dev marketplace.
Use for: Search for a date-picker component on 21st.dev, Install a published component into my project, I want to publish a new React component to the marketplace, Create a draft to edit a component in a sandbox
Not supported: Does not handle code hosting, CI builds, or runtime deployment. Use for discovering, installing, and publishing 21st.dev UI components only.
The 21st API searches and installs React UI components from the 21st.dev component marketplace and publishes your own components, templates, and themes. Developers and agents can manage personal and team libraries, check out a published component into an editable draft that spawns a sandbox, and move a submission through review. It exposes the same HTTP surface the 21st command-line tool uses, so an agent can integrate against it directly.
Install Jentic One Beta
Connect the 21st API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the 21st 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.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2F21st.dev%2F21st" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2F21st.dev%2F21st" | 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 21st API.
Search the 21st.dev marketplace for React UI components by query
Install a component with everything needed to add it to a project
Publish a new component, template, or theme, or update an existing one
Create editable component drafts that spawn a sandbox and poll their status
Manage personal and team libraries and their branding
Move a published component through submission review
Use Cases
Patterns agents use 21st API for, with concrete tasks.
★ Agent-Driven Component Discovery
An AI coding agent needs a specific UI element, such as a date picker or a pricing table, while building a React app. The 21st API lets the agent search the marketplace by query and then install the chosen component with everything needed to drop it into the project, so the agent sources a vetted component instead of writing one from scratch.
Search 21st.dev for a 'date picker' component, pick the top result, and retrieve everything needed to install it into the current project
Publishing a Component Library
A team maintaining a shared design system wants to publish components, templates, and themes to 21st.dev and keep their branding consistent. The 21st API publishes new listings or updates existing ones and manages the personal and team libraries they belong to, so a release pipeline can push updates without manual uploads.
Publish a new React component to the team library on 21st.dev and set its description and tags
Draft-to-Publish Review Flow
A contributor edits a published component in a sandbox before shipping the change. The 21st API checks a published component out into an editable draft, polls the draft status, pushes updated source, and publishes the draft as a real component, giving an agent a complete edit-and-release loop with a review step in between.
Check out a published component into a draft, push an updated source file, and publish the draft once its status is ready
Key Endpoints
32 endpoints — the 21st api searches and installs react ui components from the 21st.
METHOD
PATH
DESCRIPTION
GET
/components/search
Search components
GET
/components/install/{username}/{slug}
Get everything needed to install a component
POST
/components/publish
Publish a new component or update an existing one
POST
/components/drafts
Create a new draft that spawns a sandbox
POST
/components/drafts/{draftId}/publish
Publish a draft as a real component
GET
/libraries
List every library the caller can manage
GET
/me
Get the caller's identity, plan, and quota
GET
/components/search
Search components
GET
/components/install/{username}/{slug}
Get everything needed to install a component
POST
/components/publish
Publish a new component or update an existing one
POST
/components/drafts
Create a new draft that spawns a sandbox
POST
/components/drafts/{draftId}/publish
Publish a draft as a real component
GET
/libraries
List every library the caller can manage
GET
/me
Get the caller's identity, plan, and quota
Jentic AI Readiness Score
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
2
21st API
- Foundational (D-)43/100
53
Foundational Compliance63
Developer Experience & Jentic Compatibility20
AI-Readiness & Agent Experience94
Agent Usability60
Security65
AI DiscoverabilityPowered by JenticScoring Framework 1.0.0 | Scoring Engine 0.4.2
Show dimension breakdown
53
Foundational Compliance
Base layer of spec validity and structural soundness.
Grade: C-Signals: 4
81%
Lint Results
Aggregated quality score from linter diagnostics, weighted by severity.
100%
Resolution Completeness
Percentage of `$ref` references that resolve successfully.
0%
Specification Validity
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
30%
Structural Integrity
Structural correctness score based on schema issues using logarithmic dampening.
63
Developer Experience & Jentic Compatibility
Clarity, completeness, and ingestion readiness for developers and tooling.
Grade: B-Signals: 4
0%
Example Density
How richly the API is illustrated with examples.
100%
Example Validity
Percentage of examples that conform to their schemas.
50%
Response Coverage
Percentage of operations with complete response definitions (success, client error, server error).
100%
Tooling Readiness
Health of API ingestion, bundling, and resolution within Jentic pipelines.
20
AI-Readiness & Agent Experience
Semantic breadth, depth, and agent comprehension for AI systems.
Grade: FSignals: 4
25%
Description Coverage
Coverage of descriptions across API elements.
0%
Error Standardization
Coverage of RFC 9457 Problem Details for error responses.
0%
OperationId Quality
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
57%
Summary Coverage
Coverage of summaries across operations/tags/info.
94
Agent Usability
Functional utility, complexity comfort, and AI orchestration readiness.
Grade: A+Signals: 1
94%
Complexity Comfort
Agent comfort level based on API operational and structural complexity.
60
Security
Trust, risk posture, and security compliance.
Grade: B-Signals: 1
60%
Authentication Strength
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
65
AI Discoverability
Findability, semantic richness, and reasoning readiness.
Grade: BSignals: 1
65%
Descriptive Richness
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the 21st API by hand means handling its bearer token and learning which endpoints search, install, publish, and draft components. Through Jentic you install once, import 21st from the API Directory, store the token once, and your agent calls it.
Permission scoping
You choose which 21st operations your agent may call, so it can search and install components while the publish, unpublish, and review operations stay out of the set it may reach unless you add them.
Credential isolation
Your 21st token is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'find a date picker component' or 'publish a React component', and Jentic returns the matching 21st operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using 21st API through Jentic.
What authentication does the 21st API use?
The 21st API authenticates with a bearer token sent in the Authorization header, per its OpenAPI spec. You generate a key in your 21st.dev account and send it with each request. Through Jentic the token is stored encrypted by your own Jentic One instance and injected at call time, so it never reaches the agent's context.
Can I publish a component to 21st.dev through an agent?
Yes. The 21st API publishes a new component, template, or theme, and it can also create an editable draft that spawns a sandbox, poll that draft's status, and publish the draft as a real component once it is ready. An agent can run the whole edit-and-release loop against these operations.
What are the rate limits for the 21st API?
The OpenAPI spec does not define rate limits. Check the 21st.dev documentation at https://21st.dev for the current limits and quota tied to your plan, which the account endpoint also reports.
How do I publish a 21st.dev component through Jentic?
Import the 21st API from the Jentic directory and give your agent an intent such as 'publish a React component'. Jentic returns the publish operation with its input schema, your agent fills in the component details and calls it, and your stored token is injected at execution time. To run it on your own infrastructure, install Jentic One from its GitHub repo.
Can I limit what my agent is allowed to do with the 21st API?
Yes. Write a rule that allows only the search and install operations, so your agent can find and add components but cannot publish, unpublish, or move a submission through review, and every call it makes is logged.
Is there a 21st MCP server?
You don't need an MCP server to give your agent the 21st API. Jentic connects it directly from the API Directory: import it, store your credential once, and your agent calls it, so no extra server's tool definitions sit in the agent's context.
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