Fess API

Name: Fess API API
Brand: Fess API
Availability: InStock

✓ Official Vendor SpecDeveloper ToolsMonitoring ObservabilityapiKey19 EndpointsREST

For Agents

Run full-text and faceted searches against a self-hosted Fess enterprise search index, manage labels and favourites, and trigger crawler runs via 19 REST endpoints.

Connect the Fess API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Fess 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.

Install Jentic One Beta (Self-Hosted)

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

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 Fess API API.

Run full-text searches with faceting and pagination across crawled documents

Get autocomplete suggestions for partially typed queries

List popular search terms aggregated by Fess analytics

Mark and unmark documents as user favourites

GET STARTED

Start building with Fess API API

Explore with Jentic

View OpenAPI Document

Use Cases

Patterns agents use Fess API API for, with concrete tasks.

★ Internal Knowledge Base Search

Power a chat-based internal knowledge base by routing employee queries to the Fess search endpoint and returning ranked document snippets. Fess supports both GET and POST search variants so longer query bodies can carry filter expressions. Typical deployments index Confluence, file shares, and wikis; query latency is under 100ms for indexes up to a few million documents.

POST /api/v1/search with the user's query and a label filter, then return the top 5 hits with title and snippet

Search Analytics and Trending Topics

Surface trending search topics inside an organisation by polling /api/v1/popular-words and grouping by time window. This identifies emerging information needs that documentation teams should address. Fess records popular words automatically as part of its analytics pipeline.

GET /api/v1/popular-words and return the 10 most frequent terms, then create a Slack message summarising them

Crawler Operations

Trigger crawler runs and inspect cluster health programmatically so an agent can refresh the index after upstream content changes without manual admin console use. Fess exposes /api/admin/crawler/start and /api/v1/health for these operations behind the same API token.

POST /api/admin/crawler/start, then poll GET /api/v1/health every 30 seconds until status returns OK

AI Agent Document Retrieval via Jentic

Through Jentic, an agent can run grounded retrieval against a Fess index without writing a custom HTTP client. The agent searches Jentic for 'search documents', loads the Fess endpoint schema, and executes queries with the user's natural-language input. This unlocks RAG-style answers grounded in self-hosted enterprise content.

Search Jentic for 'search enterprise documents', load Fess /api/v1/search, and return the top 3 hits to feed into a Claude prompt

Key Endpoints

19 endpoints — fess is an open-source enterprise search server, and its rest api exposes search, suggest, label management, popular words, favourites, health checks, and admin operations across 19 endpoints.

METHOD

PATH

DESCRIPTION

GET

/api/v1/search

Search documents

POST

/api/v1/search

Search documents with body

GET

/api/v1/suggest

Get autocomplete suggestions

GET

/api/v1/popular-words

List popular search words

GET

/api/v1/health

Get cluster health

POST

/api/admin/crawler/start

Start crawler

GET

/api/v1/search

Search documents

POST

/api/v1/search

Search documents with body

GET

/api/v1/suggest

Get autocomplete suggestions

GET

/api/v1/popular-words

List popular search words

GET

/api/v1/health

Get cluster health

POST

Why though Jentic?

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

Credential isolation

Fess API tokens and host URLs are stored encrypted in the Jentic MAXsystem vault. Agents receive scoped access — the raw Authorization header value never enters the agent's context.

Intent-based discovery

Agents search by intent (e.g., 'search enterprise documents') and Jentic returns the matching Fess /api/v1/search operation with its schema, so the agent calls it directly without reading admin docs.

Time to first call

Direct Fess integration: 1-2 days for token issue, host config, and search semantics. Through Jentic: under 30 minutes — search, load, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Alternative

Meilisearch API

Open-source search engine alternative with simpler setup

Choose Meilisearch for greenfield projects wanting fewer ops; choose Fess when Java stack and out-of-the-box crawlers matter.

Alternative

Algolia API

Hosted SaaS search alternative with managed indexing

Pick Algolia when teams want zero ops and pay-per-query pricing; pick Fess for on-prem data control.

Complementary

Elastic Kibana API

Pairs with Fess deployments that store data in Elasticsearch

Use Kibana with Fess when ops teams need dashboards on the underlying Elasticsearch cluster Fess uses.

FAQs

Specific to using Fess API API through Jentic.

What authentication does the Fess API use?

Fess uses an API token sent in the Authorization header. Because Fess is self-hosted, the {host} part of the base URL is set per deployment. Through Jentic the token is encrypted in MAXsystem.

Can I run faceted search through the Fess API?

Yes. Both GET /api/v1/search and POST /api/v1/search accept filter parameters and label-based facets. Use POST when query bodies grow beyond URL length limits.

What are the rate limits for the Fess API?

Fess does not enforce server-side rate limits in the OpenAPI spec because it is self-hosted. Throughput depends on the deployment's hardware and JVM configuration.

How do I trigger the Fess crawler through Jentic?

Search Jentic for 'start search crawler', load the POST /api/admin/crawler/start schema, and execute. Run pip install jentic to get started.

Does Fess support autocomplete?

Yes. The GET /api/v1/suggest endpoint returns suggestion candidates for partial queries, suitable for type-ahead UIs and agent query refinement.

Can I check Fess cluster health programmatically?

Yes. GET /api/v1/health returns cluster status, useful for readiness probes and post-crawl verification before running queries.