Fess Codelibs Fess API
✓ 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.
Use for: Search the enterprise index for a specific document, Get autocomplete suggestions for a partial query, List the most popular search terms this week, Add a document to a user's favourites
Not supported: Does not handle web crawling configuration UI, document parsing, or index storage — use for querying and operating an existing Fess deployment only.
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. The base URL is determined per deployment via the {host} server variable, and authentication is provided through an API token sent in the Authorization header. Admin endpoints support starting and stopping the crawler and updating search list configuration.
Install Jentic One Beta
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.
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 Fess 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
Start and stop the Fess crawler against configured data sources
Inspect cluster health and search list configuration
Use Cases
Patterns agents use Fess 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
/api/admin/crawler/start
Start crawler
Why 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.
FAQs
Specific to using Fess 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.
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