CustomGPT.ai
Browse all Customgpt APIs★ Only Publicly Available OpenAPI DocumentAI/MLLanguage Modelsbearer64 EndpointsREST
For Agents
Build, configure, and query custom retrieval-augmented chatbots. Agents can create projects, add documents, run chat completions, and inspect citations.
Use for: I want to spin up a custom ChatGPT bot trained on my product docs, Send a chat message to my CustomGPT project and get a grounded answer, Reindex a document after the source page changed, List all conversations a CustomGPT agent had this week
Not supported: Does not handle raw LLM model hosting, vector database management, or generic web scraping - use for managing and querying CustomGPT-hosted retrieval agents only.
Jentic publishes the only available OpenAPI specification for CustomGPT.ai, keeping it validated and agent-ready. CustomGPT.ai is a no-code platform for building custom ChatGPT-style agents grounded in private business content, with retrieval over uploaded documents and crawled sites. The API exposes 64 endpoints for managing agents (called projects), ingesting and reindexing documents, sending chat completions in OpenAI-compatible format, and tuning persona settings, citations, and conversation history. It also covers labels, plugins, license keys, reports, and per-agent usage limits.
Install Jentic One Beta
Connect the CustomGPT.ai to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the CustomGPT.ai, 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://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 CustomGPT.ai API.
Provision a CustomGPT agent and ingest documents from URLs or file uploads via /api/v1/projects and /api/v1/projects/{projectId}/pages
Send retrieval-grounded chat completions in OpenAI-compatible format through /api/v1/projects/{projectId}/chat/completions
Inspect citation sources for each answer to surface where the bot pulled context from
Tune persona prompts and roll back to previous persona versions via /api/v1/projects/{projectId}/settings/persona-activate/{version}
Tag documents and assign user labels to enforce per-segment access control
Pull agent statistics and conversation reports to measure deflection and usage
Use Cases
Patterns agents use CustomGPT.ai API for, with concrete tasks.
★ Customer support deflection bot
Stand up a help-desk bot that answers from your knowledge base with cited sources. Create a project, upload help-center articles via /api/v1/projects/{projectId}/pages, and let users chat through the OpenAI-compatible chat completions endpoint. Retrieval and citation are handled by CustomGPT, so engineering work is limited to ingestion and front-end wiring.
Create a project named 'Support Bot', ingest the URL https://help.example.com/sitemap.xml, then send a chat completion asking 'how do I reset my password?' and return the citations array.
Sales enablement assistant
Train a project on product datasheets, pricing, and competitor battlecards so sales reps can ask natural-language questions and receive grounded answers. Personas can be versioned per region or product line and rolled back via /api/v1/projects/{projectId}/settings/persona-activate/{version}. Reports endpoints expose usage so RevOps can track adoption.
Upload the latest pricing PDF as a page, set the active persona to 'EMEA Sales', and run a chat completion asking 'what is the discount tier for >100 seats?'
Documentation Q&A widget
Embed a doc-aware bot inside a developer portal. The API lets you ingest a docs site, watch reindex status per page, and stream chat completions back to the widget. Labels segment public versus internal-only sources so the same agent can serve different audiences.
Reindex page 4567 in project 1234 and confirm status is 'finished' before exposing it to the widget.
Agent-driven knowledge base for AI workflows
Use CustomGPT.ai through Jentic to give an autonomous agent a private, citable knowledge layer. The agent searches Jentic for 'query a custom GPT bot', loads the chat completions schema, and calls the project with the user's question - no SDK, no docs reading, no key handling in the agent context.
Through Jentic, call POST /api/v1/projects/{projectId}/chat/completions on project 1234 with the message 'summarise our Q4 launch plan' and return the answer plus citations.
Key Endpoints
64 endpoints — jentic publishes the only available openapi specification for customgpt.
METHOD
PATH
DESCRIPTION
POST
/api/v1/projects
Create a new agent (project)
POST
/api/v1/projects/{projectId}/chat/completions
Send a chat message in OpenAI-compatible format
GET
/api/v1/projects/{projectId}/pages
List documents indexed in an agent
POST
/api/v1/projects/{projectId}/pages/{pageId}/reindex
Reindex a document after source changes
GET
/api/v1/projects/{projectId}/stats
Get agent usage statistics
POST
/api/v1/projects/{projectId}/replicate
Clone an agent as a new project
POST
/api/v1/projects
Create a new agent (project)
POST
/api/v1/projects/{projectId}/chat/completions
Send a chat message in OpenAI-compatible format
GET
/api/v1/projects/{projectId}/pages
List documents indexed in an agent
POST
/api/v1/projects/{projectId}/pages/{pageId}/reindex
Reindex a document after source changes
GET
/api/v1/projects/{projectId}/stats
Get agent usage statistics
POST
/api/v1/projects/{projectId}/replicate
Clone an agent as a new project
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
CustomGPT.ai bearer tokens are stored encrypted in the Jentic vault. Agents receive scoped execution access - the raw token never enters the agent's prompt or logs.
Intent-based discovery
Agents search by intent (e.g. 'send a chat message to a custom GPT bot') and Jentic returns the matching CustomGPT operation with its input schema, so the agent calls the right endpoint without browsing docs.
Time to first call
Direct CustomGPT integration: 1-2 days for auth, ingestion polling, and chat plumbing. Through Jentic: under 30 minutes - search, load, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
Alternative
CustomGPT.ai (alt bundle)
Sibling spec bundle of the same CustomGPT.ai API with a slightly different tag set
Choose this bundle if your tooling already references the customgptai slug; otherwise prefer customgpt-api which has the broader tag coverage.
FAQs
Specific to using CustomGPT.ai API through Jentic.
Why is there no official OpenAPI spec for CustomGPT.ai?
CustomGPT.ai does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call CustomGPT.ai 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 CustomGPT.ai API use?
The API uses HTTP bearer authentication - you pass your CustomGPT API token as Authorization: Bearer <token>. Through Jentic, the token is held in the encrypted vault and never enters the agent's prompt context.
Can I send chat messages to a CustomGPT agent through the API?
Yes. POST /api/v1/projects/{projectId}/chat/completions accepts the OpenAI chat-completions request shape, so existing OpenAI client code can target a CustomGPT project with only a base URL and key swap.
How do I add documents to an agent?
POST /api/v1/projects/{projectId}/pages with a sitemap URL or file payload. Indexing is asynchronous - poll the page record or use the reindex endpoint to refresh stale content.
What are the rate limits for the CustomGPT.ai API?
Rate limits are tied to your CustomGPT.ai subscription tier rather than published in the spec. Check your plan in the CustomGPT dashboard, and handle 429 responses with backoff in production code.
How do I query a CustomGPT bot through Jentic?
Run pip install jentic, then search for 'send a chat message to a custom GPT bot', load the chat-completions schema, and execute with your project ID and message. Jentic returns the structured response including citations.
GET STARTED