Clientary API
★ Only Publicly Available OpenAPI DocumentFinanceAccountingapiKey32 EndpointsREST
For Agents
Run a freelancer or agency back office: create invoices and estimates, log time and expenses, record payments, and manage clients and projects.
Use for: I need to create an invoice for a client, Send an estimate and convert it once approved, Log time entries against an active project, Record a payment received against an invoice
Not supported: Does not handle payment processing, payroll, or full general-ledger accounting — use for freelancer and agency invoicing, time, and expense tracking only.
Jentic publishes the only available OpenAPI specification for Clientary API, keeping it validated and agent-ready. Clientary is a business-management platform for freelancers and agencies, exposing endpoints for clients, invoices, estimates, projects, time entries, expenses, payments, and staff. Authentication uses an API key sent in the Authorization header. The API is designed for back-office automation: turning logged hours into invoices, reconciling payments, and keeping client records in sync with external CRMs.
Install Jentic One Beta
Connect the Clientary API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Clientary 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://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 Clientary API.
Create and send invoices to clients with line items and tax
Generate estimates and convert accepted ones into invoices
Log billable time entries against projects and staff
Record client payments and reconcile them to invoices
Track project-level expenses for reimbursement and reporting
Maintain a synced client directory across Clientary and an external CRM
Use Cases
Patterns agents use Clientary API for, with concrete tasks.
★ Time-to-Invoice Automation
Agencies that bill hourly can let an agent read approved time entries from /time-entries, group them by client and project, and create draft invoices via POST /invoices at the end of each billing period. Tax, hourly rate, and project mapping are pulled from the existing Clientary records, so the agent does not need to model pricing logic. Month-end billing that previously took a bookkeeper a full day finishes in minutes.
List time entries from the last 30 days for client id 42, group by project, and POST a single consolidated invoice with one line per project at the project's hourly rate.
Estimate-to-Invoice Workflow
Sales-led agencies can have an agent create an estimate via POST /estimates when a deal is won in their CRM, send it for client approval, and convert it into an invoice on acceptance. Because Clientary keeps both estimates and invoices keyed to the same client and project, the agent only needs to copy line items and update the document type. This shortens the gap between deal close and first invoice from days to under an hour.
Create an estimate for client id 17 with three line items totalling $4,500, then once status is 'accepted' POST a matching invoice and link it back to the original estimate.
Payment Reconciliation
Finance teams can reconcile bank deposits to outstanding invoices by having an agent list /invoices with status=open, match each amount to incoming payments fed from the bank, and POST records to /payments with the correct invoice id. Disputed or partial matches are flagged for review. This removes the manual spreadsheet step that typically follows weekly bank statement downloads.
List open invoices for the last 60 days, for each $1,200 deposit on the bank feed find the matching invoice by client and amount, and POST a payment record against that invoice.
Expense and Project Profitability
Project managers can track gross margin per project by combining time entries, expenses, and invoices. An agent calls /projects, /time-entries, /expenses, and /invoices, joins on project id, and produces a margin report. Because all four resources live in the same API, the report can run on demand rather than as an end-of-quarter exercise.
For project id 'website-redesign' fetch all time entries, expenses, and invoiced amounts year-to-date, then return the gross margin as billed minus expenses minus (hours × cost rate).
AI Agent Back-Office Assistant via Jentic
Solo founders and small agencies can register Clientary through Jentic and ask an AI assistant to handle invoicing, payments, and client updates conversationally. Jentic stores the API key server-side and exposes Clientary operations as searchable tools, so the assistant can act on an instruction like 'invoice Acme for last month' without seeing the credential. Setup time is a single Jentic search-load-execute call instead of a custom integration.
Search Jentic for 'create an invoice in clientary', load the POST /invoices schema, and execute with client_id 42 and three line items provided by the user.
Key Endpoints
32 endpoints — jentic publishes the only available openapi specification for clientary api, keeping it validated and agent-ready.
METHOD
PATH
DESCRIPTION
POST
/invoices
Create an invoice
GET
/invoices
List invoices
POST
/estimates
Create an estimate
POST
/clients
Create a client
GET
/clients/{id}
Get a single client
PUT
/invoices/{id}
Update an invoice
POST
/invoices
Create an invoice
GET
/invoices
List invoices
POST
/estimates
Create an estimate
POST
/clients
Create a client
GET
/clients/{id}
Get a single client
PUT
/invoices/{id}
Update an invoice
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
Clientary API keys are stored encrypted in the Jentic vault. Agents receive a scoped execution token — the raw Authorization header value never enters the agent's prompt or memory.
Intent-based discovery
Agents search Jentic by intent (for example, 'create an invoice in clientary' or 'list unpaid invoices') and Jentic returns the matching Clientary operation with its input schema.
Time to first call
Direct Clientary integration: roughly a day to wire auth, model invoices and time entries, and handle pagination. Through Jentic: under an hour — search, load schema, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
Complementary
Stripe API
Payment processing for cards, wallets, and bank debits.
Pair Stripe with Clientary so an agent can take card payment for a Clientary invoice and then POST the matching /payments record.
FAQs
Specific to using Clientary API through Jentic.
Why is there no official OpenAPI spec for Clientary API?
Clientary does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Clientary 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 Clientary API use?
The API uses an API key in the Authorization header. Through Jentic, the key is stored encrypted in the vault and never enters the agent's context — the agent gets a scoped execution token instead.
Can I create invoices and estimates with the Clientary API?
Yes. POST /invoices creates an invoice and POST /estimates creates an estimate. Both accept line items, client id, and tax fields, so an agent can convert an accepted estimate into an invoice by reusing the same line-item payload.
How do I record a payment against an invoice with the Clientary API?
POST /payments with the invoice id, amount, and date. The endpoint links the payment to the invoice and updates its status. Through Jentic, search for 'record a payment in clientary' to load the schema and execute.
What are the rate limits for the Clientary API?
Clientary does not publish hard rate limits in the spec. Build clients to handle 429 responses with exponential backoff and check current limits with Clientary support for your account tier.
How do I generate an invoice from time entries through Jentic?
Run pip install jentic, then chain three calls: list /time-entries filtered by project and date, group by project, and POST /invoices with one line per project. Jentic returns each operation's input schema so the agent can build payloads without manual reference to docs.
GET STARTED