Karbonhq Karbon API
Agent-ready OpenAPI document · curated by JenticProductivityTask Managementbearer45 EndpointsREST
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For Agents
Manage contacts, organisations, work items, tasks, notes, and timesheets inside an accounting firm's Karbon practice. 45 endpoints covering the full client engagement workflow.
Use for: I need to create a new client contact in Karbon, Add a tax-return work item for an existing organisation, Retrieve all open tasks assigned to a specific accountant, List timesheet entries for last week across the firm
Not supported: Does not handle general-ledger postings, payroll, or tax filing - use for accounting firm practice management (clients, work items, tasks, notes, timesheets) only.
Jentic publishes the only available OpenAPI specification for Karbon API, keeping it validated and agent-ready. Karbon is practice management software for accounting firms, and its API exposes contacts, organisations, work items, notes, timesheets, tasks, tags, and users so firms can sync client data, automate engagement workflows, and roll up time and capacity reporting. The v3 endpoints follow REST conventions and use bearer-token authentication issued from the Karbon admin console.
Install Jentic One Beta
Connect the Karbon API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Karbon 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%2Fkarbonhq.com%2Fkarbon" | 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%2Fkarbonhq.com%2Fkarbon" | 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 Karbon API.
Create and update contact records linked to organisations via /contacts and /contacts/{id}
Manage client organisations including their tags and client groups via /organizations and /clientGroups
Drive engagements with work items and tasks via /workItems and /tasks endpoints
Capture client communication and meeting notes through /notes endpoints
Pull billable and non-billable time entries via /timesheets
Resolve users and team members for assignment and capacity views via /users
Use Cases
Patterns agents use Karbon API for, with concrete tasks.
★ Client Data Sync from CRM to Karbon
Mirror client and contact data from an accounting firm's CRM into Karbon so the practice management system always has up-to-date contact details, organisation links, and tags. The /contacts and /organizations endpoints accept create and patch payloads with rich relationship fields, so a one-way sync runs cleanly on a nightly schedule. Removes a recurring source of stale-data errors when accountants pull client records during tax season.
List recent CRM updates and upsert each as a Karbon contact via POST /contacts or PATCH /contacts/{id}, linking to the parent organisation.
Engagement Automation for Tax Season
Auto-create a Karbon work item with its task list every time a new tax-return engagement is signed in the firm's onboarding system. The API creates the work item under the correct client organisation, attaches default tasks, and assigns them to the right accountant based on the firm's load balancing rules. Saves administrators 5-10 minutes per engagement during peak load.
Create a 'Tax Return 2026' work item via POST /workItems for client organisation {id} and add five tasks via POST /tasks assigned to the lead accountant.
Capacity and Utilisation Reporting
Pull timesheet entries from Karbon nightly into a data warehouse so partners can run capacity and utilisation reports outside Karbon's built-in views. The /timesheets endpoint exposes entries with user, work item, billable flag, and duration so a small ETL can compute realisation, utilisation by team, and time-by-client without a third-party BI add-on.
Pull timesheet entries via GET /timesheets for the last 7 days and aggregate hours by user and client organisation.
Agent-Driven Practice Management
An accounting firm's internal AI assistant uses Jentic to update Karbon directly when a partner asks 'mark John's tax return as complete' or 'add a meeting note for Acme Co'. Jentic resolves the right work item or organisation by name and executes the call, with the bearer token held server-side so the assistant never sees the raw secret.
Use the Jentic search 'add a note to a Karbon client', load the schema, and POST /notes with the client organisation ID and meeting summary.
Key Endpoints
45 endpoints — jentic publishes the only available openapi specification for karbon api, keeping it validated and agent-ready.
METHOD
PATH
DESCRIPTION
GET
/contacts
List client contacts
POST
/contacts
Create a new contact
GET
/organizations/{id}
Retrieve a client organisation
POST
/workItems
Create a work item for an engagement
POST
/tasks
Create a task on a work item
POST
/notes
Add a note to a client record
GET
/timesheets
List time entries for the firm
GET
/contacts
List client contacts
POST
/contacts
Create a new contact
GET
/organizations/{id}
Retrieve a client organisation
POST
/workItems
Create a work item for an engagement
POST
/tasks
Create a task on a work item
POST
/notes
Add a note to a client record
GET
/timesheets
List time entries for the firm
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Karbon API by hand means learning its bearer auth, calling api.karbonhq.com/v3, and mapping contacts, work items, tasks, and notes to their request shapes yourself. Through Jentic you install once, import the Karbon API from the API Directory, store the token once, and your agent calls it.
Permission scoping
Most Karbon writes post to collection endpoints like /workItems, /tasks, and /notes rather than a resource id in the path, so scope the agent by the operations it needs, such as creating a work item or reading timesheets. You pick that set, so an agent built to file notes is not given contact creation unless you add it.
Credential isolation
Your Karbon bearer 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 'create a Karbon work item' or 'list open tasks', and Jentic returns the matching Karbon operation with its request schema so the agent calls the right endpoint without reading Karbon's docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Karbon API through Jentic.
Why is there no official OpenAPI spec for Karbon API?
Karbon does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Karbon API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.
What authentication does the Karbon API use?
The API uses HTTP bearer tokens. Each request must include `Authorization: Bearer {token}` where the token is generated from the Karbon admin console. Through Jentic, tokens are encrypted in the vault and scoped per execution so the raw bearer never enters the agent's context.
Can I create a work item for a client engagement via the Karbon API?
Yes. POST /workItems creates a work item bound to a client organisation, and POST /tasks adds tasks under that work item. This is the standard flow for spinning up a tax-return or audit engagement programmatically at the start of the season.
What are the rate limits for the Karbon API?
Karbon enforces per-tenant throttling and returns HTTP 429 when bursts exceed the limit. The published guidance for v3 is to keep below ~10 requests per second per tenant - check the firm's Karbon plan if a heavier sync is needed and use server-side filtering on /timesheets to keep payloads small.
How do I add a meeting note to a client through Jentic?
Run `pip install jentic` and search Jentic for 'add a note to a Karbon client'. Jentic returns the schema for POST /notes; supply the organisation or contact ID and the note body, then execute to attach the note.
Can I list all open tasks assigned to a specific accountant?
Yes. GET /tasks supports filtering by assignee user ID and status, so you can return all incomplete tasks owned by a single accountant. Combine with GET /users to resolve names to IDs first.
Is the Karbon API included in every plan?
API access is available on Karbon's paid plans but not on the trial tier. Higher-volume integrations (full timesheet exports, large-firm syncs) may require a custom rate-limit arrangement with Karbon support.
Can I limit what my agent is allowed to do with the Karbon API?
Yes. Because Jentic One is self-hosted, you decide which Karbon operations and credentials your agent may use, and it can only call the endpoints you allow. Most Karbon writes post to collection endpoints such as /workItems, /tasks, and /notes, so you scope the agent by operation, for example letting it create notes without also granting contact creation on /contacts. An agent set up to file notes cannot create work items or read /timesheets unless you add those operations to its allowed set.
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