# Karbon **Canonical:** https://apis.io/providers/karbonhq/ **Website:** https://karbonhq.com/ **APIs profiled:** 2 Karbon is accounting practice management software for accounting firms, built to enhance visibility, efficiency, and connectivity for a firm no matter where its people are located. Through the Karbon Developer Center (developers.karbonhq.com) it publishes a public REST API reference plus guides covering authentication, pagination, rate limits, webhooks, work items, clients, custom fields, budgets and time, invoices and payments, and file uploads. ## Kin Score — 74.4 / 100 (exemplar) Scored 2026-10-09 under rubric 0.23.0. | Facet | Score | |---|---| | Discoverability | 67.9 | | Contract Quality | 74.7 | | Contract Governance | 76.5 | | Operational Transparency | 84.2 | | Developer Ergonomics | 56.5 | | Access Clarity | 76.3 | Regulatory layer — **Horizontal (data, software, accessibility, platform)**: 30.4 (matched via fallback). ## Agent readiness — 51.8 (agent-ready) | Dimension | Value | |---|---| | Spec Presence | yes | | Agentic Access | derived | | Reversibility Documented | no | | MCP Server | documented | | Auth Clarity | served | | Idempotency | no | | Error Semantics | verified | | OpenAPI Examples | verified | | Rate Limit Signal | documented | | Event Surface Described | yes | | Agent Skills | derived | | Well Known Catalog | no | | Consent Identity | no | | Agent Card | no | | Dry Run Mode | no | | Delegated Identity | served | | Protected Resource Metadata | no | | Dynamic Client Registration | yes | | Agentic Commerce | no | ## APIs (19) - **Karbon Billing API** — List and view an Invoice and associated line items - **Karbon Business Cards API** — View or update the Business Card attached to a Contact and/or Organization - **Karbon Client Groups API** — Create a client group to manage related contacts, create work for them, and see all related jobs in a single view. [Read more](https://help.karbonhq.com/en/articles/5880261-mana... - **Karbon Comments API** — Use comments on tasks to add notes or bring a colleague into the conversation to collaborate on the task. [Read more](https://help.karbonhq.com/en/articles/2111192-comment-and-c... - **Karbon Contacts API** — Manage your contacts and get the full overview over clients, whether they are individuals or organizations. [Read more](https://help.karbonhq.com/en/articles/5708609-overview-of... - **Karbon Custom Fields API** — Endpoints to manage Custom Fields on Contacts and Organizations in Karbon, refer to the Karbon help and support content for more information on [creating custom fields](https://... - **Karbon Estimate Summaries API** — Estimate and track time to understand jobs that are on-budget, allocate resources, and uncover performance insights to transform your firm. [Read more](https://help.karbonhq.com... - **Karbon Files API** — Handle files and attachments. [Read more](https://help.karbonhq.com/en/articles/5714089-files-and-attachments) - **Karbon Integrated Workflows API** — Endpoints that enable Karbon Integration Partners to manage integrated workflow tasks enabled for their integrations. Note that these endpoints cannot be used to access Tasks or... - **Karbon Notes API** — Hold a conversation internally within your company. Unlike an email, Notes are viewed only by members of your team. [Read more](https://help.karbonhq.com/en/s/articles/5919746-u... - **Karbon Organizations API** — Create an organization to represent marriages and couples and client groups to represent families. [Read more](https://help.karbonhq.com/en/articles/5708609-overview-of-contacts... - **Karbon Tenant Settings API** — Retrieve lists of valid Contact Types, Work Types and Work Statuses - **Karbon Timesheets and Time Entries API** — Retrieve individual (non-aggregated) time entries, each record represents a single time entry for a specific day, user, and work item. [Read more](https://help.karbonhq.com/en/s... - **Karbon Users API** — Create and view the basics & defaults for colleagues, teams and job roles to customize Karbon to represent the way you and your team work. [Read more](https://help.karbonhq.com/... - **Karbon Webhook Payloads API** — Details of the different payloads sent for Karbon Webhook subscriptions - **Karbon Webhook Subscriptions API** — Integrate your system with Karbon to receive changes made to your data in Karbon. Note: Webhook payloads take the following form: ```JSON { "ResourcePermaKey": "{EntityKey}", "R... - **Karbon Work Items API** — Manage a Work Item to best fit your workflow, including timelines, tasks and work teams. [Read more](https://help.karbonhq.com/en/articles/6057036-managing-work-items-and-teams) - **Karbon Work Schedules API** — Set a Work Item to repeat on a defined schedule. [Read more](https://help.karbonhq.com/en/articles/6096234-setup-repeating-work-on-a-schedule) - **Karbon Work Templates API** — Find and review templates that you created to fit your firm's unique workflows. [Read more](https://help.karbonhq.com/en/articles/5325202-create-and-customize-work-templates) ## MCP servers (1) - **Karbon MCP Server** — Karbon's official hosted MCP server. It lets AI agents connect to a user's Karbon account. Karbon's own llms.txt files announce it at https://mcp.karbonhq.com ("Karbon's MCP ser... ## Agentic access (1) - **Karbonhq Agentic Access** — 77 operations · 34 acting ## Security (3) - **Karbonhq Authentication** — apiKey/http · 2 schemes - **Karbonhq Domain Security** — TLSv1.3 · HSTS · DMARC - **Karbonhq Vulnerability Disclosure** — security.txt · contact published ## Plans (1) - **Karbonhq Plans Pricing** ## Tags Company, Accounting, Practice Management, Workflow, Collaboration, Professional Services, SaaS --- Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/karbonhq/). Scores are computed from the provider's own public artifacts under a published rubric.