Why a REST API matters
The new API reference gives teams a direct way to build on top of GanttFather. Instead of exporting a spreadsheet, editing it somewhere else, and importing it again, your scripts can read and write the same project data your team sees in the app.
That matters for operations teams, agencies, founders, and internal-tool builders. A Gantt chart is most useful when it stays close to the work. The API makes that possible from cron jobs, dashboards, customer portals, deployment pipelines, and lightweight integrations.
What can you automate?
The first public API surface focuses on the project data people ask to automate most often:
- list the projects your token can access
- read, create, update, reorder, and delete tasks
- keep status and progress in sync
- set assignees and task dependencies
- list members and resources
- create, update, or remove non-human resources such as equipment, rooms, and budget lines
In practice, that means you can create a launch plan from an internal intake form, update a milestone when a deployment finishes, or mirror selected work from another tool into a GanttFather timeline.
How to get started
Open GanttFather, go to Settings → AI Agents & API, and create a token. Then:
- Read the authentication guide.
- Call list projects to find the project id.
- Try create task with a small test item.
- Use pagination and rate limits before running bulk sync jobs.
curl https://api.ganttfather.com/v1/projects \
-H "Authorization: Bearer glt_your_token" \
-H "User-Agent: your-integration-name/1.0"The User-Agent is intentional. It helps support trace real integrations, debug edge cases, and keep API traffic distinct from anonymous browser traffic.
API versus MCP
Use the REST API when you are writing code and want stable HTTP endpoints. Use the MCP server guide when you want an AI assistant such as Claude, ChatGPT, Cursor, or Windsurf to work with your project through higher-level tools.
Both use the same token area in GanttFather, and both are included for every user. The difference is the interface: REST is for your program; MCP is for your agent.
Pricing and limits
API access is included on every plan. The pricing page still follows the same rule: every feature is available from day one, and paid upgrades only add capacity — more projects you own or more active editors.
Default API limits are 60 requests per minute per token and 5,000 requests per day per token. Limited requests return 429 with Retry-After; daily quota responses include X-Quota-Remaining. For larger syncs, batch writes and avoid per-field update loops. See Rate limits & quotas.
The integration pattern
The cleanest integrations usually follow this shape:
- keep a small mapping between your system id and the GanttFather task id
- read the current project state before writing
- send partial updates only for fields that changed
- use idempotency keys on create-style operations when retrying
- log the GanttFather trace id when something fails
Start small: list projects, create one task, update it, then wire the flow into your own system.
Start with a token and keep the reference open beside your editor.