Polar
Merchant-of-record billing and checkout for digital products, with an official hosted MCP and SDKs.
Hosted platform for selling digital products, subscriptions, usage-based billing, and license keys, acting as merchant of record for tax. The Builder publishes a REST API, JS and Python SDKs, and an MCP server at mcp.polar.sh (production and sandbox). Source is Apache-2.0 on GitHub but the Builder does not document self-hosting.
- I sell software, courses, or API credits and want someone else to handle VAT and sales tax
- my agent should create products, checkout links, and discounts and read orders through an official API or MCP
- Fees are per transaction: Starter 5% + 50c, Pro 3.8% + 40c, Growth 3.6% + 35c, Scale 3.4% + 30c; no flat monthly price
- MCP docs give endpoints and client setup but no tool list; treat MCP coverage as the API's until verified
- Self-hosting is not documented; the repo is for contribution
Last activity Sep 2, 2026. Fit: adaptable 1, operable 3.
Editions
Starter · Free closed source
- HostedOpen the hosted app
Pro · Free closed source
- HostedOpen the hosted app
Growth · Free closed source
No distribution recorded.
Scale · Free closed source
No distribution recorded.
Operable: what an agent can drive
Interface
OfficialAPIpublished by the builderremote
How an agent can drive an Operable Listing, in five levels: native (built for the agent as the primary interface), official (the Builder ships an agent interface), wrapped (a third party wraps the software's API), config (an agent can only drive it by editing files), gui (screen control only). An interface is official only when it is published by the same organization that ships the software. GUI-level Listings are allowed and sorted last.
Reach
Partial coverage. 9 of 10 jobs reachable through the stated interface.
| Job | Through the interface | Evidence |
|---|---|---|
| Create and manage products and prices | Reachable | API reference: Products |
| Create checkout sessions and links | Reachable | API reference: Checkouts |
| List and manage orders and refunds | Reachable | API reference: Orders, Refunds |
| Manage subscriptions | Reachable | API reference: Subscriptions |
| Manage customers | Reachable | API reference: Customers |
| Benefits and license keys | Reachable | API reference: Benefits, License Keys |
| Discounts | Reachable | API reference: Discounts |
| Usage meters and events | Reachable | API reference: Meters |
| Webhooks | Reachable | API reference: Webhooks |
| Payout and tax filing | Not reachable | handled by Polar as merchant of record; dashboard only |
Code stack
- Languages
- PythonTypeScript
- Frameworks
- FastAPINext.js
- Package manager
- –
- Database
- PostgreSQL
- Hosting target
- polar.sh
- Built
- Human-written (recorded, never ranked)
Skills
Repo tooling for Polar contributors: billing review, API surface review, local environment, ADR checks.
- Kind
- contributor
- Paths
.agents/skills/*/SKILL.md
Evidence and confidence
| Field | Where it was seen | Confidence |
|---|---|---|
| formFactor | hosted service with REST API, SDKs, and MCP | 90% |
| executionModel | no model at runtime | 95% |
| operability | polar.sh/docs/integrate/mcp lists mcp.polar.sh endpoints; API reference and SDKs under polarsource | 90% |
| effort | no supported self-host; customization null | 0% |
| editions | README Pricing section lists Starter free plus fees and paid tiers | 85% |
| active | pushedAt 2026-09-02 | – |
| reach | 80% |
Open questions
- Tool names exposed by mcp.polar.sh and its auth flow
- Whether self-hosting is supported at all (DEVELOPMENT.md is for contributors)
Sources
- github.com/polarsource/polar sourcing:ecommerce:vendor
- polar.sh/docs/integrate/mcp sourcing:ecommerce:vendor
- polar.sh/docs/llms.txt analysis