Puzzle API and MCP vs Xero API + MCP

Puzzle API and MCP 15

Hosted reading. status.puzzle.io exists but answered 403 to our reader, so no status page or history could be read (0, then 5 for no readable history). No rate limits found in the API docs (0). The errors page documents 409 RESOURCE_PROCESSING with retry later and 500 with retry, but no 429 or idempotency guidance (5). No SLA (0). MCP read access is live, write access is a beta, and the API docs say the API is under development (5). 0 + 5 + 0 + 5 + 0 + 5 = 15.

Xero API + MCP 68

Statuspage at status.xero.com with product and region components, none of them the API (20). Since 3 August the history lists tax-authority connections (HMRC, ATO, Inland Revenue), US payroll through Gusto, Partner Hub, subscriptions, third-party outages and scheduled maintenance. None names the API. The longest whole-product incidents were errors navigating Xero after logging in for about an hour on 28 October (labelled critical, component Xero Platform and Settings) and intermittent errors for some customers for 2 hours 24 minutes on 26 and 27 October, both read from their text as the web app, not the API (20). Daily limits per organisation are published on the pricing page (1,000 on Starter, 5,000 above). The minute and concurrency limits are on a JavaScript-only page we couldn't read (10). The OpenAPI spec puts an Idempotency-Key parameter on 101 operations. 429 and Retry-After handling sits on the unreadable limits page (8). No SLA found (0). GA (10).

Puzzle API and MCP 53

The MCP registry entry was published on 5 October 2026, 32 days before this check, and Puzzle's MCP post is dated 26 October (20). No release log, so changes in the 90 days can't be counted beyond the registry entry and the MCP launch (5). A help centre and support contact, but no public changelog or issue tracker (8). io.puzzle/puzzle sits under a domain-verified namespace in the official registry (15). No SDK or package to judge (5). 20 + 5 + 8 + 15 + 5 = 53.

Xero API + MCP 76

Xero-OpenAPI 19.1.0 on 1 October and a dated developer changelog entry on 15 October for the remote MCP launch (30). Spec releases 16.2.0, 17.0.0, 18.0.0, 19.0.0 and 19.1.0, xero-node 19.1.0, 19.2.0 and 20.0.0, and changelog entries from 10 August to 15 October, all since 3 August (20). Closed API with a dated changelog and developer community. The local MCP repository had five commits on 26 October after none since 5 June, none of them released yet (10). Current official SDKs in six languages, but the MCP isn't in the official registry, and npm's latest was 0.0.17 from 26 May per the 1 October check (12). The MCP repository has no CI workflows (4).

Puzzle API and MCP 49

Closed service with published terms naming Puzzle Financial Inc. (15). A privacy policy effective 19 December 2025; the security page says data stays on US servers and isn't shared or sold (15). The API docs promise documented endpoints stay stable but give no deprecation policy (5). Sub-processors not found, though the server location is stated (8). 15 + 15 + 5 + 8 = 43.

Xero API + MCP 72

Closed API with developer terms dated 4 December 2025 naming Xero Limited (NZ 1830488) and the governing law by region. MIT MCP server and SDKs (17). Developer terms forbid training or fine-tuning AI models on API data. The UK privacy notice, dated 11 February 2025, says Xero uses AI and ML on its services and keeps data while there's a business or legal need, with no periods (15). Dated deprecations with 12 to 13 months' notice, such as accounting.transactions retiring on 13 September 2027 and XPM API v3.0 on 6 May 2027 (20). Transfers to Australia, New Zealand and the United States are named, with no public subprocessor list (8).

Puzzle API and MCP 15

No x402, MPP or L402 (0). Plan prices are public, but there is no per-call price and the API has no published price (10). "Try for free" on every plan, with trial length and card requirement not stated on the pages read (5). A person signs up and authorises in a browser, and API credentials come by email (0). 0 + 10 + 5 + 0 = 15.

Xero API + MCP 35

No x402, MPP or L402 (0). Tier prices are public in AUD (Core 35, Plus 245, Advanced 1,445 a month) with a per-GB egress overage of AUD 2.40, which we scored between plan-only and per-unit (15). Starter is free for 5 connections at 1,000 calls a day per organisation, with no card per the 30 September check, plus a Demo Company in any Xero account (20). Browser signup and an OAuth consent (0).

Puzzle API and MCP 56

MCP tool count and sizes unpublished, so context cost can't be read (10 of 25). API list endpoints page with count and after or limit, and filter by date and status (16). Error codes and errorContext name the field or resource at fault (17). No idempotency keys found; the MCP server asks for confirmation before writes (8). No official SDKs; few required parameters on reads (5). 10 + 16 + 17 + 8 + 5 = 56.

Xero API + MCP 75

The official local MCP loads 51 tools with no toolsets or read-only subset. A remote Developer MCP with 39 tools launched on 15 October 2026 for apps on Core or above. The API pages at up to 100 per page and honours If-Modified-Since (12). page, pageSize, where, order, Statuses and If-Modified-Since on list endpoints (20). Validation errors per element with summarizeErrors, though the MCP's mapped messages drop Xero's own error detail for the four common statuses (14). Idempotency-Key on 101 operations. The local MCP sets no readOnlyHint or destructiveHint and includes a delete tool (14). SDKs for Node, Python, Java, .NET, PHP and Ruby, though every call needs the xero-tenant-id header (15).

Puzzle API and MCP 65

The API reference on ReadMe is generated from an OpenAPI file, though we didn't download the file itself; the MCP tool schemas aren't published (18). llms.txt and Markdown pages on puzzle-api.readme.io (10). Endpoint descriptions name the required scope and explain defaults such as cash basis (14). Typed parameters with documented limits, such as companies capped at 100 a page (11). An error table with HTTP codes and errorContext shapes, and example requests (12). No changelog or version scheme found (0). 18 + 10 + 14 + 11 + 12 + 0 = 65.

Xero API + MCP 79

OpenAPI specs for accounting, payroll, assets, files, bank feeds, projects and more in XeroAPI/Xero-OpenAPI, 235 operations in accounting alone (25). No llms.txt, and developer docs return "This app works with JavaScript enabled" to a fetch (0). MCP descriptions name the tool to call first ("can be obtained from the list-accounts tool") and explain ACCREC and ACCPAY, but don't say when not to use a tool (15). Zod schemas with enums, and enums throughout the spec (13). Examples in the spec, a summarizeErrors option for batch writes, and the MCP maps 401, 403, 404 and 429 to plain messages (11). Spec tagged 19.1.0 on 1 October and a dated developer changelog with deprecation dates (15).