Breakcold vs Close API + MCP

Breakcold 15

No x402, MPP or L402 (0). Plan prices are public, and each call's cost in usage tokens is published, but the money value of a token is not (10). The 14-day trial needs a card (0). auth.md documents an agent identity endpoint that takes an identity assertion or an anonymous request followed by a claim by a person, which we read and did not call; access still needs a paid or card-backed trial account (5 of 20). 0 + 10 + 0 + 5 = 15.

Close API + MCP 30

No x402, MPP or L402 (0). Plan prices public, Solo $9 a seat a month yearly or $19 monthly up to Scale $139 or $149, with calls at about $0.02 a minute passed through at cost, but nothing per API call (10). 14-day trial with no card, prices re-read on 1 November (20). A person signs up in a browser (0). 0 + 10 + 20 + 0 = 30.

Breakcold 45

Graded as a hosted service on the REST API and hosted MCP server. No status page is linked from the site or docs, and status.breakcold.com failed the TLS handshake (0). With no readable history the incident line scores 5. Rate limits published per organisation (600 a minute), workspace (300), identity or key (180) and route (120), for REST and MCP (15). 429 carries Retry-After and retryAfterMs, the docs give backoff guidance, and creates take an Idempotency-Key so retries return the original result (15). No SLA found in the services agreement summary, the pricing page or the docs (0). Neither surface is marked beta (10). 0 + 5 + 15 + 15 + 0 + 10 = 45.

Close API + MCP 56

Statuspage at status.close.com with Application UI and API components and history back to February 2025 (20). In the 90 days from 3 August, read from history.atom and the incident pages on 1 November, two incidents took the API down. On 11 August Close was intermittently unavailable for about 2.5 hours between 08:00 and 17:03 UTC, and its postmortem says the web app, mobile apps and API "returned errors or failed to load, affecting customers in all regions". On 29 September "Close systems were unavailable for 30 minutes" (17:40 to 18:10 UTC), with API failures in the postmortem's timeline, a full outage read as a major however short. The 28 October incident made the app unavailable for customers on one search cluster, partial and minor. Two majors (5). The 1 October check found nothing after 3 July. Limits are set per endpoint group, per key and per organisation (3 times the key limit), but the docs only give 20 a second as an example rather than a table (10 of 15). Every response carries a RateLimit header, and every 429 has both RateLimit and retry-after, with guidance to sleep for the reset value. No idempotency keys or safe-retry guidance for writes (11 of 15). No SLA found on the pricing page (0). REST and MCP carry no beta label (10). 20 + 5 + 10 + 11 + 0 + 10 = 56.

Breakcold 67

72 MCP tools (5), with tools_search and capabilities_list to find tools by capability or granted scope, and scopes that limit which tools apply (8 back). Cursor pagination, record search and a fields selection on record lists since 3 November (18 of 20). Errors carry a code, message, requestId and retryAfterMs, and the 4 November changelog removed stack frames from messages (17 of 20). Idempotency keys on creates, and compose and send tools return a non-sending draft by default; MCP annotations are not published (14 of 20). No official SDK; setup is one URL with OAuth (5 of 15). 13 + 18 + 17 + 14 + 5 = 67.

Close API + MCP 56

141 MCP tools on 1 November, 80 read, 19 safe-write and 42 destructive (5). Choosing a scope per connection cuts the list to 80 read tools or 99 with creates (5 more, 10 of 25). Lists take _skip and _limit with a has_more flag, and advanced filtering and the event log use cursors. No field selection found (16 of 20). Documented response codes, and 429s say how long to wait (13 of 20). No idempotency keys. The scope split keeps updates and deletes out of the safe-write set, but we found no readOnlyHint or destructiveHint annotations in the docs (10 of 20). The only official client is the Python closeio wrapper, last tagged v2.1 in July 2023 (7 of 15). 10 + 16 + 13 + 10 + 7 = 56.

Breakcold 60

API changelog entry on 6 November 2026 (30). More than 60 dated entries since 8 August 2026 (20). Closed service with a public API changelog, an RSS feed, a help centre and support by email; no public issue tracker (10 of 15). The CRM MCP server is not in the official MCP registry (the registry's io.github.breakcold/inboxmcp is a separate product at inbox-mcp.com), and no official SDK exists (0). No package to check (0). 30 + 20 + 10 + 0 + 0 = 60.

Close API + MCP 49

Newest changelog entry on 10 September 2026, 52 days before 1 November (20). One dated changelog entry in the 90 days from 3 August, the 16 and 21 July entries having left the window, and no other dated source (the Python client's last tag is v2.1 from July 2023 and the MCP registry entry is 1.0.1 from 22 September 2025), so fewer than three (0). Public changelog and support by email and phone. We didn't test support (10 of 15). In the official MCP registry as com.close/close-mcp, last version 1.0.1 published on 22 September 2025 (15). The Python client's CI was updated on 10 June 2026 (4 of 10). 20 + 0 + 10 + 15 + 4 = 49.

Breakcold 90

OpenAPI 3.1 contract at docs.breakcold.com/api/openapi.json with 70 operations, each with a description (25). llms.txt and a Markdown copy of each page, plus auth.md and an MCP server card (10). Tool descriptions say how to use them, such as records_create asking for every required field and a stable idempotency key and the send tools saying to send only after the user confirms (17 of 20). 84 enums and 488 required lists, with typed attribute pages for each field type (13 of 15). Every operation documents 400 to 429 responses and the error body is shown, but the spec carries only two examples (10 of 15). /api/v1, and an API changelog with dated entries and migration steps (15). 25 + 10 + 17 + 13 + 10 + 15 = 90.

Close API + MCP 82

OpenAPI 3.1 spec, 303 operations on 160 paths at developer.close.com/openapi.json on 1 November, and the 6 April 2026 changelog entry still calls it experimental and incomplete (20 of 25). llms.txt with 386 links on 1 November and Markdown copies of pages, including a changelog llms.txt (10). MCP tool descriptions say when not to call them. Delete tools read 'This action cannot be undone. ONLY call this if the user specifically instructed you to delete', and the email tool says it saves an unsent draft (16 of 20). Typed parameters in the reference, with free-form smart-view queries for search (11 of 15). Examples throughout and an HTTP response codes page (12 of 15). Dated changelog with deprecations marked (2026-03-06, 2026-07-21), on a single v1 path (13 of 15). 20 + 10 + 16 + 11 + 12 + 13 = 82.

Breakcold 60

API keys take chosen read and write scopes, an optional workspace limit and an expiry, are shown once, show activity history and can be revoked. MCP also accepts OAuth with PKCE through WorkOS AuthKit. Tokens travel in headers (30). Read-only keys are possible and message sends stay drafts until sendMode is set after the user confirms (17 of 20). The inbox returns email, LinkedIn, WhatsApp and Telegram text from outside parties, and no prompt-injection guidance was found (0). API key activity history is visible to the user; no organisation audit log was found (7 of 15). A vulnerability disclosure policy (3 September 2026) with reports to support@breakcold.com, no bounty, no security.txt (404) and no SOC 2 or ISO 27001 found (6 of 20). 30 + 17 + 0 + 7 + 6 = 60.

Close API + MCP 66

REST keys act as one user in one organisation over HTTP Basic and can be deleted. OAuth for apps has only all.full_access plus offline_access, with 1-hour access tokens and a revoke endpoint. The MCP server adds three scopes, mcp.read, mcp.write_safe and mcp.write_destructive, over OAuth with dynamic client registration or a key header (24 of 30). A read-only MCP connection is one header. Safe-write can create but not update or delete. Email tools only make drafts a person sends, and delete tools tell the model to act only on an explicit instruction (18 of 20). The MCP server reads emails, SMS and call transcripts written by outsiders, and we found no injection guidance. Draft-only email closes one exfiltration route (4 of 15). The event log API records changes and is on every plan (12 of 15). SOC 2 Type 2 on the security page. No security.txt (404 on 1 November), and no disclosure policy or bug bounty found (8 of 20). 24 + 18 + 4 + 12 + 8 = 66.