Linq vs Photon

Linq 90

The MCP server has two tools, code execution against the SDK and docs search, so its definitions cost little context (25). Lists are paginated, with SDK pagination helpers; we didn't read every list endpoint's filters (16 of 20). Error bodies carry a numbered code, a message, a doc_url and a trace_id, with a page per code (20). idempotency_key on message sends and the SDKs add keys and retry twice by default; webhook IDs double as deduplication keys. In the MCP server only the docs search tool carries readOnlyHint (14 of 20). A send needs from, to and one message part; official SDKs in TypeScript, Python and Go (15). 25 + 16 + 20 + 14 + 15 = 90.

Photon 63

Read for the TypeScript SDK an agent server runs. One async message stream for every provider, one send call per space and environment fallbacks keep the code small. Management responses can't be sized beyond list limits (17 of 25). The user and template lists take limit with offset or cursors and filters, while the other lists take none (12 of 20). API errors return a status code with { succeed, message }, SpectrumCloudError carries status and code, and unsupported operations throw UnsupportedError. No error-code catalogue for Stable was found (13 of 20). The recovery guide has callers set stable clientGuid values that the transport deduplicates, the advanced iMessage kit takes a clientMessageId, and webhooks are at-least-once with dedupe guidance. Spectrum API writes take no idempotency key (13 of 20). imessage.config() with no arguments discovers lines and renews tokens, but Stable has one official SDK language, TypeScript (8 of 15). 17 + 12 + 13 + 13 + 8 = 63.

Linq 50

Bearer API keys in a header, never in the query string, rotated or revoked in the dashboard, scoped to the account with no per-action or read-only scopes (20 of 30). Sandbox keys reach only verified handles, and the MCP server's --code-allow-http-gets and method allow and block lists limit its code tool; no approval step for sends (10 of 20). Inbound iMessage and SMS text reaches the agent, and no prompt-injection guidance was found in the docs or the MCP instructions (0 of 15). Every response carries a trace_id; no operator request log was found in the docs (5 of 15). SOC 2 Type II reports for 2024, 2025 and 2026 and a 2026 penetration test on request, a vulnerability disclosure policy open on the trust centre and SECURITY.md in the SDK repository; no security.txt or bug bounty (15 of 20). 20 + 10 + 0 + 5 + 15 = 50.

Photon 29

Project ID and secret over HTTP Basic for the Spectrum API. The secret grants full management access to the project, doesn't expire on its own and is rotated with photon projects regenerate-secret. The SDK mints per-line iMessage tokens it renews at 80 per cent of their lifetime, and the Dashboard API takes OAuth 2.1 with PKCE and consented scopes. No secret in a URL is documented (17 of 30). No read-only project credential. The CLI asks before removing a user (3 of 20). Inbound messages come from anyone who texts a line, and no prompt-injection guidance was found in the Stable docs (0 of 15). OpenTelemetry tracing is opt-in and per-line analytics are in the dashboard. API logs and traces arrive with Photon 2.0, not Stable (4 of 15). No security.txt on photon.codes. The Beta API clients' repository has a SECURITY.md with private vulnerability reporting and no acknowledgement time, while spectrum-ts has none, and the privacy policy mentions regular penetration testing. No bug bounty or certification was found, and osv.dev lists nothing for spectrum-ts, @photon-ai or photonhq-api on 4 November. The policy covers only the Beta clients, so the line keeps its partial 5 of 20 rather than the settled 7. 17 + 3 + 0 + 4 + 5 = 29.

Linq 40

No x402, MPP or L402 (0). Public plan prices only, Hobby $0 and Pro from $260 a month, with no per-message fee (10 of 20). Hobby is free with no card, and the Pro trial needs no card (20). linq signup creates an account, an API key and a number from a terminal, but a person has to read back the emailed code, so half (10 of 20). 0 + 10 + 20 + 10 = 40.

Photon 20

No x402, MPP or L402 (0). Plan prices are public. Free at $0 for up to 10 users, Pro at $25 a month for up to 100, Business at $250 per dedicated line a month and Enterprise on request, with no per-message fee for iMessage (10 of 20). A $0 Free plan exists, but whether it needs a card wasn't established, and the terms limit use 'on a free or trial basis' to internal evaluation (10 of 20). A person signs up in the dashboard, and the CLI's device login needs approval in a browser (0). 0 + 10 + 10 + 0 = 20.

Linq 93

OpenAPI 3.1 file for the Partner API and another for WhatsApp, both public (25). llms.txt, llms-full.txt and Markdown for every page (10). Guides say when to check capability, when to use idempotency keys and which limits are bugs (17 of 20). 93 enums in the spec and typed parts for messages (14 of 15). Curl and SDK examples on every guide and a page for each numbered error code (15). Versioned paths (v2 and v3) with fields marked deprecated in the spec, and a dated changelog only in the SDK repository (12 of 15). 25 + 10 + 17 + 14 + 15 + 12 = 93.

Photon 75

Read for the Stable surface. Public OpenAPI 3.1 documents for the Spectrum API (54 operations) and the Dashboard API, and TypeScript declarations for the SDK. Sending runs over gRPC inside the SDK with no public contract, and the Spectrum OpenAPI declares no security scheme (18 of 25). llms.txt, llms-full.txt, a Markdown twin of every page and a documentation MCP server (10). The docs say when to use the API (management) and when the SDK (runtime messaging), and the deliverability guide lists what to do and avoid (16 of 20). Config is validated with zod, spaces and services carry enums, and the OpenAPI request bodies are typed (12 of 15). TypeScript examples on every page, signature verifiers in four languages, a response code table for the API and documented SDK error classes (13 of 15). spectrum-ts follows semver and reached 12.14.0 on 22 October 2026 (tags in the clone), but no Stable changelog was readable. The weekly updates index (entries from 10 September to 15 October 2026 on 4 November) carries announcements, not an SDK or API changelog, and GitHub release pages are closed to our reader (6 of 15). 18 + 10 + 16 + 12 + 13 + 6 = 75.

Linq 83

Read with the hosted lines. status.linqapp.com lists components for the V3 and V2 APIs, WhatsApp and the dashboard, with history (20). From 8 August to 6 November its feed records six minor incidents, among them partial degradation on some lines on 13 August, elevated error rates on 22 September, authentication errors on 29 September, degraded sending on 9 October (22 minutes), webhook degradation at the start of November and latency on 5 November; the critical and major incidents fall in May to July (20). Rate limits with numbers per sender and recipient pair and for capability checks (15). 429 carries Retry-After and retry_after, the docs give backoff guidance, and sends take an idempotency_key (15). llms.txt states 99.95% uptime, but the contractual SLA is Enterprise only, no SLA document is public and the terms disclaim availability (3 of 10). Partner API v3 is generally available (10). 20 + 20 + 15 + 15 + 3 + 10 = 83.

Photon 67

Read with the hosted lines for Spectrum Cloud, the managed lines the SDK connects to. status.photon.codes runs on incident.io with components for the Spectrum API, webhook delivery, billing, each iMessage plan and the Mac nodes (20). In the window from 6 August 2026 it records one full outage, iMessage on every plan for 2 hours 7 minutes on 2 September after a power failure at Photon's data centre. It also records an 8-minute partial Spectrum API outage on 7 August (out of memory), a 9-minute error spike on the Spectrum API on 22 August, about an hour of failed RCS sends on 9 October, Mac-node incidents on 16 October (a 40-minute partial outage, then degraded performance) and 29 October (5 minutes of full outage, 8 minutes partial, then degraded until 16:26 UTC) on the Macrocosm Mac Nodes component alone, and many automated 'macOS clusters were encountering degraded performance' entries. Single-component incidents read as minor (10 of 30). Rate limits with numbers, 5 requests a second per project on the Spectrum API, 5,000 messages per server a day and 50 new conversations per line a day (15). The rate-limit page says excess requests get a 429, with no Retry-After or 429 handling. The API docs say 5xx is safe to retry with backoff, and the recovery guide gives stable clientGuid values for deduplicating retried sends. Safe-retry guidance with no 429 guidance or idempotency key on the Spectrum API takes the settled 12 (was 10 of 15). No SLA document. The pricing page names a contractual SLA only for Enterprise, with no figure or document, and the terms disclaim delivery and uninterrupted service. A listed SLA nobody can read gives 0 (was 3 of 10). The Stable product is generally available (10). 20 + 10 + 15 + 12 + 0 + 10 = 67.

Linq 72

Closed service with clear terms from Linq App Inc. (14 April 2026); SDKs, MCP server and CLI are Apache-2.0 (15 of 30). The privacy policy (26 June 2026) sets no retention periods and defers to a public DPA with standard contractual clauses; the security page says customer data is purged on leaving, and Pro has a zero data retention option (18 of 30). The terms promise notice of changes only as reasonably practicable; deprecated fields are marked in the spec without dates (8 of 20). Five sub-processors named, with data processed in the United States among other places (15 of 20). 15 + 18 + 8 + 15 = 56.

Photon 57

spectrum-ts, its providers, imessage-kit and the CLI are MIT, while Spectrum Cloud and the managed lines are closed. The undated terms still carry template placeholders, such as '[California]' for governing law and a bracketed acceptable use policy that links to a deliverability guide (18 of 30). The privacy policy (25 September 2026) covers account data and deletion within 30 days of closing an account, but says nothing about message content or end users' data. The terms let Photon use de-identified Usage Data to train its models. No DPA or retention period for messages was found (8 of 30). No deprecation policy. Migration notes for removed SDK options carry no dates (4 of 20). SDK telemetry is opt-in and documented with its OTLP endpoint. Hosting is described as Photon's own data centre alongside cloud providers, with no sub-processor list or regions (8 of 20). 18 + 8 + 4 + 8 = 38.