Arcmira vs Valyu

Arcmira

Four code-mode tools over a documented v1 API, OAuth 2.1 with four scopes, a read-only sign-up key from two API calls and no card, and a 1,000-credit free month. No status page, SLA or security.txt, breaking v1 changes shipped in October with same-day notice, the server is at 0.10.7, and the index covers the shows Arcmira transcribes.

Valyu

Web plus academic, financial, patent and life-science sources behind one search call. No published rate limits and no Retry-After or backoff guidance.

Arcmira

1. Call arcmira_describe once per session and write one program per question for arcmira_execute_read; return only the fields the answer needs, since output is cut at 12,000 characters and 3,000 per string.
2. Resolve names with arcmira.resolve (free) before any about, by, entity_ids or channel filter; a name in a filter fails with id_required. Plain keyword search needs no resolver call.
3. Check arcmira.status() or GET /v1/me for the plan, scopes and usage.credits.available before metered reads; on Free, media newer than 30 days and pages past the first fail with freshness_requires_paid and pagination_gated.
4. A Premium read of an untranscribed video starts a transcription that uses credits (300 per started 15 minutes) and may return pending; read the same video again later, which is never charged twice, and send retry: true only when the user asks.
5. Over HTTP send Authorization: Bearer arc_sk_..., an Idempotency-Key on every POST and PATCH, honour Retry-After on 429, and switch on error.code, following unlock.url on 402 and 403 rather than re-authenticating.
6. Use arcmira_execute_write only after listing the user's monitors; it creates, follows and pauses but never deletes, and a connection made before server 0.9.0 answers insufficient_scope until reconnected.

Valyu

1. Set max_price and max_num_results on every search to bound cost
2. Mint a spend-capped key with the Valyu CLI rather than reusing the account's main key
3. Call valyu_search. The legacy per-vertical MCP tools stop working on 2026-12-01
4. A 206 means some sources failed. Check which before treating results as complete
5. DeepResearch is async. Poll valyu_deepresearch_status rather than waiting in one call