Harmony.ai vs Vaani Developer Platform

Harmony.ai 77

A public OpenAPI 3.0.3 file covering all 11 operations at docs.harmony.ai/openapi.json (25). llms.txt, llms-full.txt and Markdown pages (10). Each operation has a short description, and the guides say who the API is for, that multi-customer integrations aren't supported, and what each write does to calling (12 of 20). 45 enums, a page size bounded at 1 to 100, required fields and a 1,000-contact cap on imports (12 of 15). The docs have curl and TypeScript examples and a documented error body with named codes, while the OpenAPI file has no examples (11 of 15). The major version is in the path and a versioning policy is published, with no changelog (7 of 15).

Vaani Developer Platform 57

A public OpenAPI 3.1 file at docs.vaani.dev/api-reference/openapi.json, version 2.0.0, but it holds 5 of the 24 operations in the API reference (trigger-call, call history, transcript, stream, call details). It declares the key only as a header parameter with no security scheme, its trigger-call schema leaves out medium and modify_agent, and four response schemas are empty. The MCP tools have typed zod inputs (8 of 25). llms.txt, llms-full.txt and a Markdown copy of each page on Mintlify (10). Pages explain what each route is for and warn where it matters, such as dispatch acceptance not meaning a completed call, transcripts returning 404 while processing, and real paid calls from trigger_call (14 of 20). Ranges and enums are documented (medium, voice_speed 0.6 to 1.4, page_size up to 200, campaign retries 1 to 10, campaign status), but metadata, modify_agent and three MCP tool payloads are free-form objects (9 of 15). Request examples in cURL, Python and JavaScript on every endpoint, a campaign error-code table, 422 and 404 bodies and an SDK exception table by status. No single error reference for the whole API (12 of 15). The docs state API version 2.0.0, but no changelog or release notes page was found (4 of 15). 8+10+14+9+12+4 = 57.

Harmony.ai 42

Read for a closed service. The press page dates the launch to October 2026, within 30 days (30). No changelog or dated releases (0). Support is through a contact form and the docs' request ID guidance, with no public changelog or community channel found (4 of 15). A hosted MCP server, not in the official registry, and no SDK (5 of 15). No package to assess (3 of 10).

Vaani Developer Platform 59

vaani-research-mcp 0.1.1 on 2026-10-14 (30). In the last 90 days, vaani-sdk 0.3.1 on 28 September and three npm versions (0.0.0-stage, 0.1.0, 0.1.1) within 40 minutes on 14 October. No dated changelog, so half (10 of 20). A closed service with no public changelog, issue tracker or community channel found. Contact is hello@vaaniresearch.com and a booking link, and we didn't test whether they answer. The MCP repository on GitHub couldn't be read from this session (4 of 15, the closed-service reading). A current official Python SDK, released seven times since April 2026. The MCP server isn't in the official MCP registry (10 of 15). The SDK's sdist ships its tests and current httpx and pydantic dependencies, and the MCP package runs its tests before publishing, but no public CI was found and the SDK has no repository (5 of 10). 30+10+4+10+5 = 59.

Harmony.ai 55

Closed service with conflicting terms. The Terms of Service are One AI Inc.'s, undated, referring to oneai.com sites and pricing, while the DPA of 10 September 2026 names monday.com Ltd. and incorporates monday.com's Terms of Service (7 of 30). Data handling statements disagree. The privacy policy (24 August 2026) keeps data while the account is active and says data may be used to train One AI's systems. The trust page says retention is configurable with no cross-customer training. The terms say all calls are recorded unless the customer opts out in writing, and the trust page lists US, EU and APAC regions while the sub-processor page lists US and EU. The DPA commits to deletion or return at termination (10 of 30). The versioning page keeps an old major version for at least 12 months after a new one, once the API is generally available (10 of 20). Nine sub-processors named with hosting regions, with a seven-day objection window in the DPA (18 of 20).

Vaani Developer Platform 42

A closed service. The terms name Vaani AI Research Private Limited, its Bengaluru address, CIN, Indian law and Bengaluru courts, but they're undated, written for the website www.vaaniresearch.com, and say nothing on billing, refunds, API use or customer data. The SDK and MCP server are MIT, with the SDK's full source in its PyPI sdist (14 of 30). The privacy policy (undated) keeps data, including voice recordings, for up to 24 months, while the pricing table gives 30 days' retention on pay as you go and zero retention on Enterprise. Voice data trains models only with explicit consent. No DPA found (8 of 30). No deprecation policy. The privacy policy promises 15 days' notice of significant changes, and the terms allow changes and termination without notice (2 of 20). The privacy policy names vendor categories (cloud hosting, analytics, voice transcription) and says data may be stored outside India. Model and telephony providers can be read from the calculator, and India data residency is offered on demand. No subprocessor list or data location for the hosted service (5 of 20). 14+8+2+5 = 29.

Harmony.ai 18

Graded on the Public API and MCP server at api.harmony.ai, read with the hosted lines. status.harmony.ai exists but is a static page. "All systems operational", "Last checked · just now", the uptime figures and the 90-day bars are fixed in the HTML from a date of 17 August 2026, and the subscribe form sends nothing. It isn't linked from harmony.ai or the docs, so it scores as no status page (0) and no readable history (5). The docs say "The API has no published rate limits yet". Pro's 10 concurrent calls and 100 calls a day are the only numbers (5 of 15). No 429 or Retry-After guidance, but the errors page says which writes are safe to retry and which can place a second call, and how to check before resending (8 of 15). No SLA found (0). The API is in beta (OpenAPI version 1.0.0-beta.1, and the versioning page has a "During the beta" section) (0).

Vaani Developer Platform 28

Graded on the hosted REST API at api.vaanivoice.ai. No status page. status.vaani.dev and status.vaanivoice.ai don't resolve, and neither the site nor the docs link one (0). With no history to read, 5. No request rate limits are published. The docs give 2 concurrent calls on pay as you go and a per-organisation campaign concurrency cap, so partial credit (5). The SDK raises RateLimitError on 429 and the MCP client retries once after 600 ms, but no Retry-After, backoff guidance or idempotency key for call creation is documented (3). The pricing table lists a 99.50 per cent uptime SLA on both plans, but no SLA document or service credits were found and the terms supply the service "as-is" with no warranties, so half (5). The API is version 2.0.0 and isn't labelled beta (10). 0+5+5+3+5+10 = 28.

Harmony.ai 15

No x402, MPP or L402 (0 of 40). Pro is $0.39 a minute plus a $250 monthly platform fee, published without a login, with the minute rate varying by voice model and a custom implementation fee (15 of 20). A Try for free signup is linked, with no trial terms on public pages and the signup not tried, so no free tier is counted (0). A person signs up in a browser and creates keys in the web app (0).

Vaani Developer Platform 22

No x402, MPP or L402 (0 of 40). The ₹1 ($0.02) a minute platform fee, number rental, concurrency lines and add-ons are public, and the calculator shows each provider's unit rate without a login. Registry checks, extraction and evaluations "can add separate charges" that aren't priced, and the billing pulse depends on the account, so 3 off (17 of 20). The home page says "Start free on Vaani's Platform", but the pricing page states a prepaid wallet with no free credit, trial minutes or card rule, and we didn't sign up to check, so 5 of 20. A person signs up with email verification at platform.vaani.dev and creates keys in the dashboard (0). 0+17+5+0 = 22.