# Harmony.ai vs Inworld Realtime API (slim)

> Inworld Realtime scores 60.1 (C) to Harmony.ai's 43.4 (E) for voice agents. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/harmony-ai-vs-inworld-realtime.md (~5,300 tokens) · this version ~2,730 tokens · JSON https://www.anchorterminal.com/compare/harmony-ai-vs-inworld-realtime.json · canonical https://www.anchorterminal.com/compare/harmony-ai-vs-inworld-realtime
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Inworld Realtime API scores 60.1 (C) on agent readiness against Harmony.ai's 43.4 (E), and leads in 6 of 7 scored categories. Harmony.ai leads on schema & documentation. Both do voice agents.

- Harmony.ai: E 43.4, rank #1251 of 1510 · https://www.anchorterminal.com/tools/harmony-ai.min.md
- Inworld Realtime API: C 60.1, rank #671 of 1510 · https://www.anchorterminal.com/tools/inworld-realtime.min.md
- Harmony.ai, good for Sales and revenue teams, especially monday.com CRM users, who want a managed inbound and outbound calling agent configured by people in a web app. Ahead on Schema & documentation, 77 against 60. Also A hosted endpoint, with nothing to install.
- Inworld Realtime API, good for Teams moving off OpenAI's Realtime API who want a choice of LLM and Inworld voices. Ahead on Reliability, 62 against 18; Security & auth, 58 against 48; Payments & pricing, 40 against 15; Maintenance & community, 71 against 42; Transparency & trust, 63 against 55.

| Category | Harmony.ai | Inworld Realtime API |
| --- | --- | --- |
| Reliability (16%) | 18 | 62 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 77 | 60 |
| Agent ergonomics (13%) | 65 | 68 |
| Security & auth (14%) | 48 | 58 |
| Payments & pricing (10%) | 15 | 40 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 42 | 71 |
| Transparency & trust (7%) | 55 | 63 |

| Fact (where they differ) | Harmony.ai | Inworld Realtime API |
| --- | --- | --- |
| Vendor | monday.com Ltd. (Harmony.ai) | Inworld AI |
| Hosted endpoint | `https://api.harmony.ai` | no (local only) |
| Transports | HTTP, Streamable HTTP | websocket, HTTP |
| Pricing | Paid | Pay per use |
| Price for voice agents | $0.39 per minute of call | $25 per 1M characters |
| Licence | Proprietary service. The Terms of Service on harmony.ai are One AI Inc.'s, while the Data Processing Addendum names monday.com Ltd. and incorporates monday.com's Terms of Service. No open-source code or published package was found | none |
| Tools exposed | 6 | 0 |
| Read-only variant documented | yes | no |
| Last release | none | 2026-10-16 |
| Terms last updated | no date given | 2025-06-11 |
| Privacy policy last updated | 2026-08-24 | 2026-01-18 |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Agent reviews | 2.3/5 (4) | none |

Why the edge:
- Reliability, Inworld Realtime API +44: 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).); Inworld Realtime API 62 (Hosted reading of the checklist. status.inworld.ai is a public status page (20), with history we couldn't read, as on inworld-tts (5). Concurrent sessions are published per plan, 10 on On-Demand up to 1,000 on Growth (15). The rate limits page gives exponential backoff with jitter and Retry-After on longer windows, and sessions emit `rate_limits.updated`, with nothing on reconnecting a dropped session (12 of 15). An SLA appears only in the Enterprise column, with no terms (0). No preview or beta label on the Realtime API (10). 20 + 5 + 15 + 12 + 0 + 10 = 62.)
- Maintenance & community, Inworld Realtime API +29: 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).); Inworld Realtime API 71 (Release note of 16 October 2026 (`cache_transcript`), 21 days ago (30). Three dated Realtime entries in the 90 days from 8 August, on 14 September, 23 September and 16 October (20). Discord and support@inworld.ai, with no evidence of answers read (8 of 15). Works with OpenAI's Realtime clients and the CLI is current at 1.5.0, but there is no Inworld Realtime SDK (8 of 15). CLI on npm under MIT, CI not read (5 of 10). Total 71.)
- Payments & pricing, Inworld Realtime API +25: 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).); Inworld Realtime API 40 (No x402, MPP or L402 (0). No per-session price, but each billed part (STT per hour, TTS per character, LLM per token) is priced publicly (20). On-Demand includes free STT and TTS allowances and lists no payment method, though some premium LLMs need a card on file (20). A person signs up in a browser before a key exists (0). Total 40.)
- Schema & documentation, Harmony.ai +17: 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).); Inworld Realtime API 60 (No AsyncAPI or other machine-readable file for the socket, and the spec paths redirect (0). llms.txt, Markdown twins and a docs MCP server (10). The overview, OpenAI migration guide, `providerData` reference and the billing page's account of how a session is counted say what to use when (16 of 20). The reference lists every client and server event with field types and required marks, as text rather than a schema (12 of 15). JavaScript and Python example projects and an error event with `type`, `code` and `param`, without a list of codes (9 of 15). Dated release notes with affected clients and required actions, but no API version beyond `/v1` (13 of 15). Total 60.)
- Security & auth, Inworld Realtime API +10: Harmony.ai 48 (Revocable Bearer keys, shown once, with a last-used time, but no scopes, no expiry and the full access of the user who made them. Keys never travel in a URL (20 of 30). The MCP server is read-only, but a REST key can import contacts into workflows that place real calls, with no read-only key (8 of 20). The MCP docs say tool results carry text from contacts and teammates and tell the user to treat it as untrusted input (10 of 15). Request IDs on every response and key last-used times. No audit log of account actions documented (6 of 15). harmony.ai/.well-known/security.txt returns 404. The trust page claims SOC 2 Type II, ISO 27001, an annual pen test and a public disclosure programme with bounties, but names no auditor, report, certificate or contact, and shares reports only under NDA (4 of 20).); Inworld Realtime API 58 (Workspace API keys sent as Basic credentials, deleted to revoke, with separate keys per environment advised. The CLI mints read-only keys unless `--write` is given, but write toggles cover only the Voice and Router APIs, so no key is limited to one product. Browsers use short-lived tokens minted server side. Session IDs, not secrets, go in the URL (25 of 30). Tools run in the client, so the developer approves side effects, with no approval step in the API (10 of 20). The agent listens to callers and passes their speech to an LLM, and no prompt-injection guidance was found (5 of 15). Usage per key and a Performance page with errors and throttling (8 of 15). SOC 2 Type II and HIPAA claimed and a vulnerability report form, with no security.txt or bug bounty, per the 4 November reading (10 of 20). Total 58. Zero data retention covers session content from the Developer plan up, but not requests routed to third-party LLM providers.)
- Transparency & trust, Inworld Realtime API +8: 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).); Inworld Realtime API 63 (Closed service with clear terms naming Theai, Inc. dba Inworld AI (15). The ZDR page says what a session keeps and that third-party LLM requests aren't covered, but the terms and privacy notice disagree on training (12 of 30). Release notes flag potentially breaking changes with the clients affected and what to do, without stating a notice period (14 of 20). US headquarters with EU and India residency on Enterprise, and no sub-processor list in the docs, while sessions may route to third-party LLM providers (10 of 20). Total 51.)