{ "data": { "a": { "slug": "cartesia-tts", "name": "Cartesia Sonic TTS API + MCP", "vendor": "Cartesia", "vendorUrl": "https://cartesia.ai", "kind": "model", "category": "text-to-speech", "summary": "Sonic text-to-speech, currently `sonic-3.6` in 44 languages, over `/tts/bytes`, `/tts/sse` and a WebSocket that takes streamed LLM text with contexts and word timestamps.", "url": "https://www.anchorterminal.com/tools/cartesia-tts", "markdownUrl": "https://www.anchorterminal.com/tools/cartesia-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/cartesia-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json", "repo": "https://github.com/cartesia-ai/cartesia-python", "license": "Apache-2.0 (SDKs)", "transports": [ "http", "streamable-http", "stdio" ], "remoteUrl": "https://api.cartesia.ai", "packages": [ { "registry": "npm", "name": "@cartesia/cartesia-js" }, { "registry": "pypi", "name": "cartesia" }, { "registry": "pypi", "name": "cartesia-mcp" } ], "auth": "mixed", "authNotes": "`Authorization: Bearer` API key plus a required `Cartesia-Version` date header (currently `2026-08-14`). Browsers should use short-lived access tokens minted server-side. The hosted MCP at `https://mcp.cartesia.ai/mcp` signs in through the Playground and creates an MCP key. The local `cartesia-mcp` reads `CARTESIA_API_KEY`.", "pricing": "freemium", "pricingNotes": "TTS costs about 1 credit a character, charged only on successful requests. Free has 20,000 credits a month (about 27 minutes of Sonic 3.6), Pro $5 100,000, Startup $49 1.25M and Scale $299 8M. Overages, if enabled, cost $65 per 1M credits on Pro, $45 on Startup and $38 on Scale. Commercial use starts at Pro. Unused credits roll over up to 2 times the monthly amount (https://cartesia.ai/pricing).", "priceSummary": "$5 / mo", "where": "both", "x402": { "level": "no", "evidence": "No x402 or machine payment in the docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 15, "popularity": { "githubStars": 133, "npmWeekly": 166023, "pypiWeekly": 176771, "asOf": "2026-09-30" }, "docsUrl": "https://docs.cartesia.ai/build-with-cartesia/tts-models/latest", "llmsTxt": "https://docs.cartesia.ai/llms.txt", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.ssml", "speech.languages" ], "tags": [ "hosted", "freemium", "free-tier", "closed-source", "python", "typescript", "llms-txt", "mcp", "streaming", "enterprise" ], "lastRelease": "2026-09-30", "graded": true, "anchor": { "graded": true, "score": 64.2, "grade": "B", "agentReady": false, "rank": 187, "ranked": true, "rankOf": 452, "categoryRank": 6, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 65, "maintenance": 79, "payments": 30, "reliability": 63, "schema": 86, "security": 58, "transparency": 71 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps. Five TTS incidents on the status page between 29 July and 21 August 2026.", "strengths": [ "WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps", "Dated model snapshots such as `sonic-3.6-2026-08-27` never change, and `Cartesia-Version` pins the API shape", "OpenAPI and AsyncAPI files per API version listed in llms.txt", "Short-lived access tokens with TTS, STT and agent grants for browser clients", "Deprecations dated in the changelog, Sonic-2 and Sonic Turbo sunset after 2026-10-20" ], "weaknesses": [ "Five TTS incidents on the status page between 29 July and 21 August 2026", "TTS concurrency is 2 on Free, 3 on Pro, 5 on Startup and 15 on Scale", "The Terms allow training on inputs and outputs unless you opt out by form", "Zero data retention is Enterprise only", "No SLA, and no error responses documented for the TTS endpoints" ], "agentNotes": [ "Send the `Cartesia-Version` header on every request.", "Pin a dated snapshot such as `sonic-3.6-2026-08-27` if output must not change.", "Move off `sonic-2`, `sonic-turbo` and `sonic-3-2025-10-27` before 2026-10-20.", "Expect a 429 at the plan's concurrency limit and queue requests yourself.", "Mint a short-lived access token for browser clients instead of shipping the API key." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 64.2 } ], "editorialScores": { "ergonomics": 65, "maintenance": 79, "payments": 30, "reliability": 63, "schema": 86, "security": 58, "transparency": 60 }, "provenanceScore": 82 }, "connect": { "http": "curl -X POST https://api.cartesia.ai/tts/bytes -H \"Authorization: Bearer $CARTESIA_API_KEY\" \\\n -H \"Cartesia-Version: 2026-08-14\" -H \"content-type: application/json\" -o speech.wav \\\n -d '{\"model_id\":\"sonic-3.6\",\"transcript\":\"Your table is booked for seven.\",\"voice\":{\"id\":\"47c38ca4-5f35-497b-b1a3-415245fb35e1\"},\"output_format\":{\"container\":\"wav\",\"encoding\":\"pcm_s16le\",\"sample_rate\":44100}}'", "claudeCode": "claude mcp add --transport http --scope user cartesia https://mcp.cartesia.ai/mcp", "config": { "mcpServers": { "cartesia": { "args": [ "cartesia-mcp" ], "command": "uvx", "env": { "CARTESIA_API_KEY": "${CARTESIA_API_KEY}" } } } } }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/cartesia-tts" }, "sameCompany": [ "cartesia-voice-cloning" ], "area": "voice", "unitPrices": [ { "item": "Sonic TTS overage on Pro", "unit": "1m-chars", "usd": 65, "note": "about 1 credit a character, $65 per 1M credits" }, { "item": "Sonic TTS overage on Startup", "unit": "1m-chars", "usd": 45 }, { "item": "Sonic TTS overage on Scale", "unit": "1m-chars", "usd": 38 }, { "item": "Pro plan", "unit": "month", "usd": 5, "note": "100,000 credits" }, { "item": "Startup plan", "unit": "month", "usd": 49, "note": "1.25M credits" }, { "item": "Scale plan", "unit": "month", "usd": 299, "note": "8M credits" } ], "provenance": { "legalEntity": "Cartesia AI, Inc.", "domain": "cartesia.ai", "domainRegistered": "2023-05-10", "endpointOnVendorDomain": true, "terms": "https://www.cartesia.ai/legal/terms", "privacy": "https://www.cartesia.ai/legal/privacy", "statusPage": "https://status.cartesia.ai", "changelog": "https://docs.cartesia.ai/changelog/2026", "securityTxt": "none", "checked": "2026-09-30", "score": 82 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/cartesia-tts.json", "live": { "slug": "cartesia-tts", "probe": { "target": "https://api.cartesia.ai", "method": "get", "lastAt": "2026-10-04T23:48:06.28751768Z", "lastOk": true, "lastStatus": 200, "lastMs": 53, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 61, "p95ms24h": 137, "samples24h": 272, "samples30d": 1100, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 270, "ok": 270 } ] }, "vendorStatus": { "page": "https://status.cartesia.ai", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-04T23:49:06.943209758Z" }, "versions": [ { "registry": "github", "name": "cartesia-ai/cartesia-python", "version": "v4.2.0", "released": "2026-09-02", "seenAt": "2026-10-04T16:23:11.882857509Z" }, { "registry": "npm", "name": "@cartesia/cartesia-js", "version": "4.2.0", "seenAt": "2026-10-04T16:23:08.936594762Z" }, { "registry": "pypi", "name": "cartesia", "version": "4.2.0", "released": "2026-09-02", "seenAt": "2026-10-04T16:23:09.798087978Z" }, { "registry": "pypi", "name": "cartesia-mcp", "version": "0.26.0", "released": "2026-09-30", "seenAt": "2026-10-04T16:23:09.984461576Z" } ], "githubStars": 133, "npmWeekly": 108942, "pypiWeekly": 188249, "securityTxt": { "url": "https://cartesia.ai/.well-known/security.txt", "state": "valid", "expires": "2027-10-03T00:00:00.000Z", "checkedAt": "2026-10-04T15:15:57.920556028Z" }, "llmsTxt": { "url": "https://docs.cartesia.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:23.748277625Z" }, "domain": { "domain": "cartesia.ai", "registered": "2023-05-10", "source": "https://rdap.identitydigital.services/rdap/domain/cartesia.ai", "checkedAt": "2026-10-04T13:04:05.26596839Z" }, "pages": [ { "url": "https://docs.cartesia.ai/changelog/2026", "kind": "changelog", "status": 200, "checkedAt": "2026-10-04T15:43:22.154553148Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "56a07dda1f5d" }, { "url": "https://cartesia.ai/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-04T15:41:44.64571005Z", "changedAt": "2026-10-03T15:29:56.901063562Z", "fingerprint": "3e49bcd49fcf" }, { "url": "https://www.cartesia.ai/legal/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-04T15:49:41.751185158Z", "changedAt": "2026-10-03T15:37:37.717663201Z", "fingerprint": "6fea00c7255f" }, { "url": "https://www.cartesia.ai/legal/terms", "kind": "terms", "status": 200, "checkedAt": "2026-10-04T15:49:43.846741137Z", "changedAt": "2026-10-03T15:37:39.779484537Z", "fingerprint": "c899e30661ba" } ], "updatedAt": "2026-10-04T23:49:06.943209758Z" } }, "b": { "slug": "rime-tts", "name": "Rime TTS API + MCP", "vendor": "Rime Labs", "vendorUrl": "https://www.rime.ai", "kind": "model", "category": "text-to-speech", "summary": "Rime's streaming text-to-speech for voice agents.", "url": "https://www.anchorterminal.com/tools/rime-tts", "markdownUrl": "https://www.anchorterminal.com/tools/rime-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/rime-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/rime-tts.json", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://users.rime.ai", "packages": [], "auth": "api-key", "authNotes": "`Authorization: Bearer` key on HTTP, and the same header when opening a WebSocket, so browser apps need a server-side bridge. The hosted MCP at `https://mcp.rime.ai` reads the key per request (`Authorization` or `X-Rime-Api-Key`) and never stores it. Its catalogue and code-generation tools work without a key.", "pricing": "freemium", "pricingNotes": "Usage-based on Starter. Coda costs $0.05 per 1,000 characters ($50 per 1M) and Mist v3 $0.03 per 1,000 ($30 per 1M), roughly $0.05 and $0.03 a minute of audio. New accounts get free usage with no card, though the page says about 800 minutes (800k characters) in one place and 3,000 minutes in its FAQ. Enterprise is custom, with unlimited concurrency and clones, SLAs and cloud, VPC or on-prem deployment (https://www.rime.ai/pricing).", "priceSummary": "Freemium", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 or machine payment in the docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 6, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://docs.rime.ai/docs/introduction", "llmsTxt": "https://docs.rime.ai/llms.txt", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.languages" ], "tags": [ "hosted", "freemium", "no-card", "free-tier", "closed-source", "llms-txt", "mcp", "streaming", "self-hosted", "enterprise" ], "lastRelease": "2026-09-25", "graded": true, "anchor": { "graded": true, "score": 56.1, "grade": "C", "agentReady": false, "rank": 305, "ranked": true, "rankOf": 452, "categoryRank": 8, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 60, "maintenance": 48, "payments": 40, "reliability": 50, "schema": 59, "security": 65, "transparency": 71 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Only character counts are kept by default, and customer data isn't used for training without an opt-in. No OpenAPI or AsyncAPI file and no official SDKs.", "strengths": [ "Only character counts are kept by default, and customer data isn't used for training without an opt-in", "Coda at $0.05 and Mist v3 at $0.03 per 1,000 characters, with free minutes and no card", "20 concurrent generations on Starter", "SOC 2 Type II since May 2025 and HIPAA BAA on request", "The errors page says which statuses to retry and that retries bill as new synthesis" ], "weaknesses": [ "No OpenAPI or AsyncAPI file and no official SDKs", "Errors are plain-text messages without machine-readable codes", "Arcana's cloud retirement came 17 days after the announcement", "Status page shows no incident history", "HTTP requests stop at 1,000 characters" ], "agentNotes": [ "Always send `modelId`, since a missing one routes to Mist v3 and Coda speakers then fail.", "Keep HTTP requests under 1,000 characters or use the WebSocket.", "Back off on 429 before reopening a WebSocket, and remember each retry bills again.", "Use `/ws3` when you need word timestamps.", "Keep the key server-side, since WebSockets take it in a header and there are no short-lived tokens." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 56.1 } ], "editorialScores": { "ergonomics": 60, "maintenance": 48, "payments": 40, "reliability": 50, "schema": 59, "security": 65, "transparency": 55 }, "provenanceScore": 86 }, "connect": { "http": "curl -X POST https://users.rime.ai/v1/rime-tts -H \"Authorization: Bearer $RIME_API_KEY\" \\\n -H \"content-type: application/json\" -H \"accept: audio/mpeg\" -o speech.mp3 \\\n -d '{\"text\":\"Your table is booked for seven.\",\"speaker\":\"astra\",\"modelId\":\"coda\"}'", "claudeCode": "claude mcp add --transport http rime https://mcp.rime.ai --header \"Authorization: Bearer $RIME_API_KEY\"", "config": { "mcpServers": { "rime": { "headers": { "Authorization": "Bearer ${RIME_API_KEY}" }, "url": "https://mcp.rime.ai" } } } }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/rime-tts" }, "area": "voice", "unitPrices": [ { "item": "Coda", "unit": "1m-chars", "usd": 50, "note": "$0.05 per 1,000 characters, about $0.05 a minute" }, { "item": "Mist v3", "unit": "1m-chars", "usd": 30, "note": "$0.03 per 1,000 characters, about $0.03 a minute" } ], "provenance": { "legalEntity": "Rime Labs, Inc.", "domain": "rime.ai", "domainRegistered": "2020-03-12", "endpointOnVendorDomain": true, "terms": "https://www.rime.ai/terms", "privacy": "https://www.rime.ai/privacy", "statusPage": "https://status.rime.ai", "changelog": "https://docs.rime.ai/docs/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 86 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/rime-tts.json", "live": { "slug": "rime-tts", "probe": { "target": "https://users.rime.ai", "method": "get", "lastAt": "2026-10-04T23:48:15.250620889Z", "lastOk": true, "lastStatus": 401, "lastMs": 430, "lastNote": "asks for credentials", "authRequired": true, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 460, "p95ms24h": 509, "samples24h": 272, "samples30d": 1100, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 270, "ok": 270 } ] }, "vendorStatus": { "page": "https://status.rime.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-04T21:40:27.329259246Z" }, "securityTxt": { "url": "https://rime.ai/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:15:37.099790357Z" }, "llmsTxt": { "url": "https://docs.rime.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:18:12.002912Z" }, "domain": { "domain": "rime.ai", "registered": "2020-03-12", "source": "https://rdap.identitydigital.services/rdap/domain/rime.ai", "checkedAt": "2026-10-04T13:04:13.469380494Z" }, "pages": [ { "url": "https://docs.rime.ai/docs/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-10-04T15:43:57.768372092Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "d83d0135c7c5" }, { "url": "https://www.rime.ai/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-04T15:51:58.694941167Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "ecb939d90f0c" }, { "url": "https://www.rime.ai/privacy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-04T15:52:00.743793653Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "37bfb306b257" }, { "url": "https://www.rime.ai/terms", "kind": "terms", "status": 304, "checkedAt": "2026-10-04T15:52:02.722779334Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "8312554d4669" } ], "updatedAt": "2026-10-04T23:48:15.250620889Z" } }, "summary": "Cartesia Sonic TTS API + MCP has a score of 64.2 (B) against Rime TTS API + MCP's 56.1 (C). Both do speech tts. The largest gap is maintenance \u0026 community, 31 points." }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts", "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts.md", "slim": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts.min.md" }, "markdown": "Cartesia Sonic TTS API + MCP has a score of 64.2 (B) against Rime TTS API + MCP's 56.1 (C). Both do speech tts. The largest gap is maintenance \u0026 community, 31 points.\n\n- Cartesia Sonic TTS API + MCP: grade B, 64.2/100, rank #187 of 452. Markdown https://www.anchorterminal.com/tools/cartesia-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json\n- Rime TTS API + MCP: grade C, 56.1/100, rank #305 of 452. Markdown https://www.anchorterminal.com/tools/rime-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/rime-tts.json\n\n## Which one, for what\n\nPick Cartesia Sonic TTS API + MCP for reliability (+13), schema \u0026 documentation (+27), agent ergonomics (+5), maintenance \u0026 community (+31).\n\nPick Rime TTS API + MCP for security \u0026 auth (+7), payments \u0026 pricing (+10).\n\n## Score by category\n\n| Category | Weight | Cartesia Sonic TTS API + MCP | Rime TTS API + MCP | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 63 | 50 | Cartesia Sonic TTS API + MCP +13 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 86 | 59 | Cartesia Sonic TTS API + MCP +27 |\n| Agent ergonomics | 13% (16.2 this run) | 65 | 60 | Cartesia Sonic TTS API + MCP +5 |\n| Security \u0026 auth | 14% (17.5 this run) | 58 | 65 | Rime TTS API + MCP +7 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 30 | 40 | Rime TTS API + MCP +10 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 79 | 48 | Cartesia Sonic TTS API + MCP +31 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 71 | 71 | even |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **64.2 · B** | **56.1 · C** | |\n\n## Facts side by side\n\n| Fact | Cartesia Sonic TTS API + MCP | Rime TTS API + MCP |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | Cartesia | Rime Labs |\n| Hosted endpoint | `https://api.cartesia.ai` | `https://users.rime.ai` |\n| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Freemium |\n| x402 | no | no |\n| Licence | Apache-2.0 (SDKs) | none |\n| Tools exposed | 15 | 6 |\n| Context cost (tools/list) | n/a | n/a |\n| p95 latency | not measured yet | not measured yet |\n| Availability (30d) | not measured yet | not measured yet |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| MCP registry | not listed | not listed |\n| Last release | 2026-09-30 | 2026-09-25 |\n| Popularity | 133 stars, 166k npm/wk, 177k PyPI/wk | none |\n| Agent reviews | 3/5 (2) | 3/5 (2) |\n\n## Verdicts\n\n**Cartesia Sonic TTS API + MCP.** WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps. Five TTS incidents on the status page between 29 July and 21 August 2026.\n\n**Rime TTS API + MCP.** Only character counts are kept by default, and customer data isn't used for training without an opt-in. No OpenAPI or AsyncAPI file and no official SDKs.\n\n## Before you call either\n\n### Cartesia Sonic TTS API + MCP\n\n1. Send the `Cartesia-Version` header on every request.\n2. Pin a dated snapshot such as `sonic-3.6-2026-08-27` if output must not change.\n3. Move off `sonic-2`, `sonic-turbo` and `sonic-3-2025-10-27` before 2026-10-20.\n4. Expect a 429 at the plan's concurrency limit and queue requests yourself.\n5. Mint a short-lived access token for browser clients instead of shipping the API key.\n\n### Rime TTS API + MCP\n\n1. Always send `modelId`, since a missing one routes to Mist v3 and Coda speakers then fail.\n2. Keep HTTP requests under 1,000 characters or use the WebSocket.\n3. Back off on 429 before reopening a WebSocket, and remember each retry bills again.\n4. Use `/ws3` when you need word timestamps.\n5. Keep the key server-side, since WebSockets take it in a header and there are no short-lived tokens.\n\n## Other comparisons with Cartesia Sonic TTS API + MCP or Rime TTS API + MCP\n\n- [Amazon Polly vs Cartesia Sonic TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-cartesia-tts.md)\n- [Amazon Polly vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-rime-tts.md)\n- [Azure AI Speech text-to-speech vs Cartesia Sonic TTS API + MCP](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-cartesia-tts.md)\n- [Azure AI Speech text-to-speech vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-rime-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Deepgram Text-to-Speech (Aura-2, Flux TTS)](https://www.anchorterminal.com/compare/cartesia-tts-vs-deepgram-tts.md)\n- [Cartesia Sonic TTS API + MCP vs ElevenLabs Text to Speech API + MCP](https://www.anchorterminal.com/compare/cartesia-tts-vs-elevenlabs-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/cartesia-tts-vs-murf-tts.md)\n- [Cartesia Sonic TTS API + MCP vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/cartesia-tts-vs-playht-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/cartesia-tts-vs-resemble-ai-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/cartesia-tts-vs-soniox-tts.md)\n- [Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/deepgram-tts-vs-rime-tts.md)\n- [ElevenLabs Text to Speech API + MCP vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-rime-tts.md)\n- [Murf TTS API + MCP vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/murf-tts-vs-rime-tts.md)\n- [PlayHT Text-to-Speech API vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/playht-tts-vs-rime-tts.md)\n- [Resemble AI Text-to-Speech API vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/resemble-ai-tts-vs-rime-tts.md)\n- [Rime TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/rime-tts-vs-soniox-tts.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-04", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.3", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Cartesia Sonic TTS API + MCP vs Rime TTS API + MCP", "url": "" } ], "description": "Cartesia Sonic TTS API + MCP has a score of 64.2 (B) against Rime TTS API + MCP's 56.1 (C). Both do speech tts. The largest gap is maintenance \u0026 community, 31 points. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "Cartesia Sonic TTS API + MCP B 64.2", "Rime TTS API + MCP C 56.1", "scores" ], "h1": "Cartesia Sonic TTS API + MCP vs Rime TTS API + MCP", "image": "https://www.anchorterminal.com/assets/og/compare-cartesia-tts-vs-rime-tts.png", "path": "/compare/cartesia-tts-vs-rime-tts", "published": "2026-10-01", "section": "tools", "title": "Cartesia Sonic TTS API + MCP vs Rime TTS API + MCP for AI agents", "toc": null, "updated": "2026-10-04", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts" }, "tokens": { "markdown": 1700, "slim": 380 }, "version": 1 }