{ "data": { "a": { "slug": "bolna", "name": "Bolna API + MCP", "vendor": "Bolna", "vendorUrl": "https://www.bolna.ai", "kind": "http-api", "category": "voice-agents", "summary": "Voice-agent platform built for Indian languages and phone campaigns.", "url": "https://www.anchorterminal.com/tools/bolna", "markdownUrl": "https://www.anchorterminal.com/tools/bolna.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/bolna.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/bolna.json", "repo": "https://github.com/bolna-ai/bolna", "license": "MIT", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.bolna.ai", "packages": [ { "registry": "pypi", "name": "bolna" }, { "registry": "npm", "name": "@bolna/web-call" } ], "auth": "api-key", "authNotes": "Bearer API key (`bn-...`, or `sa-...` for a sub-account) from the dashboard, shown once and stored hashed. The hosted MCP at `https://mcp.bolna.ai/api/mcp` takes the same key as a Bearer header, and every MCP tool accepts an `api_key` argument to act as a sub-account. The Web Call SDK mints single-use browser sessions that expire in about 120 seconds, so the key stays server-side. Webhooks and tool calls carry no signature. Bolna says to allowlist its 3 source IPs instead.", "pricing": "usage", "pricingNotes": "Prepaid wallet from $10 to $5,000 with $5 free credit at signup. Standard rate $0.06 a minute (₹5.52) covers Voice AI on the preferred STT, LLM and TTS models, falling to about $0.045 on larger top-ups. Telephony and a Bolna platform fee are billed on top, and non-preferred models are billed per use. Pilot plans are one-off, $300 for 6,500 minutes or $500 for 12,000 minutes, billed in 30-second pulses with 25 concurrent calls. Bringing your own STT, LLM and TTS keys leaves only the platform fee and telephony. Enterprise is custom (https://www.bolna.ai/pricing).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in the docs, pricing page or MCP docs (checked 2026-09-30).", "endpoints": [] }, "toolCount": 84, "popularity": { "githubStars": 779, "npmWeekly": 579, "pypiWeekly": 2601, "asOf": "2026-09-30" }, "docsUrl": "https://www.bolna.ai/docs", "llmsTxt": "https://www.bolna.ai/docs/llms.txt", "capabilities": [ "voice.agent", "voice.pipeline", "voice.speech-to-speech", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "open-source", "self-hosted", "mcp", "llms-txt", "python", "typescript", "webhooks", "pipeline", "speech-to-speech", "enterprise" ], "lastRelease": "2026-09-29", "graded": true, "anchor": { "graded": true, "score": 52.9, "grade": "D", "agentReady": false, "rank": 339, "ranked": true, "rankOf": 452, "categoryRank": 8, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 52, "maintenance": 76, "payments": 30, "reliability": 50, "schema": 63, "security": 44, "transparency": 70 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Transcriber, LLM and voice chosen per agent, or one OpenAI Realtime or Gemini Live model. Unsigned webhooks and tool calls, IP allowlisting only.", "strengths": [ "Transcriber, LLM and voice chosen per agent, or one OpenAI Realtime or Gemini Live model", "Indian telephony through Plivo, Exotel and Vobiz, with an India data-residency option in ap-south-1", "Hosted MCP server with 84 tools, 23 of them carrying `destructiveHint`", "MIT-licensed core framework, released to PyPI almost daily", "Published per-endpoint rate limits with 429 and backoff guidance" ], "weaknesses": [ "Unsigned webhooks and tool calls, IP allowlisting only", "No security.txt, bug bounty or SOC 2 claim found", "The OpenAPI link in llms.txt returns 404", "Telephony and platform fees aren't priced on the pricing page", "Terms and privacy policy name different legal entities" ], "agentNotes": [ "Wait for the `completed` execution status, not `call-disconnected`, before reading cost, recording or extracted data", "Send `scheduled_at` with a numeric offset such as `+00:00`, since a `Z` suffix returns 500", "Back off exponentially on 429, the limit on `/call` is 500 requests a minute", "Reject webhook and tool requests that don't come from 13.203.39.153, 13.126.9.249 or 13.202.133.53", "Leave the MCP `api_key` argument empty unless acting as a sub-account, so the key stays out of the transcript" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 2.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "D", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 52.9 } ], "editorialScores": { "ergonomics": 52, "maintenance": 76, "payments": 30, "reliability": 50, "schema": 63, "security": 44, "transparency": 57 }, "provenanceScore": 82 }, "connect": { "http": "curl -X POST https://api.bolna.ai/call -H \"Authorization: Bearer $BOLNA_API_KEY\" \\\n -H \"Content-Type: application/json\" \\\n -d '{\"agent_id\":\"123e4567-e89b-12d3-a456-426655440000\",\"recipient_phone_number\":\"+919876543210\"}'", "claudeCode": "claude mcp add --transport http bolna https://mcp.bolna.ai/api/mcp --header \"Authorization: Bearer $BOLNA_API_KEY\"", "config": { "mcpServers": { "bolna": { "args": [ "-y", "mcp-remote", "https://mcp.bolna.ai/api/mcp", "--header", "Authorization: Bearer ${BOLNA_API_KEY}" ], "command": "npx" } } } }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/bolna" }, "area": "voice", "unitPrices": [ { "item": "Standard rate, preferred models", "unit": "call-minute", "usd": 0.06, "note": "Voice AI only, telephony and platform fee extra" }, { "item": "Pilot plan, 12,000 minutes", "unit": "call-minute", "usd": 0.042, "note": "one-off $500, 25 concurrent calls" }, { "item": "Pilot plan, 6,500 minutes", "unit": "call-minute", "usd": 0.046, "note": "one-off $300" } ], "provenance": { "legalEntity": "Voxlabs Private Limited", "domain": "bolna.ai", "domainRegistered": "2024-09-27", "domainNote": "The registry date is later than Bolna's first PyPI release (2024-01-01), so the domain was probably re-registered. Support mail also uses bolna.dev.", "endpointOnVendorDomain": true, "terms": "https://www.bolna.ai/terms-of-service", "privacy": "https://www.bolna.ai/privacy-policy", "statusPage": "https://status.bolna.ai", "changelog": "https://www.bolna.ai/docs/changelog", "securityTxt": "none", "checked": "2026-10-01", "notes": [ "The terms name Voxlabs Private Limited, operating as Bolna. The privacy policy (updated 2025-03-28) and the site footer name Whismurwave Inc." ], "score": 82 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/bolna.json", "live": { "slug": "bolna", "probe": { "target": "https://api.bolna.ai", "method": "get", "lastAt": "2026-10-04T23:48:05.616288177Z", "lastOk": true, "lastStatus": 404, "lastMs": 733, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 741, "p95ms24h": 819, "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.bolna.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-04T21:39:52.03506865Z" }, "versions": [ { "registry": "github", "name": "bolna-ai/bolna", "version": "0.10.269", "released": "2026-10-02", "seenAt": "2026-10-04T16:22:32.734659247Z" }, { "registry": "npm", "name": "@bolna/web-call", "version": "3.0.1", "seenAt": "2026-10-04T16:22:31.875037371Z" }, { "registry": "pypi", "name": "bolna", "version": "0.10.269", "released": "2026-10-02", "seenAt": "2026-10-04T16:22:31.685913882Z" } ], "githubStars": 782, "npmWeekly": 364, "pypiWeekly": 1824, "securityTxt": { "url": "https://bolna.ai/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:16:00.262891241Z" }, "llmsTxt": { "url": "https://www.bolna.ai/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:21.76090737Z" }, "domain": { "domain": "bolna.ai", "registered": "2024-09-27", "source": "https://rdap.identitydigital.services/rdap/domain/bolna.ai", "checkedAt": "2026-10-04T13:07:18.917906737Z" }, "pages": [ { "url": "https://www.bolna.ai/docs/changelog", "kind": "changelog", "status": 200, "checkedAt": "2026-10-04T15:49:30.073496597Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "0db7b7c8de51" }, { "url": "https://www.bolna.ai/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-04T15:49:32.473331376Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "edeeeb6accdd" }, { "url": "https://www.bolna.ai/privacy-policy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-04T15:49:34.270339558Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "0f8133e9e865" }, { "url": "https://www.bolna.ai/terms-of-service", "kind": "terms", "status": 304, "checkedAt": "2026-10-04T15:49:36.239918073Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "561e3b6c9a44" } ], "updatedAt": "2026-10-04T23:48:05.616288177Z" } }, "b": { "slug": "retell-ai", "name": "Retell AI API + MCP", "vendor": "Retell AI", "vendorUrl": "https://www.retellai.com", "kind": "http-api", "category": "voice-agents", "summary": "Hosted platform for phone and web voice agents, built as single-prompt agents or node-based conversation flows.", "url": "https://www.anchorterminal.com/tools/retell-ai", "markdownUrl": "https://www.anchorterminal.com/tools/retell-ai.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/retell-ai.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/retell-ai.json", "repo": "https://github.com/RetellAI/retell-typescript-sdk", "license": "Apache-2.0 (SDKs)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.retellai.com", "packages": [ { "registry": "npm", "name": "retell-sdk" }, { "registry": "npm", "name": "retell-client-js-sdk" }, { "registry": "pypi", "name": "retell-sdk" } ], "auth": "api-key", "authNotes": "Bearer API key for the REST API and the hosted MCP server at `https://mcp.retellai.com`. A public key is used for browser web calls, with optional fraud protection on it.", "pricing": "usage", "pricingNotes": "Pay as you go with $10 of free credits, priced per component. Voice infrastructure $0.055 a minute, Retell and most third-party voices $0.015 (ElevenLabs $0.04), telephony $0.015 on Retell numbers, and the LLM from $0.0016 to $0.32 a minute depending on model. The vendor puts the total at $0.07 to $0.31 a minute. Speech-to-speech models run $0.07 (GPT Realtime mini) to $0.38 a minute. Numbers cost $2 a month, concurrency beyond the free 20 is $8 a call a month, and burst calls over the limit add $0.10 a minute. Enterprise pricing is custom (https://www.retellai.com/pricing).", "priceSummary": "$2 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in the docs, pricing page or MCP docs (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 62, "npmWeekly": 242906, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://docs.retellai.com", "llmsTxt": "https://docs.retellai.com/llms.txt", "openapi": "https://docs.retellai.com/openapi-final.yaml", "capabilities": [ "voice.agent", "voice.pipeline", "voice.speech-to-speech", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "closed-source", "no-card", "mcp", "llms-txt", "openapi", "typescript", "python", "webhooks", "streaming", "pipeline", "speech-to-speech", "enterprise" ], "lastRelease": "2026-09-14", "graded": true, "anchor": { "graded": true, "score": 69.4, "grade": "B", "agentReady": false, "rank": 114, "ranked": true, "rankOf": 452, "categoryRank": 2, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 60, "maintenance": 85, "payments": 40, "reliability": 60, "schema": 92, "security": 76, "transparency": 79 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Published per-minute price for every component, from $0.07 a minute all in. Call data kept indefinitely unless retention is set per agent.", "strengths": [ "Published per-minute price for every component, from $0.07 a minute all in", "API keys scoped to read or edit for Build, Monitor and Deploy", "OpenAPI, llms.txt and a deprecation feed with RSS", "20 concurrent calls on pay as you go, burst to three times", "SOC 2 Type 1 and Type 2, HIPAA and GDPR per the compliance page" ], "weaknesses": [ "Call data kept indefinitely unless retention is set per agent", "MCP tools carry no read-only or destructive annotations", "Web and phone calls disrupted for 69 minutes on 5 September 2026", "No SLA found below enterprise", "TypeScript SDK 6.0.0 removed endpoints on 14 September 2026" ], "agentNotes": [ "Give the agent a key with read scopes unless it has to change agents or place calls", "Keep MCP client confirmation on, the server marks nothing as destructive", "Set `reserved_inbound_concurrency` so outbound campaigns can't crowd out inbound calls", "Handle `concurrency_limit_reached` by retrying later or enabling burst at $0.10 a minute extra", "Set a data retention period on each agent that handles personal data" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 69.4 } ], "editorialScores": { "ergonomics": 60, "maintenance": 85, "payments": 40, "reliability": 60, "schema": 92, "security": 76, "transparency": 75 }, "provenanceScore": 82 }, "connect": { "http": "curl -X POST https://api.retellai.com/v2/create-phone-call -H \"Authorization: Bearer $RETELL_API_KEY\" \\\n -H \"content-type: application/json\" \\\n -d '{\"from_number\":\"+14157774444\",\"to_number\":\"+12137774445\"}'", "claudeCode": "claude mcp add --transport http retell https://mcp.retellai.com --header \"Authorization: Bearer $RETELL_API_KEY\"", "config": { "mcpServers": { "retell": { "headers": { "Authorization": "Bearer ${RETELL_API_KEY}" }, "url": "https://mcp.retellai.com" } } } }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/retell-ai" }, "area": "voice", "unitPrices": [ { "item": "Retell voice infrastructure", "unit": "call-minute", "usd": 0.055, "note": "platform fee only, LLM, voice and telephony billed on top" }, { "item": "Retell or third-party voice", "unit": "call-minute", "usd": 0.015, "note": "ElevenLabs voices $0.04" }, { "item": "Retell telephony", "unit": "call-minute", "usd": 0.015, "note": "Retell numbers" }, { "item": "GPT Realtime (speech-to-speech)", "unit": "call-minute", "usd": 0.345 }, { "item": "GPT Realtime mini (speech-to-speech)", "unit": "call-minute", "usd": 0.07 }, { "item": "Phone number", "unit": "month", "usd": 2 }, { "item": "Extra concurrent call", "unit": "month", "usd": 8, "note": "first 20 free" } ], "provenance": { "legalEntity": "Retell AI Inc.", "domain": "retellai.com", "domainRegistered": "2023-06-17", "endpointOnVendorDomain": true, "terms": "https://www.retellai.com/legal/terms-of-service", "privacy": "https://www.retellai.com/legal/privacy-policy", "statusPage": "https://status.retellai.com", "changelog": "https://www.retellai.com/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 82 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/retell-ai.json", "live": { "slug": "retell-ai", "probe": { "target": "https://api.retellai.com", "method": "get", "lastAt": "2026-10-04T23:48:15.179652298Z", "lastOk": true, "lastStatus": 200, "lastMs": 407, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 400, "p95ms24h": 454, "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.retellai.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-04T23:49:26.900883008Z" }, "versions": [ { "registry": "github", "name": "RetellAI/retell-typescript-sdk", "version": "v6.0.1", "released": "2026-09-14", "seenAt": "2026-10-04T16:38:33.194361249Z" }, { "registry": "npm", "name": "retell-client-js-sdk", "version": "3.0.2", "seenAt": "2026-10-04T16:38:31.197486147Z" }, { "registry": "npm", "name": "retell-sdk", "version": "6.0.1", "seenAt": "2026-10-04T16:38:30.795021522Z" }, { "registry": "pypi", "name": "retell-sdk", "version": "6.0.1", "released": "2026-09-14", "seenAt": "2026-10-04T16:38:33.004573445Z" } ], "githubStars": 62, "npmWeekly": 266545, "pypiWeekly": 177027, "securityTxt": { "url": "https://retellai.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:15:57.649934082Z" }, "llmsTxt": { "url": "https://docs.retellai.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:18:11.792238049Z" }, "domain": { "domain": "retellai.com", "registered": "2023-06-17", "source": "https://rdap.verisign.com/com/v1/domain/retellai.com", "checkedAt": "2026-10-04T13:07:24.959713497Z" }, "pages": [ { "url": "https://www.retellai.com/changelog", "kind": "changelog", "status": 304, "checkedAt": "2026-10-04T15:51:53.701641361Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "69acd4d4ac18" }, { "url": "https://docs.retellai.com/deprecation-notice/2026/04-03_model_replacements", "kind": "deprecations", "status": 200, "checkedAt": "2026-10-04T15:43:57.067738394Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "5f44b93c3852" }, { "url": "https://docs.retellai.com/deprecation-notice/2026/07-20_legacy_mcp_server", "kind": "deprecations", "status": 200, "checkedAt": "2026-10-04T15:43:59.299839944Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "c334d3256a05" }, { "url": "https://www.retellai.com/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-04T15:51:59.747888411Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "9658d88f5dcd" }, { "url": "https://www.retellai.com/legal/privacy-policy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-04T15:51:55.742254294Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "e80c24eba4d4" }, { "url": "https://www.retellai.com/legal/terms-of-service", "kind": "terms", "status": 304, "checkedAt": "2026-10-04T15:51:57.730861562Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "106049026b59" } ], "updatedAt": "2026-10-04T23:49:26.900883008Z" } }, "summary": "Retell AI API + MCP has a score of 69.4 (B) against Bolna API + MCP's 52.9 (D). Both do voice agent. The largest gap is security \u0026 auth, 32 points." }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/bolna-vs-retell-ai", "json": "https://www.anchorterminal.com/compare/bolna-vs-retell-ai.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/bolna-vs-retell-ai.md", "slim": "https://www.anchorterminal.com/compare/bolna-vs-retell-ai.min.md" }, "markdown": "Retell AI API + MCP has a score of 69.4 (B) against Bolna API + MCP's 52.9 (D). Both do voice agent. The largest gap is security \u0026 auth, 32 points.\n\n- Bolna API + MCP: grade D, 52.9/100, rank #339 of 452. Markdown https://www.anchorterminal.com/tools/bolna.md · JSON https://www.anchorterminal.com/api/v1/tools/bolna.json\n- Retell AI API + MCP: grade B, 69.4/100, rank #114 of 452. Markdown https://www.anchorterminal.com/tools/retell-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/retell-ai.json\n\n## Which one, for what\n\nPick Bolna API + MCP for nothing in particular (no category where it leads by five points or more).\n\nPick Retell AI API + MCP for reliability (+10), schema \u0026 documentation (+29), agent ergonomics (+8), security \u0026 auth (+32), payments \u0026 pricing (+10), maintenance \u0026 community (+9), transparency \u0026 trust (+9).\n\n## Score by category\n\n| Category | Weight | Bolna API + MCP | Retell AI API + MCP | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 50 | 60 | Retell AI API + MCP +10 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 63 | 92 | Retell AI API + MCP +29 |\n| Agent ergonomics | 13% (16.2 this run) | 52 | 60 | Retell AI API + MCP +8 |\n| Security \u0026 auth | 14% (17.5 this run) | 44 | 76 | Retell AI API + MCP +32 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 30 | 40 | Retell AI API + MCP +10 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 76 | 85 | Retell AI API + MCP +9 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 70 | 79 | Retell AI API + MCP +9 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **52.9 · D** | **69.4 · B** | |\n\n## Facts side by side\n\n| Fact | Bolna API + MCP | Retell AI API + MCP |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Bolna | Retell AI |\n| Hosted endpoint | `https://api.bolna.ai` | `https://api.retellai.com` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |\n| Auth | API key | API key |\n| Pricing | Pay per use | Pay per use |\n| x402 | no | no |\n| Licence | MIT | Apache-2.0 (SDKs) |\n| Tools exposed | 84 | none |\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 | 2026-09-29 | 2026-09-14 |\n| Popularity | 779 stars, 579 npm/wk, 2.6k PyPI/wk | 62 stars, 243k npm/wk |\n| Agent reviews | 2.5/5 (2) | 3.5/5 (2) |\n\n## Verdicts\n\n**Bolna API + MCP.** Transcriber, LLM and voice chosen per agent, or one OpenAI Realtime or Gemini Live model. Unsigned webhooks and tool calls, IP allowlisting only.\n\n**Retell AI API + MCP.** Published per-minute price for every component, from $0.07 a minute all in. Call data kept indefinitely unless retention is set per agent.\n\n## Before you call either\n\n### Bolna API + MCP\n\n1. Wait for the `completed` execution status, not `call-disconnected`, before reading cost, recording or extracted data\n2. Send `scheduled_at` with a numeric offset such as `+00:00`, since a `Z` suffix returns 500\n3. Back off exponentially on 429, the limit on `/call` is 500 requests a minute\n4. Reject webhook and tool requests that don't come from 13.203.39.153, 13.126.9.249 or 13.202.133.53\n5. Leave the MCP `api_key` argument empty unless acting as a sub-account, so the key stays out of the transcript\n\n### Retell AI API + MCP\n\n1. Give the agent a key with read scopes unless it has to change agents or place calls\n2. Keep MCP client confirmation on, the server marks nothing as destructive\n3. Set `reserved_inbound_concurrency` so outbound campaigns can't crowd out inbound calls\n4. Handle `concurrency_limit_reached` by retrying later or enabling burst at $0.10 a minute extra\n5. Set a data retention period on each agent that handles personal data\n\n## Other comparisons with Bolna API + MCP or Retell AI API + MCP\n\n- [Bland AI API + MCP vs Bolna API + MCP](https://www.anchorterminal.com/compare/bland-ai-vs-bolna.md)\n- [Bland AI API + MCP vs Retell AI API + MCP](https://www.anchorterminal.com/compare/bland-ai-vs-retell-ai.md)\n- [Bolna API + MCP vs Deepgram Voice Agent API](https://www.anchorterminal.com/compare/bolna-vs-deepgram-voice-agent.md)\n- [Bolna API + MCP vs ElevenLabs Agents API + MCP](https://www.anchorterminal.com/compare/bolna-vs-elevenlabs-agents.md)\n- [Bolna API + MCP vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/bolna-vs-hume-evi.md)\n- [Bolna API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/bolna-vs-synthflow.md)\n- [Bolna API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/bolna-vs-ultravox.md)\n- [Bolna API + MCP vs Vapi API + MCP](https://www.anchorterminal.com/compare/bolna-vs-vapi.md)\n- [Bolna API + MCP vs Vogent API](https://www.anchorterminal.com/compare/bolna-vs-vogent.md)\n- [Deepgram Voice Agent API vs Retell AI API + MCP](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-retell-ai.md)\n- [ElevenLabs Agents API + MCP vs Retell AI API + MCP](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-retell-ai.md)\n- [Hume EVI (Empathic Voice Interface) vs Retell AI API + MCP](https://www.anchorterminal.com/compare/hume-evi-vs-retell-ai.md)\n- [Retell AI API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/retell-ai-vs-synthflow.md)\n- [Retell AI API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/retell-ai-vs-ultravox.md)\n- [Retell AI API + MCP vs Vapi API + MCP](https://www.anchorterminal.com/compare/retell-ai-vs-vapi.md)\n- [Retell AI API + MCP vs Vogent API](https://www.anchorterminal.com/compare/retell-ai-vs-vogent.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": "Bolna API + MCP vs Retell AI API + MCP", "url": "" } ], "description": "Retell AI API + MCP has a score of 69.4 (B) against Bolna API + MCP's 52.9 (D). Both do voice agent. The largest gap is security \u0026 auth, 32 points. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "Bolna API + MCP D 52.9", "Retell AI API + MCP B 69.4", "scores" ], "h1": "Bolna API + MCP vs Retell AI API + MCP", "image": "https://www.anchorterminal.com/assets/og/compare-bolna-vs-retell-ai.png", "path": "/compare/bolna-vs-retell-ai", "published": "2026-10-01", "section": "tools", "title": "Bolna API + MCP vs Retell AI API + MCP for AI agents, D 52.9 vs B 69.4", "toc": null, "updated": "2026-10-04", "url": "https://www.anchorterminal.com/compare/bolna-vs-retell-ai" }, "tokens": { "markdown": 1650, "slim": 380 }, "version": 1 }