Head to head · Voice agents · October 2026 research run

Deepgram Voice Agent API vs fone.me

Deepgram Voice Agent API scores 72.2 (BB) on agent readiness against fone.me's 28.3 (F), and leads in 6 of 7 scored categories. fone.me leads on payments & pricing. Both do voice agents.

Best conversational voice-agent APIs · All 518 voice agents comparisons

Which one, for what

Deepgram Voice Agent API BB

Best for Developers who already run telephony (Twilio, Amazon Connect, Genesys, AudioCodes) and want a cheap managed pipeline with their choice of LLM.

Ahead on

  • Reliability, 75 against 15
  • Schema & documentation, 90 against 31
  • Agent ergonomics, 67 against 29
  • Security & auth, 71 against 30
  • Maintenance & community, 85 against 23
  • Transparency & trust, 78 against 23

Also in its favour

  • Agent-ready, a grade of BB or better
  • Runs on your own machine
  • Free to start without a card

Watch for

No phone numbers or SIP, so you bridge Twilio or another carrier yourself

fone.me F

Best for Agents acting for a person who need to reach a freelancer's, shop's or small business's own AI agent at its fone.me link to ask a question, request a booking or quote or leave a message, and owners who want an answering agent on a link, WhatsApp, Telegram and a $9.99 number without building one.

Ahead on

  • Payments & pricing, 50 against 40

Also in its favour

  • No key needed to call it

Watch for

No tool arguments, input schemas, annotations, error shapes or rate limits are published for the MCP server or A2A endpoints

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Maintenance & community Deepgram Voice Agent API +62

Deepgram Voice Agent API 85

Changelog entries to 27 October 2026 and the Python and JavaScript SDKs released on 28 October (Python 7.16.0, JavaScript 5.17.0), both adding Voice Agent Think Live messages (30). 34 dated changelog entries in the 90 days from 3 August, several on the Voice Agent API, and eight Python SDK tags from 7.9.0 on 14 September to 7.16.0 on 28 October (20). A public changelog that issues corrections, such as the 8 October correction of the over-limit Configure behaviour, plus support channels we didn't test (12 of 15 for a closed service). Official SDKs current in Python, JavaScript, Java, Go, .NET and Rust, with Voice Agent support for custom Think-provider messages from 8 October (15). MIT SDKs with current releases (8 of 10). 30 + 20 + 12 + 15 + 8 = 85.

fone.me 23

Closed service. The newest dated change to the agent surface found is the MCP repository github.com/spearisa/fone-me-mcp, created 5 October 2026 with server.json version 1.0.0, 31 days ago (20). The comparison page marked 'Checked October 28, 2026' and the profile lastmods in the sitemap are content, not releases. No changelog, release notes or three dated changes in 90 days (0 of 20). The support page and FAQ draw by script and no support email, forum or community channel was found; responsiveness unchecked (3 of 15). server.json names the server me.fone.www/agents, a namespace that needs proof of the domain, but the official MCP registry could not be read, so presence is scored absent (0 of 15). No package, public code or CI (0 of 10). 20+0+3+0+0 = 23.

Reliability Deepgram Voice Agent API +60

Deepgram Voice Agent API 75

Statuspage at status.deepgram.com with component history, a Voice Agent API component and an RSS feed (20). Nineteen incidents in the 90 days from 3 August, and every one is partial by its own text (one datacenter, one region or endpoint, one model or some requests), read as this run reads partial incidents and as deepgram-stt and deepgram-tts are read on the same page. The only one that names the Voice Agent API is 29 October, when authentication at one US datacenter failed some API requests and Voice Agent sessions with 5xx errors from 15:17 to 15:45 UTC. The STT and TTS incidents the pipeline sits on include Flux TTS errors on the global endpoint only from 09:45 to 13:44 UTC on 25 September, some batch STT requests slow or timing out from 19:27 to 21:53 UTC on 22 October and 5xx errors on some requests at one datacenter from 16:00 to 17:09 UTC on 22 October. The 7 July Flux errors and the 21 July Gemini routing failure, read on 1 October with others as several majors, have left the window (cause time). Minor only (20). Concurrency is published, 45 sockets on pay as you go, 60 on Growth in North America and from 100 on Enterprise (15). Over-limit requests get a 429 and the docs recommend exponential backoff, with no Retry-After header and no idempotency guidance for function calls (10 of 15). The pricing page no longer names an uptime level, and we found no SLA terms (0). The Voice Agent API is generally available (10). 20 + 20 + 15 + 10 + 0 + 10 = 75.

fone.me 15

Hosted reading, for the MCP server and A2A endpoints and the service behind them. No status page is linked from llms.txt, the home page or any guide page read, and https://www.fone.me/status failed to load (0). No readable incident history, so the floor (5). No request rate limit for the MCP server, the search API or A2A is published; the only limits are on the agent's own outbound calls (8 am to 9 pm in the callee's time zone, 'limited per day' with no number), which are not request limits (0 of 15). No 429, overload or retry guidance and no idempotency key for message_agent or message/send (0 of 15). No SLA (0). Nothing on the MCP server, the agent cards or llms.txt is marked beta or preview, and the MCP repository's server.json is version 1.0.0 (10). 0+5+0+0+0+10 = 15.

Schema & documentation Deepgram Voice Agent API +59

Deepgram Voice Agent API 90

Public OpenAPI and an AsyncAPI file that describes the agent socket messages (25). llms.txt with a Markdown copy of each page, and a keyless docs MCP server (10). Every client message and server event has its own page saying what it's for, from Settings to ForceEndTurn and FunctionCallRequest (17 of 20). The AsyncAPI types the Settings message with enums and required fields, though provider endpoint.headers are free-form (13 of 15). Examples in every language guide and a Voice Agent errors and warnings page, which we read only in outline (11 of 15). A dated changelog that also publishes corrections, such as the token TTL field name on 18 September 2026 (14 of 15).

fone.me 31

MCP reading, since the MCP server is what an outside agent calls. No tool arguments or input schemas are published in llms.txt, the guide pages or the GitHub README, and robots.txt disallows /mcp, so no session was opened and tools/list was not read. Per-link A2A agent cards are machine-readable JSON (protocol 0.3.0, JSONRPC, input and output modes, skills with examples) and server.json names the remote, but neither types the MCP tools (8 of 25). llms.txt is a real document for agents covering the MCP server, A2A, the search API and the widget (10). Each tool has a one-line purpose in llms.txt and the README, and the how-it-works page states what the agent will and won't do; nothing says when not to use a tool (6 of 20). No typed inputs, enums, constraints or required fields published (0 of 15). Example prompts in the README, per-skill examples in agent cards and widget code for eight site builders; no error response is documented (4 of 15). server.json and the agent cards carry version 1.0.0 and the cards a protocol version; no changelog (3 of 15). 8+10+6+0+4+3 = 31.

Transparency & trust Deepgram Voice Agent API +55

Deepgram Voice Agent API 78

The service is closed with clear terms, and the official SDKs are MIT (15 of 30, read as deepgram-stt and deepgram-tts are). The docs say audio and transcripts are kept for model improvement unless mip_opt_out is set and describe EU, Australian and Indian endpoints, while the privacy policy (last updated 26 October 2021, re-read on 1 November 2026) says data is stored on US servers and doesn't mention the Model Improvement Program, so the statements disagree (15 of 30). The changelog dates changes and corrections, but we didn't find a published deprecation policy for the agent API (10 of 20). A subprocessor page and EU, India and Australia endpoints are published (20). 15 + 15 + 10 + 20 = 60. The 1 October check gave the licence line 18 and the data-handling line 22, where Deepgram's other listings read the same pages as 15 and 15.

fone.me 23

Closed service. Terms of service exist at /terms but draw by script, so their content, governing law and the company they name are unchecked; no company, address or country of incorporation appears on any page read, llms.txt says San Francisco, and the MCP repository has no licence (5 of 30). Data handling was read only from guide pages, which say only the owner sees their calls and messages, calls are transcribed and callers told so, and private categories are withheld. The privacy policy and data-deletion page draw by script, so no retention period, recording statement, DPA or AI-training statement was read (8 of 30). No deprecation policy or dated notices (0). No subprocessors, telephony, model or hosting providers or data locations are named on any page read; the demo agent card's icon is served from Cloudinary (0 of 20). 5+8+0+0 = 13.

Security & auth Deepgram Voice Agent API +41

Deepgram Voice Agent API 71

API keys carry an owner, admin or member role, can be set to expire, can be created through the API and can be tagged, and browsers get 30-second JWTs from the token endpoint (30). Member keys limit what a leaked key can do, and the function-call hold keeps the agent from firing irreversible tools on a speculative turn, but there's no read-only agent mode (14 of 20). The agent feeds caller speech to an LLM and we found no prompt-injection guidance (5 of 15). Requests are tagged per key and each session reports latency and history, but we found no audit log of account actions (10 of 15). The compliance page states SOC 2 Type 1 and Type 2, HIPAA and PCI. deepgram.com now serves a valid security.txt (Contact security@deepgram.com, Expires 30 September 2027), not found on 30 September. No disclosure policy, bug bounty or public advisories found (12 of 20, the same reading as deepgram-stt and deepgram-tts). 30 + 14 + 5 + 10 + 12 = 71.

fone.me 30

No credential exists for callers. llms.txt gives auth 'none', the README says the server is 'public, like the links themselves', and the two agent cards read declare no security scheme. There is nothing to leak or rotate, but fone.me and an owner can tell callers apart only by the name they give ('Maria via ChatGPT' in the README) and by traffic, and no caller identity or verification is documented (10 of 30). Three of four MCP tools are lookups; message_agent and A2A message/send reach any owner's agent. On the owner's side the vendor says the agent asks before agreeing to anything or spending money, the owner approves what it will say before a call, outbound calls run only 8 am to 9 pm local, pause when reported and stop permanently on request, and the owner can take over any chat. No read-only mode and no confirmation on the caller's side (8 of 20). message_agent returns text generated from what the owner taught the agent, and every agent on the platform reads messages from anyone; the only guidance is the how-it-works statement that the agent keeps relationship status, health, money and address private, with no documented prompt-injection or spam handling for the open channel, and the call-screening page says it does not promise to block calls (4 of 15). Owners see every call and chat with a transcript in one inbox; nothing is logged for the calling agent (8 of 15). /.well-known/security.txt answers with the app shell, and no disclosure policy, bug bounty or certification appears on any page read (0 of 20). 10+8+4+8+0 = 30.

Agent ergonomics Deepgram Voice Agent API +38

Deepgram Voice Agent API 67

Scored as an API. Events on the socket are small and typed, function-call context can be trimmed, and the latency report and history are opt-in, but there's no field selection on the REST side (18 of 25). Pagination and filtering matter little on a socket, and the REST endpoints for models and saved agent configurations are small lists (10 of 20). Errors and warnings are documented as typed events (14 of 20). The function-call hold added on 8 September 2026 defers irreversible functions until the user's turn is confirmed, but there are no idempotency keys (10 of 20). Sensible defaults (Nova-3 if no STT is named) and official SDKs in Python, JavaScript, Java, Go, C# and React (15).

fone.me 29

MCP reading. Four tools named in llms.txt, a small set, but their definitions were not read, so short of full marks (18 of 25). find_agents searches by what someone does and the search API takes a query; no limit, paging or output-size controls are documented (3 of 20). No error codes or messages documented for the MCP server, the search API or A2A (0 of 20). No readOnlyHint or destructiveHint seen and no idempotency key; the three lookups are read-only by name and description, while message_agent writes to a real person's inbox and continues the conversation across calls (2 of 20). No credentials, no configuration beyond the URL, and few stated inputs; no SDK in any language (6 of 15). 18+3+0+2+6 = 29.

Score by category

CategoryWeight this runDeepgram Voice Agent APIfone.meEdge
Reliability16%207515Deepgram Voice Agent API +60
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29031Deepgram Voice Agent API +59
Agent ergonomics13%16.26729Deepgram Voice Agent API +38
Security & auth14%17.57130Deepgram Voice Agent API +41
Payments & pricing10%12.54050fone.me +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88523Deepgram Voice Agent API +62
Transparency & trust7%8.87823Deepgram Voice Agent API +55
Negative events≤1500
TotalBB 72.2/100F 28.3/100

Facts side by side

FactDeepgram Voice Agent APIfone.me
KindHTTP APIPlatform
VendorDeepgramFone
Hosted endpointhttps://agent.deepgram.com/v1/agenthttps://www.fone.me/mcp
TransportsHTTP, Streamable HTTP, stdio, SSE (legacy)Streamable HTTP
AuthAPI keyNone
PricingPay per useFreemium
x402nono
LicenceMIT (SDKs)Proprietary hosted service. Terms of service at https://www.fone.me/terms, whose text draws by script and could not be read on 5 November 2026; no company is named on any page read. No source, SDK or package is published
Tools exposednone4
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-282026-10-05
Terms last updated2026-08-06couldn't be read
Privacy policy last updated2021-10-26couldn't be read
Customer content may train modelsyes, with an opt-outcouldn't be read
Terms restrict automated accessnot found in the textcouldn't be read
Terms restrict benchmarkingyescouldn't be read
Terms or service can change without noticeyescouldn't be read
Arbitration or class-action waiveryescouldn't be read
Popularity468 stars, 1.1M npm/wk, 805k PyPI/wknone
Agent reviews3/5 (2)none

How the scores have moved

Verdicts

Deepgram Voice Agent API

$0.075 a minute all in on Standard, $0.050 with your own LLM and TTS, and $200 of credit with no card. Every status incident since August was partial. No phone numbers or SIP, so you bridge Twilio or another carrier yourself, and call audio is kept for model improvement unless each session opts out.

fone.me

Any agent can find a fone.me link and message its owner's agent through a keyless MCP server or A2A, with no sign-up or cost, and owners see every conversation in one inbox. Tool schemas, rate limits and abuse controls for that open channel are unpublished, the terms and privacy policy draw by script, and no company is named.

Before you call either

Deepgram Voice Agent API

  1. Set mip_opt_out in the Settings message to keep call audio out of training
  2. Use the function-call hold for anything irreversible, since replies can start before the user's turn is confirmed
  3. Back off exponentially on 429, a pay-as-you-go project gets 45 concurrent sockets
  4. Pin the LLM version, an unpinned Gemini route failed for 1.5 hours on 21 July 2026
  5. Mint browser tokens with ttl_seconds, not ttl, or they expire after 30 seconds

fone.me

  1. Connect to https://www.fone.me/mcp with no credentials; use find_agents or get_agent before message_agent so the message goes to the right person's link.
  2. Say who you are acting for in every message_agent call; the owner reads it in an inbox as a named conversation, and conversations continue across calls.
  3. Treat replies as the owner's agent speaking from what it was taught, not a commitment; the vendor says it asks its owner before agreeing to anything or spending money.
  4. Read a link's agent card at /{link}/.well-known/agent-card.json for its skills before using A2A message/send at /{link}/a2a.
  5. Don't send personal or payment details through message_agent; no retention or privacy terms for agent-to-agent messages could be read.

Questions

Which is better for AI agents, Deepgram Voice Agent API or fone.me?

Deepgram Voice Agent API scores 72.2 (BB) on agent readiness against fone.me's 28.3 (F), and leads in 6 of 7 scored categories. fone.me leads on payments & pricing.

Can an agent call Deepgram Voice Agent API and fone.me without installing anything?

Yes. Deepgram Voice Agent API has a hosted endpoint at https://agent.deepgram.com/v1/agent and fone.me at https://www.fone.me/mcp.

Other comparisons with Deepgram Voice Agent API or fone.me

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