# sipgate flow — EU-hosted real-time voice and telephony API for connecting phone calls to your own AI agents.

> Source: The Agents Index — https://theagentsindex.com/sipgate-flow (structured, researched, re-verified)
> Facts last verified: 2026-09-03

sipgate flow is a real-time voice and telephony API that connects inbound and outbound phone calls to an AI agent you build and host yourself. sipgate runs the telephony, speech-to-text and text-to-speech on EU infrastructure in Germany; your webhook owns the conversation logic.

| Fact | Value |
| --- | --- |
| Website | https://flow.sipgate.io |
| Price | from €249.95/month |
| Free tier | No |

The Flow rate card lists four paid minute packages only — Small 2.500 min / 249,95 €, Medium 10.000 min / 899,95 €, Large 25.000 min / 1999,95 €, Enterprise 50.000 min / 3499,95 € — with no free or trial Flow tier. The 'Kostenlos testen' button in the site header belongs to sipgate's cloud phone system, not to Flow.

## What it does

**Done-for-you service** · No — You build and operate the voicebot yourself; sipgate supplies only the telephony and audio layer under the API.

> Bauen Sie Ihren individuellen Voicebot einfach selbst und bringen Sie ihn mit Flow ans Telefon. Ihre Logik, unsere Telefonie, sofort einsatzbereit.
> — https://www.sipgate.de/flow · Section 'Telefonie für Ihr Projekt', body text

## How much it does unattended

**Runs autonomously** · Yes — Your application handles a whole live call unattended, answering with speak, transfer or hangup actions per event; a human only enters if you transfer.

> You receive events (session start, user speech, DTMF) over HTTP webhooks or WebSocket and respond with actions (speak, play audio, transfer, hang up).
> — https://flow.sipgate.io/faq.html · FAQ answer 'Can I build my own AI phone assistant with sipgate flow?'

**Multi-agent** · Partly — One flow owns a call; coordination between agents happens by transferring the call with context passing rather than by any orchestration framework.

> SSML für Feintuning, Weiterleitungen mit Context-Passing, Warm Handover geht alles über simple JSON-Befehle.
> — https://www.sipgate.de/flow · Feature block 'Full Control via API', body text

**Agent permissions** · Partly — In-call actions are open, but the powerful ones (outbound dialling, SMS sending, voice-to-voice mode) stay locked until sipgate support reviews the account.

> send_sms is only available upon request and after a positive review by sipgate support (fraud / scam protection).
> — https://flow.sipgate.io/api/actions/send-sms.html · Availability callout at top of Send SMS Action page

## Which models it runs on

**Claude** · Yes — Claude is used through your own backend: sipgate flow carries audio and transcripts, and the docs treat Anthropic Claude as a supported LLM to stream from.

> When integrating Large Language Models (LLMs) like OpenAI's GPT, Anthropic's Claude, or similar services with sipgate flow, how you stream responses significantly impacts the naturalness
> — https://flow.sipgate.io/api/guides/streaming-llm-responses.html · Opening paragraph of Streaming LLM Responses guide

**GPT** · Yes — Same path as Claude: OpenAI GPT is named as an LLM you stream from your own service, with sipgate flow handling speech both ways.

> When integrating Large Language Models (LLMs) like OpenAI's GPT, Anthropic's Claude, or similar services with sipgate flow, how you stream responses significantly impacts the naturalness
> — https://flow.sipgate.io/api/guides/streaming-llm-responses.html · Opening paragraph of Streaming LLM Responses guide

**Open models** · Yes — The LLM is entirely yours, so an open-weight model works; the vendor publishes no list of supported models because it never runs one for you.

> Your application owns the conversation logic and can call any LLM you choose.
> — https://flow.sipgate.io/faq.html · FAQ answer 'Can I build my own AI phone assistant with sipgate flow?'

**Model choice** · Yes — You pick the LLM outright; sipgate only chooses among its own STT and TTS providers, which you also select per session or per action.

> It handles the telephony, speech-to-text, and text-to-speech, so you keep full control over your conversation logic and your choice of LLM
> — https://flow.sipgate.io/faq.html · FAQ answer 'What is sipgate flow?'

## Where you use it

**On the command line** · No — The docs enumerate every integration path (HTTP webhook, WebSocket, TypeScript SDK) and none of them is a terminal tool.

> HTTP webhooks for serverless, WebSocket for real-time, or use our TypeScript SDK for convenience.
> — https://flow.sipgate.io/ · Homepage feature card 'Flexible Integration'

**In a browser** · Partly — A hosted web surface exists only for configuration, meaning webhook settings and shared secrets in the sipgate account, not for talking to the agent.

> When configuring your webhook settings, you can optionally store a shared secret if you want to use Flow authentication
> — https://flow.sipgate.io/api/authentication.html · Section 'Setting Up Shared Secrets'

## Whose machine it runs on

**Self-hosted** · No — The telephony and speech layer runs only on sipgate's own German infrastructure; you host your webhook, never the service itself.

> sipgate flow runs on EU infrastructure operated by sipgate in Germany, is ISO 27001-certified, and is built to meet GDPR and EU AI Act requirements
> — https://flow.sipgate.io/faq.html · FAQ answer 'Is sipgate flow GDPR-compliant and where is data processed?'

**Open source** · Partly — Only the client is open: the first-party TypeScript SDK is published under Apache-2.0, while the voice and telephony service behind it is closed and hosted.

> License: Apache-2.0
> — https://www.npmjs.com/package/@sipgate/ai-flow-sdk · npm registry package page, License field

## What it costs to run

**How it meters** · Yes — Billing is per talk minute: four prepaid minute packages, each with a published per-extra-minute rate and no base fee, cancellable monthly.

> Small 2.500 Minuten 249,95 € 9,9 ct
> — https://www.sipgate.de/flow · Table 'Alle Minutenpakete im Vergleich', Small row

**Free tier** · No — The published package table is a closed list of four paid tiers starting at 249,95 €; no free or trial Flow tier appears anywhere on it.

> Paket Inkludierte Minuten Paketpreis Jede weitere Minute in EUR Small 2.500 Minuten 249,95 € 9,9 ct
> — https://www.sipgate.de/flow · Table 'Alle Minutenpakete im Vergleich', header and first row

**API access** · Yes — The product is the API: plain JSON events and actions over HTTP webhooks or WebSocket, with no SDK required and examples in several languages.

> The API uses plain JSON over HTTP webhooks or WebSocket, with examples in Python, Node.js, Go, and Ruby.
> — https://flow.sipgate.io/faq.html · FAQ answer 'Which programming languages does sipgate flow support?'

**Bring your own key** · Partly — You bring your own LLM and its keys, but the STT and TTS providers are sipgate-side selections, and there is no bring-your-own-cloud option.

> Your application owns the conversation logic and can call any LLM you choose.
> — https://flow.sipgate.io/faq.html · FAQ answer 'Can I build my own AI phone assistant with sipgate flow?'

_Not established: MCP server_

## Buying it for a team

**A company can buy it** · Yes — Sold business-to-business by a German telco, with minute packages priced net of VAT and an explicitly multi-tenant offer for resellers.

> Sie wollen Ihren Kunden Voice-Funktionen anbieten? Flow ist der richtige Telefoniepartner dafür. Multi-Tenant-fähig, skalierbar und ganz einfach integrierbar.
> — https://www.sipgate.de/flow · Section 'Ihre Plattform für Mandanten', body text

**Seat model** · No — There are no seats and no per-user floor: the rate card meters talk minutes only, with no base fee and monthly cancellation.

> ohne Grundgebühr • minutengenaue Abrechnung • monatlich kündbar
> — https://www.sipgate.de/flow · Footnote directly beneath the 'Alle Minutenpakete im Vergleich' table

**Pooled budget** · Yes — One account-level minute allowance covers every call and every flow; minutes are billed to the second, with overage at the package's published rate.

> Medium 10.000 Minuten 899,95 € 8,9 ct
> — https://www.sipgate.de/flow · Table 'Alle Minutenpakete im Vergleich', Medium row

**Admin controls** · Partly — The sipgate account separates admin from restricted users, which governs configuration rights, not a policy engine limiting what the agent may do mid-call.

> Die sipgate Dienste ermöglichen es, eingerichtete Benutzer:innen zwischen Admin-Usern mit weitreichenden Rechten und normalen Usern mit eingeschränkten Rechten zu unterscheiden.
> — https://www.sipgate.de/sicherheit-datenschutz · Product Security section, 'Rollenbasierte Zugriffskontrolle'

**Single sign-on** · Partly — Customers who already run an SSO provider can enforce SSO login for all their users; Google and Apple sign-in is open to everyone, and neither SAML nor OIDC is named.

> Kund:innen, die einen SSO-Anbieter nutzen, können die SSO-basierte Anmeldung für alle ihre User einrichten.
> — https://www.sipgate.de/sicherheit-datenschutz · Product Security section, 'SSO-Unterstützung'

_Not established: Audit log_

## What happens to your code

**Opt out of training** · Partly — Under AI Security sipgate states model training on customer data is contractually excluded and processing stays in Europe, but the sentence covers its own ChatGPT usage, not Flow's speech subprocessors specifically.

> Eine weitere Nutzung der Daten, zum Beispiel für Machine Learning durch OpenAI, ist vertraglich ausgeschlossen.
> — https://www.sipgate.de/sicherheit-datenschutz · AI Security section, 'Umgang mit erhobenen Daten'

**Data residency** · Yes — Germany: infrastructure sits in ISO 27001 data centres in Frankfurt and Düsseldorf, and ElevenLabs voices were moved onto the EU endpoint by default.

> Unsere zuverlässigen Rechenzentren, die nach ISO 27001 zertifiziert sind, befinden sich an den Standorten Frankfurt und Düsseldorf.
> — https://www.sipgate.de/flow · Section 'Zuverlässig, sicher, nachhaltig', card 'Zertifizierte Rechenzentren'

**Getting out** · Partly — Deletion is documented and self-service under the data-processing agreement, but no data-export path is published and nothing states whether unused package minutes roll over.

> Werden Daten im Auftrag der Kund:innen gespeichert, greifen die Regelungen des Vertrags zur Verarbeitung von Daten im Auftrag. In diesen Fällen können Kund:innen ihre Daten jederzeit selbst löschen.
> — https://www.sipgate.de/sicherheit-datenschutz · Data Security section, 'Datenlöschung'

**Certifications** · Partly — ISO 27001 certification of the data centres plus GDPR and EU AI Act alignment are claimed; SOC 2 is claimed nowhere on the site.

> sipgate flow runs on EU infrastructure operated by sipgate in Germany, is ISO 27001-certified, and is built to meet GDPR and EU AI Act requirements
> — https://flow.sipgate.io/faq.html · FAQ answer 'Is sipgate flow GDPR-compliant and where is data processed?'

## Provenance

Every fact above comes from the vendor. Nothing here is independently corroborated yet.

## Coverage elsewhere

None recorded. Every fact above comes from the vendor and is not independently corroborated yet.

## What changed

- 2026-09-03 — Capabilities · Commercial terms · Free tier · Price

## Correcting this record

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