# sipgate flow — EU-hosted real-time voice and telephony API that puts your own AI agent on the phone.

> Source: The Agents Index — https://theagentsindex.com/sipgate-flow (structured, researched, re-verified)
> Facts last verified: 2026-09-26

sipgate flow is a real-time voice and telephony API that connects inbound and outbound phone calls to an AI agent you write yourself. It handles telephony, speech-to-text and text-to-speech over webhooks or WebSocket, from German infrastructure.

| Fact | Value |
| --- | --- |
| Website | https://flow.sipgate.io |
| Price | Email: ai@sipgate.de |
| Free tier | Not applicable |

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 — This is software you integrate yourself: sipgate supplies the voice layer while you write and host the conversation logic, with no build or run service offered.

> 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, 'What is sipgate flow?' answer

## How much it does unattended

**Runs autonomously** · Partly — Flow runs a whole call unattended (greeting, transcription, speech, transfer, hangup), but every decision comes from your application, so autonomy depends on the logic you supply.

> Your application owns the conversation logic and can call any LLM you choose.
> — https://flow.sipgate.io/faq.html · FAQ, '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 — Inbound handling is open once a webhook is configured, but outbound dialling is withheld until sipgate support reviews the account, which is a real gate on what the agent may initiate.

> Outbound calls are only available upon request and after a positive review by sipgate support. This restriction exists to prevent fraud and spam.
> — https://flow.sipgate.io/api/guides/outbound-calls.html · Outbound Calls, 'Access Required' warning box

## Which models it runs on

**Claude** · Yes — Claude is named as a model you integrate behind the voice layer; sipgate does not resell it, your own application makes the call.

> When integrating Large Language Models (LLMs) like OpenAI's GPT, Anthropic's Claude, or similar services with sipgate flow
> — https://flow.sipgate.io/api/guides/streaming-llm-responses.html · Streaming LLM Responses, opening paragraph

**GPT** · Yes — GPT is named in the streaming guide as a model you wire behind the webhook; inference is yours to arrange and pay for.

> When integrating Large Language Models (LLMs) like OpenAI's GPT, Anthropic's Claude, or similar services with sipgate flow
> — https://flow.sipgate.io/api/guides/streaming-llm-responses.html · Streaming LLM Responses, opening paragraph

**Open models** · Partly — Nothing stops an open-weight model being used because the LLM lives in your application, but the vendor never names one or hosts any model itself.

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

**Model choice** · Yes — Model choice is entirely the buyer's: flow carries audio and text only, and states plainly that you keep your choice of LLM.

> so you keep full control over your conversation logic and your choice of LLM — sipgate flow gives your existing AI a voice on the phone
> — https://flow.sipgate.io/ · Homepage, 'What is sipgate flow?' section

## 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** · Yes — A hosted Flow dashboard exists for configuration (webhook URL, WebSocket URL and shared secret), though the docs never show it as a build or monitoring console.

> Configure: Add your webhook URL in the Flow dashboard
> — https://flow.sipgate.io/api/quick-start.html · Quick Start, Step 3 'Expose Your Endpoint', item 3

## Whose machine it runs on

**Self-hosted** · Partly — Your half (webhook server and LLM) runs anywhere you like, but the telephony, transcription and speech synthesis run on sipgate's own EU infrastructure with no self-hosted option documented.

> 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, '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 nothing but an API: plain JSON events over HTTP webhooks or WebSocket, plus a REST endpoint to place outbound calls, usable from any language.

> 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, 'Which programming languages does sipgate flow support?'

**Bring your own key** · Partly — Inference is bring-your-own by design (your keys, your provider, your bill), while speech synthesis and transcription run through providers sipgate operates rather than accounts you supply.

> Your application owns the conversation logic and can call any LLM you choose.
> — https://flow.sipgate.io/faq.html · FAQ, '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 — Processing is stated to sit on EU infrastructure operated by sipgate in Germany, positioned explicitly as the alternative to US-hosted voice AI providers.

> 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, 'Is sipgate flow GDPR-compliant and where is data processed?'

**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** · Yes — ISO 27001 certification is claimed alongside GDPR and EU AI Act readiness, though SOC 2 is never mentioned and no certificate or audit report is linked from the site.

> is ISO 27001-certified, and is built to meet GDPR and EU AI Act requirements — a key difference from US-based voice AI providers
> — https://flow.sipgate.io/faq.html · FAQ, '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

- 2026-09-26 — Capabilities · Commercial terms · Free tier · Price
- 2026-09-03 — Capabilities · Commercial terms · Free tier · Price

## Correcting this record

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