# Letter AI

Letter AI (letter.ai): subprocessors, data processing agreement, security documents and changes, as monitored by Third Party Index.

- Page: https://thirdpartyindex.com/vendors/letter-ai
- Documents last verified: 2026-10-05
- Transparency rating: 64/100 (how much it publishes, not how secure it is): Subprocessor list 30/30; Processing locations 8/8; Purposes 7/7; Data processing addendum 0/12 (not found); Trust center 0/8 (not found); Privacy policy 6/6; security.txt 0/6 (not found); Security page 0/5 (not found); Status page 5/5; Vulnerability disclosure 0/5 (not found); Pages still reachable 8/8
- Supply chain: relies on 21 tracked vendors directly, 151 within two hops, 409 within three; 0 tracked vendors rely on it directly, 0 within two hops, 0 within three
- Cite as: Letter AI, Third Party Index, https://thirdpartyindex.com/vendors/letter-ai (data CC BY 4.0)

## Documents

| Document | URL | Last verified | Last changed |
|---|---|---|---|
| Subprocessor list | https://www.letter.ai/sub-processor-list | 2026-10-05 | 2026-10-05 |
| Privacy policy | https://www.letter.ai/privacy-policy | 2026-10-05 | 2026-10-05 |
| Terms | https://www.letter.ai/terms-of-service | 2026-10-05 | 2026-10-05 |
| Status page | https://status.letter.ai/ | 2026-10-05 | 2026-10-05 |

## Subprocessors (22)

As its own list states them.

| Subprocessor | Purpose | Location | Listed since |
|---|---|---|---|
| [Algolia](https://thirdpartyindex.com/vendors/algolia.md) | Search | USA | 2026-10-05 |
| [Amazon Web Services](https://thirdpartyindex.com/vendors/amazon-web-services.md) | Hosting services | USA | 2026-10-05 |
| [Anam](https://thirdpartyindex.com/vendors/infobip.md) | Video AI Processing; No customer data is used to train models | USA | 2026-10-05 |
| [Anthropic](https://thirdpartyindex.com/vendors/anthropic.md) (AI model provider: Anthropic) | AI inference; no customer data is used to train models | USA | 2026-10-05 |
| [Apify](https://thirdpartyindex.com/vendors/apify.md) | Web scraping | USA | 2026-10-05 |
| [Buildkite](https://thirdpartyindex.com/vendors/buildkite.md) | CI / CD | USA | 2026-10-05 |
| [ConvertAPI](https://thirdpartyindex.com/vendors/convertapi.md) | PDF conversion | USA | 2026-10-05 |
| [Datadog](https://thirdpartyindex.com/vendors/datadog.md) | Observability | USA | 2026-10-05 |
| [Deepgram](https://thirdpartyindex.com/vendors/deepgram.md) (AI model provider: Deepgram) | AI audio processing | USA | 2026-10-05 |
| [ElevenLabs](https://thirdpartyindex.com/vendors/elevenlabs.md) (AI model provider: ElevenLabs) | Voice AI processing; no customer data is used to train models | USA | 2026-10-05 |
| [Google](https://thirdpartyindex.com/vendors/google-cloud.md) | Translation Processing | USA | 2026-10-05 |
| [HeyGen](https://thirdpartyindex.com/vendors/heygen.md) | Video AI Processing; No customer data is used to train models | USA | 2026-10-05 |
| [Intercom](https://thirdpartyindex.com/vendors/intercom.md) | Customer Support Messaging and In-App Chat | USA | 2026-10-05 |
| [LiveAvatar](https://thirdpartyindex.com/vendors/heygen.md) | Video AI Processing; No customer data is used to train models | USA | 2026-10-05 |
| [Microsoft Azure](https://thirdpartyindex.com/vendors/microsoft.md) | Text Embedding Models | USA | 2026-10-05 |
| [Mux](https://thirdpartyindex.com/vendors/mux.md) | Video processing | USA | 2026-10-05 |
| [OpenAI](https://thirdpartyindex.com/vendors/openai.md) (AI model provider: OpenAI) | AI inference; no customer data is used to train models | USA | 2026-10-05 |
| [Pinecone](https://thirdpartyindex.com/vendors/pinecone.md) | Vector Database | USA | 2026-10-05 |
| [PropelAuth](https://thirdpartyindex.com/vendors/propelauth.md) | Authentication and Identity Management | USA | 2026-10-05 |
| [Retell AI](https://thirdpartyindex.com/vendors/retell-ai.md) | Voice AI processing; no customer data is used to train models | USA | 2026-10-05 |
| [SalesLoft](https://thirdpartyindex.com/vendors/salesloft.md) | Sales Engagement Plugin and Content Recommendation Processing | USA | 2026-10-05 |
| [Stripe](https://thirdpartyindex.com/vendors/stripe.md) | Payment Processing | USA | 2026-10-05 |

Read from ([evidence](https://thirdpartyindex.com/evidence/48171)). CSV: https://thirdpartyindex.com/vendors/letter-ai/subprocessors.csv

AI model providers (or a cloud provider's AI model service) among these entries: 4. All vendors that list one: https://thirdpartyindex.com/ai

## Subprocessor of (0)

No tracked vendor lists it.

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Third Party Index (https://thirdpartyindex.com) monitors vendors' public security and privacy documents and keeps each version as evidence. Data CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); vendors' own documents are theirs. API: https://thirdpartyindex.com/api