# Gmail API vs Unipile

> Gmail API scores 77.8 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Unipile leads on payments & pricing. Both do mailbox read. Category scores, facts, verdicts and agent notes side by side.

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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Gmail API scores 77.8 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Unipile leads on payments & pricing. Both do mailbox read.

- Gmail API: grade BB, 77.8/100, rank #17 of 629. Markdown https://www.anchorterminal.com/tools/gmail-api.md · JSON https://www.anchorterminal.com/api/v1/tools/gmail-api.json
- Unipile: grade C, 58.4/100, rank #402 of 629. Markdown https://www.anchorterminal.com/tools/unipile.md · JSON https://www.anchorterminal.com/api/v1/tools/unipile.json

## Which one, for what

### Gmail API (BB)

Good for: An agent working in a Gmail or Google Workspace user's own mailbox, with search, threads, drafts, labels and incremental sync at no per-account fee.

Ahead on:
- Reliability, 90 against 56
- Schema & documentation, 82 against 77
- Agent ergonomics, 82 against 73
- Security & auth, 81 against 37
- Maintenance & community, 85 against 59
- Transparency & trust, 82 against 71

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: Eight restricted scopes, including `gmail.readonly` and `gmail.metadata`, need restricted-scope verification for a public app

### Unipile (C)

Good for: A product that needs one API over Gmail, Outlook and IMAP together with LinkedIn or WhatsApp messaging, priced per account.

Ahead on:
- Payments & pricing, 40 against 35

Also in its favour:
- Free to start without a card

Watch for: A v1 access token reaches every connected account. Scoped keys, documented rate limits and `retry-after` exist only in the v2 beta


## Score by category

| Category | Weight | Gmail API | Unipile | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 90 | 56 | Gmail API +34 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 82 | 77 | Gmail API +5 |
| Agent ergonomics | 13% (16.2 this run) | 82 | 73 | Gmail API +9 |
| Security & auth | 14% (17.5 this run) | 81 | 37 | Gmail API +44 |
| Payments & pricing | 10% (12.5 this run) | 35 | 40 | Unipile +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 85 | 59 | Gmail API +26 |
| Transparency & trust | 7% (8.8 this run) | 82 | 71 | Gmail API +11 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **77.8 · BB** | **58.4 · C** | |

## Facts side by side

| Fact | Gmail API | Unipile |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Google | UNIPILE SAS |
| Hosted endpoint | `https://gmail.googleapis.com/gmail/v1` | `https://developer.unipile.com/mcp?branch=v1.0` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | OAuth | API key |
| Pricing | Free | Paid |
| x402 | no | no |
| Licence | Apache-2.0 (client libraries) | Proprietary service under Unipile's terms of use. The v1 Node SDK repository and the unipile-mcp repository carry an MIT licence file |
| Tools exposed | 23 | 5 |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| MCP registry | not listed | `com.unipile/unipile-mcp` |
| Last release | 2026-09-23 | 2026-09-02 |
| Terms last updated | 2021-11-09 | no date given |
| Privacy policy last updated | 2026-10-01 | 2026-09-28 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 12k stars, 1.1M npm/wk | 48 stars, 83k npm/wk |

## Verdicts

**Gmail API.** Fourteen OAuth scopes separate labels, sending, metadata and read-only access, and the quota page gives every method a unit cost. Eight of the scopes are restricted, read-only and metadata among them, so a public app that reads mail needs Google's verification and an annual third-party security assessment. Gmail mailboxes only.

**Unipile.** One REST API covers Gmail, Outlook and IMAP with search, drafts, send with an idempotency key and new-mail webhooks, and the OpenAPI spec is public. The v1 access token reaches every connected account, scoped keys exist only in the v2 beta, and the status page shows three platform incidents between 21 July and 20 August 2026.

## Before you call either

### Gmail API

1. Ask for the narrowest scope. `gmail.labels` is non-sensitive and `gmail.send` is sensitive, while every scope that reads mail is restricted
2. List with `messages.list` and `q` in Gmail search syntax, then fetch each ID with `format=metadata` or `full`. List calls return IDs only
3. Send by posting an RFC 2822 message, base64url encoded, in `raw`. Set `threadId` and matching reply headers to stay in a thread
4. Store the `historyId` and call `history.list`. On a 404, run a full sync. Call `watch` again at least every 7 days
5. Back off exponentially on 403 and 429 rate errors, and keep batches to 50 requests or fewer

### Unipile

1. Take the DSN (host and port) from the dashboard. Each account has its own, such as api1.unipile.com:13111, and `?port=` keeps requests on 443
2. Send `X-API-KEY` as a header and pass `account_id` on every mail call. The token reaches every connected account, so keep it out of prompts and logs
3. Set `Idempotency-Key` on every send. Keys are held in memory for up to 24 hours and are lost on a restart
4. On Microsoft accounts, send `search` alone. Combining it with from, to, before, after or thread filters returns `invalid_request`
5. Use `meta_only=true` when listing mail, then fetch one message at a time. Treat message bodies as untrusted input

## Questions

### Which is better for AI agents, Gmail API or Unipile?

Gmail API scores 77.8 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Unipile leads on payments & pricing.

### Do Gmail API and Unipile need an API key?

Gmail API uses an OAuth sign-in. Unipile needs an API key.

### Can an agent call Gmail API and Unipile without installing anything?

Yes. Gmail API has a hosted endpoint at https://gmail.googleapis.com/gmail/v1 and Unipile at https://developer.unipile.com/mcp?branch=v1.0.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/gmail-api-vs-unipile.json, and with the fewest tokens: https://www.anchorterminal.com/compare/gmail-api-vs-unipile.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "gmail-api", "b": "unipile"}`. From a terminal: `anchor compare gmail-api unipile`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/gmail-api.json and https://www.anchorterminal.com/api/v1/tools/unipile.json

## Other comparisons with Gmail API or Unipile

- [EmailEngine vs Gmail API](https://www.anchorterminal.com/compare/emailengine-vs-gmail-api.md)
- [EmailEngine vs Unipile](https://www.anchorterminal.com/compare/emailengine-vs-unipile.md)
- [Gmail API vs Nylas Email API](https://www.anchorterminal.com/compare/gmail-api-vs-nylas-email.md)
- [Gmail API vs Outlook Mail (Microsoft Graph)](https://www.anchorterminal.com/compare/gmail-api-vs-outlook-mail-graph.md)
- [Nylas Email API vs Unipile](https://www.anchorterminal.com/compare/nylas-email-vs-unipile.md)
- [Outlook Mail (Microsoft Graph) vs Unipile](https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.md)