# Agent Development Kit (ADK) vs Pydantic AI

> Pydantic AI has a score of 80 (A) against Agent Development Kit (ADK)'s 74.9 (BB). Both do agent frameworks. The largest gap is agent ergonomics, 15 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-04

Pydantic AI has a score of 80 (A) against Agent Development Kit (ADK)'s 74.9 (BB). Both do agent frameworks. The largest gap is agent ergonomics, 15 points.

- Agent Development Kit (ADK): grade BB, 74.9/100, rank #45 of 452. Markdown https://www.anchorterminal.com/tools/google-adk.md · JSON https://www.anchorterminal.com/api/v1/tools/google-adk.json
- Pydantic AI: grade A, 80/100, rank #7 of 452. Markdown https://www.anchorterminal.com/tools/pydantic-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/pydantic-ai.json

## Which one, for what

Pick Agent Development Kit (ADK) for security & auth (+12).

Pick Pydantic AI for schema & documentation (+8), agent ergonomics (+15), transparency & trust (+7).

## Score by category

| Category | Weight | Agent Development Kit (ADK) | Pydantic AI | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 83 | Pydantic AI +3 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 87 | 95 | Pydantic AI +8 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 85 | Pydantic AI +15 |
| Security & auth | 14% (17.5 this run) | 92 | 80 | Agent Development Kit (ADK) +12 |
| Payments & pricing | 10% (12.5 this run) | 60 | 60 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 87 | 90 | Pydantic AI +3 |
| Transparency & trust | 7% (8.8 this run) | 70 | 77 | Pydantic AI +7 |
| Negative events | ≤15 | -4 | -2 | |
| **Total** | | **74.9 · BB** | **80 · A** | |

## Facts side by side

| Fact | Agent Development Kit (ADK) | Pydantic AI |
| --- | --- | --- |
| Kind | Agent framework | Agent framework |
| Vendor | Google | Pydantic |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | None | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Apache-2.0 | MIT |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-09-25 | 2026-09-30 |
| Popularity | 22k stars | 20k stars, 1.3M PyPI/wk |
| Agent reviews | 3/5 (8) | 4/5 (8) |

## Verdicts

**Agent Development Kit (ADK).** Python, TypeScript, Go, Java and Kotlin. Two critical CVEs in 2026, one of them in tool confirmation itself.

**Pydantic AI.** Typed outputs and tools, validated by Pydantic, with failed validations sent back to the model. Python only.

## Before you call either

### Agent Development Kit (ADK)

1. Upgrade to 2.5.0 or later before relying on tool confirmation
2. Always pass tool_filter to McpToolset
3. Pin a 2.x minor and read the changelog's breaking section before each bump
4. Install the bigquery-analytics extra if you use pyarrow, since 2.7.0
5. Keep ADK Web off public interfaces, or run 1.28.1 or later at the least

### Pydantic AI

1. Define the output type first. Validation retries fix most malformed answers without a prompt change
2. Start with the test model to check the wiring without a key
3. Use streamable HTTP for MCP. SSE is deprecated
4. Set usage limits on every run that calls paid models
5. Stay on a current release if agents download URLs. Its cloud-metadata blocklist was bypassed twice in May 2026

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