Head to head · Agent frameworks · October 2026 research run
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.
Agent Development Kit (ADK)Google · Agent framework
BB74.9/100#45 of 452
Pydantic AIPydantic · Agent framework
A80/100#7 of 452
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 this run | Agent Development Kit (ADK) | Pydantic AI | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 80 | 83 | Pydantic AI +3 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 87 | 95 | Pydantic AI +8 |
| Agent ergonomics | 13%16.2 | 70 | 85 | Pydantic AI +15 |
| Security & auth | 14%17.5 | 92 | 80 | Agent Development Kit (ADK) +12 |
| Payments & pricing | 10%12.5 | 60 | 60 | even |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 87 | 90 | Pydantic AI +3 |
| Transparency & trust | 7%8.8 | 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 | 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)
- Upgrade to 2.5.0 or later before relying on tool confirmation
- Always pass tool_filter to McpToolset
- Pin a 2.x minor and read the changelog's breaking section before each bump
- Install the bigquery-analytics extra if you use pyarrow, since 2.7.0
- Keep ADK Web off public interfaces, or run 1.28.1 or later at the least
Pydantic AI
- Define the output type first. Validation retries fix most malformed answers without a prompt change
- Start with the test model to check the wiring without a key
- Use streamable HTTP for MCP. SSE is deprecated
- Set usage limits on every run that calls paid models
- Stay on a current release if agents download URLs. Its cloud-metadata blocklist was bypassed twice in May 2026
Other comparisons with Agent Development Kit (ADK) or Pydantic AI
Machine-readable
/api/v1/tools/google-adk.json·/api/v1/tools/pydantic-ai.json- This page as Markdown,
/compare/google-adk-vs-pydantic-ai.md