# Pydantic AI vs AI SDK (slim)

> AI SDK scores 89.8 (AA) to Pydantic AI's 81.9 (A) for agent frameworks. Prices, MCP, x402, uptime and agent notes side by side.

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AI SDK scores 89.8 (AA) on agent readiness against Pydantic AI's 81.9 (A), and leads in 3 of 7 scored categories. Pydantic AI leads on security & auth. Both do agent frameworks.

- Pydantic AI: A 81.9, rank #7 of 1510 · https://www.anchorterminal.com/tools/pydantic-ai.min.md
- AI SDK: AA 89.8, rank #1 of 1510 · https://www.anchorterminal.com/tools/vercel-ai-sdk.min.md
- Pydantic AI, good for Python teams that want typed, validated outputs and tools, many model providers and durable runs on an engine they already use. Ahead on Security & auth, 95 against 90. Also No key needed to call it.
- AI SDK, good for TypeScript teams building agents and chat UIs who want one API across many providers and a short path to MCP. Ahead on Reliability, 93 against 83; Maintenance & community, 97 against 90. Also No incidents deducted, where Pydantic AI loses 6 points for them.

| Category | Pydantic AI | AI SDK |
| --- | --- | --- |
| Reliability (16%) | 83 | 93 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 100 | 100 |
| Agent ergonomics (13%) | 95 | 95 |
| Security & auth (14%) | 95 | 90 |
| Payments & pricing (10%) | 60 | 60 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 90 | 97 |
| Transparency & trust (7%) | 87 | 89 |

| Fact (where they differ) | Pydantic AI | AI SDK |
| --- | --- | --- |
| Vendor | Pydantic | Vercel Inc. |
| Auth | None | API key |
| Licence | MIT | Apache-2.0 |
| Read-only variant documented | yes | no |
| Last release | 2026-10-30 | 2026-11-05 |
| Terms last updated | no date given | 2026-06-01 |
| Privacy policy last updated | 2024-02-21 | 2026-06-01 |
| Customer content may train models | not found in the text | yes, with an opt-out |
| Terms restrict benchmarking | yes | not found in the text |
| Popularity | 20k stars, 1.3M PyPI/wk | 28k stars, 44.9M npm/wk |
| Agent reviews | 4/5 (8) | none |

Why the edge:
- Reliability, AI SDK +10: Pydantic AI 83 (Official package on PyPI. Requires-Python is >=3.11 since 2.55.0 on 9 October, which dropped Python 3.10 in its end-of-life month (20). CI passes on main, with a coverage badge, per the 1 October check. The Actions page we read on 1 November showed run titles but no status, so it isn't re-read (25). 1.1k open issues and 469 open pull requests on 1 November, up from 560 and 219 on 1 October, with stale-issue, triage and regression-detector workflows running. We didn't read reply times, so 8 stands (8). A written version policy with no intentional breaking changes in minor releases and deprecated APIs kept until the next major (15). 2.64.0, classed 5 - Production/Stable (15).); AI SDK 93 (Official npm packages, with `ai` 7.x requiring Node 22 or newer (20). A public CI workflow with lint, type checks, unit tests, Node-version tests, MCP tests on Windows and e2e tests runs on every push to main, and the newest completed CI runs on main passed on 6 November (25). 1,517 open issues and pull requests on 6 November from GitHub's API, with 1,059 issues opened in the 90 days to 3 November; 47 of the 50 newest had a comment and 32 were closed (18). A written versioning page with breaking changes only in majors, experimental_ prefixes for unstable APIs and a migration guide per major (15). 7.0.163 (15). 20+25+18+15+15 = 93, up from 73 on 6 October, when GitHub couldn't be read.)
- Maintenance & community, AI SDK +7: Pydantic AI 90 (2.64.0 on 2026-10-30 (30). 48 V2 release tags from 3 August to 30 October 2026 (20). 1.1k open issues and 469 open pull requests on 1 November, and we couldn't see reply times (15). The Python package is current, and V1 still gets security releases (1.107.9 on 21 October) (15). CI and coverage pass on main, per the 1 October check, not re-read on 1 November (10).); AI SDK 97 (7.0.163 on 2026-11-05 (30). 226 stable npm releases of `ai` across the 7.x, 6.x and 5.x lines in the 90 days to 6 November, 70 of them since 6 October (20). 47 of the 50 newest issues commented and 32 closed, with triage automation and backport workflows (22). `ai` and the provider packages are current, and 6.x and 5.x still get patches (15). Dependabot configured and CI passing on main (10). 30+20+22+15+10 = 97.)
- Security & auth, Pydantic AI +5: Pydantic AI 95 (No telemetry unless you configure it. OpenTelemetry instrumentation and Logfire take two added lines (30). Deferred-tool approval is built in. `LocalWorkspace(read_only=True)` and `ReadOnlyWorkspace` in core (since 2.52.0 on 30 September) refuse commands and writes, and the Harness runs commands in Bubblewrap, Modal, E2B, Sprites or, since 2.56.0, smolvm sandboxes and code mode in the Monty interpreter (20). The message-history docs say never to build a system prompt from tool output or fetched pages, and the Harness has an opt-in Prompt Injection Defender for tool results, guardrails and a tool-call judge (15). OpenTelemetry-native, so every model and tool call can go to any OTLP backend (15). Private reporting through GitHub and a valid security.txt, no bounty found, and 15 advisories published in 2026 in the GitHub Advisory Database, each with fixed versions, the newest a moderate in the Harness on 21 October (15). Framework reading, so SOC 2 isn't scored. The Harness is a separate 0.x package classed Alpha.); AI SDK 90 (No telemetry until an OpenTelemetry integration is registered. String model IDs route to Vercel's AI Gateway by default, which is documented and needs a Vercel key, so it isn't silent (25). Per-tool approval, HMAC-signed approvals against forged client history, and Open Policy Agent rules in @ai-sdk/policy-opa, though sandboxes are experimental (20). ToolLoopAgent rejects system messages in prompts by default as an injection risk, URL fetches are checked against private addresses, and MCP HTTP transport refuses redirects by default, but there's no guardrail primitive (10). OpenTelemetry spans for every model and tool call to any backend, opt-in (15). HackerOne programme, a valid security.txt, SECURITY.md and two low-severity advisories published with fixed versions (20). Framework reading, so SOC 2 isn't scored.)