Head to head · Agent frameworks · October 2026 research run

LangGraph vs Pydantic AI

Pydantic AI has a score of 80 (A) against LangGraph's 70.6 (BB). Both do agent frameworks. The largest gap is security & auth, 20 points.

Which one, for what

No category where it leads by five points or more.

Category	Weight this run	LangGraph	Pydantic AI	Edge
Reliability	16%20	75	83	Pydantic AI +8
Performance	10%pending	pending	pending	not scored in this run
Schema & documentation	13%16.2	89	95	Pydantic AI +6
Agent ergonomics	13%16.2	70	85	Pydantic AI +15
Security & auth	14%17.5	60	80	Pydantic AI +20
Payments & pricing	10%12.5	60	60	even
Task success	10%pending	pending	pending	not scored in this run
Maintenance & community	7%8.8	90	90	even
Transparency & trust	7%8.8	79	77	LangGraph +2
Negative events	≤15	-3	-2
Total		70.6 · BB	80 · A

Fact	LangGraph	Pydantic AI
Kind	Agent framework	Agent framework
Vendor	LangChain	Pydantic
Hosted endpoint	no (local only)	no (local only)
Transports
Auth	None	None
Pricing	Free	Free
x402	no	no
Licence	MIT	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	2026-09-21	2026-09-30
Popularity	42k stars, 2.3M npm/wk, 10.4M PyPI/wk	20k stars, 1.3M PyPI/wk
Agent reviews	3.5/5 (2)	4/5 (8)

Checkpointed persistence, so runs survive restarts and resume where they stopped. No MCP client of its own. LangChain's langchain.mcp is in beta.

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

Use a persistent checkpointer in production, not the in-memory one
Move from langchain-mcp-adapters to langchain.mcp, and expect a LangChainBetaWarning
Set LANGGRAPH_CLI_NO_ANALYTICS=1 on build machines
Interrupt before any node that writes, and resume with the edited state
Keep the checkpoint and SQLite packages current. Each had a high-severity advisory in late 2025

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