CrewAI vs Mastra

CrewAI 74

Agent, Task and tool classes are Pydantic-typed, but we found no generated API reference for the Python library (15). llms.txt at docs.crewai.com, per the listing's earlier check (10). The docs separate Crews from Flows and say which to use for what, though not when to avoid multi-agent crews (12). Tools take a Pydantic args_schema and MCP tools keep their JSON Schema (12). Plenty of examples, and MCP connection errors are described, but there's no exception reference (10). Dated changelog at docs.crewai.com/en/changelog (15).

Mastra 98

Typed TypeScript API with a reference section (25). llms.txt with a when-to-use list and condensed instructions for coding agents (10). The docs say when to use durable agents, and point multi-agent users from .network() to supervisor agents (20). Tools take Zod schemas (15). Examples on every page, and MastraError with ids and categories documented, though errors are spread across pages (13). Per-package changelogs and migration guides (15).

CrewAI 40

No payment protocol (0). Scored on CrewAI AMP, the hosted option. Its free Basic plan is public but the only paid plan is contact-sales (0). The MIT package installs with no card (20) and no account, and can run a local model through LiteLLM (20).

Mastra 60

No payment protocol (0). Scored on the hosted platform, whose per-unit prices are public without a login ($10 per 100K observability events and $0.35 a CPU hour on Starter) (20). The Apache 2.0 packages install with no card (20) and no account, and run any model (20).

CrewAI 75

Official package on PyPI with Requires-Python >=3.10,<3.14 in the pyproject at 1.15.33 (20). The Run Tests workflow runs the suite on pull requests only, and CodeQL, a vulnerability scan and a nightly canary run on main; run results weren't re-read on 1 November because GitHub's pages answer 403 (15). Between 99 and 184 open issues, triaged with labels and a stale bot, per the 1 October check, not re-read on 1 November (18). A dated changelog that notes deprecations, but no written versioning policy, new capabilities ship in patch releases, and 1.15.29, a patch release on 23 October 2026, removed public import paths and changed how every agent runs, marked as breaking only on 28 October (7). 1.15.33, stable (15).

Mastra 87

Official npm packages, Node 22.13 or newer (20). Public CI workflows for unit, store, workspace and e2e tests; on 6 November the newest runs on main (Version Packages, Trigger Cloud Integration Tests) succeeded, while the test workflows themselves run on pull requests (22). 436 open issues and 795 open issues and pull requests on 6 November from GitHub's API, with 2,077 issues opened in the 90 days to 3 November; all 50 newest had a comment and 24 were closed, with issue-triage automation (18). A changesets CHANGELOG per package, a CI gate that needs approval for any major bump and migration guides, but no written versioning policy found, and .network() is deprecated without a removal date (12). 1.82.0 (15). 20+22+18+12+15 = 87, up from 74 on 6 October, when GitHub couldn't be read.

CrewAI 80

The mcps field gives an agent an MCP server in five lines, with static and dynamic tool filters and tool-list caching (25). max_iter defaults to 20, max_execution_time and max_rpm cap runs, and respect_context_window is on by default (20). MCP connection failures are logged as warnings and the agent carries on without those tools, and we found no exception reference (10). max_retry_limit retries an agent twice on error, and Flows persist state with @persist (20). An agent needs role, goal and backstory before it does anything, and it's Python only (5).

Mastra 92

An MCP client in about ten lines with listTools() for static or listToolsets() for per-request tools, and ToolSearchProcessor for loading tools on demand (25). Step limits, memory windows and processors such as a token limiter control what reaches the model (20). MastraError with ids and categories, and processors can abort with a reason the caller can read (17). Workflow step retries, snapshots and durable agents for resuming (20). create-mastra scaffolds a project and the model router takes a plain string, but it's TypeScript only (10).

CrewAI 88

1.15.33, tagged on 2026-10-29 (30). 23 stable releases tagged in the 90 days from 3 August, 1.15.11 (4 August) to 1.15.33, and no pre-release in that window (20). Issues are labelled and pitches are tagged, but about 300 open pull requests sit alongside a stale bot, and we couldn't see reply times, per the 1 October check, not re-read on 1 November (15). The Python package is current (15). CodeQL, a vulnerability scan and Dependabot run on main, but Python 3.14 isn't supported yet and dev builds share the PyPI name (8).

Mastra 96

@mastra/core 1.82.0 on 2026-11-04 (30). 27 stable releases in the 90 days to 6 November, 8 of them since 6 October (20). 436 open issues on 6 November, all 50 newest issues commented and 24 of them closed (22). Client, MCP and store packages are current, and @mastra/mcp 1.x stays supported beside 2.x (15). Renovate and CI configured, with the newest runs on main passing (9). 30+20+22+15+9 = 96.

CrewAI 79

MIT (30). The telemetry page lists what's collected and what isn't, but doesn't say where it goes or how long it's kept (15). Deprecations such as function_calling_llm and allow_code_execution appear in the dated changelog and docs, with no written deprecation policy (10). Telemetry disclosed in the docs and README with two opt-out variables (20).

Mastra 72

Apache 2.0 for the core, with ee/ directories source-available under the Mastra Enterprise License (25). The privacy policy (last published 25 April 2025) covers the website, the Teams plan states six months' retention, and the subprocessor list sits in a trust centre our reader couldn't render (15). Migration guides and deprecation warnings, without dated removal windows (12). Every telemetry stream is documented with links to its source and one opt-out, and the reference now spells out what the project identifiers can be correlated with (20).