What teams building AI features on Mastra report, with every finding tied to its evidence.
Read the findingsPractitioner sentiment, teams and leaders
−36 Negative from 25 sources that take a side
How this figure is madeFrom 25 authors in 24 discussions. Small sample. Build one pilot agent to measure the glue code and debugging time the framework adds.
Feb 2025 to Oct 2026.
72 sources from practitioners, by month and sentiment.
Team accounts lean negative, with 13 negative, 8 mixed and 4 positive among 25 counted, because most are bug reports from company engineers. Brex's CTO reports that about half of its agent-layer applications run on Mastra. Company engineers also report durable runs that failed to recover and the June 2026 npm compromise reaching a team's CI.
Positive, mixed and negative sources
The score counts each source once, as the split does. See How the numbers work.
See the evidenceBelow: 1 praise theme, 2 concerns and 1 disagreement.
Counted for Teams and technical leaders, from 26 sources. Change group
Every capability practitioners describe positively, ranked by how many sources say so. Open one to read who said it.
Counted for Teams and technical leaders.
Mixed
Even Westvang, Rostislav Melkumyan, and Knut Melvaer, Sanity
"Hi @s": How we built our company agent harnessCompany engineering blog, Sanity Engineering
Sanity uses Mastra for its Content Agent but built its own harness for its company-wide agents, because it wanted agents defined as Sanity documents.
Positive
Sytten, Hacker News commenter working at Caido
Comment on: A GitHub Issue Title Compromised 4k Developer MachinesHacker News comment
Builds a GitHub issue-triage action on Mastra and scopes the tools the agent can call to what it needs, after a prompt-injection incident elsewhere.
Positive
James Reggio, CTO of Brex, interviewed on Latent Space
Full Story of Brex's AI Hail MaryPodcast episode write-up, Latent Space
Brex's CTO reports that about half of the company's agent-layer applications run on Mastra, chosen to replace an internal framework built after LangChain fell short.
Mixed
Kosuke Oya, GitHub user filing a feature request with Datadog
LLMObs: Instrumentation for mastra (dd-trace-js feature request)GitHub issue
A team running Mastra in production asked Datadog for native LLM Observability instrumentation, since only OpenTelemetry traces were available.
Mixed
Uttam Kumaran, Brainforge
How we migrated to Langfuse v4 ahead of the cutoverCompany engineering blog, Brainforge Blog
Moving Brainforge's Mastra agent traces to Langfuse v4 required upgrading every @mastra package from core 1.8.0 to the 1.61 line plus aligned OpenTelemetry packages.
Negative
Mehul Kasliwal, GitHub user filing an issue
On hosted Mastra Platform, an env-var update left the old server instance running for over three days, and its stale scheduled runs sent 11 duplicate emails to a customer.
"…left the previous instance running for 3+ days…"
Positive
Zerxide, r/AI_Agents
Comment on: Mastra AI vs LangGraph/LangChain, What's the way forward?Reddit comment, r/AI_Agents
The team picked Mastra for long-running TypeScript workflows with human approval: a document-analysis run paused for review, survived a deployment and continued from the same checkpoint.
Mixed
Sebastien Castiel, Staff Software Developer at Vasco
Four Agent Frameworks in Sixteen MonthsCompany engineering blog, Vasco Engineering
Two developers moved Vasco's agent from Google ADK to Mastra in a week and a half with about 50 pull requests and found it good, then moved to the Claude Agent SDK six weeks later for better answers.
Mixed
Gilad Resisi, Postiz engineer committing to gitroomhq/postiz-app
fix(mcp): serve streamable HTTP statelessly (Postiz commit e11477ee)GitHub commit
Gilad Resisi measured Postiz's MCP service on @mastra/mcp climbing about 330 MB an hour from a 1 GB baseline until it was killed at about 5 GB twice a day, because Mastra kept every session's transport; Postiz kept Mastra and switched the server to stateless mode.
Mixed
davemo (David Mosher), Hacker News commenter
Comment on: Statecharts: hierarchical state machinesHacker News comment
A voice app for the banking sector was built on XState and Mastra, and the team later swapped Mastra for Pipecat.
GILD's fact checks, which don't count as sources
Checked Oct 28, 2026.Mastra apps deploy to any Node.js-compatible environment, as a standalone Hono server, or through built-in deployers for Vercel, Netlify, and Cloudflare. Deployment overview
Open them in the recordEvery concern practitioners raise, most raised first.
Counted for Teams and technical leaders.
Negative
OKeii (Apu.tech), GitHub user filing an issue
[BUG] EventedAgent recover() crashes after process restart when a nested durable LLM step is active (1.62+)GitHub issue
Durable EventedAgent runs could not be recovered after a process restart if a nested LLM step was in flight, shown with a two-process reproduction.
"…cannot recover an orphaned `EventedAgent` run when the original process exits while the nested `durable-llm-execution` step is still running."
Negative
Devang Padhiyar (Simplified), GitHub user filing an issue
approveToolCall rejected runs that were suspended on the requested tool call when the snapshot was large, unless the caller waited about eight seconds.
Negative
Greg McKelvey (phc-health), GitHub user filing an issue
CachingPubSub copied multi-megabyte workflow events (about 1.76 MB each) into shared Redis without a cap, despite their local-only flag.
"We measured **~1.76 MB per cached event**."
Mixed
Gilad Resisi, Postiz engineer committing to gitroomhq/postiz-app
fix(mcp): serve streamable HTTP statelessly (Postiz commit e11477ee)GitHub commit
Gilad Resisi measured Postiz's MCP service on @mastra/mcp climbing about 330 MB an hour from a 1 GB baseline until it was killed at about 5 GB twice a day, because Mastra kept every session's transport; Postiz kept Mastra and switched the server to stateless mode.
Negative
Sergey Andriyanov (Regul), GitHub user filing an issue
Switching providers inside one memory thread leaked Anthropic server tool IDs into OpenAI requests, which OpenAI rejected.
"…the OpenAI provider emits an `item_reference` with the Anthropic tool-call ID (`srvtoolu_...`)."
Negative
Bo Kou (Alipay), GitHub user filing an issue
[BUG] Mastra with ai-sdk v5 may cause duplicate assistant messagesGitHub issue
With AI SDK v5's useChat, Mastra returned assistant messages with duplicated parts, reproducible in the official example when sending messages quickly.
"When using `useChat` from `@ai-sdk/react` to call Mastra's API, assistant messages may have duplicate parts."
Negative
Aman Rawat (Fastlaneai), GitHub user filing an issue
[BUG] Memory incompatibility with GPT-5 mini reasoning models causes "required reasoning item" errorsGitHub issue
With memory on and tools enabled, a Mastra agent on GPT-5 mini failed every later message in a conversation, because the stored history dropped the reasoning items OpenAI requires. The issue is closed.
"…the agent fails on subsequent messages with conversation history due to missing reasoning items."
Negative
Leo (Outlit), GitHub user filing an issue
[BUG] Memory Leak in Mastra Workflow After Multiple RequestsGitHub issue
Running a workflow twice under mastra dev ran the Node.js process out of heap and crashed it, with a deal context of about 20,000 tokens passed in. The issue is closed.
"After running the my workflow twice in development mode (`mastra dev`), the Node.js process runs out of memory and crashes with a JavaScript heap out of memory error."
GILD's fact checks, which don't count as sources
Checked Oct 28, 2026.maxSteps caps an agent at 5 sequential LLM calls by default, so a run still calling tools at the fifth step ends there. Agents: generate() reference
Open them in the recordCounted for Teams and technical leaders.
Negative
Tomas Varga (Sudolabs), GitHub user filing an issue
Since @mastra/deployer 1.79.0, mastra build on a larger app needs about 13 times more memory and runs out of heap.
"Since @mastra/deployer 1.79.0 (@mastra/core@1.79.0 release, CLI mastra 1.35.0), mastra build on a larger app runs out of memory before "Analyzing dependencies..."."
Mixed
Uttam Kumaran, Brainforge
How we migrated to Langfuse v4 ahead of the cutoverCompany engineering blog, Brainforge Blog
Moving Brainforge's Mastra agent traces to Langfuse v4 required upgrading every @mastra package from core 1.8.0 to the 1.61 line plus aligned OpenTelemetry packages.
Negative
Diego Cesar Lerma Torres (Neuroglia Solutions), GitHub user filing an issue
Drop or patch the AI SDK v5 pin of @ai-sdk/provider-utils@3.0.30 (CVE-2026-8769)GitHub issue
@mastra/core still pinned a vulnerable AI SDK v5 provider-utils copy into every consumer's production tree, covered by CVE-2026-8769.
Negative
JaeHwan Kim, GitHub user filing an issue
During the June 2026 npm compromise, the team's dependency bot pulled the malicious @mastra/core and related versions within minutes, and failing CI installs exposed it.
Negative
Marcos Candeia, GitHub user filing an issue
[BUG] Bundle size regression (+17mb) after update is blocking cloudflare workers deploymentsGitHub issue
After a routine Mastra upgrade the Cloudflare Workers bundle grew from about 541 KiB to about 22,469 KiB and exceeded Cloudflare's startup limits, blocking deployment.
"Total Upload: 22469.30 KiB / gzip: 5650.60 KiB…"
Statements this group's sources agree on, then the ones close to agreement.
For teams and technical leaders, no statement reaches 5 sources from 3 authors.
Questions the sources split on, with the count on each side.
Evidence remains split
Kept Mastra, 7 sources
Brex, Sanity's Content Agent, Brainforge, Postiz, and individual builders on Reddit and Hacker News keep agents running on Mastra in real work.
Moved to other code, 3 sources
Others moved to the Claude Agent SDK, Pipecat, or the AI SDK alone, and one team is rebuilding in LangGraph, citing answer quality, opinionated patterns, and dependency weight.
The three groups, then every practitioner by the context they work in, and how emphasis changes with scale.
Three groups drawn from the same sources. Choose a group to select whose experience counts. Within that group, each author counts once in the practitioner sentiment, with their latest view. Signals open on Teams and technical leaders.
26 sources. Company teams and technical leaders describe where Mastra runs in their products and where they left it.
46 sources. Individual builders describe agents they shipped on Mastra, the defects they filed, and the projects they moved to other code.
72 sources. These accounts combine company engineering posts and a CTO interview with solo developers and GitHub issues, from side projects to agents serving customers.
72 sources from practitioners, by the context they work in. Filled rows count for this group.
Emphasizes TypeScript ergonomics, memory defects, and step limits
Emphasizes Opinionated patterns and moves to other frameworks
Emphasizes Durable runs, builds, and dependencies in company use
Emphasizes Mastra as the agent layer of a company's applications
What changes with scale. Individual builders file most of the defects and praise the TypeScript experience. Named companies appear as Brex's agent layer, Sanity's Content Agent, Brainforge's traced agents, Postiz's MCP server, and Vasco's move off Mastra after six weeks. Company-wide rollouts, at Factorial for 17,000 customers and at Replit's Agent 3, appear only in Mastra's own customer stories.
Where this group's sources were published.
Counted for Teams and technical leaders, from 26 sources. Change group
40 sources for this group, 14 of them documentation
Earlier evidence remains when it still applies. Records tied to issues GitHub shows closed carry Needs a recheck, and records about the launch license and launch pricing are kept as history.
See sources by originWho each source is, how it knows, whether it still applies and what it counts toward.
Newest first, on its own page. Every count above opens its sources there.
Read all 86 sourcesAbout this read
A running review of what teams building AI features on Mastra report, from individual builders to technical leaders. Each finding links to its sources, and each conflict shows both sides.
Counts cover only the sources GILD reviewed.
Choose a group to select whose experience counts. Within that group, each author counts once in the practitioner sentiment, with their latest view. GILD files each source in a group from how the account describes its author. A role or employer marked self-described is what the source states about themselves. Documentation checks facts for every group and never counts toward sentiment.
A source's date and whether it still applies are separate: a recent post can describe an old version, and an old one can still hold.
Flagged for a recheck, of the sources that take a side: teams and leaders 11 of 25, individual builders 11 of 41, all practitioners 22 of 66.
Each row opens its sources for the group you are reading.
| Finding | Teams and technical leaders | Individual builders | All practitioners | Sources |
|---|---|---|---|---|
| Current readCurrent sentiment | 4 positive, 8 mixed, 13 negative | 14 positive, 13 mixed, 14 negative | 18 positive, 21 mixed, 27 negative | Sources |
| PraiseTypeScript-First Developer Experience | 3 of 3 positive (under the minimum) | 11 of 11 positive | 14 of 14 positive | Sources |
| PraiseWorkflows, Memory & Evals Included | 2 of 2 positive (under the minimum) | 6 of 6 positive | 8 of 8 positive | Sources |
| PraiseAgents in Real Work | 10 of 10 positive | 5 of 5 positive | 15 of 15 positive | Sources |
| ConcernMemory, Recovery & Loop Defects | 8 of 8 raise it | 9 of 9 raise it | 17 of 17 raise it | Sources |
| ConcernBuilds, Bundles & Hosting Surprises | 3 of 3 raise it (under the minimum) | 4 of 4 raise it (under the minimum) | 7 of 7 raise it | Sources |
| ConcernUpgrades, Dependencies & Supply Chain | 5 of 5 raise it | 2 of 2 raise it (under the minimum) | 7 of 7 raise it | Sources |
| ConcernOpinionated Patterns | 3 of 3 raise it (under the minimum) | 5 of 5 raise it | 8 of 8 raise it | Sources |
| ConcernLicense, Lock-In & Vendor Trust | 0 of 0 raise it (under the minimum) | 5 of 5 raise it | 5 of 5 raise it | Sources |
| ConsensusThe bundle saves glue code | 1 supporting, 1 contradicting (under the minimum) | 6 supporting, 2 contradicting (below threshold) | 7 supporting, 3 contradicting (below threshold) | Sources |
| ConsensusTest recovery and retries yourself | 3 supporting (under the minimum) | 5 supporting (below threshold) | 8 supporting (below threshold) | Sources |
| ConsensusA framework over the AI SDK | 1 supporting (under the minimum) | 5 supporting (below threshold) | 6 supporting (below threshold) | Sources |
| DisagreementOnce a team has built on Mastra, does it keep it or move on? | Kept Mastra 7, Moved to other code 3 | Kept Mastra 11, Moved to other code 2 | Kept Mastra 18, Moved to other code 5 | Sources |
| Current readEvidence mix | 40 sources | 60 sources | 86 sources | Sources |
GILD's checks of claims against official documentation, kept apart from the source counts.
