{"type":"post","id":"sakana-ai-and-uc-berkeley-released-mass-a-def3df","slug":"sakana-ai-and-uc-berkeley-released-mass-a-def3df","title":"Sakana AI and UC Berkeley released MASS , a recursive self-improvement loop using one shared model for every role.","description":"MASS treats a multi-agent workflow as something a model can both improve and learn from.","retrieval_nugget":"MASS treats a multi-agent workflow as something a model can both improve and learn from.","published_at":"2026-10-11","updated_at":"2026-10-11","record_date":"2026-10-11","date_kind":"published_at","topics":[],"source_urls":["https://pub.sakana.ai/mass"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:sakana-ai-and-uc-berkeley-released-mass-a-def3df","status":"published","visuals":[],"editorial_provenance":{"schema_version":"newruntime-editorial-copy-v1","content_status":"source_grounded_final","final_copy_sha256":"sha256:59079482c62dff30d011f9d375505f83d926828ad9e8923873129c23fe573a41","reviewed_at":"2026-10-11T23:01:22.553Z","source_evidence_count":1,"verified_claim_count":3,"site_analysis_schema_version":"newruntime-site-analysis-v1","site_object_kind":"field_note","observed_fact_count":3,"implication_count":2,"watch_condition_count":1,"related_record_count":0},"analysis":{"schema_version":"newruntime-site-analysis-v1","object_kind":"field_note","thesis":"MASS makes the team’s accumulated work a self-supervision signal for a shared model.","observed_facts":[{"text":"The source says one shared language model serves as task solver, workflow optimizer, and evaluator.","source_urls":["https://pub.sakana.ai/mass"]},{"text":"The source describes an inner workflow-search loop with fixed weights and an outer loop that trains on selected workflow executions.","source_urls":["https://pub.sakana.ai/mass"]},{"text":"The source reports improved score per output token over the base model on research benchmarks and says external judgments were withheld from MASS.","source_urls":["https://pub.sakana.ai/mass"]}],"mechanism":"An inner loop has the model revise and judge multi-agent workflows; an outer loop distills selected executions into the shared model’s weights, which then resumes all three roles.","why_now":"The source motivates homogeneous recursive self-improvement for settings where expert assessment is scarce or slow, and reports benchmark gains from the proposed method.","implications":["Workflow search and execution traces can become training material rather than disposable orchestration.","The usefulness of the loop depends on whether its self-evaluator selects work that tracks real task quality."],"evidence_boundary":"The training tasks are non-verifiable and the self-evaluation signal’s correctness is unknown; external GPT-5.5 and Claude Opus 4.8 judgments were withheld from MASS and do not establish general reliability.","watch_conditions":["Whether gains persist on independently verified tasks or under external evaluation across repeated runs."],"related_records":[],"new_branch_reason":"No prior New Runtime record is supplied for this specific MASS method; the source supports a distinct research record about workflow-derived self-supervision."},"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/sakana-ai-and-uc-berkeley-released-mass-a-def3df/","markdown":"https://newruntime.com/posts/sakana-ai-and-uc-berkeley-released-mass-a-def3df.md","json":"https://newruntime.com/posts/sakana-ai-and-uc-berkeley-released-mass-a-def3df.json"},"next_reads":[{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}