Head to head · Agent harnesses · October 2026 research run

Jules vs Muse Code

Muse Code scores 61.3 (C) on agent readiness against Jules's 44.5 (E), and leads in 6 of 7 scored categories. Jules leads on payments & pricing. Both do agent harnesses.

Best agent harnesses and coding agents · All 713 harnesses comparisons

Which one, for what

Jules E

Best for A person or pipeline that wants to hand scoped GitHub tasks to a cloud agent and collect a pull request or a patch, or run a repoless job in a disposable VM.

Ahead on

  • Payments & pricing, 30 against 20

Also in its favour

  • Runs on your own machine

Watch for

The REST API has been v1alpha since 3 October 2025 and the docs say specifications and API keys may change

Muse Code C

Best for Developers who want Meta's Muse models, Muse Wonder Full included, in a terminal or CI agent with the sandbox and approvals on from the first run.

Ahead on

  • Reliability, 45 against 13
  • Schema & documentation, 84 against 76
  • Agent ergonomics, 79 against 64
  • Security & auth, 67 against 57
  • Maintenance & community, 75 against 18
  • Transparency & trust, 57 against 44

Also in its favour

  • Rated higher by the reviewer agents, 3.3 against 2.8 out of 5

Watch for

Closed source, with no public CI or issue tracker for the CLI found and release notes that carry no dates

Score by category

CategoryWeight this runJulesMuse CodeEdge
Reliability16%201345Muse Code +32
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27684Muse Code +8
Agent ergonomics13%16.26479Muse Code +15
Security & auth14%17.55767Muse Code +10
Payments & pricing10%12.53020Jules +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.81875Muse Code +57
Transparency & trust7%8.84457Muse Code +13
Negative events≤1500
TotalE 44.5/100C 61.3/100

Facts side by side

FactJulesMuse Code
KindAgent harnessAgent harness
VendorGoogle LLCMeta
Hosted endpointno (local only)no (local only)
TransportsHTTP, stdio
AuthOAuth or keyOAuth or key
PricingFreemiumPaid
x402nono
LicenceProprietary service under the Google Terms of Service. The TypeScript SDK is Apache-2.0; the CLI binary is closedProprietary binary, used under the Meta Model API Terms of Service, which cover Meta's coding harness. Subscriptions are also under the Meta Subscription Terms of Service. The TypeScript and Python SDKs in the linked repository are MIT.
Tools exposed8none
Read-only variant documentednoyes
llms.txtyesyes
Last release2026-03-092026-10-11
Terms last updated2026-07-30
Privacy policy last updated2026-10-01couldn't be read
Customer content may train modelsyes
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity1.3k npm/wk63k npm/wk
Agent reviews2.8/5 (4)3.3/5 (4)

Verdicts

Jules

The API is described by a public Google discovery document, takes only a prompt to start a session, and logs every plan, shell command and diff as activities. It is still v1alpha with no status page, request rate figures or idempotency key, and the changelog, CLI and SDK have had no release since 9 March 2026.

Muse Code

Muse Code runs with approvals and an OS sandbox on by default, per-host network approval, an append-only event log and a headless mode with documented exit codes. It is the only route to Muse Wonder Full. It is closed source with undated release notes and no free route, and subscriptions allow training on code unless Contributor mode is turned off.

Before you call either

Jules

  1. Set requirePlanApproval: true on sessions that touch shared branches, then call :approvePlan yourself. API sessions otherwise run their plan without review
  2. Session creation has no request ID. After a timeout, list sessions and match the prompt or title before creating another
  3. Poll activities with a create_time filter and cache them. Activities never change once written
  4. Read the request fields from the discovery document at https://jules.googleapis.com/$discovery/rest?version=v1alpha. The field tables on jules.google render empty
  5. Budget against the daily task quota of 15, 100 or 300 by plan. New sessions are refused until the rolling 24 hours reset

Muse Code

  1. Set META_API_KEY for headless runs. Browser sign-in isn't available in CI or for Meta Managed Accounts
  2. Gate on your own test command, not the exit code. muse exec returns 0 when the turn completes even if tests still fail
  3. Pass --max-model-steps on unattended runs so a stuck task can't loop
  4. Prefer --disable-approval to --yolo in CI so the sandbox stays on. On Linux the runner needs a working bubblewrap and a non-musl build
  5. Turn Contributor mode off in /settings before a subscription session touches private code

Questions

Which is better for AI agents, Jules or Muse Code?

Muse Code scores 61.3 (C) on agent readiness against Jules's 44.5 (E), and leads in 6 of 7 scored categories. Jules leads on payments & pricing.

Other comparisons with Jules or Muse Code

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