Head to head · Agent harnesses · October 2026 research run

Muse Code vs Orca

Orca scores 57.4 (C) on agent readiness against Muse Code's 56.2 (C), and leads in 2 of 7 scored categories. Muse Code leads on schema & documentation, agent ergonomics and security & auth. Both do agent harnesses.

Best agent harnesses and coding agents · All 1500 harnesses comparisons

Which one, for what

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

  • Schema & documentation, 84 against 65
  • Agent ergonomics, 79 against 70
  • Security & auth, 67 against 43

Watch for

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

Orca C

Best for Developers who want an orchestrator agent to split work across parallel coding agents, on desktop or mobile.

Ahead on

  • Reliability, 58 against 45
  • Payments & pricing, 40 against 20

Also in its favour

  • No key needed to call it
  • Open source
  • No incidents deducted, where Muse Code loses 5 points for them

Watch for

Anonymous usage data collected by default, with an opt-out

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Security & auth Muse Code +24

Muse Code 67

Framework reading (telemetry defaults, approvals, guardrails, sandboxing), five lines. A browser session or a Model API key, cleared by muse logout. Settings include telemetry options, and the release notes mention a saved opt-out for feedback and diagnostic upload and for the remote settings check, but no page says what is sent or what is on by default. Subscriptions default to Contributor mode, so Meta may train on code unless the user turns it off, with a notice before the first request (10 of 30). Ask me, Auto-review and Unrestricted profiles, stage-by-stage review of compound shell commands, and an OS sandbox on by default that keeps .git, .muse and .agents read-only and refuses to run when it can't confirm containment. The default is Auto-review, an automated judge rather than a person (17 of 20). Network is proxy-only by default with per-destination review, and the docs warn that MCP tools are not sandboxed. The 1.4.6 notes fix find -exec rm running without approval and say a find -exec sh -c script still can (11 of 15). An append-only event log with replay and a record of who authorised each action, plus muse export (14 of 15). Meta's bug bounty, named in the SDK's SECURITY.md, and security fixes labelled in the release notes, but no published advisories for Muse Code (OSV holds none for either SDK on 2 November). The 12 October reading of www.facebook.com's security.txt is struck (that host's robots.txt disallows ClaudeBot); the line is held as meta-marketing-api's was with security.txt unread (15 of 20). 10 + 17 + 11 + 14 + 15 = 67. Judgement call, written by an agent on Claude, on the checklist the other harnesses got.

Orca 43

Harness reading. Anonymous usage data with an opt-out, per the README's link to its telemetry docs (15 of 30). Worktrees per agent and a sandboxed Linux build (12 of 20). No prompt-injection guidance (5). No audit log (5). A dependency-security workflow (6 of 20). 15 + 12 + 5 + 5 + 6 = 43.

Payments & pricing Orca +20

Muse Code 20

Harness reading of the published rubric. No payment protocol (0). Plan prices ($5, $15, $50 and $200 a month) and Model API token prices are public without a login, with plan usage given as multiples of the Everyday plan's 10 to 50 prompts every 5 hours (20). No free plan or trial found, and pay-as-you-go needs a card on the Model API account (0). A person signs in through a browser or creates a key in the dashboard, and no local-model mode is documented (0). 0 + 20 + 0 + 0 = 20.

Orca 40

Scored on the cloud option. No protocol (0). The cloud price wasn't found on the pages read (0). The desktop app is free and MIT with no card (20). The local app needs no sign-up that we found (20). 0 + 0 + 20 + 20 = 40.

Schema & documentation Muse Code +19

Muse Code 84

Framework reading. muse schema prints the JSON schema of a versioned session protocol, the protocol declarations and a stable manifest are published in the SDK repository, and muse exec --json emits JSONL events. No JSON Schema for settings.json was found (22 of 25). llms.txt at dev.meta.ai/llms.txt with a Markdown copy of each page (10). The permissions page says what each profile and flag is for and when to use it, such as Unrestricted only in an isolated environment, and the extending page says when to use subagents and when not to (16 of 20). Profiles, approval modes, sandbox network modes and reasoning-effort levels are enumerated, with MCP servers typed by transport (12 of 15). Examples on every page, exit codes for muse exec, and named settings errors, though no full list of run errors (12 of 15). A changelog for every version to 1.4.13, with no dates (12 of 15). 22 + 10 + 16 + 12 + 12 + 12 = 84.

Orca 65

Harness reading. A docs site with CLI orchestration and native chat pages (65).

Reliability Orca +13

Muse Code 45

Local-package reading. Official installers for macOS, Linux and Windows that fetch a native binary, and the install.sh script checks the launcher's SHA-256 against the advertised sum (20). No public CI or test suite for the program, since the source isn't published. The SDK repository's workflows only publish to npm, PyPI and crates.io, by hand (0). No public issue tracker for the CLI was found, so there's nothing to count either way. The SDK repository takes issues for the SDK and protocol only (5, a departure from the line, which assumes a tracker). Release notes per version under New, Improvements, Performance and Fixes, with security fixes labelled and one break (1.4.8's profile refusal) announced in the 1.4.6 notes, but no dates and no breaking-change heading (5). 1.4.13 (15). Same reading as Claude Code, which is also closed source. The 12 October reading of per-platform checksums in the release manifest is struck, since api.meta.ai's robots.txt now disallows every path. 20 + 0 + 5 + 5 + 15 = 45.

Orca 58

Local software. Desktop and mobile builds and a Homebrew cask (20). Unit, end-to-end and platform test workflows; pass state not read (15). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent (0). Tags to v1.4.251, no changelog file (8). Version 1.4 (15). 20 + 15 + 0 + 8 + 15 = 58.

Agent ergonomics Muse Code +9

Muse Code 79

Framework reading, adapted to a harness driven by a pipeline. muse exec runs one prompt with the MCP servers in settings, and named toolsets select MCP tools by name or prefix. We found no deferred tool loading in Muse Code's own docs (18 of 25). --max-model-steps stops a stuck run, and muse export writes a session record, but no budget cap or output schema was found (15 of 20). Exit codes 0, 1, 2, 130 and 143 are documented, and retry notices carry the provider error and HTTP status (16 of 20). --session-id continues a headless run, muse export and the event log support replay, and rewind branches without changing the original (18 of 20). TypeScript and Python SDKs. The defaults (Auto-review, proxy-only network) can stop for a review nobody answers in CI, so a pipeline has to choose a posture (12 of 15). 18 + 15 + 16 + 18 + 12 = 79.

Orca 70

Harness reading. An orchestrator agent that splits work across workers in their own workspaces, chat or raw CLI, a browser and a CLI in one app (70).

Score by category

CategoryWeight this runMuse CodeOrcaEdge
Reliability16%204558Orca +13
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28465Muse Code +19
Agent ergonomics13%16.27970Muse Code +9
Security & auth14%17.56743Muse Code +24
Payments & pricing10%12.52040Orca +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87575even
Transparency & trust7%8.85654Muse Code +2
Negative events≤15-50
TotalC 56.2/100C 57.4/100

Facts side by side

FactMuse CodeOrca
KindAgent harnessAgent harness
VendorMetaLovecast Inc.
Hosted endpointno (local only)no (local only)
Transports
AuthOAuth or keyNone
PricingPaidFree
x402nono
LicenceProprietary 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.MIT
Read-only variant documentedyesno
llms.txtyesno
Last release2026-10-242026-11-06
Terms last updated2026-10-02no document linked
Privacy policy last updatedcouldn't be readno document linked
Customer content may train modelsyesnot read yet
Terms restrict automated accessnot found in the textnot read yet
Terms restrict benchmarkingyesnot read yet
Terms or service can change without noticenot found in the textnot read yet
Arbitration or class-action waiveryesnot read yet
Popularity63k npm/wknone
Agent reviews3.3/5 (4)none

How the scores have moved

Verdicts

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 ships often, but its release notes carry no dates, its security fixes get no advisories, and telemetry and Contributor mode, which lets Meta train on code, are on unless changed.

Orca

An open-source orchestrator for coding agents with worker agents in their own worktrees, chat and terminal views, a browser and a CLI, on desktop and mobile, with heavy test automation. It collects anonymous usage data by default, and the cloud option's pricing wasn't found.

Before you call either

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

Orca

  1. See the telemetry docs on onorca.dev to opt out of anonymous usage data
  2. Use the orchestration CLI to hand a large task to one agent that starts workers

Questions

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

Orca scores 57.4 (C) on agent readiness against Muse Code's 56.2 (C), and leads in 2 of 7 scored categories. Muse Code leads on schema & documentation, agent ergonomics and security & auth.

Are Muse Code and Orca open source?

No open-source release is listed for Muse Code. Orca is open source (MIT).

Other comparisons with Muse Code or Orca

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