Jules vs Letta

Jules 18

Closed service. The newest API or product change is the changelog entry of 9 March 2026, 241 days before 5 November (0). The changelog's 29 October 2026 entry announces the wind-down and an export route through the CLI, which is a notice, not an API change. No package releases, commits or tags in the 90 days, and the jules-sdk repository's last commit is 18 March 2026 (0). A public changelog and a Discord channel. The 18 October issue and pull request counts came from shields.io badges and are struck (8 of 15, a partial held). The official TypeScript SDK and MCP packages last published 0.2.0 on 9 March 2026, per the 18 October registry reading, and no official MCP registry entry could be read (5). The SDK has a CI workflow on pull requests whose results couldn't be read, and two runtime dependencies. The CLI wrapper downloads a closed binary on install and declares no licence (5). 0 + 0 + 8 + 5 + 5 = 18.

Letta 85

v0.34.42 on 6 November 2026 (30). Dozens of releases in 90 days (20). Pull requests are merged daily; recent issues from users have few replies (15 of 25). npm and PyPI packages and the Agent SDK track the releases (12 of 15). Lock files, CI and nightly smoke tests (8 of 10). Total 85.

Jules 13

Hosted reading. No status page for Jules was found (0). With no page there is no incident history to read (5, the score for no readable history). The plans page, re-read on 5 November, publishes task quotas with numbers, 15, 100 and 300 tasks a rolling 24 hours and 3, 15 and 60 concurrent, and list pageSize is capped at 100, but no request rate figures were found (8 of 15). 429 is listed as a status and the auth page says a quota error may mean rate limits, with no Retry-After or backoff guidance, and session creation has no request ID (0). No SLA found (0). The API is v1alpha and labelled experimental, and the changelog of 29 October 2026 says Jules turns read-only after 11 November (0). 0 + 5 + 8 + 0 + 0 + 0 = 13.

Letta 58

Local-software lines, read for the harness. @letta-ai/letta-code on npm with Node.js 22.19 or newer, and PyPI wheels for glibc Linux, macOS 14 and Windows x64 with Python 3.9 or newer stated (20). ci.yml, nightly update smoke tests and Telegram live smoke tests exist, but GitHub's API answered with a rate limit, so run results were unread (15 of 25, unchecked). 332 open issues and pull requests, mostly pull requests; recent bug reports such as recall reading the wrong conversation have no reply yet (15 of 25). 398 tags at 0.34.x with release notes on GitHub, no changelog file, and breaking removals such as AgentFile announced in the README (8 of 15). Pre-1.0 (0). Total 58.

Jules 30

Published rubric. No payment protocol (0). Plans and their Jules limits are public without a login, and Jules sits inside the Google AI plans. The prices render per locale and weren't read, and there's no per-task price (10). A free plan of 15 tasks a day with a Google account, and no card step in the sign-up docs, until new tasks stop after 11 November 2026 (20). A person signs in, accepts the privacy notice, installs the GitHub app and creates the key in the web app (0). 0 + 10 + 20 + 0 = 30.

Letta 60

No x402, MPP or L402 (0 of 40). Per-unit API prices are public, $0.10 per active agent a month and $0.00015 a second of tool execution, plus plan prices (20). A $0 plan with bring-your-own keys; no card is mentioned (20). The CLI runs locally without signing in (20). Total 60.

Jules 57

Hosted reading. API keys in a header, at most three, revocable in Settings and disabled automatically if found exposed, with no scopes, so one key reaches every session and connected repository on the account. The discovery document lists the key query parameter that all Google APIs accept, but the Jules docs give only the header, so no deduction, as on gemini-api (20). Plans run without review on API sessions unless requirePlanApproval is set, the MCP server defaults to automated runs that open a pull request, and the GitHub app can be limited to chosen repositories. No read-only key (10). Each VM has internet access and the FAQ puts the burden on the user. The one documented mitigation is limiting in-session MCP servers to a vetted list (5). Activities log every plan, message, bash command and patch per session. No account audit log of key use found (8). www.google.com security.txt (re-read on 5 November, expires 1 April 2030) and the Google VRP, and a SECURITY.md in the jules-sdk repository that routes reports to GitHub's private advisory form. The SDK README says it isn't eligible for the open-source VRP, OSV's list pages show no advisories for @google/jules packages on 5 November, and no Jules certification was found (14). 20 + 10 + 5 + 8 + 14 = 57.

Letta 35

Harness reading of the framework checklist, as for the other harnesses. 30 for what leaves the machine by default, 20 for approvals and sandboxing, 15 for injection posture, 15 for audit and 20 for the security programme. Letta Cloud is the default backend, so agent state and conversations go to Letta's servers, and telemetry is on by default (10 of 30). The default permission mode is unrestricted; standard, acceptEdits and strict are opt-in, and cloud sandboxes exist for remote work (4 of 20). No prompt-injection guidance found for fetched pages or channel messages (5 of 15). Conversation search and git history of memory give an operator a record of what the agent saw and changed (10 of 15). SECURITY.md routes reports to support@letta.com and scopes out the retired server; no security.txt, bounty or certification found (6 of 20). Total 35.

Jules 76

API reading. A public Google discovery document for v1alpha, revision 20261015, with 13 methods and 33 typed schemas, per the 18 October check. It sits on the API's own host and wasn't requested again (25). docs/llms.txt and a Markdown twin of every docs page (10). Discovery descriptions are one line per method, the field tables on the jules.google reference pages render empty, and the MCP tool descriptions say when to use each tool but two name tools that don't exist (jules_sync, jules_select) (8). Enums for automationMode and state, fields marked Required, Optional, Output only or Input only, and pageSize bounded 1 to 100 (11). curl examples on every endpoint page and an error table with the JSON body, without a catalogue of reasons (12). A versioned path and a dated public changelog, but archive and unarchive are in the discovery document without docs or a changelog entry (10). 25 + 10 + 8 + 11 + 12 + 10 = 76.

Letta 70

Harness reading. docs.letta.com serves llms.txt and a Markdown version of every page, with an applies_to block saying which backend and interface each page covers (10). TypeScript types for the Agent SDK and a documented App Server WebSocket protocol, but no JSON Schema or OpenAPI for the harness (15 of 25). Pages say when to use local or cloud backends, subagents and channels (14 of 20). Permission modes and options are typed in the SDK (12 of 15). Example applications and a remote client reference (11 of 15). Releases most days but no changelog file (8 of 15). Total 70.