Letta vs OpenHands

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.

OpenHands 90

Read as a local package. Official npm package @openhands/agent-canvas (Node 24 or later, plus uv), a Docker image on GHCR and openhands-sdk on PyPI (Python 3.12 or later) (20). A CI workflow (ci.yml) runs on main beside desktop, Docker and end-to-end workflows; the runs passed on every load on 1 October, and GitHub's pages refused us on 1 November, so the award rests on that check (25). 456 open issues and 395 open pull requests with priority labels and a high-priority Cloud resume bug (#17664), per the 1 October check, not re-read on 1 November (18). Dated release notes for every Canvas version and a written SDK rule of at least five minor releases before a public API or REST contract is removed, which the SDK followed on 28 October when it dropped the ACP curated model lists at their stated 1.59.0 deadline, but the Canvas CHANGELOG.md still stops at 1.0.0-alpha.2 (12). Canvas is 1.34.0 and the SDK 1.59.0, and the README's beta badge was removed on 23 October 2026 (commit 4d1c4d1, noted in the 1.33.0 release notes), so the product is no longer labelled beta. Only the Apps extension API keeps a beta label (15).

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.

OpenHands 64

Harness reading of the framework checklist, as for goose and the other agent harnesses. 30 for what leaves the machine by default, 20 for approvals and sandboxing, 15 for prompt-injection posture, 15 for audit and 20 for the security programme. Agent Canvas still sends a canvas_install event to PostHog through z.openhands.dev on first use "regardless of consent" (telemetry.ts header, re-read on 1 November), and the consent banner's box is still defaultChecked. AGENT_CANVAS_DISABLE_TELEMETRY=1, --disable-telemetry, VITE_DO_NOT_TRACK=1 or the browser's Do Not Track setting stops all of it, the last since 1.26.0 (15). Confirmation policies (always, never, at or above a risk level) and a Docker sandbox per conversation exist, but Canvas still starts with confirmation_mode: false and the npm install runs on the host with full filesystem access. No network egress controls found. Local listeners bind to 127.0.0.1 with an injected session key, and since SDK 1.52.0 (5 October) DockerWorkspace publishes its ports on loopback (12). LLM, Invariant and GraySwan risk analysers and a policy-rail module, documented, all advisory (11). Conversation event logs, completion logs and OpenTelemetry tracing through Laminar, with hosted Laminar setup documented on 16 October (13). Security programme. openhands.dev's security.txt expired on 28 October 2026 (re-read on 1 November), though the responsible-disclosure policy it names still loads. A Vanta-hosted trust page per the 1 October check, and the git diff injection published as an OpenHands advisory with a CVE. CVE-2026-112346, the SDK's unauthenticated sandbox server, was published by VulnCheck on 26 October with no OpenHands advisory found. No bug bounty found. 13, down from 15 for the expired file, read as shopware's and tokeneconomizer's expired files are (still credited for the policy behind them, less than a valid file).

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.

OpenHands 90

The Agent Server REST API has an OpenAPI 3.1 spec in the docs repository (40 paths, still labelled 0.1.0), the Cloud API has another (155 paths), SDK models are Pydantic-typed and there's a TypeScript client (25). llms.txt at docs.openhands.dev (551 lines on 1 November), with no CLI, local GUI or V0 pages in it (10). The docs have a when-to-use page and examples of good and bad task instructions. On 23 October the Deprecated Projects group (local GUI, CLI, V0) was taken out of the navigation and links to it reworded towards Agent Canvas, though the pages stay reachable by URL and the SDK architecture page still links the CLI repository (15). Confirmation policies, security analysers and MCP configs are discriminated Pydantic unions with validators (13). SDK examples are checked by a CI workflow and there are troubleshooting pages, but we found no error reference for the Agent Server (12). Dated release notes for each Canvas version in the docs (1.25.0 to 1.34.0 added since 1 October), and release tags (15).

Letta 55

Apache-2.0 (30). The privacy policy has no date, no legal entity and no retention periods, and says hosted message data may train future models (8 of 30). The README and docs mark AgentFile, the Electron app and the V1 server as deprecated or retired, without dated notice periods (12 of 20). Telemetry is described in the privacy policy only as basic and opt-out when supported; the LETTA_CODE_TELEM=0 switch appears only in the source (5 of 20). Total 55.

OpenHands 67

MIT across Canvas, SDK, tools and Agent Server (30). The privacy policy (effective 3 September 2025, re-read on 1 November) doesn't separate the open-source stack from the Cloud service, keeps data as long as reasonably necessary, allows training on content from the Services and has no subprocessor list (12). A written SDK deprecation runway of five minor releases, kept on 28 October when the ACP model lists were removed at their 1.59.0 deadline, and the CLI's unmaintained notice in its README without a date on the page (15). The consent prompt calls the data anonymous and the Docker page documents AGENT_CANVAS_DISABLE_TELEMETRY, but no user-facing page mentions the install event sent before consent (10).

Letta 67

Harness reading. Toolsets switch with /model, skills load per agent, and subagents run in the background (18 of 25). Context is managed through memory blocks, reflection and dreaming (12 of 20). letta -p --output-format json for scripted runs and an App Server for programmatic control (12 of 20). Conversations resume by agent and conversation id, and memory is git-tracked so changes can be reverted (15 of 20). Runs with no account on the local backend, with one SDK language, TypeScript (10 of 15). Total 67.

OpenHands 78

Harness reading of the framework line, scored on what an agent or pipeline driving it has to supply. The default agent carries three tools (terminal, file editor, task tracker), and filter_tools_regex trims MCP tools before they reach the model (23). Stuck detection is on by default and a condenser compacts long histories, but Canvas leaves max_iterations unset and we found no cost cap (15). Headless runs go through the SDK, the Agent Server REST API or the Cloud API with typed events, and the old CLI's --headless mode is unmaintained (14). Conversations persist and resume, and a Docker conversation keeps its workspace and history when the container is replaced (16). Python SDK and TypeScript client, but the quickstart needs Node 24 and uv, and the defaults skip both confirmation and the sandbox (10).