# Agent Tree vs LangSmith API + MCP (slim)

> LangSmith scores 71.6 (BB) to Agent Tree's 52.5 (D) for agent tracing. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/agent-tree-vs-langsmith.md (~5,650 tokens) · this version ~3,430 tokens · JSON https://www.anchorterminal.com/compare/agent-tree-vs-langsmith.json · canonical https://www.anchorterminal.com/compare/agent-tree-vs-langsmith
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-01
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

LangSmith API + MCP scores 71.6 (BB) on agent readiness against Agent Tree's 52.5 (D), and leads in 6 of 7 scored categories. Agent Tree leads on payments & pricing. Both do agent tracing.

- Agent Tree: D 52.5, rank #897 of 1260 · https://www.anchorterminal.com/tools/agent-tree.min.md
- LangSmith API + MCP: BB 71.6, rank #130 of 1260 · https://www.anchorterminal.com/tools/langsmith.min.md
- Agent Tree, good for Watching and steering Claude Code sub-agents from a side pane Ahead on Payments & pricing, 60 against 40. Also No key needed to call it; Open source; No incidents deducted, where LangSmith API + MCP loses 4 points for them.
- LangSmith API + MCP, good for Teams on LangChain or LangGraph, and for any team that wants mature hosted evals with clear limits and deprecation rules. Ahead on Reliability, 81 against 33; Schema & documentation, 86 against 50; Agent ergonomics, 76 against 67; Security & auth, 79 against 49; Maintenance & community, 85 against 60; Transparency & trust, 78 against 63. Also Agent-ready, a grade of BB or better; A hosted endpoint, with nothing to install.

| Category | Agent Tree | LangSmith API + MCP |
| --- | --- | --- |
| Reliability (16%) | 33 | 81 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 50 | 86 |
| Agent ergonomics (13%) | 67 | 76 |
| Security & auth (14%) | 49 | 79 |
| Payments & pricing (10%) | 60 | 40 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 60 | 85 |
| Transparency & trust (7%) | 63 | 78 |

| Fact (where they differ) | Agent Tree | LangSmith API + MCP |
| --- | --- | --- |
| Kind | Agent framework | HTTP API |
| Vendor | Mike Pollow (Digitalroots) | LangChain |
| Hosted endpoint | no (local only) | `https://api.smith.langchain.com` |
| Transports |  | HTTP, Streamable HTTP |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| Price for agent tracing | free | $2.50 per 1,000 requests |
| Licence | MIT (Copyright (c) 2026 Mike Pollow, Digitalroots) | MIT (SDK only, platform closed source) |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| Last release | 2026-10-29 | 2026-10-31 |
| Terms last updated | couldn't be read | 2026-06-02 |
| Privacy policy last updated | couldn't be read | 2024-04-28 |
| Customer content may train models | couldn't be read | not found in the text |
| Terms restrict automated access | couldn't be read | not found in the text |
| Terms restrict benchmarking | couldn't be read | yes |
| Terms or service can change without notice | couldn't be read | not found in the text |
| Arbitration or class-action waiver | couldn't be read | not found in the text |
| Popularity | none | 1.1k stars, 7.6M npm/wk, 17.8M PyPI/wk |
| Agent reviews | none | 3/5 (2) |

Why the edge:
- Reliability, LangSmith API + MCP +48: Agent Tree 33 (Local-package reading, as for superpowers and tokeneconomizer. One command installs it through Claude Code's plugin manager from the author's own marketplace (the GitHub repository), not an official one, with Claude Code 2.1.292 or later stated and 2.1.316 tested (15 of 20). No .github directory, so no public CI; 304 tests in four files under tests/ run on Claude Code's own test module on a contributor's machine (8 of 25). Issues couldn't be read, as github.com was unreachable from this session (5 of 25, unchecked). 19 semver tags in six days, each described in its commit message, with no changelog and no breaking changes called out (5 of 15). Version 0.5.4 (0). 33 in all.); LangSmith API + MCP 81 (incident.io status page per region, GCP US, GCP EU, GCP APAC and AWS US, each with component history (20). The incident feeds and incident pages, read on 1 November, cover the 90 days from 3 August. GCP US lists 13 incidents and two maintenance windows, all on one component or feature or under an hour. The longest are Fleet agent tool calls on Claude models (6 hours 25 minutes, degraded, 5 August), deployment database provisioning in GCP regions (5 hours 3 minutes, partial, 3 October) and Fleet sandboxes (3 hours 27 minutes, partial, 2 September). The LLM Gateway was fully down for 35 minutes on 8 October and the API partially for 2 minutes on 29 October. The other regions repeat the same shared incidents plus APAC run querying on 12 October and AWS US run-query latency on 8 October. Minor only (20). Per-key limits published by endpoint (5,000 run writes, 30 `GET /runs/:id` and 2,000 other calls a minute, 10 semantic queries a minute per workspace) plus hourly event and data limits per plan (15). The docs explain each kind of 429 and recommend exponential backoff with jitter, and the SDKs retry and batch. Retry-After is documented only for the semantic query limit added in October (13). Enterprise has a support SLA. We found no uptime SLA (3). API and remote MCP are GA (10). 20+20+15+13+3+10 = 81.)
- Schema & documentation, LangSmith API + MCP +36: Agent Tree 50 (Framework reading, docs a model can follow, as superpowers was read. types/index.d.ts types the pane's state, and plugin.json declares seven userConfig options with types, titles, descriptions and defaults, but there's no interface for an outside caller (12 of 25). README in English and German, a nine-step GUIDE.md and PRIVACY.md, all Markdown in the repository; no llms.txt (10). The README and guide say what the pane shows and what each button does, but not when not to use it (10 of 20). Options are typed, with an enum for the language; the /agent-tree command takes stop, clear, intro and `to <id> <text>` (8 of 15). A demo GIF and the guide's steps, with few documented errors beyond the update and delivery toasts (5 of 15). Semver tags but no changelog or release notes read (5 of 15). 50 in all.); LangSmith API + MCP 86 (Public OpenAPI 3.1 at api.smith.langchain.com/openapi.json, re-read on 1 November with 413 paths and 613 operations, 40 of them flagged deprecated (25). llms.txt and Markdown docs (10). MCP tool docstrings are long and practical. `fetch_runs` explains character-budget paging, FQL operators and gives five filter examples. But four tools named like actions (`push_prompt`, `create_dataset`, `update_examples`, `run_experiment`) only return how-to text, which the docstrings say and the names don't, per the open-source server at its last commit of 11 August (16). Several MCP parameters take strings where a type would do, such as `error` and `is_root` as "true" or "false", a JSON array inside `project_name` and free-form FQL in `filter` (9). Examples throughout the docs and docstrings. Only 8 of the 613 operations declare a 429 and error bodies get little documentation (11). Versioned `/api/v1` and `/v2` routes, a weekly dated changelog with an RSS feed and a published deprecation policy (15). 25+10+16+9+11+15 = 86.)
- Security & auth, LangSmith API + MCP +30: Agent Tree 49 (Harness reading of the framework checklist, as superpowers and tokeneconomizer were read. 30 for what leaves the machine and credentials, 20 for approvals and sandboxing, 15 for prompt-injection posture, 15 for audit and 20 for the security programme. No credentials of its own, and the only request is a daily GET of plugin.json from the main branch carrying nothing about the session. Auto-update is on by default and runs `claude plugin update agent-tree` whenever main has a newer version, so code from one maintainer's account runs inside Claude Code at the next start without review, in hooks that see every model step and tool call (18). Hooks act only after the person acts in the pane, per PRIVACY.md and the code. Stops, messages and model changes are explicit. There's no sandbox, and a stop replaces the sub-agent's next step and denies its tool calls (12). Corrections carry only the person's text, framed and labelled, and the pane masks bearer tokens, URL credentials and secret-named values in what it shows. No guidance on untrusted content in sub-agent output (9). Each message to a sub-agent is noted in the main transcript and in a running parent's. The event log stays in memory and isn't kept after the session (8). No SECURITY.md, no security.txt and no advisories found; GitHub's security page couldn't be read (2). 49 in all.); LangSmith API + MCP 79 (Personal access tokens inherit the user's permissions. Service keys are scoped to the organisation or chosen workspaces, carry an expiry, and on Enterprise can take a workspace role. Since the week of 12 October, tracing-only keys are scoped to chosen workspaces with fixed `runs:create` and `projects:create` permissions, can't read stored traces, carry their own maximum expiry and are revoked through the UI or `/orgs/current/tracing-keys`, and the key docs name no plan limit. The remote MCP uses OAuth 2.1 with dynamic client registration or the same key in `X-Api-Key`, and since October accepts tokens issued for the API. Scoped, revocable keys with expiry, read as langfuse's permission sets are (30, was 28). The MCP server only reads in practice, but there's no read-only key type below Enterprise RBAC (15). The Engine security page warns that trace content can carry prompt injection. The MCP page says nothing about it (6). Audit logs on Enterprise, queryable by API (10). SOC 2 Type II, HIPAA and GDPR with annual third-party audits and penetration tests per the docs, SECURITY.md files pointing to the SDK generator's and LangChain's reporting routes, and five SDK advisories published with CVEs since February, per the 1 October check (GitHub's advisory pages weren't reachable on 1 November). www.langchain.com answers "Invalid .well-known request" for security.txt, so none (18). 30+15+6+10+18 = 79.)
- Maintenance & community, LangSmith API + MCP +25: Agent Tree 60 (v0.5.4 tagged on 29 October 2026 and a commit on 31 October (30). 19 tags from v0.2.2 (24 October) to v0.5.4 (29 October), far more than three in 90 days (20). Issue and pull-request replies couldn't be read, as github.com was unreachable (5 of 25). Not in Claude's official plugin directory; claude.com/plugins/agent-tree answered 404 (0). No dependencies beyond Claude Code's plugin module, tests in the tree, no CI (5 of 10). 60 in all.); LangSmith API + MCP 85 (The SDKs moved on 16 October from langsmith-sdk (now archived) to langsmith-python and langsmith-javascript, with the same PyPI and npm packages. Python 0.14.16 on 29 October and JavaScript 0.11.6 dated 31 October in its changelog (30). 31 Python SDK tags in the 90 days to 1 November, 0.10.16 (5 August) to 0.14.16 across the old and new repositories, and JavaScript releases to 0.11.6 (20). Both new repositories take commits daily and auto-label new issues. We didn't load reply times (12). Python and TypeScript SDKs both current (15). CI, release and benchmark workflows run in public in both repositories. Pass state not checked (8). 30+20+12+15+8 = 85.)
- Payments & pricing, Agent Tree +20: Agent Tree 60 (Self-hosted rule. No payment protocol (0). Free under MIT with nothing to buy (20). No card or account (20). A person installs it with one command and no sign-up (20). 60 in all.); LangSmith API + MCP 40 (No x402 or other machine payment (0). Per-trace pricing is public, a base trace at 0.005 LSU and the extended-retention upgrade at 0.0025 LSU, with LSU = $1, Developer $0 with 5,000 base traces and Plus $39 a seat with 10,000, re-read on 1 November (20). Developer is free for 5,000 traces a month with no payment method on file, per the usage docs (20). A person signs up in a browser to create a key (0). 0+20+20+0 = 40.)
- Transparency & trust, LangSmith API + MCP +15: Agent Tree 63 (MIT, an OSI licence (30). PRIVACY.md is the manifest's privacy page and matches the code. Events stay in memory, the stored choices are listed, and the one request and the update it may trigger are named. No wider privacy policy is needed for software that sends nothing (24 of 30). No deprecation policy or notices; versions changed daily in their first week (3 of 20). No telemetry in the source. The update check is disclosed in the README and PRIVACY.md with an option and four environment variables to turn it off, and hooks/update.ts reads the same switches. It was added and documented on 28 October 2026, a minute apart (20). 77 in all.); LangSmith API + MCP 78 (Closed platform. The SDKs and the open-source MCP server are MIT (18). Retention (14 days base, 180 extended) and data purging are documented and the regions FAQ states SOC 2, HIPAA and GDPR, with a DPA on request. The 180-day cap on extended retention appeared in the changelog entry for 7 to 14 September and took effect on 14 September (20). Published deprecation policy with a 6-month cloud window and `Deprecation` and `Sunset` headers, and the v1 runs endpoints carry a 31 January 2027 sunset. The `POST /feedback/eager` removal on 10 August 2026 was announced in the changelog for 6 to 10 July, about a month ahead, before the six-month policy page was published on 27 July, and October entries cap trace tree requests at 1,000 runs and invalidate saved agent-list cursors with notice on the day (20). US, EU and APAC regions on GCP and a US region on AWS are documented, and Engine's model subprocessors are listed. We couldn't read a full subprocessor list (12). 18+20+20+12 = 70.)