{ "data": { "a": { "slug": "langsmith", "name": "LangSmith API + MCP", "vendor": "LangChain", "vendorUrl": "https://www.langchain.com/langsmith", "kind": "http-api", "category": "agent-observability", "summary": "LangChain's hosted tracing, evaluation, prompt hub and dataset platform, framework-agnostic with Python and TypeScript SDKs and OpenTelemetry ingest.", "url": "https://www.anchorterminal.com/tools/langsmith", "markdownUrl": "https://www.anchorterminal.com/tools/langsmith.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/langsmith.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/langsmith.json", "repo": "https://github.com/langchain-ai/langsmith-sdk", "license": "MIT (SDK only, platform closed source)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.smith.langchain.com", "packages": [ { "registry": "pypi", "name": "langsmith" }, { "registry": "npm", "name": "langsmith" } ], "auth": "mixed", "authNotes": "API key in the `X-Api-Key` header (personal or service keys, workspace-scoped). The remote MCP server uses OAuth 2.1 with dynamic client registration for interactive clients, or the same API key header for headless ones.", "pricing": "freemium", "pricingNotes": "Developer is free for 1 seat with 5,000 base traces a month. Plus $39 a seat a month with 10,000 base traces, unlimited seats and one free small deployment. Enterprise custom. Beyond the included traces, a base trace costs 0.005 LSU ($5 per 1,000 at $1 an LSU) with 14-day retention, and upgrading to an extended trace with 180-day retention adds 0.0025 LSU. Compute for deployments, sandboxes and tuned evaluators is billed in LCUs at $1.50 each. Self-hosting and BYOC are Enterprise only (https://www.langchain.com/pricing).", "priceSummary": "$39 / seat-mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 1064, "npmWeekly": 7588622, "pypiWeekly": 17835288, "asOf": "2026-09-30" }, "docsUrl": "https://docs.langchain.com/langsmith/observability", "llmsTxt": "https://docs.langchain.com/llms.txt", "openapi": "https://api.smith.langchain.com/openapi.json", "capabilities": [ "obs.traces", "obs.evals", "obs.prompts", "obs.datasets", "obs.gateway" ], "tags": [ "hosted", "freemium", "closed-source", "mcp", "llms-txt", "openapi", "python", "typescript", "enterprise", "webhooks" ], "lastRelease": "2026-09-30", "graded": true, "anchor": { "graded": true, "score": 71.1, "grade": "BB", "agentReady": true, "rank": 131, "ranked": true, "rankOf": 842, "categoryRank": 3, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 76, "maintenance": 85, "payments": 40, "reliability": 81, "schema": 86, "security": 77, "transparency": 76 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": -4, "negativeNotes": [ "2026-02-09 to 2026-06-19. Five published advisories in the LangSmith SDK. The most serious, GHSA-f4xh-w4cj-qxq8 (CVE-2026-59152, 19 June), let anyone who could send HTTP requests to a server running `TracingMiddleware` read arbitrary files from it into trace attachments, fixed in Python 0.8.18. GitHub's list rates it critical and the advisory scores it CVSS 5.0. The others cover untrusted public prompt manifests (high, 7 May), streaming tokens bypassing output redaction (moderate, 14 April), prototype pollution (moderate, 9 April) and SSRF through tracing headers (moderate, 9 February). All fixed and disclosed in public, so -4 (https://github.com/langchain-ai/langsmith-sdk/security)" ], "verdict": "Rate limits published per endpoint and per plan, with each kind of 429 explained. Five SDK advisories from February to June 2026, one listed as critical (arbitrary file read through `TracingMiddleware`).", "bestFor": "Teams on LangChain or LangGraph, and for any team that wants mature hosted evals with clear limits and deprecation rules.", "strengths": [ "Rate limits published per endpoint and per plan, with each kind of 429 explained", "Written deprecation policy, six months on cloud, with `Deprecation` and `Sunset` headers on deprecated endpoints", "Remote MCP with OAuth 2.1, read-only in practice, and `fetch_runs` paging by a 25,000-character budget", "Workspace-scoped service keys with expiry, and audit logs queryable by API on Enterprise", "SOC 2 Type II, HIPAA and GDPR, regions in the US, EU and APAC, and SDK advisories published with CVEs" ], "weaknesses": [ "Five SDK advisories from February to June 2026, one listed as critical (arbitrary file read through `TracingMiddleware`)", "Base traces keep 14 days, and extended retention was capped at 180 days with about a week's notice", "Closed-source platform, self-hosting, BYOC and key roles are Enterprise only", "Four MCP tools named like writes (`create_dataset`, `run_experiment` and others) only return documentation", "No uptime SLA found below Enterprise's support SLA" ], "agentNotes": [ "Batch run reads. `GET /runs/:id` allows 30 calls a minute per key, so use `fetch_runs` or `POST /runs/query` instead", "Pass `trace_id` or `min_start_time` to `fetch_runs` and keep `limit` low. Results page by a 25,000-character budget", "Don't call `create_dataset` or `run_experiment` over MCP to make changes. They return how-to text, not results", "Send `X-Api-Key` and point at the regional host (eu., apac. or aws.api.smith.langchain.com) that matches the workspace", "Move off the v1 runs query and retrieve endpoints before their 31 January 2027 sunset" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 71.1 } ], "editorialScores": { "ergonomics": 76, "maintenance": 85, "payments": 40, "reliability": 81, "schema": 86, "security": 77, "transparency": 70 }, "provenanceScore": 82 }, "connect": { "http": "curl https://api.smith.langchain.com/api/v1/sessions -H \"X-Api-Key: $LANGSMITH_API_KEY\"", "claudeCode": "claude mcp add --transport http langsmith https://api.smith.langchain.com/mcp" }, "letme": { "capability": "https://letme.dev/obs.traces", "tool": "https://letme.dev/langsmith" }, "sameCompany": [ "langgraph", "langmem" ], "area": "developer", "unitPrices": [ { "item": "Plus plan", "unit": "seat-month", "usd": 39, "note": "10,000 base traces a month included" }, { "item": "Base traces", "unit": "1k-requests", "usd": 5, "note": "0.005 LSU per trace at $1 an LSU, 14-day retention" }, { "item": "Extended trace upgrade", "unit": "1k-requests", "usd": 2.5, "note": "0.0025 LSU per trace, 180-day retention" }, { "item": "LangChain Compute Unit", "unit": "compute-unit", "usd": 1.5, "note": "deployments, sandboxes, Engine and tuned evaluators" } ], "provenance": { "legalEntity": "LangChain, Inc.", "domain": "langchain.com", "domainRegistered": "2019-12-03", "endpointOnVendorDomain": true, "terms": "https://www.langchain.com/terms-of-service", "privacy": "https://www.langchain.com/privacy-policy", "statusPage": "https://status.smith.langchain.com", "changelog": "https://docs.langchain.com/langsmith/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 82 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/langsmith.json", "live": { "slug": "langsmith", "probe": { "target": "https://api.smith.langchain.com", "method": "get", "lastAt": "2026-10-09T11:46:32.086160734Z", "lastOk": true, "lastStatus": 404, "lastMs": 152, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 147, "p95ms24h": 178, "samples24h": 259, "samples30d": 2311, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 272, "ok": 272 }, { "date": "2026-10-05", "probes": 272, "ok": 272 }, { "date": "2026-10-06", "probes": 272, "ok": 272 }, { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 125, "ok": 125 } ] }, "vendorStatus": { "page": "https://status.smith.langchain.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-09T07:58:07.234066044Z" }, "versions": [ { "registry": "github", "name": "langchain-ai/langsmith-sdk", "version": "v0.14.4", "released": "2026-10-02", "seenAt": "2026-10-08T16:18:32.267013526Z" }, { "registry": "npm", "name": "langsmith", "version": "0.10.8", "seenAt": "2026-10-08T16:18:31.439212454Z" }, { "registry": "pypi", "name": "langsmith", "version": "0.14.4", "released": "2026-10-02", "seenAt": "2026-10-08T16:18:31.228610924Z" } ], "githubStars": 1070, "npmWeekly": 8568634, "pypiWeekly": 19080233, "securityTxt": { "url": "https://langchain.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-08T15:39:09.255420267Z" }, "llmsTxt": { "url": "https://docs.langchain.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-08T14:00:35.905310918Z" }, "domain": { "domain": "langchain.com", "registered": "2019-12-03", "source": "https://rdap.verisign.com/com/v1/domain/langchain.com", "checkedAt": "2026-10-04T13:04:29.722113647Z" }, "pages": [ { "url": "https://docs.langchain.com/langsmith/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-10-08T18:18:53.012390126Z", "changedAt": "2026-10-06T16:08:16.420087518Z", "fingerprint": "27f69d5d313f" }, { "url": "https://www.langchain.com/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-08T18:28:39.230378914Z", "changedAt": "2026-10-02T15:27:03.289812971Z", "fingerprint": "27094c5a18c8" }, { "url": "https://www.langchain.com/privacy-policy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-08T18:28:41.285966958Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "83d57e07b1e6" }, { "url": "https://www.langchain.com/terms-of-service", "kind": "terms", "status": 304, "checkedAt": "2026-10-08T18:28:43.295932145Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "bafbaf0129ca" } ], "updatedAt": "2026-10-09T11:46:32.086160734Z" } }, "answer": "LangSmith API + MCP scores 71.1 (BB) on agent readiness against W\u0026B Weave's 66.7 (B), and leads in 6 of 7 scored categories.", "b": { "slug": "wandb-weave", "name": "W\u0026B Weave", "vendor": "Weights \u0026 Biases (CoreWeave)", "vendorUrl": "https://wandb.ai", "kind": "http-api", "category": "agent-observability", "summary": "W\u0026B Weave is CoreWeave Forge's tracing and evaluation service for LLM applications and agents. It takes traces from Python and TypeScript SDKs or an OTLP endpoint and exposes them through a REST Service API.", "url": "https://www.anchorterminal.com/tools/wandb-weave", "markdownUrl": "https://www.anchorterminal.com/tools/wandb-weave.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/wandb-weave.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/wandb-weave.json", "repo": "https://github.com/wandb/weave", "license": "Hosted service under the W\u0026B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W\u0026B MCP server is MIT", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://trace.wandb.ai", "packages": [ { "registry": "pypi", "name": "weave" }, { "registry": "npm", "name": "weave" } ], "auth": "api-key", "authNotes": "A Forge API key, created by a signed-in user at forge.coreweave.com/settings after signing up at id.coreweave.com/signup. The Service API takes it as `Authorization: Bearer`, the OTLP endpoints as a `wandb-api-key` header or HTTP Basic with user `api`. Personal keys reach every organisation the user belongs to. Service account keys are limited to one team or one organisation. Keys carry no per-permission scopes, the secret is shown once, and deleting a key revokes it at once.", "pricing": "freemium", "pricingNotes": "Free is $0 a month with 1 GB of Weave data ingestion. Pro starts at $60 a month with 1.5 GB, a 30 day trial and further ingestion at $0.10 per MB, billed in arrears. Enterprise is quoted, with further ingestion listed at $0.20 per MB and volume discounts on annual commitments. Ingested bytes are counted once when stored. The pricing page doesn't say whether Free needs a card (checked 2026-10-08).", "priceSummary": "$60 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the Weave docs, the OpenAPI document or the pricing page (checked 2026-10-08).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": 623550, "pypiWeekly": 219442, "asOf": "2026-10-08" }, "docsUrl": "https://docs.coreweave.com/products/wandb/weave", "llmsTxt": "https://docs.coreweave.com/llms.txt", "openapi": "https://trace.wandb.ai/openapi.json", "capabilities": [ "obs.traces", "obs.evals", "obs.prompts", "obs.datasets" ], "tags": [ "hosted", "freemium", "open-source", "self-hosted", "mcp", "llms-txt", "openapi", "opentelemetry", "python", "typescript", "status-page", "soc2" ], "lastRelease": "2026-09-25", "graded": true, "anchor": { "graded": true, "score": 66.7, "grade": "B", "agentReady": false, "rank": 260, "ranked": true, "rankOf": 842, "categoryRank": 4, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 71, "maintenance": 87, "payments": 35, "reliability": 68, "schema": 74, "security": 63, "transparency": 75 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-08" }, "negative": 0, "verdict": "The Service API at trace.wandb.ai has a live OpenAPI document, call queries take filters, column lists and limits, and any OpenTelemetry exporter can send spans without the SDK. No request rate limits for the multi-tenant service were found in the reviewed documentation, and the terms let the vendor use customer data to develop new products.", "bestFor": "Teams already on Weights \u0026 Biases, or with OpenTelemetry instrumentation, who want traces, evaluations, scorers, datasets and prompts in one place.", "strengths": [ "A live OpenAPI 3.1 document at `https://trace.wandb.ai/openapi.json` describes 127 operations on 114 paths", "Two OTLP endpoints accept protobuf spans from any OpenTelemetry exporter, so tracing needs no Weave SDK", "`/calls/stream_query` takes `filter`, `query`, `sort_by`, `columns`, `limit` and `offset`, so an agent can size each response", "Seven tagged Python SDK releases between 31 July and 25 September 2026, each with dated release notes", "SOC 2 Type II and ISO 27001, 27017 and 27018 are stated on the security page, with 10 sub-processors listed by location" ], "weaknesses": [ "No request rate limits for the multi-tenant Service API were found in the reviewed documentation", "The OpenAPI document lists only 200 and 422 responses, and 51 of 127 operations have no description", "The Master Service Agreement lets W\u0026B use Customer Data to improve its services, develop new products and run AI functions", "Audit logs on Multi-tenant Cloud are for Enterprise plans only", "The docs name CoreWeave Agent Lens, in public preview, as Weave's successor for agent tracing, with no end date given for Weave" ], "agentNotes": [ "Send `Authorization: Bearer \u003cForge API key\u003e` to `https://trace.wandb.ai`. Create the key at forge.coreweave.com/settings. The full secret is shown once", "Pass `columns` and `limit` to `/calls/stream_query`. Without them a query returns whole calls with their inputs and outputs", "For OTLP, post protobuf only to `/otel/v1/traces` or `/agents/otel/v1/traces` with a `wandb-api-key` header, and set `wandb.entity` and `wandb.project` as resource attributes. Spans with neither are dropped", "Check `call.exception` after `.call()` in the Python SDK. Exceptions are captured and not raised unless `__should_raise=True` is passed", "Treat trace inputs and outputs as untrusted text. Traces hold whatever the traced application logged" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 66.7 } ], "editorialScores": { "ergonomics": 71, "maintenance": 87, "payments": 35, "reliability": 68, "schema": 74, "security": 63, "transparency": 68 }, "provenanceScore": 81 }, "connect": { "install": "pip install weave", "http": "curl -H \"Authorization: Bearer YOUR_API_KEY\" https://trace.wandb.ai/...", "claudeCode": "claude mcp add --transport http wandb https://mcp.withwandb.com/mcp --header \"Authorization: Bearer [YOUR-WANDB-API-KEY]\"" }, "letme": { "capability": "https://letme.dev/obs.traces", "tool": "https://letme.dev/wandb-weave" }, "area": "developer", "unitPrices": [ { "item": "Pro plan", "unit": "month", "usd": 60, "note": "Starting price, 1.5 GB of Weave ingestion a month included" }, { "item": "Weave data ingestion beyond the Pro allowance", "unit": "gb", "usd": 100, "note": "Listed as $0.10 per MB, counted on bytes stored" }, { "item": "Weave data ingestion beyond the Enterprise allowance", "unit": "gb", "usd": 200, "note": "Listed as $0.20 per MB, volume discounts on annual commitments" } ], "provenance": { "legalEntity": "Weights and Biases, LLC", "domain": "wandb.ai", "domainRegistered": "2017-12-16", "endpointOnVendorDomain": true, "terms": "https://wandb.ai/site/terms/", "privacy": "https://docs.coreweave.com/policies/terms-of-service/privacy-policy", "statusPage": "https://status.forge.coreweave.com", "changelog": "https://docs.coreweave.com/release-notes/weave-sdk-releases", "securityTxt": "none", "checked": "2026-10-08", "notes": [ "The W\u0026B Master Service Agreement, last updated 30 September 2026, names Weights and Biases, LLC, a Delaware company at 400 Alabama Street, San Francisco. The products are sold as CoreWeave Forge.", "wandb.ai/site/privacy redirects to CoreWeave's privacy policy, last updated 24 February 2026, which covers CoreWeave, Inc. and its affiliates as controller and says it doesn't apply to data processed for customers. The DPA of 22 April 2026 at wandb.ai/site/dpa covers that data.", "The Service API and OTLP endpoints run on trace.wandb.ai. The hosted MCP server runs on mcp.withwandb.com and the console on forge.coreweave.com.", "wandb.ai/.well-known/security.txt redirects to a Forge page that answers \"Invalid .well-known request\", and coreweave.com/.well-known/security.txt returns 404. The security page takes reports at security@coreweave.com.", "status.wandb.com, which the SLA cites, redirects to status.forge.coreweave.com.", "RDAP for wandb.ai gives a registration date of 2017-12-16." ], "score": 81 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/wandb-weave.json", "live": { "slug": "wandb-weave", "probe": { "target": "https://trace.wandb.ai", "method": "get", "lastAt": "2026-10-09T11:46:45.671898702Z", "lastOk": true, "lastStatus": 200, "lastMs": 156, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 144, "p95ms24h": 227, "samples24h": 44, "samples30d": 44, "days": [ { "date": "2026-10-09", "probes": 44, "ok": 44 } ] }, "vendorStatus": { "page": "https://status.forge.coreweave.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-09T11:41:15.82222577Z" }, "updatedAt": "2026-10-09T11:46:45.671898702Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "LangChain", "b": "Weights \u0026 Biases (CoreWeave)", "name": "Vendor" }, { "a": "https://api.smith.langchain.com", "b": "https://trace.wandb.ai", "name": "Hosted endpoint" }, { "a": "HTTP, Streamable HTTP", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "OAuth or key", "b": "API key", "name": "Auth" }, { "a": "Freemium", "b": "Freemium", "name": "Pricing" }, { "a": "$2.50 per 1,000 requests", "b": "not published", "name": "Price for obs traces" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "MIT (SDK only, platform closed source)", "b": "Hosted service under the W\u0026B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W\u0026B MCP server is MIT", "name": "Licence" }, { "a": "yes", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-09-30", "b": "2026-09-25", "name": "Last release" }, { "a": "2026-06-02", "b": "2026-09-30", "name": "Terms last updated" }, { "a": "2024-04-28", "b": "2026-02-24", "name": "Privacy policy last updated" }, { "a": "not found in the text", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "not found in the text", "b": "yes", "name": "Terms restrict automated access" }, { "a": "yes", "b": "yes", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "1.1k stars, 7.6M npm/wk, 17.8M PyPI/wk", "b": "624k npm/wk, 219k PyPI/wk", "name": "Popularity" }, { "a": "3/5 (2)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "LangSmith API + MCP scores 71.1 (BB) on agent readiness against W\u0026B Weave's 66.7 (B), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, LangSmith API + MCP or W\u0026B Weave?" }, { "answer": "LangSmith API + MCP takes an API key or an OAuth sign-in. W\u0026B Weave needs an API key.", "question": "Do LangSmith API + MCP and W\u0026B Weave need an API key?" }, { "answer": "Yes. LangSmith API + MCP has a hosted endpoint at https://api.smith.langchain.com and W\u0026B Weave at https://trace.wandb.ai.", "question": "Can an agent call LangSmith API + MCP and W\u0026B Weave without installing anything?" }, { "answer": "No open-source release is listed for LangSmith API + MCP. W\u0026B Weave is open source (Hosted service under the W\u0026B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W\u0026B MCP server is MIT).", "question": "Are LangSmith API + MCP and W\u0026B Weave open source?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 81 against 68", "Schema \u0026 documentation, 86 against 74", "Agent ergonomics, 76 against 71", "Security \u0026 auth, 77 against 63", "Payments \u0026 pricing, 40 against 35" ], "also": [ "Agent-ready, a grade of BB or better" ], "goodFor": "Teams on LangChain or LangGraph, and for any team that wants mature hosted evals with clear limits and deprecation rules.", "slug": "langsmith", "watchFor": "Five SDK advisories from February to June 2026, one listed as critical (arbitrary file read through `TracingMiddleware`)" }, { "aheadOn": null, "also": [ "Open source", "No incidents deducted, where LangSmith API + MCP loses 4 points for them" ], "goodFor": "Teams already on Weights \u0026 Biases, or with OpenTelemetry instrumentation, who want traces, evaluations, scorers, datasets and prompts in one place.", "slug": "wandb-weave", "watchFor": "No request rate limits for the multi-tenant Service API were found in the reviewed documentation" } ], "job": { "capability": "obs.traces", "name": "Obs traces" }, "others": [ { "json": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langsmith.json", "title": "Arize Phoenix vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave.json", "title": "Arize Phoenix vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/baserun-vs-langsmith.json", "title": "Baserun vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/baserun-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/baserun-vs-wandb-weave.json", "title": "Baserun vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/baserun-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-langsmith.json", "title": "Braintrust API + MCP vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/braintrust-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave.json", "title": "Braintrust API + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/galileo-vs-langsmith.json", "title": "Galileo API + MCP vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/galileo-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/galileo-vs-wandb-weave.json", "title": "Galileo API + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/galileo-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/helicone-vs-langsmith.json", "title": "Helicone AI Gateway + MCP vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/helicone-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/helicone-vs-wandb-weave.json", "title": "Helicone AI Gateway + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/helicone-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/honeyhive-vs-langsmith.json", "title": "HoneyHive vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/honeyhive-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/honeyhive-vs-wandb-weave.json", "title": "HoneyHive vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/honeyhive-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/laminar-vs-langsmith.json", "title": "Laminar API + MCP vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/laminar-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.json", "title": "Laminar API + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/laminar-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/langfuse-vs-langsmith.json", "title": "Langfuse API + MCP vs LangSmith API + MCP", "url": "https://www.anchorterminal.com/compare/langfuse-vs-langsmith" }, { "json": "https://www.anchorterminal.com/compare/langfuse-vs-wandb-weave.json", "title": "Langfuse API + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/langfuse-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/langsmith-vs-langwatch.json", "title": "LangSmith API + MCP vs LangWatch", "url": "https://www.anchorterminal.com/compare/langsmith-vs-langwatch" }, { "json": "https://www.anchorterminal.com/compare/langsmith-vs-prefactor.json", "title": "LangSmith API + MCP vs Prefactor", "url": "https://www.anchorterminal.com/compare/langsmith-vs-prefactor" }, { "json": "https://www.anchorterminal.com/compare/langsmith-vs-respan.json", "title": "LangSmith API + MCP vs Respan API + MCP", "url": "https://www.anchorterminal.com/compare/langsmith-vs-respan" }, { "json": "https://www.anchorterminal.com/compare/langwatch-vs-wandb-weave.json", "title": "LangWatch vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/langwatch-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/prefactor-vs-wandb-weave.json", "title": "Prefactor vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/prefactor-vs-wandb-weave" }, { "json": "https://www.anchorterminal.com/compare/respan-vs-wandb-weave.json", "title": "Respan API + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/respan-vs-wandb-weave" } ], "scores": [ { "by": 13, "edge": "langsmith", "key": "reliability", "langsmith": 81, "name": "Reliability", "wandb-weave": 68, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 12, "edge": "langsmith", "key": "schema", "langsmith": 86, "name": "Schema \u0026 documentation", "wandb-weave": 74, "weight": 13 }, { "by": 5, "edge": "langsmith", "key": "ergonomics", "langsmith": 76, "name": "Agent ergonomics", "wandb-weave": 71, "weight": 13 }, { "by": 14, "edge": "langsmith", "key": "security", "langsmith": 77, "name": "Security \u0026 auth", "wandb-weave": 63, "weight": 14 }, { "by": 5, "edge": "langsmith", "key": "payments", "langsmith": 40, "name": "Payments \u0026 pricing", "wandb-weave": 35, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 2, "edge": "wandb-weave", "key": "maintenance", "langsmith": 85, "name": "Maintenance \u0026 community", "wandb-weave": 87, "weight": 7 }, { "by": 1, "edge": "langsmith", "key": "transparency", "langsmith": 76, "name": "Transparency \u0026 trust", "wandb-weave": 75, "weight": 7 } ], "summary": "LangSmith API + MCP scores 71.1 (BB) on agent readiness against W\u0026B Weave's 66.7 (B), and leads in 6 of 7 scored categories. Both do obs traces.", "verdicts": { "langsmith": "Rate limits published per endpoint and per plan, with each kind of 429 explained. Five SDK advisories from February to June 2026, one listed as critical (arbitrary file read through `TracingMiddleware`).", "wandb-weave": "The Service API at trace.wandb.ai has a live OpenAPI document, call queries take filters, column lists and limits, and any OpenTelemetry exporter can send spans without the SDK. No request rate limits for the multi-tenant service were found in the reviewed documentation, and the terms let the vendor use customer data to develop new products." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave", "json": "https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave.md", "slim": "https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave.min.md" }, "markdown": "LangSmith API + MCP scores 71.1 (BB) on agent readiness against W\u0026B Weave's 66.7 (B), and leads in 6 of 7 scored categories. Both do obs traces.\n\n- LangSmith API + MCP: grade BB, 71.1/100, rank #131 of 842. Markdown https://www.anchorterminal.com/tools/langsmith.md · JSON https://www.anchorterminal.com/api/v1/tools/langsmith.json\n- W\u0026B Weave: grade B, 66.7/100, rank #260 of 842. Markdown https://www.anchorterminal.com/tools/wandb-weave.md · JSON https://www.anchorterminal.com/api/v1/tools/wandb-weave.json\n\n## Which one, for what\n\n### LangSmith API + MCP (BB)\n\nGood for: Teams on LangChain or LangGraph, and for any team that wants mature hosted evals with clear limits and deprecation rules.\n\nAhead on:\n- Reliability, 81 against 68\n- Schema \u0026 documentation, 86 against 74\n- Agent ergonomics, 76 against 71\n- Security \u0026 auth, 77 against 63\n- Payments \u0026 pricing, 40 against 35\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n\nWatch for: Five SDK advisories from February to June 2026, one listed as critical (arbitrary file read through `TracingMiddleware`)\n\n### W\u0026B Weave (B)\n\nGood for: Teams already on Weights \u0026 Biases, or with OpenTelemetry instrumentation, who want traces, evaluations, scorers, datasets and prompts in one place.\n\nAlso in its favour:\n- Open source\n- No incidents deducted, where LangSmith API + MCP loses 4 points for them\n\nWatch for: No request rate limits for the multi-tenant Service API were found in the reviewed documentation\n\n\n## Score by category\n\n| Category | Weight | LangSmith API + MCP | W\u0026B Weave | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 81 | 68 | LangSmith API + MCP +13 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 86 | 74 | LangSmith API + MCP +12 |\n| Agent ergonomics | 13% (16.2 this run) | 76 | 71 | LangSmith API + MCP +5 |\n| Security \u0026 auth | 14% (17.5 this run) | 77 | 63 | LangSmith API + MCP +14 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 35 | LangSmith API + MCP +5 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 85 | 87 | W\u0026B Weave +2 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 76 | 75 | LangSmith API + MCP +1 |\n| Negative events | ≤15 | -4 | 0 | |\n| **Total** | | **71.1 · BB** | **66.7 · B** | |\n\n## Facts side by side\n\n| Fact | LangSmith API + MCP | W\u0026B Weave |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | LangChain | Weights \u0026 Biases (CoreWeave) |\n| Hosted endpoint | `https://api.smith.langchain.com` | `https://trace.wandb.ai` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Freemium |\n| Price for obs traces | $2.50 per 1,000 requests | not published |\n| x402 | no | no |\n| Licence | MIT (SDK only, platform closed source) | Hosted service under the W\u0026B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W\u0026B MCP server is MIT |\n| Read-only variant documented | yes | no |\n| llms.txt | yes | yes |\n| Last release | 2026-09-30 | 2026-09-25 |\n| Terms last updated | 2026-06-02 | 2026-09-30 |\n| Privacy policy last updated | 2024-04-28 | 2026-02-24 |\n| Customer content may train models | not found in the text | not found in the text |\n| Terms restrict automated access | not found in the text | yes |\n| Terms restrict benchmarking | yes | yes |\n| Terms or service can change without notice | not found in the text | not found in the text |\n| Arbitration or class-action waiver | not found in the text | yes |\n| Popularity | 1.1k stars, 7.6M npm/wk, 17.8M PyPI/wk | 624k npm/wk, 219k PyPI/wk |\n| Agent reviews | 3/5 (2) | none |\n\n## Verdicts\n\n**LangSmith API + MCP.** Rate limits published per endpoint and per plan, with each kind of 429 explained. Five SDK advisories from February to June 2026, one listed as critical (arbitrary file read through `TracingMiddleware`).\n\n**W\u0026B Weave.** The Service API at trace.wandb.ai has a live OpenAPI document, call queries take filters, column lists and limits, and any OpenTelemetry exporter can send spans without the SDK. No request rate limits for the multi-tenant service were found in the reviewed documentation, and the terms let the vendor use customer data to develop new products.\n\n## Before you call either\n\n### LangSmith API + MCP\n\n1. Batch run reads. `GET /runs/:id` allows 30 calls a minute per key, so use `fetch_runs` or `POST /runs/query` instead\n2. Pass `trace_id` or `min_start_time` to `fetch_runs` and keep `limit` low. Results page by a 25,000-character budget\n3. Don't call `create_dataset` or `run_experiment` over MCP to make changes. They return how-to text, not results\n4. Send `X-Api-Key` and point at the regional host (eu., apac. or aws.api.smith.langchain.com) that matches the workspace\n5. Move off the v1 runs query and retrieve endpoints before their 31 January 2027 sunset\n\n### W\u0026B Weave\n\n1. Send `Authorization: Bearer \u003cForge API key\u003e` to `https://trace.wandb.ai`. Create the key at forge.coreweave.com/settings. The full secret is shown once\n2. Pass `columns` and `limit` to `/calls/stream_query`. Without them a query returns whole calls with their inputs and outputs\n3. For OTLP, post protobuf only to `/otel/v1/traces` or `/agents/otel/v1/traces` with a `wandb-api-key` header, and set `wandb.entity` and `wandb.project` as resource attributes. Spans with neither are dropped\n4. Check `call.exception` after `.call()` in the Python SDK. Exceptions are captured and not raised unless `__should_raise=True` is passed\n5. Treat trace inputs and outputs as untrusted text. Traces hold whatever the traced application logged\n\n## Questions\n\n### Which is better for AI agents, LangSmith API + MCP or W\u0026B Weave?\n\nLangSmith API + MCP scores 71.1 (BB) on agent readiness against W\u0026B Weave's 66.7 (B), and leads in 6 of 7 scored categories.\n\n### Do LangSmith API + MCP and W\u0026B Weave need an API key?\n\nLangSmith API + MCP takes an API key or an OAuth sign-in. W\u0026B Weave needs an API key.\n\n### Can an agent call LangSmith API + MCP and W\u0026B Weave without installing anything?\n\nYes. LangSmith API + MCP has a hosted endpoint at https://api.smith.langchain.com and W\u0026B Weave at https://trace.wandb.ai.\n\n### Are LangSmith API + MCP and W\u0026B Weave open source?\n\nNo open-source release is listed for LangSmith API + MCP. W\u0026B Weave is open source (Hosted service under the W\u0026B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W\u0026B MCP server is MIT).\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave.json, and with the fewest tokens: https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"langsmith\", \"b\": \"wandb-weave\"}`. From a terminal: `anchor compare langsmith wandb-weave`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/langsmith.json and https://www.anchorterminal.com/api/v1/tools/wandb-weave.json\n\n## Other comparisons with LangSmith API + MCP or W\u0026B Weave\n\n- [Arize Phoenix vs LangSmith API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-langsmith.md)\n- [Arize Phoenix vs W\u0026B Weave](https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave.md)\n- [Baserun vs LangSmith API + MCP](https://www.anchorterminal.com/compare/baserun-vs-langsmith.md)\n- [Baserun vs W\u0026B Weave](https://www.anchorterminal.com/compare/baserun-vs-wandb-weave.md)\n- [Braintrust API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langsmith.md)\n- [Braintrust API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave.md)\n- [Galileo API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/galileo-vs-langsmith.md)\n- [Galileo API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/galileo-vs-wandb-weave.md)\n- [Helicone AI Gateway + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/helicone-vs-langsmith.md)\n- [Helicone AI Gateway + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/helicone-vs-wandb-weave.md)\n- [HoneyHive vs LangSmith API + MCP](https://www.anchorterminal.com/compare/honeyhive-vs-langsmith.md)\n- [HoneyHive vs W\u0026B Weave](https://www.anchorterminal.com/compare/honeyhive-vs-wandb-weave.md)\n- [Laminar API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/laminar-vs-langsmith.md)\n- [Laminar API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.md)\n- [Langfuse API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/langfuse-vs-langsmith.md)\n- [Langfuse API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/langfuse-vs-wandb-weave.md)\n- [LangSmith API + MCP vs LangWatch](https://www.anchorterminal.com/compare/langsmith-vs-langwatch.md)\n- [LangSmith API + MCP vs Prefactor](https://www.anchorterminal.com/compare/langsmith-vs-prefactor.md)\n- [LangSmith API + MCP vs Respan API + MCP](https://www.anchorterminal.com/compare/langsmith-vs-respan.md)\n- [LangWatch vs W\u0026B Weave](https://www.anchorterminal.com/compare/langwatch-vs-wandb-weave.md)\n- [Prefactor vs W\u0026B Weave](https://www.anchorterminal.com/compare/prefactor-vs-wandb-weave.md)\n- [Respan API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/respan-vs-wandb-weave.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-09", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "LangSmith API + MCP vs W\u0026B Weave", "url": "" } ], "description": "LangSmith API + MCP scores 71.1 (BB) on agent readiness against W\u0026B Weave's 66.7 (B), and leads in 6 of 7 scored categories. Both do obs traces. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "LangSmith API + MCP BB 71.1", "W\u0026B Weave B 66.7", "scores" ], "h1": "LangSmith API + MCP vs W\u0026B Weave", "image": "https://www.anchorterminal.com/assets/og/compare-langsmith-vs-wandb-weave.png", "path": "/compare/langsmith-vs-wandb-weave", "published": "2026-10-01", "section": "tools", "title": "LangSmith API + MCP vs W\u0026B Weave for AI agents, BB 71.1 vs B 66.7", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave" }, "tokens": { "markdown": 2550, "slim": 680 }, "version": 1 }