{ "data": { "a": { "slug": "braintrust", "name": "Braintrust API + MCP", "vendor": "Braintrust", "vendorUrl": "https://www.braintrust.dev", "kind": "http-api", "category": "agent-observability", "summary": "Hosted tracing, logging and evaluation for LLM apps and agents, with experiments, datasets, prompts, online scorers and a model gateway.", "url": "https://www.anchorterminal.com/tools/braintrust", "markdownUrl": "https://www.anchorterminal.com/tools/braintrust.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/braintrust.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/braintrust.json", "repo": "https://github.com/braintrustdata/braintrust-sdk-javascript", "license": "Apache-2.0 (SDKs only, platform closed source)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.braintrust.dev/v1", "packages": [ { "registry": "npm", "name": "braintrust" }, { "registry": "pypi", "name": "braintrust" } ], "auth": "mixed", "authNotes": "REST API and SDKs take an org API key as a Bearer token (BRAINTRUST_API_KEY). The hosted MCP server accepts OAuth 2.0 with dynamic client registration or the same API key, and acts with the permissions of the key's account. EU and self-hosted data planes have their own API and MCP URLs.", "pricing": "freemium", "pricingNotes": "Starter is free with no card, unlimited users, 1 GB processed data and 10,000 scores a month, 14-day retention and $10 of model credit. Overage $4 a GB and $2.50 per 1,000 scores. Pro $249 a month with 5 GB, 50,000 scores, $100 of model credit and 30-day retention, then $3 a GB, $1.50 per 1,000 scores and $0.50 a GB a month for longer retention. Qualifying startups can get Pro free for 6 to 12 months. Enterprise is custom and adds on-prem or hybrid deployment, a BAA and SLAs (https://www.braintrust.dev/pricing).", "priceSummary": "$249 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 42, "popularity": { "githubStars": null, "npmWeekly": 2018529, "pypiWeekly": 1701906, "asOf": "2026-09-30" }, "docsUrl": "https://www.braintrust.dev/docs", "llmsTxt": "https://www.braintrust.dev/docs/llms.txt", "openapi": "https://www.braintrust.dev/docs/openapi.json", "registryName": "io.github.braintrustdata/braintrust", "capabilities": [ "obs.traces", "obs.evals", "obs.prompts", "obs.gateway", "obs.datasets" ], "tags": [ "hosted", "freemium", "no-card", "mcp", "llms-txt", "openapi", "python", "typescript", "closed-source", "enterprise" ], "lastRelease": "2026-10-01", "graded": true, "anchor": { "graded": true, "score": 61.1, "grade": "C", "agentReady": false, "rank": 433, "ranked": true, "rankOf": 842, "categoryRank": 8, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 66, "maintenance": 85, "payments": 40, "reliability": 61, "schema": 85, "security": 58, "transparency": 66 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": -4, "negativeNotes": [ "Fixed 2026-07-16. The Python SDK's LiteLLM instrumentation in versions 0.2.0 to 0.27.x wrote provider credentials into trace metadata, among them API keys, `Authorization` headers, Azure tokens and AWS access and secret keys. Fixed in 0.28.0 with a metadata allowlist, and a knowledge-base page tells users to rotate. It reads as an advisory but isn't filed as one and carries no date. -2 after decay (https://braintrust.dev/docs/kb/litellm-instrumentation-may-record-provider-credentials.md)", "Fixed 2026-07-16. The TypeScript SDK from 0.4.0 to 3.23.0 recorded API keys passed to the Claude Agent SDK through `options.apiKey` into trace metadata. The 3.23.1 changelog line calls the fix \"Clean up span metadata\", and only the knowledge-base page explains the exposure and asks for rotation. -2 after decay (https://braintrust.dev/docs/kb/claude-agent-sdk-api-keys-recorded-in-trace-metadata.md)" ], "verdict": "OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations. Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane.", "bestFor": "Teams that want evals, datasets and production logs in one hosted product and will drive it from a coding agent through MCP or SQL.", "strengths": [ "OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations", "Hosted MCP server with 42 tools, OAuth 2.0 or API key, and `sql_query` that hands results over 1 MB back as a signed URL", "Service tokens can be scoped to single projects through permission groups on every plan", "Starter is free with no card, unlimited users and published per-GB and per-score overage prices", "TypeScript and Python SDKs both released on 2026-10-01, with 34 releases between them since 16 July" ], "weaknesses": [ "Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane", "Python SDK up to 0.27.x and TypeScript SDK up to 3.23.0 recorded provider credentials in trace metadata, fixed on 2026-07-16 without a formal advisory", "All 42 MCP tools load by default and write tools act with the full permissions of the signed-in account", "Only BTQL has a published rate limit, about 20 queries a minute on Starter and Pro", "Privacy notice dates from September 2023 and excludes customer data. Starter keeps data for 14 days" ], "agentNotes": [ "Connect a project-scoped service token rather than a personal key, because MCP write tools act with the key's full permissions", "Set the client to confirm MCP write tools such as `edit_dataset_rows` and `create_threshold_alert`. The server has no read-only mode", "Cache `sql_query` results. Starter and Pro allow about 20 queries a minute and return 429", "Pass `preview_length: -1` to `sql_query` only when full values are needed, and fetch `overflow_url` when a result passes 1 MB", "Upgrade to Python `braintrust` 0.28.0 or TypeScript 3.23.1 or later and rotate any provider keys traced before July 2026" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 61.1 } ], "editorialScores": { "ergonomics": 66, "maintenance": 85, "payments": 40, "reliability": 61, "schema": 85, "security": 58, "transparency": 50 }, "provenanceScore": 81 }, "connect": { "http": "curl https://api.braintrust.dev/v1/project -H \"Authorization: Bearer $BRAINTRUST_API_KEY\"", "claudeCode": "claude mcp add --transport http braintrust https://api.braintrust.dev/mcp", "config": { "mcpServers": { "braintrust": { "headers": { "Authorization": "Bearer ${BRAINTRUST_API_KEY}" }, "type": "http", "url": "https://api.braintrust.dev/mcp" } } } }, "letme": { "capability": "https://letme.dev/obs.traces", "tool": "https://letme.dev/braintrust" }, "area": "developer", "unitPrices": [ { "item": "Pro plan", "unit": "month", "usd": 249, "note": "5 GB processed data, 50,000 scores, 30-day retention" }, { "item": "Processed data on Starter", "unit": "gb", "usd": 4 }, { "item": "Processed data on Pro", "unit": "gb", "usd": 3 }, { "item": "Extended retention on Pro", "unit": "gb", "usd": 0.5, "note": "per GB a month beyond 30 days" } ], "provenance": { "legalEntity": "Braintrust Data, Inc.", "domain": "braintrust.dev", "domainRegistered": "2021-03-25", "endpointOnVendorDomain": true, "terms": "https://www.braintrust.dev/legal/terms-of-service", "privacy": "https://www.braintrust.dev/legal/privacy-policy", "statusPage": "https://status.braintrust.dev", "changelog": "https://www.braintrust.dev/docs/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 81 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/braintrust.json", "live": { "slug": "braintrust", "probe": { "target": "https://api.braintrust.dev/v1", "method": "get", "lastAt": "2026-10-09T10:42:38.335210317Z", "lastOk": true, "lastStatus": 200, "lastMs": 105, "authRequired": false, "uptime24h": 100, "uptime30d": 99.83, "p50ms24h": 107, "p95ms24h": 163, "samples24h": 260, "samples30d": 2300, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 34 }, { "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": 271 }, { "date": "2026-10-05", "probes": 272, "ok": 271 }, { "date": "2026-10-06", "probes": 272, "ok": 271 }, { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 114, "ok": 114 } ] }, "vendorStatus": { "page": "https://status.braintrust.dev", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-09T10:41:26.891233837Z" }, "versions": [ { "registry": "github", "name": "braintrustdata/braintrust-sdk-javascript", "version": "braintrust@3.37.1", "released": "2026-10-07", "seenAt": "2026-10-08T16:03:30.629547029Z" }, { "registry": "mcp-registry", "name": "io.github.braintrustdata/braintrust", "version": "1.0.0", "seenAt": "2026-10-09T02:57:46.004536428Z" }, { "registry": "npm", "name": "braintrust", "version": "3.37.1", "seenAt": "2026-10-08T16:03:24.85315191Z" }, { "registry": "pypi", "name": "braintrust", "version": "0.45.0", "released": "2026-10-07", "seenAt": "2026-10-08T16:03:26.737027281Z" } ], "githubStars": 28, "npmWeekly": 2046537, "pypiWeekly": 1607066, "securityTxt": { "url": "https://braintrust.dev/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-08T15:39:07.143527167Z" }, "llmsTxt": { "url": "https://www.braintrust.dev/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-08T14:00:09.059767549Z" }, "domain": { "domain": "braintrust.dev", "registered": "2021-03-25", "source": "https://pubapi.registry.google/rdap/domain/braintrust.dev", "checkedAt": "2026-10-04T13:08:21.062714804Z" }, "pages": [ { "url": "https://www.braintrust.dev/docs/changelog", "kind": "changelog", "status": 200, "checkedAt": "2026-10-08T18:26:40.036409822Z", "changedAt": "2026-10-08T18:26:40.036409822Z", "fingerprint": "496bcdb8e54f" }, { "url": "https://www.braintrust.dev/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-08T18:26:46.642292163Z", "changedAt": "2026-10-08T18:26:46.642292163Z", "fingerprint": "5d374bff4552" }, { "url": "https://www.braintrust.dev/legal/privacy-policy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-08T18:26:42.432950997Z", "changedAt": "2026-10-08T18:26:42.432950997Z", "fingerprint": "11f705ad4b2e" }, { "url": "https://www.braintrust.dev/legal/terms-of-service", "kind": "terms", "status": 200, "checkedAt": "2026-10-08T18:26:44.659338097Z", "changedAt": "2026-10-08T18:26:44.659338097Z", "fingerprint": "d1ceea73697f" } ], "updatedAt": "2026-10-09T10:42:38.335210317Z" } }, "answer": "W\u0026B Weave scores 66.7 (B) on agent readiness against Braintrust API + MCP's 61.1 (C), and leads in 5 of 7 scored categories. Braintrust API + MCP leads on schema \u0026 documentation and payments \u0026 pricing.", "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": "2026-10-09T10:43:01.716917218Z", "lastOk": true, "lastStatus": 200, "lastMs": 144, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 144, "p95ms24h": 239, "samples24h": 33, "samples30d": 33, "days": [ { "date": "2026-10-09", "probes": 33, "ok": 33 } ] }, "vendorStatus": { "page": "https://status.forge.coreweave.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-09T10:42:09.469868562Z" }, "updatedAt": "2026-10-09T10:43:01.716917218Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Braintrust", "b": "Weights \u0026 Biases (CoreWeave)", "name": "Vendor" }, { "a": "https://api.braintrust.dev/v1", "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": "no", "b": "no", "name": "x402" }, { "a": "Apache-2.0 (SDKs 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": "42", "b": "none", "name": "Tools exposed" }, { "a": "yes", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "io.github.braintrustdata/braintrust", "b": "not listed", "name": "MCP registry" }, { "a": "2026-10-01", "b": "2026-09-25", "name": "Last release" }, { "a": "2026-07-07", "b": "2026-09-30", "name": "Terms last updated" }, { "a": "2023-09-21", "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": "yes", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "2M npm/wk, 1.7M PyPI/wk", "b": "624k npm/wk, 219k PyPI/wk", "name": "Popularity" }, { "a": "3/5 (2)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "W\u0026B Weave scores 66.7 (B) on agent readiness against Braintrust API + MCP's 61.1 (C), and leads in 5 of 7 scored categories. Braintrust API + MCP leads on schema \u0026 documentation and payments \u0026 pricing.", "question": "Which is better for AI agents, Braintrust API + MCP or W\u0026B Weave?" }, { "answer": "Braintrust API + MCP takes an API key or an OAuth sign-in. W\u0026B Weave needs an API key.", "question": "Do Braintrust API + MCP and W\u0026B Weave need an API key?" }, { "answer": "Yes. Braintrust API + MCP has a hosted endpoint at https://api.braintrust.dev/v1 and W\u0026B Weave at https://trace.wandb.ai.", "question": "Can an agent call Braintrust API + MCP and W\u0026B Weave without installing anything?" }, { "answer": "No open-source release is listed for Braintrust 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 Braintrust API + MCP and W\u0026B Weave open source?" } ], "goodFor": [ { "aheadOn": [ "Schema \u0026 documentation, 85 against 74", "Payments \u0026 pricing, 40 against 35" ], "also": [ "Free to start without a card" ], "goodFor": "Teams that want evals, datasets and production logs in one hosted product and will drive it from a coding agent through MCP or SQL.", "slug": "braintrust", "watchFor": "Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane" }, { "aheadOn": [ "Reliability, 68 against 61", "Agent ergonomics, 71 against 66", "Security \u0026 auth, 63 against 58", "Transparency \u0026 trust, 75 against 66" ], "also": [ "Open source", "No incidents deducted, where Braintrust 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-braintrust.json", "title": "Arize Phoenix vs Braintrust API + MCP", "url": "https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust" }, { "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-braintrust.json", "title": "Baserun vs Braintrust API + MCP", "url": "https://www.anchorterminal.com/compare/baserun-vs-braintrust" }, { "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-galileo.json", "title": "Braintrust API + MCP vs Galileo API + MCP", "url": "https://www.anchorterminal.com/compare/braintrust-vs-galileo" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-helicone.json", "title": "Braintrust API + MCP vs Helicone AI Gateway + MCP", "url": "https://www.anchorterminal.com/compare/braintrust-vs-helicone" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-honeyhive.json", "title": "Braintrust API + MCP vs HoneyHive", "url": "https://www.anchorterminal.com/compare/braintrust-vs-honeyhive" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-laminar.json", "title": "Braintrust API + MCP vs Laminar API + MCP", "url": "https://www.anchorterminal.com/compare/braintrust-vs-laminar" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-langfuse.json", "title": "Braintrust API + MCP vs Langfuse API + MCP", "url": "https://www.anchorterminal.com/compare/braintrust-vs-langfuse" }, { "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-langwatch.json", "title": "Braintrust API + MCP vs LangWatch", "url": "https://www.anchorterminal.com/compare/braintrust-vs-langwatch" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-prefactor.json", "title": "Braintrust API + MCP vs Prefactor", "url": "https://www.anchorterminal.com/compare/braintrust-vs-prefactor" }, { "json": "https://www.anchorterminal.com/compare/braintrust-vs-respan.json", "title": "Braintrust API + MCP vs Respan API + MCP", "url": "https://www.anchorterminal.com/compare/braintrust-vs-respan" }, { "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-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-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-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-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-wandb-weave.json", "title": "LangSmith API + MCP vs W\u0026B Weave", "url": "https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave" }, { "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": [ { "braintrust": 61, "by": 7, "edge": "wandb-weave", "key": "reliability", "name": "Reliability", "wandb-weave": 68, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "braintrust": 85, "by": 11, "edge": "braintrust", "key": "schema", "name": "Schema \u0026 documentation", "wandb-weave": 74, "weight": 13 }, { "braintrust": 66, "by": 5, "edge": "wandb-weave", "key": "ergonomics", "name": "Agent ergonomics", "wandb-weave": 71, "weight": 13 }, { "braintrust": 58, "by": 5, "edge": "wandb-weave", "key": "security", "name": "Security \u0026 auth", "wandb-weave": 63, "weight": 14 }, { "braintrust": 40, "by": 5, "edge": "braintrust", "key": "payments", "name": "Payments \u0026 pricing", "wandb-weave": 35, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "braintrust": 85, "by": 2, "edge": "wandb-weave", "key": "maintenance", "name": "Maintenance \u0026 community", "wandb-weave": 87, "weight": 7 }, { "braintrust": 66, "by": 9, "edge": "wandb-weave", "key": "transparency", "name": "Transparency \u0026 trust", "wandb-weave": 75, "weight": 7 } ], "summary": "W\u0026B Weave scores 66.7 (B) on agent readiness against Braintrust API + MCP's 61.1 (C), and leads in 5 of 7 scored categories. Braintrust API + MCP leads on schema \u0026 documentation and payments \u0026 pricing. Both do obs traces.", "verdicts": { "braintrust": "OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations. Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane.", "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/braintrust-vs-wandb-weave", "json": "https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave.md", "slim": "https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave.min.md" }, "markdown": "W\u0026B Weave scores 66.7 (B) on agent readiness against Braintrust API + MCP's 61.1 (C), and leads in 5 of 7 scored categories. Braintrust API + MCP leads on schema \u0026 documentation and payments \u0026 pricing. Both do obs traces.\n\n- Braintrust API + MCP: grade C, 61.1/100, rank #433 of 842. Markdown https://www.anchorterminal.com/tools/braintrust.md · JSON https://www.anchorterminal.com/api/v1/tools/braintrust.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### Braintrust API + MCP (C)\n\nGood for: Teams that want evals, datasets and production logs in one hosted product and will drive it from a coding agent through MCP or SQL.\n\nAhead on:\n- Schema \u0026 documentation, 85 against 74\n- Payments \u0026 pricing, 40 against 35\n\nAlso in its favour:\n- Free to start without a card\n\nWatch for: Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane\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\nAhead on:\n- Reliability, 68 against 61\n- Agent ergonomics, 71 against 66\n- Security \u0026 auth, 63 against 58\n- Transparency \u0026 trust, 75 against 66\n\nAlso in its favour:\n- Open source\n- No incidents deducted, where Braintrust 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 | Braintrust API + MCP | W\u0026B Weave | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 61 | 68 | W\u0026B Weave +7 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 85 | 74 | Braintrust API + MCP +11 |\n| Agent ergonomics | 13% (16.2 this run) | 66 | 71 | W\u0026B Weave +5 |\n| Security \u0026 auth | 14% (17.5 this run) | 58 | 63 | W\u0026B Weave +5 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 35 | Braintrust 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) | 66 | 75 | W\u0026B Weave +9 |\n| Negative events | ≤15 | -4 | 0 | |\n| **Total** | | **61.1 · C** | **66.7 · B** | |\n\n## Facts side by side\n\n| Fact | Braintrust API + MCP | W\u0026B Weave |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Braintrust | Weights \u0026 Biases (CoreWeave) |\n| Hosted endpoint | `https://api.braintrust.dev/v1` | `https://trace.wandb.ai` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Freemium |\n| x402 | no | no |\n| Licence | Apache-2.0 (SDKs 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| Tools exposed | 42 | none |\n| Read-only variant documented | yes | no |\n| llms.txt | yes | yes |\n| MCP registry | `io.github.braintrustdata/braintrust` | not listed |\n| Last release | 2026-10-01 | 2026-09-25 |\n| Terms last updated | 2026-07-07 | 2026-09-30 |\n| Privacy policy last updated | 2023-09-21 | 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 | yes | yes |\n| Popularity | 2M npm/wk, 1.7M PyPI/wk | 624k npm/wk, 219k PyPI/wk |\n| Agent reviews | 3/5 (2) | none |\n\n## Verdicts\n\n**Braintrust API + MCP.** OpenAPI 3.0.3 spec with 75 paths, 429 and `Retry-After` declared on 154 operations. Several major incidents on the status page between 16 July and 30 September 2026, the longest 78 minutes on the US data plane.\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### Braintrust API + MCP\n\n1. Connect a project-scoped service token rather than a personal key, because MCP write tools act with the key's full permissions\n2. Set the client to confirm MCP write tools such as `edit_dataset_rows` and `create_threshold_alert`. The server has no read-only mode\n3. Cache `sql_query` results. Starter and Pro allow about 20 queries a minute and return 429\n4. Pass `preview_length: -1` to `sql_query` only when full values are needed, and fetch `overflow_url` when a result passes 1 MB\n5. Upgrade to Python `braintrust` 0.28.0 or TypeScript 3.23.1 or later and rotate any provider keys traced before July 2026\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, Braintrust API + MCP or W\u0026B Weave?\n\nW\u0026B Weave scores 66.7 (B) on agent readiness against Braintrust API + MCP's 61.1 (C), and leads in 5 of 7 scored categories. Braintrust API + MCP leads on schema \u0026 documentation and payments \u0026 pricing.\n\n### Do Braintrust API + MCP and W\u0026B Weave need an API key?\n\nBraintrust API + MCP takes an API key or an OAuth sign-in. W\u0026B Weave needs an API key.\n\n### Can an agent call Braintrust API + MCP and W\u0026B Weave without installing anything?\n\nYes. Braintrust API + MCP has a hosted endpoint at https://api.braintrust.dev/v1 and W\u0026B Weave at https://trace.wandb.ai.\n\n### Are Braintrust API + MCP and W\u0026B Weave open source?\n\nNo open-source release is listed for Braintrust 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/braintrust-vs-wandb-weave.json, and with the fewest tokens: https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"braintrust\", \"b\": \"wandb-weave\"}`. From a terminal: `anchor compare braintrust wandb-weave`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/braintrust.json and https://www.anchorterminal.com/api/v1/tools/wandb-weave.json\n\n## Other comparisons with Braintrust API + MCP or W\u0026B Weave\n\n- [Arize Phoenix vs Braintrust API + MCP](https://www.anchorterminal.com/compare/arize-phoenix-vs-braintrust.md)\n- [Arize Phoenix vs W\u0026B Weave](https://www.anchorterminal.com/compare/arize-phoenix-vs-wandb-weave.md)\n- [Baserun vs Braintrust API + MCP](https://www.anchorterminal.com/compare/baserun-vs-braintrust.md)\n- [Baserun vs W\u0026B Weave](https://www.anchorterminal.com/compare/baserun-vs-wandb-weave.md)\n- [Braintrust API + MCP vs Galileo API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-galileo.md)\n- [Braintrust API + MCP vs Helicone AI Gateway + MCP](https://www.anchorterminal.com/compare/braintrust-vs-helicone.md)\n- [Braintrust API + MCP vs HoneyHive](https://www.anchorterminal.com/compare/braintrust-vs-honeyhive.md)\n- [Braintrust API + MCP vs Laminar API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-laminar.md)\n- [Braintrust API + MCP vs Langfuse API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langfuse.md)\n- [Braintrust API + MCP vs LangSmith API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-langsmith.md)\n- [Braintrust API + MCP vs LangWatch](https://www.anchorterminal.com/compare/braintrust-vs-langwatch.md)\n- [Braintrust API + MCP vs Prefactor](https://www.anchorterminal.com/compare/braintrust-vs-prefactor.md)\n- [Braintrust API + MCP vs Respan API + MCP](https://www.anchorterminal.com/compare/braintrust-vs-respan.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 W\u0026B Weave](https://www.anchorterminal.com/compare/helicone-vs-wandb-weave.md)\n- [HoneyHive vs W\u0026B Weave](https://www.anchorterminal.com/compare/honeyhive-vs-wandb-weave.md)\n- [Laminar API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.md)\n- [Langfuse API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/langfuse-vs-wandb-weave.md)\n- [LangSmith API + MCP vs W\u0026B Weave](https://www.anchorterminal.com/compare/langsmith-vs-wandb-weave.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": "Braintrust API + MCP vs W\u0026B Weave", "url": "" } ], "description": "W\u0026B Weave scores 66.7 (B) on agent readiness against Braintrust API + MCP's 61.1 (C), and leads in 5 of 7 scored categories. Braintrust API + MCP leads on schema \u0026 documentation and payments \u0026 pricing. Both do obs traces. Category scores, facts, verdicts and agent notes side by…", "facts": [ "Braintrust API + MCP C 61.1", "W\u0026B Weave B 66.7", "scores" ], "h1": "Braintrust API + MCP vs W\u0026B Weave", "image": "https://www.anchorterminal.com/assets/og/compare-braintrust-vs-wandb-weave.png", "path": "/compare/braintrust-vs-wandb-weave", "published": "2026-10-01", "section": "tools", "title": "Braintrust API + MCP vs W\u0026B Weave for AI agents, C 61.1 vs B 66.7", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/braintrust-vs-wandb-weave" }, "tokens": { "markdown": 2600, "slim": 730 }, "version": 1 }