Langsmith Fetch Agent Skill
Fetches LangSmith traces for debugging agent behavior. Use when troubleshooting agent issues, reviewing conversation history, or investigating tool calls.
Install
one command, takes just this skill from the repositorynpx skills add https://github.com/langchain-ai/lca-skills --skill langsmith-fetchThe instruction itself
5 sections, as written by the authorFetching LangSmith Traces
Requires langsmith-fetch in project dependencies and LANGSMITH_API_KEY in a .env file.
Setup
First, find the .env file containing LANGSMITH_API_KEY:
find . -name ".env" -type f 2>/dev/null | head -5
Commands
Use --env-file <path-to-.env> with all commands:
# Fetch recent traces (uses LANGSMITH_PROJECT from .env, or specify --project-uuid)
uv run --env-file <path> langsmith-fetch traces ./traces --limit 10
uv run --env-file <path> langsmith-fetch traces ./traces --project-uuid <uuid> --limit 10
# Fetch single trace by ID
uv run --env-file <path> langsmith-fetch trace <trace-id>
# Include metadata (timing, tokens, costs)
uv run --env-file <path> langsmith-fetch trace <trace-id> --include-metadata
Output Formats
--format pretty- Human-readable (default)--format json- Pretty-printed JSON--format raw- Compact JSON for piping
Troubleshooting Workflow
- Find
.env:find . -name ".env" -type f 2>/dev/null - Fetch recent traces:
uv run --env-file <path> langsmith-fetch traces ./debug --limit 10 - Find relevant trace in saved JSON files
- Check: What tools were called? What did they return? Was it correct/expected?
Other skills for the same job
different authors, same section of the catalogue
Integration with protocols.io API for managing scientific protocols. This skill should be used when working with protocols.io to search, create, update, or publish protocols; manage protocol steps and materials; handle discussions and comments; organize workspaces; upload and manage files; or integrate protocols.io functionality into workflows. Applicable for protocol discovery, collaborative protocol development, experiment tracking, lab protocol management, and scientific documentation.
Analyzes job descriptions and generates tailored resumes that highlight relevant experience, skills, and achievements to maximize interview chances
Generate Excalidraw diagrams from natural language descriptions. Use when asked to "create a diagram", "make a flowchart", "visualize a process", "draw a system architecture", "create a mind map", or "generate an Excalidraw file". Supports flowcharts, relationship diagrams, mind maps, and system architecture diagrams. Outputs .excalidraw JSON files that can be opened directly in Excalidraw.
Build and distribute Expo development clients locally or via TestFlight
Use when you have a written implementation plan to execute in a separate session with review checkpoints
Data structure for annotated matrices in single-cell analysis. Use when working with .h5ad files or integrating with the scverse ecosystem. This is the data format skill—for analysis workflows use scanpy; for probabilistic models use scvi-tools; for population-scale queries use cellxgene-census.
Benchling R&D platform integration. Access registry (DNA, proteins), inventory, ELN entries, workflows via API, build Benchling Apps, query Data Warehouse, for lab data management automation.
Comprehensive molecular biology toolkit. Use for sequence manipulation, file parsing (FASTA/GenBank/PDB), phylogenetics, and programmatic NCBI/PubMed access (Bio.Entrez). Best for batch processing, custom bioinformatics pipelines, BLAST automation. For quick lookups use gget; for multi-service integration use bioservices.
How to use it
Take langchain-ai/langsmith-fetch from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.