aftersight

Observability infrastructure for self-improving agents.

An agent cannot improve on a run it cannot read. Aftersight writes every run into the repository as plain files, so the agent can read its own history with the tools it already has.

The problem

Coding agents already explore repositories with file search, shell commands and plain text. Agent telemetry usually lives somewhere else: behind a dashboard, an API or a remote MCP server.

Aftersight writes the evidence into the repository instead. A coding agent can use the tools it already knows to:

1. diagnose why one run failed;
2. find failures that recur across runs;
3. inspect the exact inputs and outputs of models and tools.

Start in one command

pip install aftersight
aftersight run python my_agent.py

No account, API key, service or initialization step is required.

Ask your coding agent

Each telemetry root includes a NAVIGATE.md with verified rg and jq recipes. Tell your coding agent:

Read .runs/NAVIGATE.md and find out why the latest run failed.

For Claude Code, the optional command below installs the bundled navigation skill:

aftersight skill

What gets recorded

.runs/
  NAVIGATE.md
  index.jsonl
  latest -> runs/<run_id>
  runs/<run_id>/
    outline.md
    agent.logs
    trace.jsonl
    analytics.json
    meta.json
    blobs/
    artifacts/

outline.md is the short map. agent.logs is the complete readable transcript. trace.jsonl, analytics.json and index.jsonl are stable machine-readable views for scripts and frontends. The same #seq anchor identifies an event in every projection.

Use it from Python

import aftersight

aftersight.start()

Add explicit detail only where it helps:

with aftersight.span("planner"):
    with aftersight.span("web_search", kind="tool", args={"q": query}) as span:
        span.output = search(query)

@aftersight.trace
def read_file(path): ...

aftersight.log("cache miss", key=key)

Works with OpenTelemetry

Aftersight attaches a span processor to the application's existing OpenTelemetry setup and reads common gen_ai.*, OpenInference and generic input/output attributes. Frameworks that already emit compatible spans need no aftersight-specific adapter. An existing tracer provider and its exporters are left in place.

How it compares

LangSmith, Langfuse, Phoenix and Braintrust provide mature observability with dashboards and programmatic access through APIs, exports or MCP.

Aftersight has a narrower default: ordinary files in the repository, with no hosted project, credentials or remote query round trips. Those platforms are a better fit when you need centralized durability, team dashboards or managed evaluation workflows. See Why aftersight exists for the fuller comparison.

Local by default

Aftersight itself makes no network requests and does not upload telemetry. Payload redaction is enabled by default, and the run folder is added to .gitignore when it is first created.

If the application already has an OpenTelemetry exporter, that exporter may still send its own spans. Aftersight can run in production, but local disk can disappear with an ephemeral, replaced or failed host, so it should not be the only durable production record.

Documentation

• Quickstart
• Framework support
• Navigating runs
• Python API
• Run folder format
• Architecture

Full documentation: https://nebulaanish.github.io/aftersight/