Caesar ships agentskills.io-format skills that teach an agent the search, read, and feedback loop.
For the fastest single-skill install, use the Skills CLI:
npx skills add caesar-data/skills --skill caesar-search
curl -fsSL https://search-api-staging-779189860552.europe-west1.run.app/skills/install.sh | bash
~/.claude/skills/ and a caesar-subagent definition into ~/.claude/agents/ (Claude Code’s default locations), then prints: restart your agent session or run /caesar-setup to pick them up.
Two install rails
| Rail | Command | Use when |
|---|
| Skills CLI | npx skills add caesar-data/skills --skill caesar-search | You want the quickest install into an agent that supports skills. |
| API installer | curl -fsSL https://search-api-staging-779189860552.europe-west1.run.app/skills/install.sh | bash | You want all four skills and the Claude Code subagent in one step. |
skills npm CLI can install from the GitHub shorthand instead:
npx skills add caesar-data/skills --skill '*' -g -y
npx skills add caesar-data/skills --skill caesar-search -g -y
caesar-data/skills) plus --skill ...; bare npx skills add caesar-search is not a valid source.
For Claude Code, prefer the curl installer because it also writes ~/.claude/agents/caesar-subagent.md. The npx skills path installs the SKILL.md folders only.
Served by the API itself
The SKILL.md files are embedded in the API server and served from /skills routes — so the API-hosted installer ships with every API deploy. They are also mirrored to the public caesar-data/skills repo for npx skills add. The /skills routes require no authentication.
To update skills later, re-run the same installer. New skill content arrives with API deploys; the installer always fetches the current version.
The four skills
| Skill | What it teaches |
|---|
caesar-search | Default for web search, research, lookups, and any question needing current information. Results carry stable doc_ids you can read as focused excerpts or full documents and cite. |
caesar-read | Read a web page as clean markdown with provenance. Use when you already have a URL or doc_id. Handles long pages with character-offset continuation. |
caesar-setup | Install, authenticate, verify, and update the caesar-search CLI. Run once, then use the other skills for actual searching. |
caesar-best-practices | Reference for implementing Caesar in code — choosing between the CLI, SDKs, MCP server, and raw HTTP, plus cross-surface conventions. |
Routes
| Route | Returns |
|---|
GET /skills | JSON index of skills, agents, and the install one-liner |
GET /skills/{skill}/SKILL.md | Skill markdown (the four names above; anything else returns 404) |
GET /skills/agents/caesar-subagent.md | The subagent definition |
GET /skills/install.sh | The installer script |
curl -s https://search-api-staging-779189860552.europe-west1.run.app/skills
name, description, and url fields, so an agent can discover and fetch skills without the installer.
Installing for other agents
The skill files are standard agentskills.io markdown. Any agent that reads SKILL.md files can use them. Use the Skills CLI when available:
npx skills add caesar-data/skills --skill caesar-search
curl -fsSL https://search-api-staging-779189860552.europe-west1.run.app/skills/install.sh | CAESAR_SKILLS_DIR=~/.agents/skills bash
| Variable | Effect |
|---|
CAESAR_SKILLS_DIR | Install the skills into this directory instead of ~/.claude/skills. When set, the caesar-subagent file is not installed — subagent definitions are a Claude Code concept. |
CAESAR_SKILLS_BASE_URL | Download from a different API base URL (defaults to the host that served the script). |
For non-Claude agents, the context: fork and agent frontmatter fields are ignored and the skills still work inline.
How the runtime skills stay token-cheap
caesar-search and caesar-read declare context: fork and agent: caesar-subagent in their frontmatter. When invoked, the skill runs in a forked context executed by the caesar-subagent — a Bash-only subagent — so raw search and read JSON never lands in the main conversation’s token budget. Only the distilled answer comes back.
Because the subagent has no file-read tool, the skills write CLI output with -o /tmp/$SLUG.json (which suppresses stdout so harness limits can’t truncate it) and the subagent reads the file with cat. The subagent’s hard rules: only cite URLs that appear in command output, preserve doc_id and search_id verbatim, and report the output file path so the main context can reference it later without re-searching.
Relationship to the CLI
The skills are thin drivers for the caesar-search CLI — they run caesar-search search, caesar-search read, and friends rather than calling the API directly. If the CLI is missing, caesar-setup walks through installing it.
The runtime skills also carry a version gate: if the CLI rejects a flag or command as unknown, the installed CLI is outdated — the runtime skills (caesar-search, caesar-read) instruct the agent to run caesar-search update and retry. caesar-search update detects its install channel (npm, Homebrew, or standalone) and upgrades in place.
Strict agentskills.io validators flag the Claude Code extension frontmatter fields (context: fork, agent, user-invocable, argument-hint) as unknown. This is intentional — consumers ignore unknown fields. Don’t “fix” these validation warnings.
For agents
- Install the search skill with
npx skills add caesar-data/skills --skill caesar-search, or install the full bundle with the API installer above. Then invoke /caesar-setup once where available to verify the CLI and auth. After that, use /caesar-search for queries and /caesar-read for URLs or doc_ids.
- No installer access? Fetch the skill content directly —
GET /skills lists every URL, and each /skills/{skill}/SKILL.md is plain markdown. No API key needed.
- The skill names are a server-side allowlist (
caesar-search, caesar-read, caesar-setup, caesar-best-practices). Unknown names return a 404 envelope whose hint says to GET /skills.
- Anonymous use works: the runtime skills require only the CLI and network access;
CAESAR_API_KEY is optional (the anonymous tier is rate-limited). Never paste a literal key into chat — use caesar-search auth login or the env var.
- Skills do not auto-update. Re-run the curl installer to refresh them; only the CLI itself self-updates via
caesar-search update.
